JP2008168446A - Molding method of cushioning pad and foaming mold for cushioning pad - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foaming mold for a cushioning pad which is capable of preventing the occurrence of an air pockets in corner parts of the crossing parts of a plurality of the ridge parts provided in a lower mold, in a foaming process of a raw liquid comprising a foamable resin injected in the mold. <P>SOLUTION: An air venting groove 54 is formed to the corner part 53 of the crossing part of ridge parts 46A and 46B formed to the base of the lower mold 42. A closure preventing part 55 is integrally formed in the vicinity of the upper end opening part 54a of the air venting groove 54, and the air venting groove 57 of the closure preventing part 55 communicates with the air venting groove 54. When the foamable resin is moved toward a first region 48 from the third region 50 on the left side of the ridge part 46A so as to get over the ridge part 46A as shown by the arrow, it is guided to the lateral part of the upper end opening part 54a by a shield part 56 to prevent the closure of the opening part 54a and the air of the corner part 53 is discharged through the air venting grooves 54 and 57 to prevent the air pocket from being formed to the corner part 53. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to, for example, a seat seat installed in an automobile or the like, and relates to a method for molding a seat pad serving as a seat portion of the seat and a cushion pad used for a backrest, and a foam molding die used therefor.

  As a cushion pad of a seat cushion constituting a seat portion of a seat for an automobile, a cushion pad 14 formed by a foaming mold using urethane foam is used as shown in FIG. As shown in FIG. 14, a leather or fabric seat skin 15 is mounted on the surface of the cushion pad 14 to constitute a seat cushion. As shown in FIG. 13, the cushion pad 14 includes a front support portion 21 that mainly supports the thigh of the occupant, a rear support portion 22 that mainly supports the buttocks, and a side support that supports the sides of the thigh and the buttocks. It is divided roughly into parts 23 and 23. Concave mounting grooves 24a and 24b are formed in an H shape in plan view as a whole at the boundary portions of the support portions 21, 22, and 23, respectively. An insert wire (not shown) is embedded in the cushion pad 14 at the inner bottom of the mounting grooves 24a and 24b, and a clip for connecting the seat skin 15 is hooked on the wire, and the skin 15 is placed in the mounting grooves 24a and 24b. Has been drawn. By this drawing, the skin 15 is maintained in a stretched state. The side support portion 23 is made of urethane foam having a hardness higher than that of the urethane foam forming the front support portion 21 and the rear support portion 22 so that the side portions of the thigh and the buttock of the occupant can be stably supported. I have to.

  The cushion pad 14 is formed by a foaming mold (only the lower mold 42 is shown) shown in FIG. On the bottom surface of the lower mold 42, a plurality of protrusions 46A and 46B are integrally formed in an H shape in plan view. The mounting grooves 24a and 24b are formed on the surface of the cushion pad 14 by the protruding portions 46A and 46B. The lower mold 42 includes a first region 48 in which the front support portion 21 is formed by the protrusions 46A and 46B, a second region 49 in which the rear support portion 22 is formed, and two side support portions 23. It is partitioned into a third region 50.

In the molding operation of the cushion pad 14, as shown in FIG. 15, a urethane foam stock solution is used by using injection nozzles 51, 52 in the first region 48, the second region 49, and the third region 50 of the opened lower mold 42. P1 and P2 are injected. Thereafter, the upper die is bonded to the upper surface of the lower die 42, and the stock solutions P1 and P2 are foamed and cured to form the cushion pad 14. (See Patent Document 1)
Japanese Patent Laid-Open No. 2001-70083

  As shown in FIG. 16, the conventional foaming mold 41 is formed by foaming the stock solution P <b> 1 at the initial stage of the foaming process of urethane foam at the lower end corner 53 of the intersecting portion where the protrusion 46 </ b> A and the protrusion 46 </ b> B are orthogonal to each other. There is a risk of air pockets without urethane. In this specification, as shown in FIG. 16, the side surface S1 on the first region 48 side of the protrusion 46A, the side surface S2 on the first region 48 side of the protrusion 46B, and the bottom surface S3 of the lower mold 42 are provided. One intersecting point (narrowly defined corner; black point) and its vicinity (widely defined corner) are collectively referred to as a lower end corner 53. In order to eliminate the air pocket at the lower end corner 53, the injection nozzle 51 is moved by an injection robot along a preset movement path to the lower end corner 53 of the first region 48 and the second region 49. The stock solution P1 may be supplied over the entire area. However, when the density of the urethane foam decreases, the amount of the stock solution P1 to be injected also decreases, and the stock solution P1 cannot be supplied to the entire region 48, 49. In this case, from the viewpoint of keeping the quality of the cushion pad 14 formed in consideration of the volume expansion in the foaming process of the stock solution P1, the stock solution P1 is provided only in the central portion of the first and second regions 48 and 49. At present, the stock solution P1 is not supplied to the corner 53.

  In order to avoid the occurrence of air pockets at the corner 53 described above, it is conceivable to form an air escape groove 54 extending in the vertical direction on the side surface S1 corresponding to the lower end corner 53 as shown in FIG. However, the upper end opening 54a of the air escape groove 54 is at the same position as the upper surface of the protrusion 46A. Further, the injection amount of the stock solution P1 and the stock solution P2 and the rate at which they expand and the volume increases are not the same. For this reason, the foamed urethane of the stock solution P2 injected into the third region 50 may get over the upper surface of the protrusion 46A in FIG. 16, and in this case, the urethane foam that has reached the upper surface of the protrusion 46A is The upper end opening 54 a of the air escape groove 54 is closed, and the effect of escaping the air at the corner 53 is lowered, and an air pocket is generated at the corner 53.

  When an air pocket is generated at the corner 53, a defective portion 14a having no urethane foam is formed at the intersection of the mounting grooves 24a and 24b of the cushion pad 14 as shown in FIG. When the defect 14a is generated, there is a problem that when the seat cover 15 is attached to the cushion pad 14 as shown in FIG. 14, a dent is formed, the appearance is impaired, and the quality of the product is deteriorated.

  The present invention eliminates the above-mentioned conventional problems, and in the foaming step of the foamed resin stock solution injected into the mold, the air pockets are formed at the corners of the intersections of the plurality of protrusions provided in the lower mold. It is an object of the present invention to provide a cushion pad molding method and a foam molding die used for the cushion pad that can prevent the occurrence of defects due to air pockets in the cushion pad.

  In order to solve the above problems, the invention according to claim 1 is characterized in that a stock solution of foamed resin is respectively applied to a plurality of regions partitioned by a plurality of protruding ridges intersecting each other formed on the inner bottom surface of the lower mold. inject. In the foaming process of the stock solution, air that tends to stay at the lower end corner of the intersecting portion of the ridge is released upward from an air escape passage formed in the ridge. Then, the blocking prevention means prevents the upper opening of the air escape passage from being blocked by the foamed resin entering the region on the lower end corner portion side from the other region.

  According to a second aspect of the present invention, there is provided a foam molding die in which a resin raw material is injected into a bottom portion of a cavity formed by a lower die and an upper die, and a cushion pad is foam-molded. On the other hand, a plurality of ridges intersecting each other are provided. Further, the bottom portion of the lower mold is divided into a plurality of regions by the respective ridge portions, and a groove-like or tunnel-like air escape is vertically formed in the ridge portion corresponding to the lower end corner portion of the intersecting portion of each ridge portion. Each passage is provided. Further, a blocking preventive means such as a block-shaped shielding portion for preventing the resin foam from overcoming the protruding portion from another region with respect to the upper end opening of the air escape passage and closing the upper end opening. Is provided.

According to a third aspect of the present invention, in the second aspect of the present invention, the blocking prevention means is formed by a shielding portion provided so as to be directed upward corresponding to the opening of the air escape passage.
According to a fourth aspect of the present invention, in the third aspect, the shielding portion is provided at a position closer to the upper end opening of the air escape passage with respect to the width direction of the upper surface of the protruding portion, and on the upper surface of the protruding portion. On the other hand, the space which supports the insert wire for attaching an outer skin to the surface of a cushion pad is formed.

According to a fifth aspect of the present invention, in the third or fourth aspect, the shielding portion is formed such that an air escape passage communicating with an upper end opening of the air escape passage is directed upward.
According to a sixth aspect of the present invention, in the third or fourth aspect, the shielding portion is formed so as to surround respective upper end openings of two adjacent air escape passages.

(Function)
In the present invention, the air that tends to stay at the corner of the intersection of the ridges provided in the lower mold of the mold is released upward from the air escape passage formed in the ridges. At this time, when the foamed resin enters the region on the corner side from the other region over the protruding portion, the upper end opening of the air escape passage is prevented from being blocked by the blocking prevention means. For this reason, it is prevented that the air pocket without the foamed resin is formed in the corner.

  According to the present invention, air pockets without foamed resin are prevented from being formed at the corners of the intersecting portions of the protrusions, so that air pockets are formed at the intersecting portions of the mounting grooves formed in the cushion pad. Defects can be prevented from occurring, and the seat skin can be properly attached to the surface of the cushion pad.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a method for forming a cushion pad for a seat seat of an automobile and its foaming mold will be described below with reference to FIGS. In addition, the thing of the same structure as the structure of the cushion pad 14 demonstrated in background art and the structure of the lower mold | type 42 of a foaming mold is attached | subjected, and description is abbreviate | omitted or simplified.

  FIG. 6 shows only the cushion pad 14 of the seat cushion that becomes the seat portion of the automobile seat, and is the same configuration as that of the cushion pad 14 shown in FIG. 13, except that the missing portion 14a does not exist. FIG. 7 shows a seat cushion in which a seat pad 15 is properly coated on the cushion pad 14.

Next, the foaming mold of the cushion pad 14 will be described with reference to FIGS.
As shown in FIG. 4, the foam mold 41 includes a lower mold 42 that molds the upper side of the cushion pad 14, and a middle mold 43 that is also an upper mold that molds the back surfaces of the front support portion 21 and the rear support portion 22. And an upper mold 44 that forms the back surface of the side support portion 23. The lower mold 42, the middle mold 43, and the upper mold 44 are clamped as shown in FIG. 5 to form a cavity 45 for molding the seat cushion pad 14.

  As shown in FIGS. 3 to 5, on the bottom surface of the lower mold 42, two right and left protrusions 46A for forming the mounting grooves 24a and 24b and one protrusion perpendicular to both protrusions 46A are provided. The strip 46B is formed in an H shape in plan view as a whole. The interior of the lower mold 42 is partitioned into a first region 48, a second region 49, and left and right third regions 50 by the protrusions 46A and 46B.

Next, description will be made based on the configuration of the main part of this embodiment.
As shown in FIG. 1, the four lower end corners 53 (see FIG. 3) at the intersections of the protrusion 46A and the protrusion 46B are not filled with urethane foam in the foam molding process of the cushion pad 14. In order to prevent the formation of an air pocket, an air escape groove 54 is formed as an air escape passage through which the air in each corner 53 escapes upward. The air escape groove 54 is formed on the side surface S1 on the first region 48 side of the protrusion 46A, and one side surface of the air escape groove 54 is a side surface on the first region 48 side of the protrusion 46B. It is flush with S2.

  On the upper surface of the protrusion 46A, the upper end opening 54a of the air escape groove 54 is prevented from being blocked by the foamed urethane to flow from the third region 50 to the first region 48 or the second region 49. For this purpose, a blocking prevention portion 55 is provided as a blocking prevention means. Since each blocking prevention part 55 is comprised similarly, the structure by the side of the 1st area | region 48 is demonstrated below.

  That is, on the upper surface of the protrusion 46A, a block-shaped shielding part 56 is integrally formed so as to be directed upward corresponding to the upper end opening 54a of the air escape groove 54. An air escape groove 57 as an air escape passage is formed in the vertical direction so as to communicate with the upper end opening 54 a of the air escape groove 54. The shielding portion 56 is formed at a position near the upper end opening 54a of the air escape groove 54 in the width direction of the upper surface of the protrusion 46A, and a space for supporting the insert wire Y is formed on the upper surface of the protrusion 46A. Yes.

  The width W of the air escape grooves 54 and 57 shown in FIG. 1 is set to 2 mm, for example, in the range of 1 mm to 5 mm. The depth d of the air escape grooves 54 and 57 shown in FIG. 2 is set to 2 mm, for example, in the range of 1 mm to 5 mm. The height h from the upper surface of the protrusion 46B of the shielding part 56 is set to, for example, 10 mm in the range of 5 to 20 mm. If the width W of the air escape groove 54 is 1 mm or less, the air escape effect of the corner 53 is lowered, and if it is 5 mm or more, the urethane foam easily enters the air escape grooves 54 and 57, which is not preferable. If the depth d of the air escape grooves 54 and 57 is 1 mm or less, the air escape effect is reduced. If the depth d is 5 mm or more, not only is the mold processing difficult, but also the foamed urethane foam is cut off from the seat cushion pad. This is not desirable because it tends to remain in the air escape grooves 54 and 57. If the height h of the shielding part 56 is 5 mm or less, the blocking prevention effect is lowered, and if it is 20 mm or more, processing becomes difficult, which is not preferable.

Next, a method for molding the seat cushion pad 14 using the foam molding die 41 configured as described above will be described.
First, as shown in FIG. 4, with the middle mold 43 and the upper mold 44 being released upward from the lower mold 42, an injection nozzle is formed at the center in the first area 48 and the second area 49 of the lower mold 42. 51 is used to inject a low hardness urethane foam stock solution P1. Further, a high-hardness urethane foam stock solution P2 is injected into both the third regions 50 using an injection nozzle 52.

  Next, as shown in FIG. 5, the middle mold 43 and the upper mold 44 are joined to the opening 42a of the lower mold 42 and clamped. In this state, two types of urethane foam stock solutions P1 and P2 are foamed to fill a predetermined region in the cavity 45, and the seat cushion pad 14 is formed.

  After the urethane foam stock solutions P1, P2 are foamed and cured, the middle mold 43 and the upper mold 44 are separated from the lower mold 42, and the seat cushion pad 14 is removed from the lower mold 42. In the seat cushion pad 14 thus molded, mounting grooves 24a and 24b are formed on the surface of the cushion pad 14 by the protrusions 46A and 46B.

Therefore, according to the foam molding die 41 of the above embodiment, the following effects can be obtained.
(1) In the embodiment described above, air escapes to the side surface S1 of the ridge 46A so as to correspond to the corner 53 of the intersecting portion where the ridge 46A and the ridge 46B formed on the bottom surface of the lower mold 42 intersect. In addition to forming the groove 54, a blocking prevention portion 55 for preventing the upper end opening 54a of the air escape groove 54 from being blocked is formed on the upper surface of the protrusion 46A. For this reason, as shown in FIG. 2, before the stock solution P1 in the first region 48 is foamed and the urethane foam P1a reaches the upper surface of the protrusion 46B, the foamed urethane of the stock solution P2 injected into the third region 50 Even if P2a flows on the upper surface of the protrusion 46A, the urethane foam P2a flows to the side of the upper end opening 54a of the air escape groove 54 as shown by the arrow in FIG. It is not blocked by the urethane foam P2a. As a result, it is possible to prevent the air remaining in the corner portion 53 from being discharged upward by the air escape grooves 54 and 57 and forming an air pocket in the corner portion 53, and the molded cushion pad 14. In other words, the defect portion is not formed on the surface of the cushion pad 14, and the surface of the cushion pad 14 can be appropriately covered with the surface of the cushion pad 14 as shown in FIG.

  (2) In the above embodiment, the shielding portion 56 is formed near the upper end opening 54a of the air escape groove 54 in the width direction of the upper surface of the protrusion 46A, and the cover 15 is attached to the upper surface of the protrusion 46A. A space for supporting the insert wire Y is formed. For this reason, it can be used for forming the cushion pad 14 in which the insert wire Y is embedded.

(3) In the above embodiment, since the air escape grooves 54 and 57 are provided corresponding to the corner 53, the air in the corner 53 can be discharged efficiently.
In addition, you may change this embodiment as follows.
-You may form the shielding part 56 of the same width as the width W of the air escape groove 54, as shown in FIG.
As shown in FIG. 9, the upper end openings 54 a of the two air escape grooves 54 formed so as to be adjacent to two locations may be surrounded by one shielding portion 56.
As shown in FIG. 10, the air escape groove 54 and the blocking prevention portion 55 may be formed in the vicinity (broadly defined corner) away from one point (black dot, narrowly defined corner) of the corner 53. The distance L from one point of the corner 53 to the outer edge of the air escape groove 54 is set in the range of 1 to 10 mm, and preferably in the range of 1 to 5 mm.
As shown in FIG. 11, the shielding part 56 of the blocking prevention part 55 may be formed so as to cover the upper end opening part 54a of the air escape groove 54 on the upper surface of the protruding part 46A.

  As shown in FIG. 12, in place of the air escape grooves 54 and 57, a tunnel-like air escape passage 61 is formed, and a tunnel-like air escape passage communicating with the upper end opening 61a of the passage 61 is formed in the shielding portion 56. 62 may be formed.

-Although not shown in figure, you may form the air escape groove 54 and the obstruction | occlusion prevention part 55 in the side surface S2 side of the said protrusion 46B.
The present invention can be applied to the seat cushion pad 14 for an automobile seat and the seat back pad for supporting the back as described above, but is also applicable to a seat cushion pad, a seat back pad, etc. other than for an automobile. be able to.

The expansion perspective view which shows the principal part of the foaming mold of the cushion pad of this invention. The longitudinal cross-sectional view explaining the effect | action of the principal part of a foaming mold. The perspective view which shows a lower mold | type. The cross-sectional view explaining the molding method of the seat cushion pad by a foaming mold. The cross-sectional view of the clamping state explaining the molding method of the seat cushion pad by a foaming mold. The perspective view of the seat cushion pad of the passenger | crew compartment of a motor vehicle. The cross-sectional view which coat | covered the skin on the seat cushion pad. The fragmentary perspective view which shows another embodiment of the foaming die of this invention. The fragmentary perspective view which shows another embodiment of the foaming die of this invention. The fragmentary perspective view which shows another embodiment of the foaming die of this invention. The fragmentary longitudinal cross-section which shows another embodiment of the foaming die of this invention. The fragmentary longitudinal cross-section which shows another embodiment of the foaming die of this invention. The perspective view of the seat cushion pad of the passenger | crew compartment of a motor vehicle. The cross-sectional view which coat | covered the skin on the seat cushion pad. The perspective view of the lower mold | type of the conventional foaming mold. The partial expansion perspective view of the lower mold | type of the conventional foaming mold.

Explanation of symbols

  Y ... insert wire, 14 ... cushion pad, 41 ... foaming mold, 42 ... lower mold, 44 ... upper mold, 45 ... cavity, 46A, 46B ... ridge, 54 ... air relief groove, 54a, 61a ... upper end opening Reference numeral 55: Blocking prevention part as blocking prevention means, 56: Shielding part, 61, 62: Air escape passage.

Claims (6)

A foamed resin stock solution is injected into each of a plurality of regions partitioned by a plurality of projecting ridges intersecting each other formed on the inner bottom surface of the lower mold, and in the foaming process of the stock solution, The air that is about to stay in the lower end corner escapes upward from the air escape passage formed in the ridge, and passes through the ridge from the other area and enters the area on the lower end corner side to release the air. A method for forming a cushion pad, wherein the upper end opening of the passage is blocked by a blocking prevention means. In a foam molding die in which a resin raw material is injected into the bottom of a cavity formed by a lower die and an upper die, and a cushion pad is foam-molded,
Provided with a plurality of ridges intersecting each other with respect to the inner bottom surface of the lower mold, the bottom of the lower mold is partitioned into a plurality of regions by each of the ridges, the lower end corner of the intersection of the ridges, Correspondingly, an air escape passage is provided in the ridge portion in the vertical direction, and the resin foam crosses the ridge portion from the other region with respect to the upper end opening portion of the air escape passage and closes the upper end opening portion. A foam molding die for a cushion pad, characterized in that it is provided with a blocking prevention means for preventing the above. 3. The cushion pad foaming mold according to claim 2, wherein the blocking prevention means is formed by a shielding portion provided so as to be directed upward corresponding to the opening of the air escape passage. . In Claim 3, The said shielding part is provided in the position near the upper end opening part of the said air escape passage regarding the width direction of the upper surface of the said rib part, The space which supports an insert wire is formed in the upper surface of the said rib part. Cushion pad foaming mold, characterized by 5. The foam molding die for a cushion pad according to claim 3, wherein an air escape passage communicating with an upper end opening of the air escape passage is directed upward in the shielding portion. 5. The cushion pad foaming mold according to claim 3, wherein the shielding portion is formed so as to surround each upper end opening of two adjacent air escape passages.

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