JP2004160750A - Method for manufacturing pad for seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a pad for a seat having a laminated structure wherein only a main upper layer is set to a soft layer while ensuring shape preciseness in the boundary surface of foam. <P>SOLUTION: Ridges 63 and 65 which demarcate the main upper layer 21 from the other part thereof are provided to a lower mold 6 to inject a soft foamable raw material 82 in the recessed part of the lower mold demarcated by the ridges. A first upper mold 71 is closed to be brought into contact with the ridges 63 and 65 in a sealed state to form a foaming space 51 demarcated by the ridges between the lower mold 6 and the first upper mold 71 and the soft foamable raw material 82 charged in the foaming space is foamed to mold the main upper layer 21 comprising the soft layer. Next, a hard foamable raw material 84 is injected in the foaming space and a second upper mold 72 is closed to foam the raw material 84 to integrally laminate a main lower layer 22 comprising a hard layer and a side part 3. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a seat pad used for a vehicle or furniture seat. In particular, a part of the upper layer is made of a foam having a different hardness from the lower part and the other parts of the upper part. The present invention relates to a method for manufacturing a sheet pad having a laminated structure formed.
[0002]
[Prior art]
Conventionally, in order to impart excellent characteristics to a sheet pad, a sheet pad having a laminated structure having a structure in which foams having different hardnesses are laminated has been proposed.
[0003]
[Patent Document 1] Japanese Patent Publication No. 3-60280.
[0004]
[Patent Document 2] JP-A-2002-200626.
[0005]
In the above-mentioned Patent Document 1, two lower molds are provided so as to be openable and closable by hinge joints, respectively. First, a first foaming material is injected into the lower mold, and the first upper mold is closed, and the lower mold and the first mold are closed. (1) The first foaming material is foam-filled with the upper mold to form an upper layer, and then the second foaming material is injected onto the molded upper layer, and the second upper mold is closed to close the upper layer. A method is described in which a second foaming material is foam-filled between a first upper mold and a second upper mold to laminate and integrate a lower layer portion.
[0006]
In the above Patent Document 2, a flexible film is arranged in a concave portion of a lower mold so that an opening is formed, a first foaming material is injected into the film from the opening, and a portion other than the opening is formed. , And then the lower mold and the upper mold are closed, and the first foaming material and the second foaming material are integrally foamed using the film as a boundary layer. A method for manufacturing a sheet pad having a two-layer structure of one foam and a second foam made of a second foam material is described.
[0007]
[Problems to be solved by the invention]
According to the method of Patent Document 1, since the boundary between the upper layer and the lower layer is defined by the mold (first upper die), it is possible to obtain a sheet pad having excellent shape accuracy at the boundary. Can be. However, Patent Literature 1 does not disclose a method in which the entire upper layer portion is formed of a soft foam, and a part of the upper layer portion is formed of a foam having a different hardness from the other portions.
[0008]
On the other hand, according to the method of Patent Document 2, a part of the upper layer can be formed of a foam having a hardness different from that of the other part. However, in this method, the first foam is formed using the flexible film as a boundary layer. Since the body and the second foam are laminated and integrated, the shape of the boundary surface between the two foams is not stable, and therefore, there is a problem that it is difficult to secure a certain quality as a seat pad such as sitting comfort. .
[0009]
The present invention has been made in view of such a point, and a sheet pad having a laminated structure in which a part of the upper layer portion is formed of a foam having a different hardness from the other portions is provided. It is an object of the present invention to provide a method that can be manufactured while ensuring the shape accuracy on a surface.
[0010]
[Means for Solving the Problems]
In the method for manufacturing a sheet pad according to the present invention, a part of an upper layer is different from other parts of a lower layer and an upper layer using a molding die having a lower die, a first upper die, and a second upper die. A method for manufacturing a pad for a sheet made of a foam having hardness, wherein the lower die includes a ridge for partitioning the part of the upper layer part from the other part, and a lower die recess defined by the ridge. A first foaming material is injected into the inside, and the first upper mold is closed to abut against the ridge in a sealed state, whereby the lower mold and the first upper mold are partitioned by the ridge. Forming a part of the upper layer portion made of the first foam by foaming and filling the first foaming material in the foaming space, and then opening the first upper mold. Inject a second foaming material into the lower mold, close the second upper mold, and move the lower mold and the second upper mold between the lower mold and the second upper mold. 2, characterized in that shaping the remainder of the second foam comprising the lower layer by causing foaming raw material is foam filling.
[0011]
In the manufacturing method of the present invention, the foaming space of the first foam forming a part of the upper layer portion is hermetically formed by contacting the ridge provided on the lower mold with the first upper mold in a sealed state, That is, the first foaming material is foam-filled between the lower mold and the first upper mold after being separated from the other parts by the ridges. As described above, since the boundary between the first foam and the second foam is defined by the molding die, the sheet pad having a partially laminated structure can be formed while securing the shape accuracy at the boundary. This increases the degree of freedom in design in terms of performance and cost.
[0012]
In the above, the seat pad has a main portion and side portions on both the left and right sides thereof, the part of the upper layer portion is a main portion upper layer portion, and the main portion upper layer portion is a main portion lower layer portion and a side portion. A pad for a sheet made of a foam having low hardness, and when manufacturing the pad, extends as a protrusion contacting the first upper mold in a sealed state at a boundary between a main portion and side portions on both left and right sides thereof. A pair of left and right vertical ridges forming a groove on the pad surface may be provided, and the first foaming material may be injected into a lower mold recess between the left and right vertical ridges. In this case, a seat pad is obtained in which only the upper part of the main part such as the seating part is made of the soft layer, and the lower part of the main part and the side part are made of the hard layer. Also has excellent hold feeling.
[0013]
Further, in this case, a horizontal ridge connecting the left and right vertical ridges is further provided as the ridge that comes into contact with the first upper mold in a sealed state, and the horizontal ridge is narrower than the vertical ridge. The groove may be formed in the shape of a flake so as to form the groove on the pad surface. Alternatively, the left and right vertical protrusions are provided over the entire length of the lower die in the front-rear direction, and at least one end of each of the front and rear ends thereof is formed into a lamella so as to form a groove narrower than the other portion on the pad surface. It may be in a state. Generally, a seating stability groove is provided at the boundary between the main portion and the side portion on the pad surface, but this groove alone may not be able to partition the foaming space of the first foam to be the soft layer. In such a case, a flaky ridge that forms a narrow groove that does not cause a problem in design is provided in the lower mold, and the foaming space is formed by the flared ridge together with the ridge that forms the seating stability groove. By dividing, the boundary between the soft layer and the hard layer can be set at an arbitrary position.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiment, a cushion pad 1 for an automobile seat including a main portion 2 as a seating portion and side portions 3 and 3 formed in an upwardly protruding shape on both left and right sides will be described. The present invention is not limited to this, and can be similarly applied to back pads and pads for various seats other than those for vehicles.
[0015]
(1st Embodiment)
As shown in FIGS. 1 to 3, the cushion pad 1 has a soft polyurethane foam in which the upper layer 21 of the main part 2 and other parts, that is, the lower layer 22 and the side parts 3, 3 of the main part 2 have different hardnesses. It is formed with. Specifically, only the main upper layer portion 21 is a soft layer, and the main lower layer portion 22 and the side portions 3, 3 are hard layers.
[0016]
A seating stability groove having a certain groove width (for example, 5 to 20 mm) is provided on the pad surface. Specifically, a pair of left and right vertical grooves 41, 41 extending in the front-rear direction at the boundary between the main part 2 and the side parts 3, 3 on both sides thereof, and a horizontal groove 42 extending in the left-right direction connecting the two at a center part in the front-rear direction. And The vertical groove 41 terminates slightly before the rear edge of the pad 1, and the left and right vertical groove rear ends 41A, 41A have a narrow width (for example, 1 to 5 mm) that does not cause a problem in design. Are connected by a narrow lateral groove 43 extending to the side. The narrow lateral groove 43 is a boundary between the soft layer and the hard layer. Therefore, the main upper layer portion 21 has a main lower layer portion 22 and a side portion 3 at a rear end portion 21A behind the narrow lateral groove 43. 3 and a region other than the rear end 21A (a hatched region S1 in FIG. 1) is formed of a soft layer.
[0017]
As shown in FIGS. 4 to 6, the mold 5 for molding the cushion pad 1 is a concave lower mold 6 for molding the surface side of the pad 1 and two upper molds capable of opening and closing the lower mold 6. It comprises a first upper die 71 and a second upper die 72. The first upper die 71 and the second upper die 72 are attached to the lower die 6 by a hinge joint (not shown) so as to be freely opened and closed.
[0018]
The lower die 6 is composed of a main molding part 61 for molding the main part 2 and side molding parts 62, 62 which are depressed downward on both right and left sides to form the side parts 3, 3. The lower mold 6 is provided with a pair of left and right vertical protrusions 63 extending in the front-rear direction and forming the vertical groove 41 on the pad surface at the boundary between the main molding portion 61 and the side molding portion 62. The lower die 6 is provided with a ridge 64 extending in the left-right direction to form the horizontal groove 42 on the pad surface by connecting the left and right vertical ridges 63 at the center in the front-rear direction. As shown in the figure, there is also provided a flaky horizontal ridge 65 extending in the left-right direction and connecting the rear ends of the vertical ridges 63, 63 to form the narrow horizontal groove 43 on the pad surface. The height of the ridge 64 is set lower than the height of the vertical ridge 63 so that the ridge 64 does not come into contact with the first upper die 71 when the first upper die 71 described later is closed. Therefore, the left and right vertical protrusions 63, 63 and the flaky horizontal protrusions 65 form an enclosure that partitions the main upper layer portion 21 serving as a soft layer from other portions.
[0019]
As shown in FIGS. 4B and 6, the first upper die 71 is closed on the lower die 6 so that the left and right vertical ridges 63, 63 and the horizontal ridge 65 have respective upper ends. It is formed so as to contact in a sealed state, that is, without any gap. Therefore, at the time of closing the mold, between the lower mold 6 and the first upper mold 71, a closed foaming space 51 for molding the main upper layer portion 21 serving as a soft layer is provided with the vertical protrusions 63, 63 and the horizontal protrusions 63. It is formed by being partitioned by the ridge 65.
[0020]
The second upper mold 72 is a mold for molding the back surface side of the cushion pad 1, and forms a foaming space for a foam to be a hard layer with the lower mold 6 when the mold is closed.
[0021]
When molding the cushion pad 1 using the mold 5, as shown in FIG. 4A, the main molding portion 61 defined by the vertical ridges 63, 63 and the horizontal ridge 65 of the lower die 6. A soft foaming raw material 82 for forming a soft layer is injected into the concave portion by using an injection device 81 for soft. At that time, the mold may be heated in the range of 50 to 100 ° C. Then, after the injection, as shown in FIG. 4B, the first upper mold 71 is closed to form a sealed foam space 51 for the soft layer between the lower mold 6 and the lower mold 6. In the inside, a soft foaming raw material 82 is foam-filled to form a main upper layer portion 21 composed of a soft layer.
[0022]
Next, immediately before or immediately after the end of the tack-free time of the foam of the main upper layer portion 21, the first upper die 71 is opened, and the left and right concave side molding portions 62 of the lower die 6 as shown in FIG. , 62 and the formed main upper layer portion 21 are injected with a hard foaming raw material 84 for forming a hard layer by using a hard injection device 83. After the injection, as shown in FIG. 5B, the second upper mold 72 is closed, and the hard foaming raw material 84 is foam-filled in the foaming space formed thereby, so that the main lower layer portion 22 composed of the hard layer and After molding the side parts 3 and 3 and curing, the mold is released as shown in FIG. 5 (c), thereby obtaining the cushion pad 1 in which the soft layer and the hard layer are integrally laminated.
[0023]
According to the first embodiment described above, the foaming space 51 forming the main upper layer portion 21 applies the ridges 63, 63, 65 provided on the lower die 6 to the lower surface of the first upper die 71 in a sealed state. The soft foaming raw material 82 is foam-filled between the lower mold 6 and the first upper mold 71 in a range surrounded by the ridges 63, 63, 65 as described above. . Therefore, since the boundary surface between the soft layer and the hard layer is defined by the first upper mold 71, the cushion pad 1 having the soft layer only in the main upper layer portion 21 is formed while ensuring the shape accuracy at the boundary surface. Can be.
[0024]
Further, in the obtained cushion pad 1, only the main upper layer portion 21 is made of a soft layer, and the main portion lower layer portion 22 and the side portions 3, 3 are made of hard layers. It has sufficient hardness in the above load range, and the side portions 3 and 3 are hard layers, so that the occupant also has an excellent hold feeling.
[0025]
Further, while the left and right vertical grooves 41, 41 are terminated before the rear edge of the pad 1, the thin flared horizontal ridge 65 forming the narrow horizontal groove 43 that does not cause a problem in design is lowered. The cushion pad 1 having the narrow lateral groove 43 as a boundary between the soft layer and the hard layer can be obtained by providing the mold 6 and abutting the first upper mold 71.
[0026]
(Second embodiment)
A second embodiment will be described with reference to FIGS. In this embodiment, the shape of the groove formed on the surface of the cushion pad 1 is different from that of the first embodiment.
[0027]
That is, in the second embodiment, the left and right vertical grooves 41, 41 are not provided over the entire length of the pad surface in the front-rear direction, but each end slightly short of the front and rear edges. For this reason, it is not possible to form an enclosure for the soft foaming raw material 82 in the lower mold 6 as it is, and in this embodiment, the left and right vertical protrusions 63, 63 are extended over the entire length of the lower mold 6 in the front-rear direction. As shown in FIG. 10, the front and rear end portions 63A are formed in a flaky shape in which a groove narrower than the other portions is formed on the pad surface, as shown in FIG. The front and rear end portions 41B and 41C of 41 are formed by narrow grooves having a narrow width (for example, 1 to 5 mm) so as not to cause a problem in design.
[0028]
Others can be manufactured in the same manner as in the first embodiment. In this case, as shown in FIGS. 8 and 9, the main upper layer portion 21 is a soft layer (the hatched area S2 in FIG. 8) over the entire front-back direction. Thus, the cushion pad 1 in which the main lower layer portion 22 and the side portions 3, 3 are hard layers is obtained.
[0029]
(Third embodiment)
In the third embodiment, as shown in FIGS. 11 and 12, only the central portion 21B in the front-rear direction of the main upper layer portion 21 is a soft layer (the hatched area S3 in FIG. 11), and the front and rear side portions thereof and the main lower layer portion 22 are formed. The side portions 3 and 3 are hard layers. Therefore, in this embodiment, the front and rear lateral grooves 44, 44 for connecting the left and right vertical grooves 41, 41 at two places in the front and rear direction are provided, and the lower mold is provided with the front and rear center portions 41D, 41D of the vertical grooves. Are formed, and the front and rear lateral protrusions forming the front and rear transverse grooves 44, 44 are provided, and these four protrusions are brought into contact with the first upper mold in a sealed state, thereby providing a soft state. The foaming space of the layer is sealed.
[0030]
Otherwise, the cushion pad 1 can be manufactured in the same manner as in the first embodiment, whereby the cushion pad 1 having a laminated structure in which only the central portion 21B of the main upper layer portion 21 is a soft layer is obtained.
[0031]
(Fourth embodiment)
In the fourth embodiment, as shown in FIGS. 13 and 14, only the front part 21C of the main upper part 21 is a soft layer (the shaded area S4 in FIG. 13), and the rear part of the main upper part 21 and the main lower part The part 22 and the side parts 3, 3 are hard layers. For this reason, in this embodiment, the left and right vertical grooves 41, 41 are provided with a horizontal groove 45 that connects them at the center in the front-rear direction, and the lower die is provided with left and right vertical protrusions that form the front portions 41E, 41E of the vertical grooves. And a horizontal ridge forming the horizontal groove 45, and the three ridges are brought into contact with the first upper die in a sealed state, so that a soft layer is formed between the lower die and the first upper die. The foaming space is sealed.
[0032]
Otherwise, the cushion pad 1 can be manufactured in the same manner as the first embodiment, whereby the cushion pad 1 having a laminated structure in which only the front portion 21C of the main upper layer portion 21 is a soft layer is obtained. In this case, compared with the case of the third embodiment, it is possible to soften a portion where the leg portion abuts particularly when the driver operates the pedal.
[0033]
【The invention's effect】
According to the present invention, it is possible to manufacture a sheet pad having a laminated structure in which a part of an upper layer part is formed of a foam having a different hardness from other parts, while ensuring shape accuracy at a boundary surface of the foam. Can be.
[Brief description of the drawings]
FIG. 1 is a plan view of a cushion pad according to a first embodiment.
FIG. 2 is a sectional view taken along line II-II of FIG.
FIG. 3 is a sectional view taken along line III-III of FIG. 1;
FIG. 4A is a cross-sectional view when a soft foaming raw material is injected into a lower mold, and FIG. 4B is a cross-sectional view in a state where the first upper mold is closed thereafter.
5A is a cross-sectional view when a hard foaming material is injected into a lower mold, FIG. 5B is a cross-sectional view when the second upper mold is closed, and FIG. 5C is a cross-sectional view when the mold is removed. .
FIG. 6 is a front-rear sectional view of the first embodiment when the first upper mold is closed.
FIG. 7 is an enlarged perspective view of a main part of a lower die according to the first embodiment.
FIG. 8 is a plan view of a cushion pad according to a second embodiment.
FIG. 9 is a front-rear direction cross-sectional view of a cushion pad according to a second embodiment.
FIG. 10 is an enlarged perspective view of a main part of a lower die according to a second embodiment. FIG. 11 is a plan view of a cushion pad according to a third embodiment.
FIG. 12 is a front-rear direction cross-sectional view of a cushion pad according to a third embodiment.
FIG. 13 is a plan view of a cushion pad according to a fourth embodiment.
FIG. 14 is a front-rear direction cross-sectional view of a cushion pad according to a fourth embodiment.
[Explanation of symbols]
1 ... Cushion pad (pad for seat)
2 Main part 21 Main upper part 22 Main lower part 3 Side part 41 Vertical groove 43 Narrow horizontal groove 5 Mold 6 Lower die 63 Vertical protrusion 65 ... Flake-like horizontal protrusion 71... First upper mold 72.

Claims (4)

Using a mold having a lower mold, a first upper mold, and a second upper mold, manufactures a sheet pad in which a part of the upper layer is made of a foam having a different hardness from the lower layer and the other parts of the upper layer. A way to
The lower mold is provided with a ridge for partitioning the part of the upper layer part from other parts, a first foaming material is injected into a lower mold recess defined by the ridge, and the first upper mold is closed. The foamed space defined by the ridges is formed between the lower mold and the first upper mold by bringing the first foamed material into contact with the ridges in a sealed state. By foaming and filling, the part of the upper layer portion made of the first foam is molded,
Next, the first upper mold is opened, a second foaming material is injected into the lower mold, and the second upper mold is closed to foam the second foaming material between the lower mold and the second upper mold. A method of manufacturing a pad for a sheet, characterized in that a remaining portion including the lower layer portion is formed of a second foam by filling. A seat pad having a main portion and side portions on both left and right sides thereof, wherein the part of the upper layer portion is a main portion upper layer portion, and the main portion upper layer portion has lower hardness than the main portion lower layer portion and the side portion. The method for producing a sheet pad according to claim 1, comprising a foam.
The protrusions that come into contact with the first upper mold in a sealed state include a pair of left and right vertical protrusions that form a groove extending on the boundary between the main portion and the left and right side portions on the pad surface. A method of manufacturing, comprising: injecting the first foaming material into a lower mold recess between ridges. The ridge that comes into contact with the first upper mold in a sealing state further includes a horizontal ridge that connects the left and right vertical ridges, and the horizontal ridge has a narrower groove than the vertical ridge on the pad surface. 3. The method for manufacturing a sheet pad according to claim 2, wherein the sheet pad is formed in a flake shape. The left and right vertical ridges are provided over the entire length of the lower mold in the front-rear direction, and at least one end of each of the front and rear ends has a flaky shape so that a groove narrower than other portions is formed on the pad surface. 3. The method for manufacturing a seat pad according to claim 2, wherein:

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