JP5112654B2 - Vehicle seat back pad and method of manufacturing the same - Google Patents

Description

  The present invention relates to a vehicle seat back pad and a method for manufacturing the vehicle seat back pad.

  A seat back pad used for a vehicle seat includes a backrest portion disposed on the front surface side of the seat, a shoulder portion extending rearward from the upper end of the backrest portion, and a back portion extending downward from the rear end of the shoulder portion. There is something. The back portion is provided to give the seat a high-class appearance, or to improve the feel when the passenger on the back seat touches the back of the back portion of the front seat, for example. Yes.

  Conventionally, as a method for manufacturing this type of seat back pad, for example, there are those disclosed in Patent Documents 1 and 2. In the manufacturing method of Patent Document 1, as shown in FIG. 8, the backrest portion of the seat back pad is molded in the first cavity 51 of the mold 50. Further, the shoulder is formed in the second cavity 52 of the mold 50. Further, the back portion is molded in the third cavity 53 of the mold 50. The mold 50 is configured such that the third cavity 53 is located above the first cavity 51. This is because, in foam molding of the seat back pad, first, the first cavity 51 having the largest capacity is filled with the foam material, and then the second cavity 52 and the third cavity 53 are filled with the foam material. It is. Further, a baffle plate 54 is formed in the first cavity 51.

  When the vehicle seat back pad is manufactured, the foam material is injected into the left side of the baffle plate 54. The foam material turns to the first cavity 51, the second cavity 52, and the third cavity 53 along with foaming. At this time, the baffle plate 54 restricts the movement of the foam material to the right side of the baffle plate 54. For this reason, it becomes easy for the foam raw material to pass around the third cavity 53 located higher than the first cavity 51 and the second cavity 52, and the generation of voids in the back portion is effectively prevented.

Further, in the manufacturing method described in Patent Document 2, the backrest portion is formed in the first cavity 61 of the forming die 60 as shown in FIG. Further, a shoulder is formed in the second cavity 62 of the mold 60. Further, the back portion is molded in the third cavity 63 of the mold 60. The mold 60 is configured such that the third cavity 63 is positioned above the first cavity 61. In the mold 60, a shortened passage 64 a that communicates both the cavities 61 and 63 is formed in the partition wall 64 that partitions the first cavity 61 and the third cavity 63. Then, the foam raw material injected into the first cavity 61 bypasses the partition wall 64 and turns to the third cavity 63 via the second cavity 62 and also turns to the third cavity 63 via the shortened passage 64a. For this reason, the generation of voids in the back is effectively prevented.
JP-A-8-183040 JP 2005-238514 A

  By the way, in the structure of patent document 1, as shown in FIG. 8, the 3rd cavity 53 of the shape swelled upwards in the position higher than the parting line PL as the shaping | molding die 50 is provided. When the seat back pad is molded using such a mold 50, even if the baffle plate 54 is provided, gas tends to remain in the third cavity 53, and the molded seat back pad is shown by a two-dot chain line in FIG. It is easy to generate void B as shown. Such void B causes a decrease in appearance quality of the molded product. In order to prevent the generation of void B, the mold 50 is tilted during foam molding, and the parting line PL on the tip side of the back is disposed at a position higher than the third cavity 53, and gas is discharged from the parting line PL. There is also a way to make it easier to remove. However, in this case, equipment for changing the inclination of the mold 50 is required.

  Moreover, in the shaping | molding die 60 described in the said patent document 2, the backrest part shape | molded by the 1st cavity 61 and the back part shape | molded by the 3rd cavity 63 will be in the state connected through the shortening channel | path 64a. For this reason, when the molded seat back pad is removed from the mold 60, the backrest portion and the back portion must be separated, and the demolding operation becomes troublesome. In addition, the back portion and the back portion are not always well separated, and the back portion or the back portion may be damaged.

  An object of the present invention is to provide a vehicle seat back pad that is less likely to cause voids in the back portion, that is easy to remove, and that can prevent damage to the main body due to removal, and a method for manufacturing the same.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a backrest portion and a shoulder portion extending rearward from the upper end of the backrest portion by injecting a foam raw material into the cavity of the mold and foaming and curing the foam material. And a seat back pad manufacturing method for forming a seat back pad that extends downward from the rear end of the shoulder portion and has a tip portion that is formed so as to be thinned toward the backrest portion side. In the cavity, at a position corresponding to the backrest portion side of the back portion, it has a mountain-shaped cross section as a whole, and is formed to be inclined downward toward the tip side of the back portion and the opposite side thereof. The auxiliary foam is disposed, and the flow path corresponding to the tip side of the back portion in the cavity is further gradually narrowed from the top position of the auxiliary foam toward the tip, and this state Foamed by injecting a foaming resin material into the Oite cavity, and cured in a state in which flowed to the tip side of the back, characterized in that for coupling integrally the auxiliary foam molded seat back pad.

According to a second aspect of the present invention, in the vehicle seat back pad manufactured by the manufacturing method according to the first aspect, the auxiliary foam is embedded on the backrest side of the back portion. .

(Function)
In the first and second aspects of the invention, the flow path corresponding to the back portion where the flow of the foamed resin raw material easily stagnate when the seat back pad is molded is narrowed by the auxiliary foam provided on the backrest portion side of the back portion. . For this reason, the flow rate of the foamed resin material flowing through the back channel is increased, and the foamed resin material flows and fills without stagnation in the back channel. Therefore, the generation of voids at the back is effectively prevented.

In addition , the foamed resin raw material flowing through the flow path corresponding to the back portion when the seat back pad is molded smoothly flows along the surface of the auxiliary foam, and no gas remains around the auxiliary foam. For this reason, generation of voids around the auxiliary foam is effectively prevented.

  According to the present invention, it is possible to provide a vehicle seat back pad and a method for manufacturing the same that are less likely to cause voids in the back portion, are easy to remove, and can prevent damage to the main body due to removal.

Next, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, the vehicle seat back pad 10 includes a backrest portion 11 disposed on the front side of a seat frame (not shown), a shoulder portion 12 extending rearward from the upper end of the backrest portion 11, and a rear portion of the shoulder portion 12. A main body portion 14 is provided that includes a back portion 13 that is inverted and extended downward from the end. The main body 14 is made of a synthetic resin foam that is integrally foam-molded with a synthetic resin such as polyurethane resin. The shoulder 12 is disposed on the upper side of the seat frame. The back portion 13 is disposed at the upper part on the back side of the seat frame, and the tip thereof is formed so as to become thinner toward the backrest portion 11 side.

  An auxiliary foam 15 is embedded on the back portion 11 side of the back portion 13 in the main body portion 14. The auxiliary foam 15 has a large number of polyurethane foam chips joined together by a binder. As shown in FIG. 2, the cross section of the auxiliary foam 15 has an overall chevron shape, and faces the tip of the back portion 13 and the opposite side. Are formed so as to be inclined downward. The auxiliary foam 15 is integrally joined to the main body 14 by a foam raw material that has penetrated into the surface when the main body 14 is molded.

  Further, a covering sheet 16 made of, for example, a nonwoven fabric, a woven fabric, or a knitted fabric is integrally joined to the back surface of the backrest portion 11, the lower surface of the shoulder portion 12, and the front surface of the back portion 13 in the main body portion 14. The cover sheet 16 is bonded to the main body 14 by the permeation of the foam material when the main body 14 is foam-molded. The auxiliary foam 15 is disposed inside the covering sheet 16. The covering sheet 16 protects the main body portion 14 from direct contact with the seat frame.

Next, a method for manufacturing the vehicle seat back pad configured as described above will be described.
The vehicle seat back pad 10 is foam-molded using a molding die 20 shown in FIGS. 3 and 4. The mold 20 includes a lower mold 21, an upper mold 22, and a middle mold 23. The upper mold 22 and the middle mold 23 are connected to one end side of the lower mold 21 through support shafts 24a and 24b so as to be opened and closed.

  A cavity 25 for molding the main body 14 is formed by the lower mold 21, the upper mold 22, and the middle mold 23. In the cavity 25, a first space 25a for forming the backrest portion 11 of the main body portion 14, a second space 25b for forming the shoulder portion 12, and a third space 25c for forming the back portion 13 are formed. The second space 25b and the third space 25c are disposed above the first space 25a.

  In order to mold the vehicle seat back pad 10 using the molding die 20, first, as shown in FIG. 4, with the upper die 22 and the middle die 23 opened, the bottom surface of the lower die 21, ie, the first The foamed resin raw material M of the main body portion 14 is injected into the 1 space 25a. Further, the covering sheet 16 is pasted on the molding surface of the middle mold 23 by, for example, a double-sided tape. Further, the auxiliary foam 15 is temporarily fixed with a double-sided tape, for example, on the covering sheet 16 on the molding surface corresponding to the third space 25c in the middle mold 23. In this state, the middle mold 23 and the upper mold 22 are closed, and the foamed resin material M is foamed.

  As the foaming progresses, the foamed resin material M in the first space 25a first fills the first space 25a as shown in FIG. At this time, the gas in the first space 25 a corresponding to the lower end of the backrest portion 11 is discharged to the outside from between the mating surfaces of the lower mold 21 and the middle mold 23.

  In addition, the foamed resin material M in the first space 25a flows into the third space 25c after filling the second space 25b. As shown in FIG. 6, the flow path of the foamed resin raw material M in the third space 25c is gradually from the second space 25b side toward the tip of the third space 25c due to the presence of the auxiliary foam 15 having a mountain-shaped cross section. It has become narrower. That is, the upper molding surface of the third space 25c is at the highest position in the cavity 25 from the second space 25b side to the front position of the tip, and is formed so as to incline downward from the front position toward the tip. Has been. And the top part position of the auxiliary | assistant foam 15 is arrange | positioned in the position corresponding to the near position of the 3rd space 25c. For this reason, the flow path in the third space 25 c is gradually narrowed from the second space 25 b side to the top position of the auxiliary foam 15. The flow path in the third space 25c is further gradually narrowed from the top position of the auxiliary foam 15 toward the tip of the third space 25c. For this reason, the foamed resin material M flowing into the third space 25c flows smoothly through the flow path in the third space 25c while gradually increasing the flow velocity. As a result, the gas in the third space 25c is smoothly pushed out of the molding die 20 from between the mating surfaces of the upper mold 22 and the middle mold 23, and the foamed resin material M leaves the gas in the third space 25c. The third space 25c is smoothly filled without any trouble. Then, as shown in FIG. 7, the foamed resin material M filled in the cavity 25 is cured to become the main body portion 14. At this time, the auxiliary foam 15 is disposed between the covering sheet 16 and the back portion 13 which are combined and integrated on the backrest portion 11 side of the back portion 13. Therefore, the generation of voids in the back portion 13 of the main body portion 14 is effectively prevented.

  In addition, as shown by a two-dot chain line in FIG. 6, the auxiliary foam 15 is greatly lowered and inclined from the top toward the tip of the third space 25c, so that the flow path in the third space 25c is sub-foamed. Even if it gradually widens from the top position of the body 15 toward the tip of the third space 25c, generation of voids in the back portion 13 is effectively prevented. That is, voids are likely to occur in the upper part of the third space 25c. This is because if the foamed resin raw material M flows through the flow path of the third space 25c without increasing the flow velocity, the foamed resin raw material M becomes difficult to turn to the upper part of the third space 25c, and gas tends to remain. is there. On the other hand, since the upper part of the third space 25c is positioned in a flow path that gradually narrows from the second space 25b side to the front end position, the foamed resin material M is located above the third space 25c. The foamed resin raw material M is rotated until the gas is effectively prevented from remaining. Furthermore, since the space from the top of the auxiliary foam 15 to the tip of the third space 25c is lower than the upper portion of the third space 25c, gas hardly remains.

  Further, since the auxiliary foam 15 has a mountain-shaped cross section as a whole and has a shape that is inclined downward toward the tip side of the third space 25c and the opposite side thereof, the foamed resin raw material M is composed of the auxiliary foam 15. The gas flows smoothly along the surface of the gas and no gas remains around the auxiliary foam 15. As a result, generation of voids around the auxiliary foam 15 of the molded back portion 13 is effectively prevented.

The embodiment described above in detail has the following effects.
(1) The auxiliary foam 15 was embedded in the backrest part 11 side of the back part 13 in the main body part 14 of the vehicle seat back pad 10. For this reason, generation | occurrence | production of a void can be prevented effectively in the back part 13 in which the flow of the foamed resin raw material M is easy to stagnate at the time of shaping | molding of the main-body part 14. Incidentally, the third space 25c of the cavity 25 is located on the terminal side of the flow of the foamed resin raw material M, and the upper portion of the third space 25c is located above the lower end of the parting line PL. When the body 15 does not exist, the flow of the foamed resin raw material M tends to be stagnant. Therefore, voids are likely to occur on the upper side of the third space 25c.

  (2) The auxiliary foam 15 has a mountain-shaped cross section as a whole, and is formed so as to be inclined downward toward the distal end side of the back portion 13 and the opposite side thereof. For this reason, the foamed resin material M that has flowed into the third space 25 c flows smoothly along the surface of the auxiliary foam 15, and does not leave gas around the auxiliary foam 15. Therefore, generation of voids around the auxiliary foam 15 can be effectively prevented. On the other hand, the upstream or downstream end of the foamed resin raw material M of the auxiliary foam 15 is cut off without being inclined, and the upstream or downstream end surface of the foamed resin raw material M flows in the flowing direction. , The flow of the foamed resin material M is entangled, and voids are likely to occur in that portion.

  (3) Unlike the molding method described in Patent Document 2, the backrest portion 11 and the back portion 13 are not connected when the main body portion 14 is molded. Therefore, the main body 14 can be easily removed from the mold 20 and the backrest 11 or the back 13 can be prevented from being damaged during the removal.

  (4) As the auxiliary foam 15, a urethane chip block having higher rigidity than the main body portion 14 was used. For this reason, the back portion of the seat does not bend excessively even if it is manually pressed by the passenger, and a high-class feeling can be imparted to the seat. Further, when a passenger in the rear seat hits the back of the front seat due to a vehicle collision or the like, the impact is effectively absorbed by the auxiliary foam 15. Furthermore, if the auxiliary foam 15 is manufactured using the recycled urethane chip, the vehicle seat back pad 10 can be manufactured at low cost.

In addition, this embodiment can also be changed and embodied as follows.
-The auxiliary | assistant foam 15 should just be elastically deformable, for example, a single synthetic resin foam may be sufficient as it.

  -You may divide the auxiliary | assistant foam 15 into two right and left in the center part of the width direction, as shown with a dashed-two dotted line in FIG.

1 is a perspective view of a part of a vehicle seat back pad according to an embodiment. Sectional drawing which similarly shows the back part of a vehicle seat back pad. The longitudinal cross-sectional view which shows a shaping | molding die. The longitudinal cross-sectional view which shows the shaping | molding die of a mold open state. The longitudinal cross-sectional view which shows the shaping | molding die at the time of foam molding. The longitudinal cross-sectional view which shows the principal part in FIG. The longitudinal cross-sectional view which shows the shaping | molding die at the time of completion | finish of foaming. The longitudinal cross-sectional view which shows the shaping | molding die of the vehicle seat back pad in the past. The longitudinal cross-sectional view which similarly shows a shaping | molding die.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Vehicle seat back pad, 11 ... Backrest part, 12 ... Shoulder part, 13 ... Back part, 14 ... Main-body part, 15 ... Auxiliary foam, 20 ... Mold, 25 ... Cavity, M ... Foamed resin raw material.

Claims (2)

The foam raw material is injected into the mold cavity and foamed and cured, and the backrest, the shoulder extending backward from the upper end of the backrest, and the rear end of the shoulder extending downward and the tip of the backrest A vehicle seat back pad manufacturing method for forming a seat back pad including a back portion formed so as to become thinner toward a portion side,
In the cavity, the auxiliary foam has a mountain-shaped cross section as a whole at a position corresponding to the backrest portion side of the back portion, and is formed so as to incline downward toward the tip side of the back portion and the opposite side thereof. And the flow path corresponding to the tip side of the back portion in the cavity is further gradually narrowed from the top position of the auxiliary foam toward the tip,
In this state, the foamed resin raw material is injected into the cavity and foamed, and cured in a state of flowing to the tip side of the back part,
A method for manufacturing a vehicle seat back pad, wherein the auxiliary foam is combined and integrated with a molded seat back pad. In the vehicle seat back pad manufactured by the manufacturing method according to claim 1,
The vehicle seat back pad according to claim 1, wherein the auxiliary foam is embedded on a backrest side of the back portion .

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