JP4218548B2 - Manufacturing method and manufacturing apparatus for foam molded article - Google Patents

Description

  The present invention relates to a manufacturing method and a manufacturing apparatus for a foam molded product that is foam-molded by filling a mold with a foamable raw material.

As a method for producing a foamed molded product by foaming and filling the foamable raw material in the mold, for example, using a mold having a lower mold and an upper mold, and injecting the foamable raw material into the lower mold, A method of foam molding by closing the upper mold with respect to the lower mold is known.
Depending on the type of the foam molded product to be molded, for example, the portion folded back with respect to the main body portion of the foam molded product (folded portion) or the main body portion of the foam molded product is folded at a predetermined interval. Some have a portion (folded portion) or the like.

  When manufacturing such a foam-molded product, a molding including a lower mold and an upper mold for forming a main cavity for molding the main body and a subcavity for molding the folded portion or the folded portion. Use a mold. Then, the foamable raw material is injected into the main cavity in the lower mold, and then the lower mold and the upper mold are closed, and the foamable raw material is foamed and flown in the main cavity and from the main cavity to the subcavity. The company manufactures foam molded products.

  However, depending on the shape of the foam molded product, there is a long flow path of the foamable raw material from the main cavity to the tip of the subcavity. In this case, the foamable raw material foams and flows to the tip of the subcavity. It takes time. Therefore, a sufficient amount of foamable raw material does not reach the tip of the subcavity, resulting in a thinned portion in the foamed molded product after molding, or reaction of the foamable raw material that has reached the tip of the subcavity Is not sufficiently performed, the foamed molded product after molding may be crushed, which may cause a problem of molding failure.

  In addition, as a method for injecting a foamable raw material from an injection port formed in a mold and causing the foamable raw material to foam and flow in the mold, a foamed molded product is produced, for example, as shown in Patent Document 1 is there. In this Patent Document 1, a bag-shaped skin material having a core material disposed therein is disposed in a mold in a state of being suspended and held on a mold holding hanger, and a foamable raw material is disposed inside the bag-shaped skin material. By performing foam molding by injecting resin, it is possible to prevent the occurrence of resin leakage and core position displacement during molding. However, even in Patent Document 1, it takes time for the foamable raw material that foams and flows inside the bag-like skin material to reach the gap portion separated by the core material, which may cause the above-described problem of molding defects. is there.

Japanese Patent No. 3169260

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a method and an apparatus for producing a foamed molded product that does not cause molding defects such as crushing and lacking.

The first invention uses a molding die that can be opened and closed and forms a molding cavity when closed, and in the method of manufacturing a foam molded product by filling the molding cavity with a foamable raw material,
The molding cavity includes a first cavity, a second cavity formed to be bent with respect to the first cavity, and a third cavity formed continuously from the second cavity so as to face the first cavity. And the first cavity and the third cavity are communicated with each other by a shortened flow path that allows foaming flow of the foamable raw material from the first cavity to the third cavity. And
The shortened flow path has a substantially circular cross section and has a narrow portion having the smallest inner diameter in the shortened flow path.
The narrow portion is formed between an inlet opening where the shortened flow path opens into the first cavity and an outlet opening where the shortened flow path opens into the third cavity;
The inner diameter gradually decreases from the inlet opening and the outlet opening toward the narrow part,
In producing the foamed molded article, an injection step of injecting the foamable raw material onto the mold surface forming the first cavity with the mold open.
A first foaming flow step of closing the mold and foaming and flowing the foamable raw material in the first cavity;
A second foaming flow in which the foamable raw material is foamed and flowed from the first cavity to the third cavity through the second cavity and from the first cavity to the third cavity through the shortened flow path. Process,
The foamable raw material that has flowed into the third cavity via the second cavity and the foamable raw material that has flowed into the third cavity via the shortened flow path are integrated into the first to third cavities. A foam molding step of molding the foam molded article with the foamable raw material filled in
Open the mold, by relatively moving the above foam molded article and the mold, the foam molded article integrally with the foam molded flow paths foam to the shorter flow path, the narrow portion And a take- out step of taking out the divided flow-path foamed body from the mold together with the foamed molded product. Item 1).

In the manufacturing method of the present invention, in manufacturing the foam molded product foam-molded into the first to third cavities, the foaming flow of the foamable raw material from the first cavity to the third cavity is changed to the second cavity. The flow of foaming into the third cavity of the foamable raw material is improved by performing not only via the route but also via the shortened flow path.
Therefore, a sufficient amount of the foamable raw material is supplied to the third cavity, and the time required for the foamable raw material to foam and flow into the third cavity can be shortened.

In the third cavity, the foamable raw material that has flowed in through the second cavity and the foamable raw material that has flowed in through the shortened flow path merge and are integrated. Thus, good foaming of the foamable raw material can be performed to fill the inside of the third cavity. And after hardening the foamable raw material filled into the 1st-3rd cavity substantially uniformly, a shaping | molding die is opened and the shape | molded foaming molded product is taken out.
Therefore, according to the manufacturing method of the present invention, it is possible to mold a foam molded product that does not cause molding defects such as crushing or lacking.

The second invention is an apparatus for producing a foam molded product by filling a foaming raw material into a molding cavity formed in a mold that can be opened and closed.
The molding cavity includes a first cavity, a second cavity formed to be bent with respect to the first cavity, and a third cavity formed continuously from the second cavity so as to face the first cavity. A cavity,
Further, the mold has a partition wall that separates the first cavity and the third cavity, and the partition wall has a shortened flow path that allows the first cavity and the third cavity to communicate with each other. Formed ,
The shortened flow path has a substantially circular cross section and has a narrow portion having the smallest inner diameter in the shortened flow path.
The narrow portion is formed between an inlet opening where the shortened flow path opens into the first cavity and an outlet opening where the shortened flow path opens into the third cavity;
In molded foam manufacturing apparatus characterized by inner diameter toward respective said narrow section from the inlet opening and the outlet opening is gradually reduced (claim 5).

The manufacturing apparatus of this invention has the said shortening flow path in the said partition part. And like the said invention, the foaming flow of the foamable raw material from the 1st cavity to the 3rd cavity is performed not only via the 2nd cavity but also via the shortening channel. Therefore, a sufficient amount of foamable raw material is supplied to the third cavity, and the time for filling the third cavity with the foamable raw material can be shortened.
Therefore, according to the manufacturing apparatus of the present invention, it is possible to mold a foam molded product that does not cause molding defects such as crushing or lacking.

A preferred embodiment in the first and second inventions described above will be described.
In the first and second inventions, the third cavity can be formed above the first cavity. And a foamable raw material can be made to flow into a 3rd cavity from a 1st cavity by making the inside of a 2nd cavity and the inside of a shortening flow path foam and flow upwards.
Further, a partition wall that separates the first cavity and the third cavity may be disposed, and the second cavity may be formed around the end of the partition wall.

Further, the molding die can be configured such that the upper mold can be opened and closed with respect to the lower mold, and is configured by a two-sheet structure of the lower mold and the upper mold in which the partition wall is provided. Can do. In this case, the foamed molded product after molding can be released from the lower mold while being attached to the upper mold when the upper mold is opened with respect to the lower mold, and then removed from the upper mold.
Moreover, the said shaping | molding die can also be comprised by the 3 piece type structure of the lower mold | type, the middle mold | type which forms the said partition part, and an upper mold | type.

Here, the above-mentioned crushing means that the strength of the foamed cell formed inside the foamed molded product by the foaming reaction of the foamable raw material becomes a predetermined value because the foaming raw material is not sufficiently cured. It means a phenomenon that does not reach and collapses due to shrinkage of the raw material resin component after molding, a difference between the internal pressure of the foamed cell and the atmospheric pressure, or the like.
The underfill refers to a cavity or a dent portion generated in a foamed molded product because the foamable raw material does not reach the entire molding cavity and an unfilled portion is formed in the molding cavity.

Further, in the first invention, in the second foaming flow step, a flow leading portion of a foamable raw material that foams and flows to the third cavity through the second cavity opens toward the third cavity. Before reaching the outlet opening of the shortened flow path, it is preferable that the flow front end of the foamable raw material that foams and flows in the shortened flow path reaches the third cavity from the outlet opening. ).
In this case, when the foamable raw material that foams and flows in the shortened flow path reaches the third cavity from the outlet opening, the foamable raw material that flows into the third cavity through the second cavity is obstructed. It will not be done. Therefore, the foamable raw material can be smoothly flowed from the shortened flow path into the third cavity, particularly into the portion where the foamable raw material is difficult to reach, such as the end portion in the third cavity, and the above-described molding defect is more effectively generated. Can be prevented.

In the second foaming flow step, the foamable raw material flowing into the third cavity via the shortened flow path is more cured than the foamable raw material flowing into the third cavity via the second cavity. It is preferable to reach the third cavity in a state in which the degree of progression of is small.
In this case, since a large amount of foamable raw material flows into the third cavity in a state where the progress degree of the curing reaction is small, compared to the case where the foamable raw material flows into the third cavity via the second cavity, The curing reaction of the foamable raw material can proceed in the third cavity from an earlier stage. Therefore, favorable foaming is performed, and the occurrence of the above molding defects can be more effectively prevented.

Moreover, in the said extraction process, the flow-path foam body foam-molded integrally with the said foam-molded product in the said shortened flow path is parted by moving the said foam-molded product and the said shaping | molding die relatively. .
Thereby , only by relatively moving the foam-molded product after molding and the mold, the flow-path foam is divided, and the foam-molded product can be easily taken out from the mold.

Further, the shortened flow path has a general part and a narrow part having a smaller cross-sectional area than the general part, and in the extraction process, the flow path foam is formed by the narrow part. It divides | segments in a thin part, and this parted flow-path foam is taken out from the said shaping | molding die with the said foaming molded product .
Thereby , the flow-path foam can be easily divided at the thin-walled portion only by relatively moving the molded foam-molded product and the mold. Therefore, the divided flow channel foam can be taken out together with the foam molded product while being connected to the foam molded product, and the flow channel foam can be prevented from remaining in the shortened flow channel.

The shortened flow path has a substantially circular cross section, and includes an inlet opening where the shortened flow path opens into the first cavity, and an outlet opening where the shortened flow path opens into the third cavity. In between, it has the narrow part with the smallest inner diameter in the shortened flow path, and the inner diameter gradually decreases from the inlet opening and the outlet opening toward the narrow part, The thin portion is formed in the narrow portion .
As a result , when the foamed molded product after molding is taken out from the mold, the flow path foam formed in the shortened flow path is divided into two parts at the thin wall part and becomes shorter, and the inlet opening and the outlet It can be easily extracted from both sides of the opening. Therefore, it can prevent more reliably that a flow path foam remains in a shortened flow path.

Further, before performing the injection step, the partition wall that separates the first cavity and the third cavity has a through hole at a position corresponding to the shortened flow path, and is integrated with the foam molded product. It is preferable to perform the auxiliary material arrangement | positioning process which arrange | positions the cloth-like auxiliary material which reinforces a foaming molded article (Claim 4 ).
In this case, the auxiliary material is integrated with the foam molded product, and the strength of the foam molded product can be improved.

In the second invention, the shortened flow path has a general part and a narrow part having a smaller cross-sectional area than the general part .
Thereby , when taking out the foam-molded product after shaping | molding from a shaping | molding die, the flow-path foam body shape | molded in the shortened flow path can be easily parted in the thin part shape | molded by the said narrow part.

The shortened flow path has a substantially circular cross section, and includes an inlet opening where the shortened flow path opens into the first cavity, and an outlet opening where the shortened flow path opens into the third cavity. during has the smallest the narrow portion is an inner diameter in the shorter flow path, and are gradually reduced inner diameter toward respective said narrow section from the inlet opening and the outlet opening.
Thus, it is easy to process to form a shortened flow path, when taking out the molded foam after molding from the mold, flow paths foam molded shorter flow path is two in the thin part It is divided and shortened, and can be easily extracted from both sides of the inlet opening and the outlet opening. Therefore, it can prevent more reliably that a flow path foam remains in a shortened flow path.

Below, the example concerning the manufacturing method and manufacturing apparatus of a foaming molded article of the present invention is explained with a drawing.
As shown in FIGS. 1 to 3, the foam molded product 8 manufactured in this example is a cushion body 8 used for a backrest portion of a vehicle seat, and is disposed opposite to the seat body 81 and the seat body 81. The sheet facing portion 83 is connected. Further, the sheet facing portion 83 is connected to the sheet main body portion 81 via the one side connecting portion 82A at one end portion 835, and via the connecting portion 82B at the left and right end portions 836. It is connected.

  As shown in FIG. 1, the seat body 81 includes a center portion 811 that receives a load from the back of the seated person on the seat, a headrest portion 812 that receives a load from the head of the seated person, and a center portion 811. And a pair of left and right side portions 813 for holding the posture of the seated person. As shown in FIG. 2, the sheet facing portion 83 includes a headrest facing portion 831 located on the back side (rear side) of the headrest portion 812 and a part of the back side (rear side) of the center portion 811, and each side portion 813. Side opposing portions 832 respectively located on the back side (rear side) of each.

  As shown in FIGS. 2 and 3, the headrest facing portion 831 forms a bag shape together with the headrest portion 812, the one side connecting portion 82A and the left and right side connecting portions 82B, and the side facing portion 832 The folded portion is folded back with respect to the side portion 813 through the remaining portion of the left and right side connecting portion 82B. Further, a space 833 formed inside the bag shape by the headrest facing portion 831 and a space 834 formed inside the folded shape by the side facing portion 832 are seat frames for assembling the cushion body 8 to the vehicle ( (Not shown) is used for insertion.

The cushion body 8 has a cloth-like auxiliary material 85 that is integrally joined to the cushion body 8 and reinforces the cushion body 8 on the back surface side. As this auxiliary material 85, for example, a nonwoven fabric such as felt is suitable.
In addition, a supplement made of block-like or plate-like urethane chips can be arranged inside the cushion body 8.

As shown in FIGS. 4 to 9, the molding die 2 used in this example includes a lower die 3 and an upper die 5 that can be opened and closed with respect to the lower die 3. A molding cavity 20 for foam-molding the foam-molded product 8 is formed therebetween.
As shown in FIGS. 4 and 5, the molding die 2 of this example has a three-sheet structure including a lower die 3, a middle die 4 and an upper die 5. The partition wall portion 42 of this example is formed on the middle die 4 that is rotatably arranged with respect to the lower die 3 and the upper die 5. Further, as shown in FIG. 6, an undercut-shaped molding cavity 20 is formed by the partition wall 42 in the molding die 2 of this example.

  Further, the manufacturing apparatus 1 for the foam molded product 8 of this example supplies an injection nozzle 29 for injecting the foamable raw material 80 into the molding cavity 20 of the mold 2 and supplies the foamable raw material 80 to the injection nozzle 29. It is used together with an injection head (not shown), a supply pump (not shown), a storage tank (not shown) for storing the foamable raw material 80, and the like.

  Also, as shown in FIGS. 4 to 9, the molding cavity 20 is formed to face the first cavity 21 for molding the sheet main body portion 81 and the first cavity 21, and the sheet facing portion 83 is formed. A third cavity 23 for molding and a second cavity 22 for communicating the first cavity 21 and the third cavity 23 and molding the connecting portion 82 are included.

  In addition, the second cavity 22 of the present example includes a first-side second cavity 22A that communicates the first cavity 21 and the third cavity 23 at one end 235 of the third cavity 23 (see FIG. 7). Left and right second cavities communicating the first cavity 21 and the third cavity 23 at the left and right end portions 236 of the third cavity 23 (a pair of end portions 236 in a direction substantially orthogonal to the one end portion 235) 22B (see FIG. 8).

  As shown in FIG. 6, the first cavity 21 is formed between the molding surface 31 of the lower mold 3 and the lower molding surface 41 </ b> A of the middle mold 4, and the third cavity 23 is the upper molding surface 41 </ b> B of the middle mold 4. And the molding surface 51 of the upper die 5. The second cavity 22 is formed between the end portion 421 of the partition wall portion 42 and the side surface portion of the molding surface 31 of the lower mold 3 so as to communicate the first cavity 21 and the third cavity 23. .

Further, as shown in FIG. 9, the first cavity 21 has a center cavity 211 for molding the center portion 811 and the headrest portion 812 and a side cavity 212 for molding the side portion 813. .
7-9, the third cavity 23 has a center upper cavity 231 for molding the headrest facing portion 831 and a side upper cavity 232 for molding the side facing portion 832. is doing.

  As shown in FIGS. 4 and 9, the center cavity 211 and the side cavities 212 are divided by two first convex portions 32 </ b> A formed along the front-rear direction of the mold 2. The center cavity 211 and each side cavity 212 are formed between the lower molding surface 41A of the middle die 4 and the upper end surface of the first convex portion 32A when the middle die 4 is closed with respect to the lower die 3. The partition opening 33A communicates.

  As shown in FIGS. 4 and 6, the center cavity 211 is divided into three mold surfaces 211 </ b> A to 211 </ b> C by two second convex portions 32 </ b> B formed along the left-right direction of the mold 2. The three mold surfaces 211A to 211C are partitions formed between the lower molding surface 41A of the middle mold 4 and the upper end surface of the second convex portion 32B when the middle mold 4 is closed with respect to the lower mold 3. The opening 33B communicates.

  The vertical direction of the mold 2 refers to the direction of gravity, and the front-back direction of the mold 2 corresponds to the vertical direction when the cushion body 8 to be molded in the molding cavity 20 is attached to the seat back portion. The center cavity 211 and the pair of side cavities 212 are formed in substantially parallel directions. Further, the left-right direction of the mold 2 refers to a direction corresponding to the left-right direction when the cushion body 8 to be molded in the molding cavity 20 is attached to the backrest portion of the seat. The direction formed adjacently.

  4, 6, and 8, a partition wall 42 that separates the first cavity 21 and the third cavity 23 is disposed between the first cavity 21 and the third cavity 23. A shortened flow path 24 that allows the foaming raw material (foamable resin raw material) 80 to flow from the first cavity 21 to the third cavity 23 is formed by communicating the cavity 21 and the third cavity 23.

As shown in FIGS. 6 and 13, the shortened flow path 24 of the present example facilitates the division of the flow path foam 84 formed in the shortened flow path 24 and facilitates the removal of the flow path foam 84 after the separation. In order to achieve this, a general portion 241 and a narrow portion 242 having a smaller cross-sectional area than the general portion 241 are provided.
More specifically, as shown in FIG. 13, the shortened flow path 24 has a substantially circular cross section, and the narrow portion 242 includes an inlet opening 245 where the shortened flow path 24 opens into the first cavity 21. The shortened flow path 24 is formed between the outlet opening 246 that opens to the third cavity 23 as the portion having the smallest inner diameter. And the shortening flow path 24 is formed in the funnel shape so that an internal diameter may become small gradually toward the narrow part 242 from the inlet opening part 245 and the outlet opening part 246, respectively.

Moreover, it is preferable that the internal diameter of the narrow part 242 is (phi) 2-20 mm. When the inner diameter of the narrow portion 242 is smaller than φ2 mm, the flow resistance when the foamable raw material 80 passes through the shortened flow path 24 increases, and there is a possibility that a sufficient amount of the foamable raw material 80 cannot be supplied to the third cavity 23. is there. On the other hand, if the inner diameter of the narrow portion 242 is larger than φ20 mm, it is difficult to break when the flow path foam is taken out.
As shown in FIG. 6, a plurality of shortened flow paths 24 are formed in the partition wall portion 42, and are formed at two locations along the front-rear direction of the mold 2 in this example.

As a reference example , the shortened flow path 24 has an inner diameter from one of the inlet opening 245 in the shortened flow path 24 and the outlet opening 246 in the shortened flow path 24 as shown in FIG. It can also be formed in a funnel shape so that becomes gradually smaller. In this case, the narrow portion 242 can be formed in the inlet opening 245 or the outlet opening 246 having the smallest inner diameter in the shortened flow path 24.
Further, the shortened flow path 24 is not necessarily formed toward the center of the flow path, and may be formed eccentrically with respect to the center of the flow path, for example, as shown in FIG.

Next, a method for manufacturing the foam molded product 8 using the manufacturing apparatus 1 for the foam molded product 8 provided with the mold 2 (hereinafter referred to as the foam molded product manufacturing apparatus 1) will be described in detail.
In manufacturing the foam molded article 8, first, as shown in FIG. 5, in the state where the middle mold 4 and the upper mold 5 are opened with respect to the lower mold 3, as the auxiliary material arranging step, An auxiliary material 85 having a through hole 851 is disposed at a position corresponding to the shortened flow path 24. At this time, the auxiliary material 85 is disposed so that the bag-like portion 852 is covered with the partition wall portion 42, and the sheet-like portion 853 located on the opposite side to the bag-like portion 852 is placed in the middle size by a latch member 854 such as a pin. Fix to 4.
Here, the through-hole 851 has an inner diameter equal to or larger than each opening 245, 246 of the shortened flow path 24 in order not to hinder the flow of the foamable raw material 80 in each opening 245, 246 of the shortened flow path 24. It is preferable.

  Then, as shown in FIG. 5, as an injection process, the foamable raw material 80 is injected into the first cavity 21 with the middle mold 4 and the upper mold 5 being opened. At this time, in this example, the foamable raw material 80 is injected into the three mold surfaces 211A to 211C in the center cavity 211, respectively. The foamable raw material 80 is obtained by adding a foaming agent (in this example, water) and a curing reaction promoting catalyst (mainly an amine-based catalyst in this example) to a mixture of a polyol-based raw material and an isocyanate-based raw material. , To make urethane foam.

Next, as shown in FIG. 6, as the first foaming flow process, the middle mold 4 and the upper mold 5 are closed with respect to the lower mold 3, and the foamable raw material 80 is foamed and flowed in the first cavity 21.
At this time, as shown in FIG. 7 to FIG. 9, as the second foaming flow step, the foamable raw material 80 that foams and flows in the first cavity 21 expands in volume upward along with foaming, Then, the foam flows into the third cavity 23. Further, the foamable raw material 80 that foams and flows in the first cavity 21 foams and flows into the third cavity 23 via the second cavity 22.

  In this example, as shown in FIGS. 7 and 8, the foamable raw material 80 that foams and flows in the first cavity 21 foams and flows in the shortened flow path 24 before foaming and flowing in the second cavity 22. Then, before the flow front end 801 of the foamable raw material 80 that foams and flows into the third cavity 23 via the second cavity 22 reaches the outlet opening 246 in the shortened flow path 24, the flow of the foamable raw material 80 foams and flows in the shortened flow path 24. The flow front end 802 of the foamable raw material 80 to reach the third cavity 23 from the outlet opening 246. Many of the third cavities 23 are foam-filled by the foamable raw material 80 that has flowed from the shortened flow path 24.

  Thus, in this example, the foaming flow of the foamable raw material 80 from the first cavity 21 to the third cavity 23 is performed not only via the second cavity 22 but also via the shortened flow path 24. . Therefore, a sufficient amount of the foamable raw material 80 is supplied to the third cavity 23, and after the foamable raw material 80 foams and flows toward the third cavity 23, the entire third cavity 23 is filled. Can be shortened.

  Further, in this example, before the flow front end 801 of the foamable raw material 80 flows from the second cavity 22 into the third cavity 23, the flow front end 802 of the foamable raw material 80 passes from the shortened flow path 24 to the third cavity. 23 flows in. Therefore, most of the foamable raw material 80 that flows into the third cavity 23 via the shortened flow path 24 has a lower degree of progress of the curing reaction than the foamable raw material 80 that flows into the third cavity 23 via the second cavity 22. In the state, that is, in the early stage of the curing reaction, the third cavity 23 is reached and good foaming is performed.

  That is, in the reaction of the foamable raw material 80, the foaming reaction and the curing reaction proceed in parallel. First, the foaming reaction proceeds mainly, and the curing reaction proceeds so as to follow the foaming reaction. Therefore, in this example, while the foaming reaction of the foamable raw material 80 injected into the first cavity 21 is mainly proceeding, the foamable raw material 80 flows into the third cavity 23 from the shortened flow path 24 in a short time. By doing so, the foamable raw material 80 can be spread over the entire molding cavity 20 in a short time. In addition, the foaming reaction and the curing reaction can be performed more uniformly in the entire molding cavity 20.

Next, as shown in FIGS. 10 and 11, as a foam molding process, the foamable raw material 80 that has flowed into the third cavity 23 through the second cavity 22 and the flow into the third cavity 23 through the shortened flow path 24. The foamable raw material 80 is integrated.
In this example, the vicinity of the central portion 230 and the vicinity of the other end 237 of the third cavity 23 are filled with the foamable raw material 80 that has flowed from the shortened flow path 24. Further, the vicinity of one end portion 235 and the vicinity of both left and right end portions 236 of the third cavity 23 are filled with the foamable raw material 80 flowing from the second cavity 22.

Then, in the vicinity of one end 235 of the third cavity 23 and in the vicinity of both left and right ends 236, the flowable front end 801 of the foamable raw material 80 that has flowed in through the second cavity 22 and the shortened flow path 24 flow in. The flowable front end portion 802 of the foamable raw material 80 is joined (see dotted lines L1 and L2 in FIGS. 10 and 11).
In this way, the foamable raw material 80 is quickly filled into the entire first to third cavities 21 to 23 (molding cavities 20), and the foamability that has flowed in through the second cavities 22 in the third cavities 23. The raw material 80 and the foamable raw material 80 that has flowed in through the shortened flow path 24 are integrated.

  A seat body 81 of the cushion body 8 is formed in the first cavity 21, a connecting portion 82 of the cushion body 8 is formed in the second cavity 22, and a cushion is formed in the third cavity 23. A sheet facing portion 83 of the body 8 is formed. In addition, the seat body 81, the connecting portion 82, and the seat facing portion 83 are formed of the same foamable raw material 80, and the cushion body 8 is integrally coupled to the auxiliary material 85. A flow path foam 84 is formed in the shortened flow path 24, and a thin portion 842 is formed in the flow path foam 84 corresponding to the narrow part 242 of the shortened flow path 24.

Next, as shown in FIG. 12, as an extraction process, the middle mold 4 is opened with respect to the lower mold 3, and the upper mold 5 is opened with respect to the middle mold 4. At this time, the foam molded product 8 is released from the lower mold 3 and the upper mold 5 in a state of covering the partition wall portion 42 of the middle mold 4.
Then, the foamed molded article 8 after molding is directed toward the tip end portion of the partition wall portion 42 located on the opposite side of the partition wall portion 42 in the middle mold 4 from the side where the hinge portion (opening / closing fulcrum portion) 43 is formed. And remove it from the middle mold 4. At this time, the flow path foam 84 integrally foamed with the foam molded product 8 in the shortened flow path 24 is divided (broken) at the thin wall portion 842.

Then, the divided flow path foam 84 is extracted from the shortened flow path 24 at the same time as the foam molded product 8 is removed from the partition wall 42 of the middle mold 4 while being connected to the foam molded product 8. Thereby, it is possible to prevent the flow channel foam 84 from remaining in the shortened flow channel 24.
Therefore, according to the foam molded product manufacturing apparatus 1 and the manufacturing method using the same according to the present example, the time required for the foaming flow of the foamable raw material 80 is prevented from being uneven depending on the part, and the entire molding cavity 20 is uniform. By filling the foamable raw material 80 into the foamed molded product 8, which does not cause molding defects such as crushing or lacking in thickness, can be molded.

The front view which shows the foaming molded product of the state seen from the front side in an Example. The back view which shows the foaming molded product of the state seen from the back surface side in an Example. It is a figure which shows the foaming molded article in an Example, and is AA arrow sectional drawing in FIG. Cross-sectional explanatory drawing which shows the shaping | molding die in the state which opened the upper mold | type with respect to the lower mold | type and the middle mold in the Example in the state seen from upper direction. FIG. 5 is a diagram showing a molding die in a state in which an intermediate die and an upper die are opened with respect to a lower die and a foamable raw material is injected into a first cavity in the embodiment, and is a cross-sectional view corresponding to the line AA in FIG. 4. The figure which shows the shaping | molding die of the state which closes a middle mold | type and an upper mold | type with respect to a lower mold | type in an Example, and foams and flows a foamable raw material within a 1st cavity, and is sectional drawing equivalent to the AA line arrow in FIG. . FIG. 5 is a view showing a molding die in a state in which the foamable raw material is foamed and flowed to the third cavity through the shortened flow path and the second cavity in the embodiment, and is a cross-sectional view corresponding to the line AA in FIG. 4. FIG. 5 is a view showing a molding die in a state in which a foamable raw material is foamed and flowed to a third cavity through a shortened flow path and a second cavity in the embodiment, and is a cross-sectional view corresponding to the arrow BB in FIG. 4. FIG. 5 is a diagram illustrating a mold in a state in which a foamable raw material is foamed and flowed into a third cavity through a second cavity in the embodiment, and is a cross-sectional view corresponding to the line CC in FIG. 4. The figure which shows the shaping | molding die in the state which shape | molded the foaming molded product in the shaping | molding cavity in an Example, and is sectional drawing equivalent to the AA arrow in FIG. The figure which shows the shaping | molding die of the state which shape | molded the foaming molded product in the shaping | molding cavity in an Example, and sectional drawing equivalent to the BB arrow in FIG. FIG. 5 is a view showing a molding die in a state where an intermediate die and an upper die are opened with respect to a lower die and a foamed molded product after molding is taken out from the middle die, and is a cross-sectional view corresponding to the line AA in FIG. 4. Sectional drawing which expands and shows a shortening flow path in an Example. Sectional drawing which expands and shows the other shortened flow path in a reference example. Sectional drawing which expands and shows the other shortened flow path in a reference example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus 2 Molding die 20 Molding cavity 21 1st cavity 22 2nd cavity 23 3rd cavity 24 Short flow path 241 General part 242 Narrow part 245 Inlet opening part 246 Outlet opening part 3 Lower mold 4 Middle mold 42 Partition part 5 Upper mold 8 Foam molded product (cushion body)
80 Foamable Raw Material 81 Sheet Main Body 82 Connecting Portion 83 Sheet Opposing Portion 84 Flow Channel Foam 842 Thin Wall 85 Supplement Material 851 Through Hole

Claims (5)

In a method for producing a foam molded product by using a mold that forms a mold cavity when it can be opened and closed, and filling the mold cavity with a foamable raw material,
The molding cavity includes a first cavity, a second cavity formed to be bent with respect to the first cavity, and a third cavity formed continuously from the second cavity so as to face the first cavity. And the first cavity and the third cavity are communicated with each other by a shortened flow path that allows foaming flow of the foamable raw material from the first cavity to the third cavity. And
The shortened flow path has a substantially circular cross section and has a narrow portion having the smallest inner diameter in the shortened flow path.
The narrow portion is formed between an inlet opening where the shortened flow path opens into the first cavity and an outlet opening where the shortened flow path opens into the third cavity;
The inner diameter gradually decreases from the inlet opening and the outlet opening toward the narrow part,
In producing the foamed molded article, an injection step of injecting the foamable raw material onto the mold surface forming the first cavity with the mold open.
A first foaming flow step of closing the mold and foaming and flowing the foamable raw material in the first cavity;
A second foaming flow in which the foamable raw material is foamed and flowed from the first cavity to the third cavity through the second cavity and from the first cavity to the third cavity through the shortened flow path. Process,
The foamable raw material that has flowed into the third cavity via the second cavity and the foamable raw material that has flowed into the third cavity via the shortened flow path are integrated into the first to third cavities. A foam molding step of molding the foam molded article with the foamable raw material filled in
By opening the molding die and relatively moving the foam molded product and the molding die, the flow path foam formed integrally with the foam molded product in the shortened flow channel is formed into the narrow portion. A method for producing a foam molded article, comprising: a step of dividing the thin foam portion molded by the step of taking out the separated flow path foam from the mold together with the foam molded article.   2. The shortened flow path according to claim 1, wherein in the second foaming flow step, a flow leading portion of a foamable raw material that foams and flows to the third cavity through the second cavity opens toward the third cavity. Before reaching the outlet opening of the foamed molded article, the flow leading portion of the foamable raw material that foams and flows in the shortened flow path is allowed to reach the third cavity from the outlet opening. .   3. The foamable raw material flowing into the third cavity through the second cavity in the second foaming flow step is the foamable raw material flowing into the third cavity through the second cavity. A method for producing a foam molded article, wherein the third cavity is reached in a state in which the progress of the curing reaction is less than that. The through-hole is provided at a position corresponding to the shortened flow path in the partition wall that separates the first cavity and the third cavity before performing the injection step. A method for producing a foam-molded product, comprising performing an auxiliary material arranging step of arranging an auxiliary material that reinforces the foam-molded product integrally with the foam-molded product . In an apparatus for producing a foam molded product by filling a foaming raw material into a molding cavity formed in a mold that can be opened and closed,
The molding cavity includes a first cavity, a second cavity formed to be bent with respect to the first cavity, and a third cavity formed continuously from the second cavity so as to face the first cavity. A cavity,
The molding die has a partition wall that separates the first cavity and the third cavity, and the partition wall has a shortened flow path that allows the first cavity and the third cavity to communicate with each other. Formed ,
The shortened flow path has a substantially circular cross section and has a narrow portion having the smallest inner diameter in the shortened flow path.
The narrow portion is formed between an inlet opening where the shortened flow path opens into the first cavity and an outlet opening where the shortened flow path opens into the third cavity;
An apparatus for manufacturing a foam-molded product, wherein an inner diameter gradually decreases from the inlet opening and the outlet opening toward the narrow portion .

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