JP2012061092A - Seat cushion pad and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve sitting and riding comfort on a seat and to reduce pressure to femoral regions.SOLUTION: A slit 28 extending in the width direction is arranged in the front edge side of a pad front surface in a sitting portion 12. The slit 28 is formed in an attitude tilting backward towards the pad back surface side from the pad front surface, and a front edge part 30 on the front side beyond the slit 28 is formed of a foam body with lower hardness than that of a sitting portion body 32 on the back side. In a molding die 50, a sitting portion molding region 64 of a lower die 52 is divided, by a separation board 78 protruded on a cavity bottom face 76, into a front edge molding region 80 for molding the front edge part 30 and a body part molding region 82 for molding the sitting portion 32, and the separation board 78 is formed in an attitude tilting backward toward the upper side from the cavity bottom face 76.

Description

  The present invention relates to a seat cushion pad mainly used for a vehicle seat including an automobile, and a manufacturing method thereof.

  In general, seat cushion pads made of soft polyurethane foam with high cushioning properties are used for automobile seats. The seat cushions are placed on a support frame and covered with a skin material. It is configured as.

  In such a seat cushion pad, in order to improve sitting comfort and riding comfort, a different hardness seat pad using a foam having different hardness depending on a part is known. For example, the seat cushion pad 100 shown in FIG. 11 includes a seating portion 102 at the center in the width direction and side portions 104 and 104 that are raised on the left and right sides. The seating portion 102 further receives and supports the heel portion. And a front thigh lower portion 108 that receives and supports the thigh. In order to improve the holdability of the body of the seated person, the side portion 104 is set to have a high hardness with respect to other parts, and in order to improve the seating comfort, the lower buttocks 106 is set against the lower thigh 108. It is known to set a high hardness (see Patent Documents 1 and 2 below).

  Conventionally, when the side portion 104, the bottom bottom portion 106, and the thigh bottom portion 108 are set to have different hardnesses as described above, a suspension groove 110 that is used to suspend the skin when covering the seat cushion pad with the skin material is used. ing. That is, different hardness is achieved by dividing the molding area of the lower mold by the protrusions provided in the lower mold to mold the hanging groove 110 and injecting different foaming stock solutions into each section ( See Patent Document 1 below).

  Further, in order to divide the side portion 104 into two outer and inner sections and to achieve different hardness, a slit narrower than the hanging groove 110 is provided, and the different hardness is achieved with the slit as a boundary. Is also known (see Patent Documents 3 and 4 below).

  On the other hand, in Patent Document 5 below, the thigh of a seated person makes contact with the front edge portion of the relatively hard seat, and the feeling of leg numbness and fatigue, as well as the pedal depression in the case of a driver. In order to reduce fatigue due to compression of the thigh at the time, it is disclosed that the foam hardness of the front edge portion of the seating portion is lower than the foam hardness of the rear portion.

Japanese Patent Laid-Open No. 2002-300936 JP 2006-204887 A Japanese Patent Laid-Open No. 2001-070083 JP 2003-094452 A JP 2001-025418 A

  However, in order to make the front edge portion of the seating portion low in hardness as described above, for example, when using a hanging groove for hanging the epidermis, the arrangement of the hanging groove is limited, so the thigh It is difficult to perform different hardness at the optimum position for reducing the pressure of the material. In addition, when there is no hanging groove at the optimum position and there is no partition for partitioning the molding region, there is no partition for partitioning the molding region, so that the different hardness cannot be achieved at an accurate position. In this case, it is conceivable to provide a slit narrower than the hanging groove and to achieve different hardness at the slit, but in the conventional slit configuration, the hardness change on both sides of this slit portion is large, This adversely affects sitting comfort.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a seat cushion pad capable of improving seating comfort and riding comfort of a seat and reducing pressure on a thigh.

  The seat cushion pad according to the present invention is a foam cushion-formed seat cushion pad, and a slit extending in the width direction is provided on the front edge side of the pad surface in the seating portion, and the slit extends from the pad surface to the pad back surface side. The front edge portion of the front side of the slit is formed of a foam having a lower hardness than the seating portion main body of the rear side of the slit. is there.

  According to a preferred embodiment of the present invention, the rear edge of the opening on the pad surface of the slit may be formed into a shape raised with respect to the front edge.

  In the seat cushion pad manufacturing method according to the present invention, the lower mold for molding the pad surface side is provided with a seating portion molding region for molding the seating portion, and the seating portion molding region for molding the slit. A partition plate extending in the width direction projecting from the cavity bottom surface is partitioned into a front edge portion molding region for molding the front edge portion and a body portion molding region for molding the seat portion main body, and the partition Using a mold provided in a posture in which the plate is inclined rearwardly upward from the bottom surface of the cavity, the first foaming stock solution is injected into the body portion molding region, and the first edge portion molding region is filled with the first. A second foaming stock solution that forms a foam having a lower hardness than the foaming stock solution is injected, and then the mold is closed to perform foam molding.

  According to a preferred embodiment of the manufacturing method, the partition plate may be configured such that the height of the partition plate portion corresponding to the injection point of the second foaming stock solution is set higher than the height of the other partition plate portions. Good.

  According to the present invention, since the front edge of the front side of the slit provided in the front edge of the seating part is made lower in hardness than the seating body of the rear side, the front edge of the seating part is brought into contact with It is possible to reduce the numbness and fatigue of the leg due to, and the pressure on the thigh when the driver depresses the pedal, and it is easy to provide a slit at the optimum position to achieve different hardness. In addition, due to the inclination of the slit, the boundary surface between the low-hardness foam on the front edge and the higher-hardness foam on the seating part main body is inclined, and the thickness ratio of the two gradually changes. Therefore, the influence of the hardness change between the front edge portion and the seating portion main body is reduced, and the sitting comfort can be improved. Furthermore, when the slit is inclined as described above, the slit can be easily closed in one direction when the skin material is put on the seat cushion pad, and therefore, the trace of the slit appearing on the skin can be reduced.

The perspective view of the seat cushion pad concerning one embodiment Top view of the seat cushion pad Sectional view of the seat cushion pad (sectional view taken along line III-III in FIG. 2) Sectional view of the seat cushion pad (sectional view taken along line IV-IV in FIG. 2) Plan view of the seat cushion pad mold Cross section of the same mold Expanded cross-sectional view of the main part of the mold during injection of the foaming stock solution The principal part expanded sectional view in the slit vicinity of the seat cushion pad which concerns on other embodiment. Cross-sectional view of main parts showing hardness data of seat cushion pad Front view showing a modified example of the partition plate in the mold A perspective view of a conventional seat cushion pad

  Embodiments of the present invention will be described below with reference to the drawings.

  The seat cushion pad 10 of one embodiment shown in FIGS. 1 to 4 is a pad used for a seat cushion for supporting the buttocks of an occupant who is a seat in an automobile seat, and has elasticity such as a flexible polyurethane foam. It consists of a foamed molded product.

  The seat cushion pad 10 has a seating portion 12 in the center in the width direction for receiving a portion from the buttocks of the occupant to the thigh, and is formed in a bulging shape upward on both the left and right sides to support the occupant from the left and right and maintain a sitting posture. Side portions 14, 14. The seating portion 12 includes a rear bottom lower portion 16 that receives and supports the occupant's buttocks, and a front thigh lower portion 18 that receives and supports the occupant's thigh.

  A pair of left and right vertical suspension grooves 20, 20 extending in the front-rear direction X and the front-rear direction are provided on the pad surface, that is, the upper surface of the seat cushion pad 10, in order to lock a skin material (not shown) covering the pad surface. A horizontal suspension groove 22 extending in the width direction Y is provided at the center. And the width direction outer side becomes a side part 14 and 14 rather than a pair of vertical suspension groove | channels 20 and 20, and the space | interval becomes the seating part 12. Further, the rear side of the horizontal hanging groove 22 is a bottom part 16, and the front side is a thigh part 18. In this example, a second horizontal suspension groove 24 that connects the rear ends of the left and right vertical suspension grooves 20, 20 is further provided, and a central lateral suspension groove 22 and the second lateral suspension groove 24 are provided. The 2nd vertical hanging groove 26 which connects center part of each is provided.

  In the seat cushion pad 10 of the present embodiment, a slit 28 extending in the width direction Y is provided on the front edge side of the pad surface in the seating portion 12. The slit 28 is a narrow groove that is narrower than the above-described suspension grooves 20, 22, 24, and 26, and is provided across the seat portion 12 in the entire width direction Y thereof. In detail, the slit 28 is provided in the front edge part of the thigh lower part 18, and is formed so as to divide the front edge side of the thigh lower part 18 in the front-rear direction by connecting the left and right vertical suspension grooves 20, 20. ing. Thus, with the slit 28 as a boundary, the front side of the slit 28 becomes the front edge portion 30, and the rear side of the slit 28 becomes the seating portion main body 32 composed of the majority of the thigh lower portion 18 and the bottom portion 16. . The groove width of the slit 28 is not particularly limited, but is preferably about 1 to 10 mm, more preferably about 3 to 5 mm.

  As shown in FIG. 3, the slit 28 is formed in a posture inclined backward Xr from the pad surface toward the pad back surface side. That is, the slit 28 is not provided along the thickness direction Z of the seat cushion pad 10, but is formed to be inclined backward Xr and downward Zd from the pad surface.

Then, with the slit 28 inclined as described above as a boundary, the front edge portion 30 on the front side of the slit 28 is formed of a foam having a lower hardness than the seating portion main body 32 on the rear side. That is, the seat portion 12 is formed such that the foam hardness of the front edge portion 30 is lower than the foam hardness of the seat portion main body 32. Although not particularly limited, the foam of the front edge portion 30 preferably has a 25% hardness of 80 to 150 N / φ200 mm according to the hardness test of JASO-B408, and the foam of the seat portion 32 is the same. The 25% hardness is preferably 150 to 300 N / φ200 mm. The means for different hardness is not particularly limited, and the density of the foam may be changed. For example, the foam density of the front edge portion 30 is 25 to 40 kg / m ³ , and the foaming of the seat portion 32 The density of the body may be 40 to 80 kg / m ³ and the former may be set to a lower density. Further, the hardness may be changed by changing the composition of the raw material itself constituting the foam, and in this case, the density of the foam in the front edge portion 30 and the seating portion main body 32 may be the same.

  Since the slit 28 is inclined as described above, the boundary surface between the low hardness front edge portion 30 and the high hardness seat portion main body 32 is also inclined in the cross-sectional shape shown in FIG. In the portion where the slits 28 are provided, the thickness of the low-hardness foam (front edge portion 30) gradually decreases toward the rear, and the thickness of the high-hardness foam (seat portion main body 32) increases instead. It is formed in a layer structure.

  As shown in FIGS. 1 and 4, in the seat cushion pad 10 of the present embodiment, the foam hardness of the left and right side portions 14, 14 is higher than that of the seating portion 12 (specifically, the seating portion main body 32) therebetween. It is formed higher than the foam hardness. This enhances the function of maintaining a sitting posture during cornering by the side portion 14 while ensuring good sitting comfort and riding comfort at the seating portion 12. In addition, at the rear end portion of the seat cushion pad 10, the foam hardness of both side portions in the portion on the rear side of the second lateral suspension groove 24 is the same as that of the side portion 14, and the seat portion 12 on the center side. A pair of left and right small slits 34, 34 are provided in order to form a hardness higher than the foam hardness.

  Next, a method for manufacturing the seat cushion pad 10 will be described. 5 and 6 show a mold 50 used for manufacturing.

  The mold 50 includes a lower mold 52 that opens upward to mold the pad surface side, and an upper mold 54 that molds the pad back surface side. The upper die 54 is provided so as to be rotatable with respect to the lower die 52 via a hinge 56 disposed on one side of the lower die 52. By opening and closing the upper surface opening of the lower die 52, A cavity 58 that is a foaming space corresponding to the pad shape is formed between the two.

  The lower mold 52 is provided with a pair of left and right vertical ridges 60 and 60 for forming the vertical hanging groove 20 and a horizontal ridge 62 for forming the horizontal hanging groove 22. Thus, the seat portion forming region 64 for forming the seat portion 12 between the pair of vertical ridges 60, 60 and the left and right portions for forming the side portions 14, 14 on both outer sides in the width direction are provided. The side part molding regions 66 and 66 are respectively provided in a concave shape. In addition, the seat part forming region 64 is formed by a lateral protrusion 62 into a bottom part forming region 72 for forming the bottom part 16 and a thigh lower part forming region 74 for forming the thigh part 18 in the front-rear direction. It is partitioned. The lower mold 52 is also provided with a second horizontal protrusion 68 for forming the second horizontal hanging groove 24 and a second vertical protrusion 70 for forming the second vertical hanging groove 26. It has been.

  In the seat portion forming region 64, a partition plate 78 for forming the slit 28 protrudes from the cavity bottom surface 76. The partition plate 78 has a flat plate shape extending in the width direction Y. With the partition plate 78, the seat portion forming region 64 forms the front edge portion forming region 80 for forming the front edge portion 30 and the seat portion main body 32. The main body part forming region 82 is partitioned. In this example, the partition plate 78 is a wall portion that divides the front edge of the thigh lower molding region 74 back and forth, and the main body molding region 82 on the rear side of the partition plate 78 is a large portion of the thigh lower molding region 74. It consists of a bottom bottom molding region 72.

  The partition plate 78 is formed in a posture inclined backward from the cavity bottom surface 76 in the same manner as the above-described inclined configuration of the slit 28. Although the thickness of the partition plate 78 is not particularly limited, it is preferably about 1 to 10 mm, more preferably about 3 to 5 mm, like the groove width of the slit 28. The inclination angle θ of the partition plate 78 (the same applies to the slit 28) with respect to the horizontal plane (the plane perpendicular to the thickness direction Z) is preferably 30 to 80 degrees, more preferably 40 to 70 degrees (see FIG. 7). ). The height of the partition plate 78 is preferably 10 mm or more, and is usually set to about 20 to 70 mm.

  A foaming raw material is injected into the lower mold 52 from the injection head 84 of the injection apparatus using the mold 50. In that case, the first foaming stock solution M1 in which each component is adjusted and blended so as to have a medium hardness is injected into the main body forming region 82, and the leading edge forming region 80 is filled with the first foaming stock solution M1. Also, the second foaming stock solution M2 in which each component is adjusted and blended so as to have a low hardness is injected so that the side portion molding region 66 has a higher hardness than the first and second foaming stock solutions M1 and M2. A third foaming stock solution (not shown) in which each component is adjusted and blended is injected.

  As shown in FIG. 7, the front edge portion 30 of the seat cushion pad 10 has an undercut shape. However, by inclining the partition plate 78 as described above, the front edge portion molding region 80 is formed from the injection head 84. It is possible to inject the second foaming stock solution M2. Since the diameter D of the injection head 84 is usually about 5 to 50 mm, the distance E from the parting edge 86 of the lower mold 52 to the tip of the partition plate 78 is preferably set to be larger than the diameter D. The distance E is preferably about 10 to 100 mm.

  Although the height of the partition plate 78 can be constant in the width direction Y, as shown in FIG. 5, in this example, the injection point of the second foaming stock solution M2 (at the position of the injection head 84 in the figure). The height of the central portion 78A corresponding to () is set higher than the height of the partition plate portions 78B on both sides in the width direction. By partially changing the height in this way, the injection workability can be improved without impairing other performance.

  In addition, the injection | pouring point of 2nd foaming undiluted | stock solution M2 is not limited to the width direction center part as shown in FIG. 5, For example, you may set to the width direction edge part. In that case, a partition plate portion set to be high corresponding to the injection point is also provided at the end in the width direction of the partition plate 78. For example, in the example of FIG. 10A, the partition plate portion 78C protrudes upward in a semicircular shape so that the height of the partition plate portion 78C corresponding to the injection point is increased at the right end portion of the partition plate 78. Is provided. Further, the height of the partition plate portion 78B on the left side of the partition plate portion 78C is set to be constant. In the example of FIG. 10B, the upper side of the partition plate portion 78B on the left side of the high partition plate portion 78C corresponding to the injection point is inclined so that the height decreases toward the left side. Yes. Thus, by setting the height of the partition portion 78C at the right end portion high, it is advantageous in reducing the pressure when the accelerator pedal is depressed by the right foot in the case of the driver's seat.

  After injecting the foaming stock solution into the lower mold 52 as described above, the mold is closed as shown in FIG. 6, the seat cushion pad 10 is foam-molded in the cavity 58, the upper mold 54 is opened, By removing the mold, the seat cushion pad 10 is obtained. The obtained seat cushion pad 10 forms a vehicle seat by covering the pad surface with a skin material (not shown) using the suspension grooves 20, 22, 24, and 26 and locking them. Can do.

  In the present embodiment as described above, since the front edge 30 on the front side is made lower than the rear seat 32 on the slit 28 provided on the front edge side of the seat 12, the seat 12 It is possible to reduce the numbness and fatigue of the legs due to contact with the front edge portion 30 and further the pressure on the thigh when the driver steps on the pedal. Further, since the slit 28 can be freely set, unlike the horizontal suspension groove 22, the slit 28 is provided at the optimum position for the above purpose, and the different hardness is limited to the front edge portion 30 with an accurate position. Can be achieved.

  Further, by inclining the slit 28 as described above, the boundary surface between the low-hardness foam of the front edge portion 30 and the high-hardness foam of the seating portion main body 32 is inclined, and the thickness ratio between them is Since the shape gradually changes, the influence of the hardness change in the vicinity of the boundary portion between the front edge portion 30 and the seating portion main body 32 is reduced, and the sitting comfort can be improved.

  FIG. 9 is a diagram showing measurement results of hardness change for the examples and comparative examples. (A) Example 1 in which the inclination angle θ of the slit is 45 degrees, (b) Example 2 in which the inclination angle θ is 30 degrees, and (c) that the slit is not inclined (that is, the inclination angle). θ = 90 degrees) Comparative Example 1 and (d) are Comparative Example 2 in which the front edge portion is not made different in hardness. For the measurement of hardness, a push-pull hardness measuring machine (φ20 mm disc) was used. In the comparative example 2 of (d), the whole seating part main body was hard, whereas in the comparative example 1 of (c), the hardness difference in the vicinity of the boundary between the front edge part and the seating part main body was large. On the other hand, in Examples 1 and 2, the hardness at the front side portion of the seating portion main body in contact with the front edge portion 30 was reduced, and the change in hardness could be reduced.

  When the slit 28 is inclined as described above, the slit 28 can be easily closed in one direction when the seat cushion pad 10 is covered with the skin material. Therefore, the appearance of the slit 28 appearing on the skin is reduced. Can be improved.

  Further, since the partition plate 78 for forming the slit 28 is also inclined as described above, the distance from the parting edge 86 to the tip of the partition plate 78 even if the leading edge forming region 80 has an undercut shape. E can be secured, and the second foaming stock solution M2 can be easily injected from the injection head 84 to the leading edge forming region 80.

  As shown in FIGS. 5 and 6, in the mold 50, the front edge side of the seat cushion pad 10 is the hinge 56 side, and when removing the mold 50, the operator holds the seat cushion pad 10 forward from the anti-hinge side. At this time, the partition plate 78 is inclined at an angle close to the pulling direction, so that it is easy to remove the mold, and the tearing of the seat cushion pad 10 in the vicinity of the slit 28 at the time of releasing can be prevented. it can.

  FIG. 8 is an enlarged view of the vicinity of a slit portion of a seat cushion pad according to another embodiment. In this example, the rear edge 28A in the opening of the slit 28 is shaped so as to be raised with respect to the front edge 28B, whereby a step 36 is formed between the front and rear edges 28A, 28B. Is formed. Specifically, the front edge portion of the seating portion main body 32 on the rear side of the slit 28 is gently bulged with respect to the original cross-sectional shape indicated by the alternate long and short dash line S, so that the opening edges before and after the slit 28 are formed. A step 36 is formed.

  By providing the step 36 as described above, the surface of the rear edge portion 28A and the surface of the front edge portion 28B are set to be flush with each other in a state in which the skin 28 is covered and the slit 28 is closed. be able to. Specifically, when the slit 28 is inclined, when the skin material is suspended, the front and rear edges 28A and 28B of the slit 28 are deformed so that one of them closes the slit 28 toward the other. At that time, if the step 36 as described above is not provided (in the case of the shape of the alternate long and short dash line S in FIG. 8), in the state where the slit 28 is closed, it is deformed as shown by the two-dot chain line T in FIG. A step will occur. Therefore, if this step is taken into account, the front and back surfaces of the slit 28 are flush with each other when the slit 28 is closed. Therefore, the appearance of the slit 28 appearing on the skin can be further reduced and the appearance can be improved. About this embodiment, other composition is the same as that of the above-mentioned embodiment, and the same operation effect is produced.

  In the above embodiment, the seat portion main body 32 is formed of a single foam. However, the seat portion main body 32 is further formed with the lower buttocks 16 and the lower thigh 18 (excluding the front edge portion 30). For example, the bottom part 16 may be formed with a higher hardness than the thigh part 18 by changing the foam hardness. Further, in the above embodiment, the side portion 14 is formed to have a higher foam hardness than the seating portion 12, but the side portion 14 and the seating portion 12 (however, excluding the front edge portion 30) are formed of a common foaming stock solution. Alternatively, the foam hardness may be set in reverse. Moreover, although the above embodiment demonstrated the seat cushion pad used for a seat of 1 person, it is applicable similarly to the seat cushion pad used for a seat of 2 or 3 persons called a bench type. it can. Although not enumerated one by one, various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Seat cushion pad 12 ... Seating part 28 ... Slit 28A ... Rear edge 28B ... Front edge 30 ... Front edge 32 ... Seating body 50 ... Mold 52 ... Lower mold 58 ... Cavity 64 ... Seating part Molding area 76 ... Cavity bottom surface 78 ... Partition plate 80 ... Leading edge molding area 82 ... Main body molding area M1 ... First foaming concentrate M2 ... Second foaming concentrate

Claims (4)

  A seat cushion pad formed by foaming, wherein a slit extending in the width direction is provided on the front edge side of the pad surface in the seating portion, and the slit is formed in a posture inclined backward from the pad surface toward the pad back surface side. The seat cushion pad is characterized in that a front edge portion on the front side of the slit is formed of a foam having a hardness lower than that of the seating portion main body on the rear side of the slit with the slit as a boundary.   The seat cushion pad according to claim 1, wherein a rear edge of the opening on the pad surface of the slit is shaped to be raised with respect to a front edge. A method for producing the seat cushion pad according to claim 1 or 2,
The lower mold for molding the pad surface side is provided with a seating portion molding region for molding the seating portion, and the seating portion molding region extends in the width direction projecting from the bottom surface of the cavity for molding the slit. The partition plate is divided into a front edge portion molding region for molding the front edge portion and a body portion molding region for molding the seating body, and the partition plate is inclined rearward upward from the cavity bottom surface. Using the mold provided in the posture
Injecting the first foaming stock solution into the body part molding region, and injecting the second foaming stock solution forming a foam having a hardness lower than that of the first foaming stock solution into the leading edge molding region, A method of manufacturing a seat cushion pad, wherein the mold is closed and foamed.   4. The seat cushion pad according to claim 3, wherein the partition plate is set such that the height of the partition plate portion corresponding to the injection point of the second foaming concentrate is higher than the height of the other partition plate portions. Manufacturing method.

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