JP2016107801A - Vehicular seat back - Google Patents

Abstract

An object of the present invention is to provide a vehicle seat back that has excellent cushioning properties when seated or on a person's seat, can be reduced in weight, and is excellent in recyclability. [MEANS FOR SOLVING PROBLEMS] A plurality of rods or a plurality of plates made of a synthetic resin foam having a bending deflection amount of 20 mm or more measured in accordance with the method described in JIS K7221-2: 2006 and a load at the time of 20 mm deflection is 2 to 100N. A seat back pad provided with a backrest surface support body that has a backrest surface against which the body abuts when seated and bends rearwardly, and the backrest surface support behind the backrest surface support body of the seatback pad. The problem can be solved by providing an elastic body that is capable of bending deformation of the body and has a damping property by compressive deformation with respect to the bending deformation of the backrest surface support due to the load of the seated person. [Selection] Figure 3

Description

  The present invention relates to weight reduction of a vehicle seat back, and more particularly to a vehicle seat back characterized by being highly recyclable and having a good fit and cushioning.

  In general, a vehicle seat back includes a metal seat frame or wire, and generally uses urethane foam as a cushioning material and is entirely covered with a skin material. The weight of the occupant is supported mainly by bending the urethane foam layer sandwiched between the seat frame or wire and the skin material in the compression direction, and the cushioning and fitting properties are mainly in the compression direction of the urethane foam layer. It was obtained by the reaction force, the restoring force, and the bending when bent.

  In addition, as a technology related to weight reduction of the seat back, Patent Document 1 has a seat frame having a frame shape, a cross section of the seat frame has a mountain shape, and one side of the mountain shape is formed on the inner peripheral side of the frame shape of the seat frame. The seat frame has an inclined surface facing the seated person, and the seat frame is covered with an elastic net, and its periphery is drawn from the top of the chevron of the seat frame and fixed to the other side of the chevron to make a seat with a concave curved surface A technique has been disclosed in which a stretch is formed so as to form a surface, and an angle is provided between the net and the inclined surface of the seat frame.

  As another technique related to weight reduction, Patent Document 2 discloses a base plate detachably attached to a seat frame, a block disposed on the base plate, a spring plate disposed on the block, and the spring plate. And the block is disposed so as to form a predetermined space between the base plate and the spring plate, and the spring plate is PP (elastic foam). Polypropylene) beads foam, PE (polyethylene) beads foam, PP foam, PE foam, AS resin (acrylonitrile / styrene resin) foam, EVA (ethylene vinyl acetate copolymer resin) and urethane foam material The spring seat is molded from the foam that is formed , Technical relates to a vehicle seat deflected into said space is disclosed when a force to said base plate direction was added.

JP 2002-28044 A Japanese Patent No. 4009490

In conventional general seat backs, urethane foam is used as a cushioning material, and since the cushioning property is extremely high and the comfort is excellent, it is still frequently used. However, the urethane foam has a problem that it is inferior in recycling performance. Furthermore, the seat back is required to have a function of supporting the occupant's body at an optimal position against the longitudinal and lateral acceleration applied to the occupant as the automobile moves, in addition to the general cushioning property. It is necessary to support the body in an optimal position to reduce fatigue when riding for a long time. For this reason, the function cannot be satisfied with only a very lightweight and flexible urethane foam, and in order to obtain a certain degree of rigidity, the density of the urethane foam needs to be a certain level or more. There was no problem.

In the technology described in Patent Document 1, the net material that supports the load by the occupant is drawn into the seat frame installed around the seat back and firmly fixed, and the load applied by the occupant's seating is finally transmitted through the net material. It was supported by the rigidity of the seat frame. Therefore, the structure of the seat frame must maintain a certain level of strength. For this reason, although the weight of the net material itself corresponding to the conventional cushion material is light, the weight of the seat frame tends to increase and the overall weight There was a problem that the reduction effect was not sufficient.

Furthermore, the cushioning property of the net material is limited because it is obtained mainly by the elongation of the material, and there is a tendency that sagging occurs due to long-term use and the merchantability is inferior. In addition, since the flat net material is stretched around the seat frame, the basic seat back shape is flat, and the three-dimensional shape necessary to support the occupant's body in an optimal position is obtained. As a result, there is a problem that the passengers feel uncomfortable. This is because an unstable hammock-like net material cannot stably support the occupant's body when a lateral G is applied to the occupant by the movement of the automobile.

Next, as for the technique of Patent Document 2, the spring plate is a plate-like foam having a substantially rectangular outer shape, and a plurality of grooves are formed in the lateral direction on the side of the spring plate on which an occupant sits. However, if the groove is shallow, flexibility cannot be given, and if the groove is deep, when the cushion material bends, excessive tensile force concentrates on the connecting part of the remaining groove bottom, causing large elongation deformation. There was a high risk of permanent deformation that could not be restored or fracture. If even a part of the connecting portion at the groove bottom is broken, the support is lost at once, the apparent hardness of the entire cushioning material is drastically lowered, and the function as the cushioning material is greatly impaired. Therefore, it is practically difficult to design the deflection of the cushion material to a certain level or more in order to avoid breakage, and it is difficult to provide a sufficient fit and comfort when seated.

Moreover, although the technique of patent document 2 has described that it can obtain a favorable seating feeling personally by selecting suitably the block from which height differs according to a passenger | crew's physique, There was a problem that in reality it had to be difficult to implement, because it had to be changed to a block of height suitable for me before sitting down by light weight.

Accordingly, an object of the present invention is to provide a vehicle seat back that is rich in fit and cushioning when seated by an occupant, can be reduced in weight, and is highly recyclable.

In the present invention, the synthetic resin foam is flexible and capable of bending deformation and is excellent in resilience. The method described in JIS K7221-2: 2006 (23 ° C. ± 2 ° C., relative humidity 50 ± 350mm long with skin removed in 5% atmosphere
A load is applied to a test piece having a width of 100 mm and a thickness of 25 mm at a fulcrum distance of 300 mm and a test speed of 20 ± 1 mm / min until the maximum deflection is 90 mm, and a load deflection curve is recorded. ) Refers to a synthetic resin foam molded article having a bending deflection of 20 mm or more and a load of 2 to 100 N when bent by 20 mm. Specifically, it refers to foamed polypropylene, foamed polyethylene, other polyolefin resin foams, modified polystyrene resin foams, and the like. The synthetic resin foam includes a bead foam molded body, and examples of the bead foam molded body include a polypropylene-based bead foam molded body and a polyethylene-based bead foam.

In the specific selection of materials, both ends of a bar-like or plate-like test piece having a length of about 400 mm are supported, the center is pushed back and forth about 25 mm and held for 30 minutes, and then the sample is recovered from deformation immediately after releasing the load. Is desirably 90% or more. Alternatively, in accordance with a test performed on a conventional urethane foam seat back, the center portion of the sample supporting both ends is repeatedly pressed and deformed a predetermined number of times, and the residual strain (also referred to as residual displacement) measured thereafter is measured. It is desirable that the amount is not more than a predetermined amount.

Such materials satisfying, for example, the density of the foamed polypropylene ^{0.06g / cm 3 ~0.015g / cm 3} , more preferably a density 0.035g ^/ cm ³ ~0.015g ^/ cm 3 or polyethylene foam, such as density 0.08g ^/ cm ³ ~0.03g ^/ cm 3 are preferred. On the other hand, rigid foamed urethane, polystyrene foam and the like which are poor in flexibility and can be easily broken by bending deformation are not preferable.

The inventors have studied materials in order to reduce the weight. As an example of a material that can be changed to urethane foam with an open-cell structure, synthetic resin foam that has a closed-cell structure is generally lighter and more rigid than urethane foam that has been conventionally used as a cushion material for seat backs. It has the advantage that it is rich and easy to recycle, but when using a cushion in the direction of compression and restoring force, the reaction force tends to increase rapidly with the deformation of the foam due to the repulsive force of the encapsulated air Therefore, it was felt that the cushioning property was lacking and the comfort was inferior.

In general, when a synthetic resin foam having a closed cell structure is used as a cushioning material by being bent in the compression direction like a urethane foam, it gradually loses its recovery force and generates creep as it is used for a long period of time. This is largely due to fatigue due to repeated deformation of the resin film constituting the bubbles and a drop in the pressure of the air contained therein. Therefore, it is not preferable as a material for an automobile seat back used for a long time.

Therefore, the inventors analyzed the physical properties of the synthetic resin foam from various angles, so that it is not a structure that has been bent in the compression direction that has been used as a conventional general cushioning material, but can be bent and deformed. The present inventors have found that a method of utilizing the bending deformation and recoverability of a support made of a synthetic resin foam excellent in the above as a cushioning material is optimal.

In order to solve the problem described in “Problems to be Solved by the Invention”, the invention of the seat back 2 according to claim 1 has an amount of bending deflection measured according to the method described in JIS K7221-2: 2006. A backrest that has a backrest surface 4 that has a backrest surface 4 with which the body abuts when seated and is made of a synthetic resin foam having a load of 20 mm or more and a load of 2 to 100 N when bent by 20 mm. The seat back pad 3 provided with the surface support 5 and the back support surface 5 of the seat back pad 3 can be bent and deformed behind the back support surface 5 and the back of the seat back pad 3 due to the load of the seated person. And an elastic body 11 having a damping property by compressive deformation with respect to the bending deformation of the rounded surface support body 5.

The invention of the seat back 2 according to claim 2 is characterized in that, in claim 1, the elastic body 11 is disposed between the backrest support 5 and the support 19 of the seat back pad. And

The invention of the seat back 2 according to claim 3 is the invention according to claim 1 or 2, wherein the elastic body 11 has a hardness at 20% compression of 20 to 600 N as defined in JIS K6400-2: 2012. It is characterized by.

The invention of the seat back 2 according to claim 4 is characterized in that in any one of claims 1 to 3, a synthetic resin foam is contained in the elastic body 11.

The invention of the seat back 2 according to claim 5 is the backrest support according to any one of claims 1 to 4, wherein the backrest support is formed from the gaps between the plurality of rod-like or plate-like backrest supports 5. The elastic body 11 disposed behind 5 is projected forward from the back surface 4 of the back surface support 5.

The invention of the seat back 2 according to claim 6 is characterized in that in any one of claims 1 to 5, a hole 13 and a cavity 12 are provided in the elastic body 11.

The invention of the seat back 2 according to claim 7 is characterized in that in any one of claims 1 to 6, an elastic body 11 is provided so as to cover the backrest surface 4 of the backrest support 5. To do.

The invention of the seat back 2 according to claim 8 increases the thickness in the front-rear direction of the rod-like or plate-like backrest surface support body 5 in contact with the waist of the seated person in any one of the first to seventh aspects. Thus, the backrest surface support body 5 that comes into contact with the waist of the seated person has a lumbar support function for supporting the waist of the seated person.

The invention of the seat back 2 according to claim 9 is the left and right side support respectively provided on both sides in the seat width direction of the backrest surface support 5 having the backrest surface 4 in any one of the first to eighth aspects. The part 6 is characterized in that the outer peripheral wall side of the side support part 6 is the synthetic resin foam, and the elastic body 11 is disposed inside the outer peripheral wall.

The invention of the vehicle seat back 2 according to claim 1 can replace the urethane foam, which has been conventionally used in general, with a synthetic resin foam. Improvement is possible. Despite the use of synthetic resin foam, which is relatively hard and inferior to cushioning, fit, and creep resistance, it is possible to give high cushioning and fit, and freedom of design High degree of comfort and high occupant body support, high comfort and high creep resistance equivalent to that of urethane foam seat back pads even after long-term use There is an effect of having merchantability.

Further, the elastic body 11 which is compressible in the bending deformation area of the backrest support body 5 and has a damping property against the bending deformation of the backrest support body 5 due to the load of the seated person. By disposing, the bending deformation generated in the backrest support 5 can be attenuated, and the cushioning property can be enhanced. Further, durability against an impact caused by, for example, jumping of a child or collision of a heavy object with respect to the support 5 can be improved.

The invention described in claim 2 has the same effect as that of the invention described in claim 1, and further, the elastic body 11 is supported by the support 19 of the seat back pad having rigidity. There is an effect that the compression deformation is further ensured. In addition, since the seat back pad 3 is composed of a synthetic resin foam on the front side and an elastic body 11 on the rear side, the seat back pad 3 can be used in a portion other than the backrest support 5 of the vehicle seat back 2 in a front view. The cushioning property can be enhanced by reducing the thickness of the synthetic resin foam and the elastic body 11 having a damping property and compressively deforming to have a restoring property, and the synthetic resin foam is destroyed by excessive bending deformation or the like. Can be effectively prevented.

The invention described in claim 3 has the same effect as that of the invention described in claim 1 or 2, and further, the elastic body 11 to be used has appropriate compression hardness and damping properties as a cushioning material for the vehicle seat back 2. Thus, the elastic body 11 can be restored from compression deformation.

The invention according to claim 4 has the same effect as the invention according to any one of claims 1 to 3, and further, since the synthetic resin foam is inherent in the elastic body 11, When the weight applied to the vehicle seat back 2 changes, the cushioning property can be changed stepwise, and the hardness can be partially changed only at necessary places such as the waist.

The invention according to claim 5 achieves the same effect as the invention according to any one of claims 1 to 4, and further, for the seated person, the rod-like or plate-like support body of the backrest surface support body 5. There is an effect of relieving the uncomfortable feeling of feeling the unevenness of the corners due to the level difference that occurs in the.

The invention according to claim 6 has the same effect as the invention according to any one of claims 1 to 5, and the cushioning property of the elastic body 11 is more finely provided by providing the elastic body 11 with the hole 13 and the cavity 12. There is an effect of partially adjusting the air permeability and improving the air permeability.

The invention according to claim 7 has the same effect as the invention according to any one of claims 1 to 6, and further has an effect that the cushioning property at the moment when the seated person is seated can be enhanced.

The invention according to claim 8 has the same effect as the invention according to any one of claims 1 to 7, and further has a rod-like or plate-like backrest surface support 5 having an increased thickness in the front-rear direction. Since it has a lumbar support function that supports the waist of the person, the seated person has the effect of being less tired even if he / she has been riding for a long time.

The invention according to claim 9 achieves the same effect as the invention according to any one of claims 1 to 8, and the side support portion 6 is also reduced in weight and recycled as compared to the conventional form made of urethane foam alone. Despite the use of a synthetic resin foam that has improved cushioning, inferior cushioning, fit, and creep resistance, the side support part 6 is easily bent and compressed easily. Can increase the sex.

It is a schematic diagram of a vehicle seat. It is a schematic diagram of a vehicle seat back with the skin removed. FIG. 2 is a cross-sectional view taken along the line AA in FIG. 2 and a backrest surface forming a flat surface. When (a) is a back plate and (b) is a spring, It is a schematic diagram in the case of consisting of a wire or the like. It is the figure which attached the skin to the AA sectional view in Drawing 2, and is a schematic diagram which made a synthetic resin foam exist inside an elastic body. It is AA sectional drawing in FIG. 2, and is a schematic diagram which shows the form which the elastic body protrudes from the gap | interval between the rod-shaped or plate-shaped backrest support bodies of a synthetic resin foam on the backrest surface, (a) It is an outline sectional view of a vehicular seat back, and (b) is an enlarged view of section C of (a). It is AA sectional drawing in FIG. 2, and is the schematic which provided the cavity in the elastic body. It is the schematic which provided the hole in the elastic body, (a) is AA sectional drawing in FIG. 2, (b) is the perspective schematic diagram which looked at the elastic body from the backrest side. It is AA sectional drawing in FIG. 2, It is explanatory drawing of the form provided with the lumbar support function which increases the thickness of the back-and-forth direction of a part of backrest surface support body, protrudes, and supports a seated person's waist | hip | lumbar part. FIG. 2 is a cross-sectional view taken along the line AA in FIG. 2 and includes a lumbar support function for supporting a seated person's waist in a form in which the backrest surface is increased in thickness in the front-rear direction and the backrest surface is smoothed. It is explanatory drawing of the form. FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2, showing a form of a vehicle seat back in which a layer made of an elastic body is formed on the back surface side of the back surface support body. It is a perspective view of a seat back frame, and when a support of a seat back pad is (a) a back board, (b) is a schematic diagram in case consisting of a spring, a wire, etc. It is a BB sectional view in Drawing 2, and is a figure showing the form of the vehicular seat back which arranged the elastic body in the side support part, (a) is the figure showing the form of the vehicular seat back, (b) is (b) It is an enlarged view of the F part of a). FIG. 3 is a cross-sectional view taken along the line BB in FIG. 2, in which an elastic body is disposed in a side support portion. It is a figure which shows a headrest, (a) shows an external appearance, (b) is the EE sectional drawing in (a), and is a cross-sectional schematic diagram except for the skin, (c) is the head contact surface of a head surface support body It is the cross-sectional schematic diagram which covered the elastic body on the side. It is a figure which shows an armrest, (a) shows an external appearance, (b) is the FF sectional drawing in (a), and is a cross-sectional schematic diagram except the skin, (c) is the forearm contact surface side of an arm surface support body It is the cross-sectional schematic diagram which covered the elastic body.

Hereinafter, an embodiment of a vehicle seat back 2 according to the present invention will be described.

A vehicle seat back 2 according to the present invention is a vehicle seat back 2 constituting the vehicle seat 1 shown in FIG. 1, and, as shown in FIG. 3, according to the method described in JIS K7221-2: 2006. A backrest surface 4 having a plurality of rod-like or plate-like shapes made of a synthetic resin foam having a measured bending deflection of 20 mm or more and a load at the time of 20 mm deflection of 2 to 100 N, with which the body abuts when seated. A seat back pad 3 having a backrest surface support body 5 that is bent and deformed, and a back deformation surface support body 5 of the seat back pad 3 that can be bent and deformed behind the backrest surface support body 5. And an elastic body 11 having a damping property by compressive deformation with respect to the bending deformation of the backrest surface support body 5 due to the load of the person.

As shown in FIG. 3A, the vehicle seat back 2 includes seat back pad supports 19 such as an outer skin 8, a backrest support 5, an elastic body 11, and a back plate 9 in order from the seated side. Arranged. The back plate 9 is made of a synthetic resin, a metal plate, or a composite material thereof, has rigidity, and is a wall presence when the elastic body 11 is compressed and deformed, as shown in FIGS. 3 to 5. There is a form separate from the surface support 5 or an integral form with the backrest support 5 as shown in FIG. 6 or 7.

A plurality of rod-like or plate-like backrest surface supports 5 made of a synthetic resin foam, and have a damping property that enables the backrest surface support 5 to bend and deform behind the backrest surface support 5. The form with the elastic body 11 is demonstrated with AA sectional drawing of the vehicle seat back 2 which removed the skin shown in FIG.

As shown in FIG. 2, the seat back pad 3 includes a plurality of rod-like or plate-like backrest surface supports 5 as components, and the backrest surface support 5 is rearward by a load of a seated person. Bend and deform. In order to reduce the magnitude of bending deformation when a seated person's load is applied, as shown in FIG. 3, the region on the bending deformation side of the backrest support 5 is easily compressed and attenuated with respect to the load. A flexible elastic body 11 is disposed.

Examples of the elastic body 11 include urethane foam, foamed resin molded body, foamed resin particles, foamed rubber, elastomer, fibrous material, three-dimensional knitted fabric, wool, silk, cotton, and fiber joints such as a three-dimensional spring structure. It consists of a material that has resilience to repeated loads, such as stretchable bags or spheres sealed with gas, and a material that has damping properties, such as fibers and rubber. It is a pressure plate of a flat disk having a diameter of 200 mm as defined in JIS K6400-2: 2012 regarding the method for determining the thickness, and it has a hardness at 25% compression (D method) of preferably 20 to 600N. Depending on the shape and size of the elastic body 11, the hardness at which the attenuation is optimal is set. If it is less than 20N, it is too soft and the reaction force to return to its original form after being compressed is too weak to have damping. If it exceeds 600N, it is too hard when a load is applied and it is compressed and deformed. Does not have attenuating property.

The backrest surface support 5 and the elastic body 11 are configured in such a manner that the backrest surface 4 is smoothed by disposing the elastic body 11 in the gap 15 between the backrest surface supports 5 as shown in FIG. 5, the elastic body 11 is disposed in the gap 15 between the backrest surface supports 5 and further extended to extend the backrest surface of the backrest surface support 5. 4, or as shown in FIG. 6, the elastic body in the region where the backrest surface support 5 is bent without deforming the elastic body 11 in the gap 15 between the backrest surface supports 5. 11 may be used as long as the elastic body 11 is disposed on the back side of the back support 5 which is the side where the back support 5 is bent and deformed.

Further, as shown in FIG. 3A or 3B, a seat back pad support 19 can be disposed at the rear end of the vehicle seat back 2. The seat back pad support 19 forms a rear end portion of the vehicle seat back 2, and as shown in FIG. 11 (a), generally corresponds to a rigid back plate 9 made of a resin or metal plate. Alternatively, as shown in FIG. 11 (b), it is composed of a wire stretched around the seat back frame 7, a spring 18 and the like and is in contact with the seat back pad 3 and supported from behind. Accordingly, the cushioning property can be enhanced even in a portion other than the portion where the vehicle seat back 2 is bent and deformed in front view.

Furthermore, the synthetic resin foam 10 may be included in the elastic body 11 as shown in FIG. Even in the case of this form, the entire elastic body 11 including the synthetic resin foam 10 is preferably made to have a hardness at 25% compression of 20 to 600 N. The embedded synthetic resin foam 10 may have any form such as a columnar shape, a spherical shape, a cubic shape, a rectangular parallelepiped shape, and a conical shape. What is necessary is just to provide suitably the form of the said synthetic resin foam 10 to be made to exist, a position, a number, and a magnitude | size so that comfortable cushioning properties may be obtained according to the form and magnitude | size of the elastic body 11. FIG. The hardness can be partially adjusted by the internal synthetic resin foam 10.

Regardless of the form of the backrest surface support body 5 and the elastic body 11, the elastic body 11 having a damping property is disposed on the side of the backrest surface support body 5 that is bent and deformed. Since the load of the passenger is supported by the bending deformation of the backrest support 5 and the compression deformation of the elastic body 11, higher follow-up is also achieved against acceleration applied laterally to the occupant's body during a turning motion during traveling. Demonstrate and cushioning. In addition, the elastic body 11 can prevent the backrest surface support 5 made of a synthetic resin foam from being damaged even when a heavy object collides with an unspecified position on the vehicle seat back 2.

Since the epidermis is covered on the seat back side of the backrest surface 4, the seated person hardly perceives the corners of the rod-like or plate-like back support surface support 5 as uncomfortable, but FIG. 5 (a) and (b) If the elastic body 11 is protruded from the surface of the backrest support 5 as shown in FIG. 2, the seated person becomes more difficult to feel the corner of the rod-like or plate-like backrest support 5 as an uncomfortable feeling.

Moreover, as shown in FIG. 6, the cavity 12 is provided in the elastic body 11, and the hole 13 is provided in the front-back direction as shown in FIG. 7 (a) or (b). The hole 13 may be a through-hole or a non-penetrating hole. By providing the holes 13 and the cavities 12 in the elastic body 11, the cushioning property of the elastic body 11 can be partially adjusted or the air permeability can be improved.

Next, as shown in FIG. 8 or FIG. 9, the thickness of the rod-like or plate-like backrest support 5 that contacts the waist of the seated person is increased. Increase thickness. As a result, the bending rigidity of the backrest support 5 that abuts against the waist of the seated person is increased, and a lumbar support function for supporting the waist is provided. Moreover, even if the elastic body 11 having a higher hardness than that of the portion other than the waist is disposed on the back surface of the portion of the backrest support 5 that supports the waist, it has a lumbar support function that supports the waist of the seated person.

8, the rod-like or plate-like backrest surface support 5 that abuts the waist of the seated person is protruded forward from the backrest surface support 5 of the other part. In this case, since the seated person pushes the waist of the seat stronger from the moment when the seated person sits, the seated person can feel comfort in the waist from the moment of seating.

Further, as shown in a point D of FIG. 9, a rod-like or plate-like backrest support 5 that abuts the seated person's lower back is smoothed in the same manner as the backrest support 5 of other parts. In the case of the form in which the reclining surface 4 is formed, the backrest surface support body 5 having an increased thickness in the front-rear direction has a higher bending rigidity than the other backrest surface support bodies 5, so that the seated person can sit down. When a load is applied, the seat occupant can feel comfort in the waist because it is easily bent and deformed and does not move backward and stays in an accurate position to support the waist.

Next, as shown in FIG. 10, a layer made of the elastic body 11 is formed on the backrest surface 4 side of the backrest support 5. In the case of this form, the seated person first comes into contact with the elastic body 11 having a damping property at the moment of sitting, so that when the hardness of the elastic body 11 is preferably 20N to 250N, a soft touch is felt from the moment of sitting. You can feel cushioning.

Next, the form of the left and right side support portions 6 provided on both sides in the seat width direction of the backrest support 5 having a backrest will be described. As shown in FIG. 12 or FIG. 13, the outer peripheral wall side of the side support portion 6 is formed of a synthetic resin foam, and the elastic body 11 is disposed on the inner side surrounded by the outer peripheral wall. And the outer peripheral wall of the said side support part 6 is a form where the outer peripheral wall of the side support part 6 and the backrest support body 5 were connected continuously as shown in FIG. 12, or the seated person as shown in FIG. The backrest surface support 5 and the outer peripheral wall of the side support portion 6 are separated from each other at the point of contact between the backrest surface support 5 and the outer peripheral wall of the side support portion 6. There is a form.

Even if it is any form, since the elastic body 11 which has a damping property is arrange | positioned inside, the cushioning property of the side support part 6 is high.

12 (a) and 12 (b), the ratio of the elastic body 11 and the synthetic resin foam in the side support portion 6 is as large as possible while ensuring cushioning properties. By doing so, weight reduction of the vehicle seat back 2 can be achieved.

Further, as shown in FIG. 13, by separating the backrest surface support 5 and the outer peripheral wall of the side support portion 6, the side support portion 6 is pulled by the bending deformation of the backrest surface support 5 so that the inner side is supported. Since it is difficult for the occupant to fall down, the occupant is less likely to feel a pressure from the left and right directions, and the side support portion 6 itself is easily deformed by a light load, so that cushioning is enhanced.

The headrest 20 shown in FIG. 14A can have the same effect as the seat back pad 3. In FIG. 14B, the headrest 20 has a plurality of independent rod-like or plate-like heads made of a synthetic resin foam, and has a head contact surface 23 with which the head abuts when seated, and is bent and deformed backward. A headrest pad 22 provided with the headrest support 22, and the head surface support 21 can be bent and deformed behind the head surface support 21 of the headrest pad 22, and the head surface support 21 is caused by a load on the head of the seated person. And an elastic body 11 having a damping property against an impact during bending deformation. And as shown in FIG.14 (c), there also exists a form which covers the elastic body 11 which has a damping | damping property so that the head contact surface 23 of the head surface support body 21 may be covered.

Therefore, the headrest 20 can also have a high cushioning property against the load on the seated person's head, like the seat back pad 3.

The armrest 25 shown in FIG. 15A can have the same effect as the seat back pad 3. In FIG. 15 (b), the armrest 20 has a plurality of independent rod-like or plate-like arm-shaped support bodies 28, which are made of synthetic resin foam, and have an arm contact surface 28 with which the arm abuts when seated, and bend and deform downward. An armrest pad 27 provided with the armrest pad 26, and the arm surface support body 26 can be bent and deformed below the arm surface support body 26 of the armrest pad 27, and the arm surface support body 26 is loaded by the load of the arm portion of the seated person. And an elastic body 11 having a damping property against an impact during bending deformation. And as shown in FIG.15 (c), there also exists a form which covers the elastic body 11 which has a damping | damping property so that the arm contact surface 28 of the arm surface support body 26 may be covered.

Accordingly, the armrest 25 can also have a high cushioning property against the load on the seated person's forearm, similarly to the seat back pad 3.

Next, the synthetic resin foam will be described. The synthetic resin foam in the present invention is flexible, can be bent and deformed, and has excellent restorability. The method described in JIS K7221-2: 2006 (23 ° C. ± 2 ° C., relative humidity 50 ± 5% A test piece having a length of 350 mm, a width of 100 mm, and a thickness of 25 mm, with the skin removed, is applied with a load of up to 90 mm at a fulcrum distance of 300 mm and a test speed of 20 ± 1 mm / min, and a load deflection curve is recorded. It refers to a synthetic resin foamed molded article having a bending deflection of 20 mm or more measured according to the above and a load of 2 to 100 N at the time of 20 mm deflection. A synthetic resin foam molded article that causes fracture when the bending deflection is less than 20 mm is not suitable from the viewpoint of durability. When the cross-section of the support 3 required to support the pressing by the body becomes very large and the load at the time of 20 mm deflection is less than 2N or more than 100N, it is difficult to generate a preferable deflection amount by the load applied by the occupant. Both of them are difficult to design. Specifically, it refers to foamed polypropylene, foamed polyethylene, other polyolefin resin foams, modified polystyrene resin foams, and the like. Among the foams, an in-mold molded body of resin foam particles is preferable from the viewpoint of shape flexibility (designability) considering a fit.

The polyolefin resin constituting the expanded particles used in the present invention is a polyolefin resin having an olefin component unit as a main component, specifically, a polypropylene resin, a polyethylene resin, and a mixture of two or more thereof. Is mentioned. The above-mentioned “main component” means that the olefin component unit is contained in the polyolefin resin in an amount of 50% by weight or more, and the content thereof is preferably 75% by weight or more, more preferably 85% by weight. % Or more, more preferably 90% by weight or more.

Examples of the polypropylene-based resin include resins having a propylene component unit of 50% by weight or more, and examples thereof include a propylene homopolymer or a copolymer with another olefin copolymerizable with propylene. Examples of other olefins copolymerizable with propylene include ethylene, 1-butene, isobutylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3,4-dimethyl-1-butene, 1 Examples thereof include α-olefins having 4 to 10 carbon atoms such as heptene and 3-methyl-1-hexene. The copolymer may be a random copolymer or a block copolymer, and may be not only a binary copolymer but also a ternary copolymer. The other olefin copolymerizable with propylene in the copolymer is preferably contained in a proportion of 25% by weight or less, particularly 15% by weight or less, and the lower limit is 0.3% by weight. Preferably there is. These polypropylene resins can be used alone or in combination of two or more. Polypropylene resin has a tensile elastic modulus (E) specified in JIS K7161: 1994 (test piece: JIS K 7162 (1994), test piece 1A type (direct molding by injection molding), test speed: 1 mm / min)). A resin foam obtained by foaming a base resin having a value of 600 MPa or more is preferable.

Examples of the polyethylene resin include resins having an ethylene component unit of 50% by weight or more, such as high density polyethylene, low density polyethylene, linear low density polyethylene, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer. A copolymer, an ethylene-propylene-butene 1 copolymer, an ethylene-butene 1 copolymer, an ethylene-hexene 1 copolymer, an ethylene-4 methylpentene 1 copolymer, an ethylene-octene 1 copolymer, and the like. The mixture of 2 or more types is mentioned.

Then, in the specific selection of the synthetic resin foam, both ends of a rod-shaped test piece having a length of about 400 mm are supported, the center is pushed back and forth by 25 mm and held for 30 minutes, and then the load is released, and then the deformation from the sample is changed. Residual strain measured after repeatedly deforming the center part of the sample supporting both ends a predetermined number of times in accordance with tests performed on materials with 90% or more recovery, or conventional urethane foam seat backs A material in which is less than a predetermined amount is desirable. The predetermined number of times or the predetermined amount conforms to a specification arbitrarily determined when each vehicle manufacturer selects a conventional material.

Such materials satisfying, for example, the density of the foamed polypropylene ^{0.06g / cm 3 ~0.015g / cm 3} , more preferably a density ^{0.035g / cm 3 ~0.015g / cm 3} , or of foamed polyethylene such as density 0.08g ^/ cm ³ ~0.03g ^/ cm 3 are preferred. Such a material is obtained by the method described in JIS K7221-2: 2006 (a test piece having a length of 350 mm, a width of 100 mm, and a thickness of 25 mm with the skin removed in an atmosphere of 23 ° C. ± 2 ° C. and a relative humidity of 50 ± 5%. In a test conducted in accordance with a distance between fulcrums of 300 mm, a test speed of 20 ± 1 mm / min up to a maximum of 90 mm, and a load deflection curve is recorded. However, the flexible urethane foam that has been used generally has a load of 0.46 N when the bending deflection is 20 mm, and the bending rigidity is greatly inferior. It is not suitable as a constituent material.

  Below, the creep property and bending rigidity at the time of using a synthetic resin foam are demonstrated. First, in order to evaluate creep property, the compression set according to JIS K6767: 1999 was measured. A test piece having a length of 50 mm, a width of 50 mm, and a thickness of 25 mm is compressed into a 25% distorted state and left at a temperature of 23 ° C. ± 2 ° C. for 22 hours. The thickness is measured 24 hours after the end of compression. The compression set was determined by compression set (%) = (test piece original thickness (mm) −thickness 24 mm after completion of compression (mm)) ÷ test piece original thickness (mm) × 100.

As a result of the test, the compression set of the 45-fold polypropylene foam particle molded body was 11%. On the other hand, the compression set of the polyurethane foam by the same measuring method is 2% or less. This is because conventional urethane foam, which is generally used as a cushioning material for seat backs, exhibits cushioning properties by compressive deformation, and if it is simply replaced with a synthetic resin foam, a compression set is generated. It is shown that it is difficult to maintain the product and the commercial value is lowered.

DESCRIPTION OF SYMBOLS 1 Vehicle seat 2 Vehicle seat back 3 Seat back pad 4 Backrest surface 5 Backrest surface support body 6 Side support part 7 Seat back frame 8 Skin 9 Back plate 10 Synthetic resin foam 11 Elastic body 12 Cavity 13 Hole 15 Gap 18 Spring 19 Seat back pad support 20 Headrest 21 Head surface support 22 Headrest pad 23 Head contact surface 25 Armrest 26 Arm surface support 27 Armrest pad 28 Arm contact surface

Claims (9)

At the time of sitting in the form of a plurality of rods or a plurality of plates made of a synthetic resin foam having a bending deflection amount measured in accordance with the method described in JIS K7221-2: 2006 of 20 mm or more and a load at the time of 20 mm deflection of 2 to 100 N A seat back pad provided with a backrest support body that has a backrest surface against which the body abuts and bends and deforms backward;
The backrest support body can be bent behind the backrest support body of the seat back pad, and the backrest support body is deformed by a compressive deformation and attenuating with respect to the bending deformation of the backrest surface support body due to a seated person's load. And an elastic body having a vehicle seat back.   The vehicle seat back according to claim 1, wherein the elastic body is disposed between the backrest surface support body and a seat back pad support body.   The vehicular seat back according to claim 1 or 2, wherein the elastic body has a hardness at 20% compression of 20 to 600 N as defined in JIS K6400-2: 2012.   The vehicle seat back according to any one of claims 1 to 3, wherein a synthetic resin foam is contained in the elastic body.   From the gap between the plurality of rod-like or plate-like backrest surface supports, the elastic body disposed behind the backrest surface support is moved forward from the backrest surface of the backrest surface support. The vehicle seat back according to any one of claims 1 to 4, wherein the vehicle seat back is protruded into the vehicle. 6. The vehicle seat back according to claim 1, wherein a hole or a cavity is provided in the elastic body.   The vehicular seat back according to any one of claims 1 to 6, wherein an elastic body is provided so as to cover a backrest surface of the backrest surface support body. The back surface support that abuts against the waist of the seat occupant increases the thickness in the front-rear direction of the rod-shaped or plate-like back support that abuts against the waist of the seat occupant, and supports the waist of the seat occupant The vehicle seat back according to any one of claims 1 to 7, further comprising a lumbar support function. The left and right side support portions provided on both sides in the seat width direction of the backrest support body having the backrest surface are surrounded by the outer peripheral wall with the outer peripheral wall side of the side support portion being the synthetic resin foam. The vehicular seat back according to any one of claims 1 to 8, wherein an elastic body is disposed inside.

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