JP6910857B2 - Cushion pad - Google Patents

Description

The present invention relates to a cushion pad in which a seating sensor is arranged between the frame and the cushion pad.

Some seat cushions incorporating a seating sensor for detecting that an occupant is seated include a seating sensor arranged between a frame and a cushion pad supported by the frame (Patent Document 1). When molding defects such as voids (missing parts due to poor liquid circulation during molding) and sink marks occur on the pressure receiving surface of the cushion pad that applies pressure to the seating sensor, and the seating sensor hits the molding defective part, the cushion pad Since the force is not transmitted well to the seating sensor, the detection accuracy of the seating sensor deteriorates. In the technique disclosed in Patent Document 1, by providing ribs adjacent to the pressure receiving surface made of soft foam, when the soft foam is cured in the molding die, the groove of the molding die corresponding to the ribs causes the vicinity of the pressure receiving surface. Since air can be easily released, it is possible to suppress molding defects on the pressure receiving surface.

Japanese Unexamined Patent Publication No. 2015-205339

However, in the above-mentioned conventional technique, since the pressure receiving surface is made of soft foam, there is a possibility that molding defects may occur on the pressure receiving surface, and there is a possibility that the detection accuracy of the seating sensor cannot be sufficiently ensured.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a cushion pad capable of improving the detection accuracy of a seating sensor.

In order to achieve this object, the cushion pad of the present invention has a pressure receiving surface on which a seating sensor is arranged between the cushion pad and the frame, and is attached to a pad body made of soft foam and the back surface of the pad body. A sheet-like elastic member having at least a part forming the pressure receiving surface and having elasticity, and a backing material attached to the back surface of the pad body other than the portion where the elastic member is arranged are provided . Has a smaller elongation rate than the elongation rate of the elastic member .

According to the cushion pad according to claim 1, a pressure receiving surface is formed by at least a part of a sheet-shaped elastic member having elasticity. As a result, even if molding defects such as voids and sink marks occur on the back surface of the pad body between the stretchable member, the load from the pad body can be transmitted from the pressure receiving surface of the stretchable member at the molding defective portion to the seating sensor. As a result, it is possible to suppress variations in the load applied to the seating sensor from the pad body via the pressure receiving surface, so that the detection accuracy of the seating sensor can be ensured.

Further, since the pressure receiving surface is formed by the elastic member having elasticity, when the pad body is deformed by the load applied to the position horizontally separated from the seating sensor by placing a load or the like, the deformation is caused by the elastic member. It can be absorbed by the expansion and contraction of the pad body to suppress the transmission of the load from the pad body to the pressure receiving surface. As a result, it is difficult to transmit the load applied to the seating sensor at a position horizontally separated from the seating sensor by placing a load or the like from the pressure receiving surface, so that false detection of the seating sensor can be suppressed. As a result, the detection accuracy of the seating sensor can be improved.
A back surface material having an elongation rate smaller than that of the expansion / contraction member is attached to the back surface of the pad body other than the portion where the expansion / contraction member is arranged. Therefore, the back surface of the pad body can be reinforced.

According to the cushion pad according to claim 2, since the elastic member is integrated with the back surface of the pad body, it is possible to prevent the pressure receiving surface of the elastic member from bending or wrinkling on the pressure receiving surface. As a result, in addition to the effect of claim 1, the detection accuracy of the seating sensor can be further improved.

According to the cushion pad according to claim 3, the stretchable member made of the stretchable non-woven fabric is joined to the pad body by a part of the soft foam cured in a state of penetrating between the fibers of the stretchable non-woven fabric. As a result, when molding the pad body, air near the pressure receiving surface is easily released through the stretchable non-woven fabric, and the soft foam is easily spread along the stretchable non-woven fabric. Can be suppressed. As a result, the variation in the load applied from the pad body to the seating sensor via the pressure receiving surface can be further suppressed, so that in addition to the effect of claim 2, the detection accuracy of the seating sensor can be further improved.

According to the cushion pad according to claim 4, the pressure receiving surface with which the seating sensor contacts is arranged inside the opening formed in the back surface material. The contact portion of the telescopic member with which the seating sensor contacts and the inner peripheral edge of the opening are connected by the connecting portion of the telescopic member. The shortest distance of the connecting portion connecting the contact portion and the inner peripheral edge of the opening is set to be larger than the thickness of the seating sensor. By extending the connecting part according to the shortest distance of the connecting part, the displacement of the backing material due to the load applied at a position horizontally away from the seating sensor is absorbed, and the transmission of the load from the backing material to the contact part is suppressed. can. As a result, it is difficult to transmit the load applied to the seating sensor at a position horizontally separated from the seating sensor from the contact portion to the seating sensor, so that false detection of the seating sensor can be suppressed. As a result, in addition to the effect of any one of claims 1 to 3, the detection accuracy of the seating sensor can be further improved.

It is a perspective view of the vehicle seat in 1st Embodiment of this invention. It is sectional drawing of the seat cushion in line II-II of FIG. It is a bottom view of a cushion pad. It is a partially enlarged cross-sectional view of the seat cushion in which the occupant was seated. It is a tension-load curve of the elastic member and the back surface material. It is a bottom view of the cushion pad in the 2nd Embodiment. It is sectional drawing of the cushion pad in line VII-VII of FIG. It is sectional drawing of the seat cushion in 3rd Embodiment. It is a bottom view of a cushion pad.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of a vehicle seat 1 according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view of the seat cushion 2 in line II-II of FIG. FIG. 3 is a bottom view of the cushion pad 10. In addition, in FIGS. 2 and 3 and the like, the dimensions of the seating sensor 7 and the recess 16 are exaggerated and shown in a large size for easy understanding.

As shown in FIG. 1, the vehicle seat 1 is a seat mounted on an automobile, and is particularly suitable for a passenger seat and a rear seat. The vehicle seat 1 includes a seat cushion 2 that supports the buttocks of the occupant, a seat back 3 that serves as a backrest for the occupant, and a headrest 4 that supports the head of the occupant.

As shown in FIG. 2, the seat cushion 2 includes a frame 5 made of a rigid material such as metal or synthetic resin, a cushion pad 10 supported by the frame 5, and a cover 6 covering the surface of the cushion pad 10. The frame 5 supports substantially the entire lower surface of the cushion pad 10 from below. The frame 5 may have a spring bridged over a square frame-shaped frame member, and the cushion pad 10 may be supported from below by the frame member and the spring.

The cover 6 is a soft member formed in a bag shape mainly by sewing natural leather, synthetic leather, artificial leather, cloth and the like. The cover 6 is fixed by hooking a hook or the like (neither of them is shown) on a wire, a clip or the like embedded in the cushion pad 10.

A seating sensor 7 is attached to the back surface (frame 5 side) of the cushion pad 10 at a position facing the frame 5 by adhesion or the like. The pressure receiving surface 13 is a predetermined area on the back surface of the cushion pad 10 to which the seating sensor 7 is attached. The pressure receiving surface 13 is a surface that receives the load from the cushion pad 10 and transmits it to the seating sensor 7. Since the seating sensor 7 is attached after the cushion pad 10 is molded, the pressure receiving surface 13 is set large in the front-rear and left-right directions with respect to the seating sensor 7.

The seating sensor 7 is a seat-shaped pressure-sensitive sensor that detects the seating of an occupant on the seat cushion 2. In vehicles equipped with a vehicle seat 1, airbags for passenger seats and rear seats (Fig.) Only when the seating sensor 7 of the passenger seat 1 in the passenger seat or the rear seat detects the seating of an occupant. Not shown) is activated. Further, when the seating sensor 7 detects the seating of the occupant and the seatbelt is not fastened, a warning device (not shown) for prompting the seatbelt to be fastened may be activated. In order to suppress the malfunction of the airbag and the warning device, it is required to improve the detection accuracy of the seating sensor 7.

As shown in FIGS. 2 and 3, the cushion pad 10 includes a pad body 11 made of a soft foam such as a flexible polyurethane foam, and a sheet-shaped back surface material 14 and an elastic member 15 attached to the back surface 12 of the pad body 11. Be prepared. The back surface 12 of the pad body 11 includes a recess 16 recessed upward with the pressure receiving surface 13 as the bottom surface. The entire bottom surface of the recess 16 is the pressure receiving surface 13. As a result, when the seating sensor 7 is attached to the pressure receiving surface 13 after the cushion pad 10 is molded, the mounting location of the seating sensor 7 can be clarified by the recess 16. Further, it is preferable to arrange the seating sensor 7 at the center of the pressure receiving surface 13 which is larger in the front-rear and left-right directions with respect to the seating sensor 7 in the front-rear direction and the left-right direction.

In the no-load state of the seat cushion 2, the periphery of the recess 16 on the back surface 12 is supported (contacted) by the frame 5, and a predetermined space is formed between the recess 16 and the frame 5. The depth L1 of the recess 16 is set to be larger than the thickness L2 (height from the pressure receiving surface 13) of the seating sensor 7. As a result, it is possible to prevent the load from being applied to the seating sensor 7 provided on the pressure receiving surface 13 on the bottom surface of the recess 16 when a small load such as placing a light load on the seat cushion 2 is input. As a result, erroneous detection of the seating sensor 7 can be suppressed.

The recess 16 is located at the center of the cushion pad 10 in the left-right direction and behind the center in the front-rear direction (the position of the buttocks of the seated occupant). By arranging the recess 16 at this position, it is possible to easily apply the load from the seated occupant to the seating sensor 7 provided on the pressure receiving surface 13 of the recess 16. As a result, the detection accuracy of the seating sensor 7 can be ensured.

The position of the seating sensor 7 can be appropriately set as long as the load from the seated occupant is likely to be applied (near the buttocks, particularly near the ischium). Further, the seating sensor 7 and the recess 16 are not limited to one, and a plurality of seating sensors 7 and the recess 16 may be provided. In this case, the accuracy of detecting the seating of the occupant on the seat cushion 2 can be improved by comparing the load distribution when the occupant is seated on the seat cushion 2 with the detected values of the plurality of seating sensors 7. However, as the number of seating sensors 7 increases, the seating detection accuracy of the occupant can be improved, but the number of parts, the cost of parts, the work process increase, and the control becomes complicated.

The back surface material 14 is a non-woven fabric that reinforces the back surface 12 side of the pad body 11 in order to suppress rubbing or tearing of the cushion pad 10. The back surface material 14 is not limited to the case of being composed of a non-woven fabric, and can be formed of a coarse blanket, a lawn cloth, felt, press felt, a woven or knitted fabric, or a laminated composite thereof. Further, a molded product using these materials may be used as the back surface material 14.

The back surface material 14 includes an opening 17 that opens through a portion corresponding to the bottom surface (pressure receiving surface 13) of the recess 16 in the cloth thickness direction. The pressure receiving surface 13 and the seating sensor 7 are arranged inside the opening 17. By arranging the seating sensor 7 in the center of the pressure receiving surface 13, the inner peripheral edge of the opening 17 is separated from the seating sensor 7 over the entire circumference.

The elastic member 15 is made of an elastic non-woven fabric having a higher elongation rate (having elasticity) than the back surface material 14. The stretchable non-woven fabric preferably has an elongation rate of 150% or more. The elongation rate of the stretchable non-woven fabric is measured by a method (standard tensile strength and elongation rate) according to JIS L1913 (2010 version) prepared based on ISO9073-3. Specifically, a test piece with a width of 50 mm and a length of 250 mm collected from a sample is attached to a tensile tester at an interval of 150 mm with an initial load, and a load is applied in the length direction until the test piece breaks at a tensile speed of 200 mm. Add. Elongation under maximum load is measured up to 1 mm, and the elongation rate is calculated from this elongation. The initial load when attaching the test piece to the tensile tester shall be the state in which the test piece is pulled by hand to the extent that slack does not occur.

In the stretchable non-woven fabric, in addition to the non-woven fabric itself having elasticity, a stretchable material (elastic material such as rubber or thermoplastic elastomer) is fixed (joined, etc.) to the non-woven fabric as a base material to impart elasticity. Also included. Examples of the stretchable non-woven fabric in which the non-woven fabric itself has elasticity include commercially available elastic non-woven fabrics and elastomer spunbonded non-woven fabrics. Specifically, Straflex (manufactured by Idemitsu Unitech), Espancione (manufactured by KB Seiren) and the like (all registered trademarks) can be preferably used. In these elastic non-woven fabrics and elastomer spunbonded non-woven fabrics, the non-woven fabric itself has elasticity.

The elastic member 15 is arranged so as to close the opening 17 of the back surface member 14, and the pressure receiving surface 13 is formed inside the opening 17. The telescopic member 15 includes a contact portion 15a to which the seating sensor 7 is attached (contacts), and a connecting portion 15b that connects the contact portion 15a and the inner peripheral edge of the opening 17. The connecting portion 15b is overlapped with the pad body 11 side of the back surface material 14 outside the opening 17. The overlapped portion is sewn with a thread 19 over the entire circumference of the opening 17, and the elastic member 15 is joined to the back surface material 14. The connecting portion 15b may be overlapped on the frame 5 side of the back surface material 14.

The connecting portion 15b connects the inner peripheral edge of the opening 17 and the contact portion 15a at the shortest distance L3. That is, the seating sensor 7 and the back surface material 14 are arranged at a distance of L3 or more, which is the shortest distance. The shortest distance L3 is set to be larger than the depth L1 of the recess 16 and the thickness L2 of the seating sensor 7.

In order to manufacture the cushion pad 10, first, the back surface material 14 and the elastic member 15 are formed into a predetermined shape, and the back surface material 14 and the elastic member 15 are sewn with a thread 19. Next, the back surface member 14 and the expansion / contraction member 15 are fixed to a molding die (not shown) with a magnet or a mounting pin. Next, the foaming stock solution of the soft foam is injected into the molding mold, and the foaming stock solution is foamed and cured in the molding mold to mold the pad body 11.

At this time, the foamed stock solution penetrates between the fibers of the back surface material 14 and the elastic member 15 (stretchable non-woven fabric), and the soft foam is cured in that state. As a result, the back surface material 14 and the expansion / contraction member 15 are joined and integrated with the back surface 12 of the pad body 11. Then, the cushion pad 10 is obtained by removing the mold from the molding mold.

Since the elastic member 15 is joined (sewn) to the back surface material 14 and then the back surface material 14 and the elastic member 15 are fixed to the molding die, as compared with the case where the elastic member 15 and the back surface material 14 are fixed to the molding die, respectively. , The expansion / contraction member 15 can be easily fixed to the molding die. This is because the stretchable member 15 made of the stretchable non-woven fabric is softer than the back surface material 14 and has no waist, so that it is difficult to handle the stretchable member 15 alone. Further, since the stretchable non-woven fabric is more expensive than the back surface material 14, by using the stretchable non-woven fabric and the back surface material together, the back surface is compared with the case where all the stretchable non-woven fabric is made without using the back surface material 14. The resource cost required for the material 14 and the stretchable non-woven fabric can be reduced.

Next, the seat cushion 2 in which the occupant is seated will be described with reference to FIGS. 4 and 5. FIG. 4 is a partially enlarged cross-sectional view of the area around the seating sensor 7 of the seat cushion 2 on which the occupant is seated. FIG. 5 is a tension-load curve of the telescopic member 15 and the back surface member 14.

As shown in FIG. 4, when the occupant sits on the seat cushion 2 and the cushion pad 10 bends, the seating sensor 7 comes into contact with the frame 5, and the seating sensor 7 is sandwiched between the pressure receiving surface 13 and the frame 5. When a load of a predetermined value or more is applied to the seating sensor 7 between the pressure receiving surface 13 and the frame 5, the seating sensor 7 detects that the occupant is seated on the seat cushion 2.

Here, in the conventional technique (for example, Patent Document 1) in which the pressure receiving surface 13 is made of a pad body 11 (soft foam), molding defects such as voids and sink marks may occur on the pressure receiving surface 13. When the seating sensor 7 is located (hits) at the defective molding, the force is not transmitted well from the pressure receiving surface 13 to the seating sensor 7, and the load transmitted from the pressure receiving surface 13 to the seating sensor 7 tends to vary, and the seating sensor The detection accuracy of 7 cannot be sufficiently ensured.

In this case, in order to reliably operate the airbag when seated on the seat cushion 2, it is necessary to set so that the seating sensor 7 can detect the seating of the occupant even with a small load. However, in this case, the seating sensor 7 tends to erroneously detect that the occupant is seated even though the luggage or the like is placed on the seat cushion 2, which is not preferable.

On the other hand, in the present embodiment, since the pressure receiving surface 13 is formed by the sheet-shaped elastic member 15, the pressure receiving surface 13 is flat even if the back surface 12 of the pad body 11 between the elastic member 15 and the elastic member 15 has a molding defect. Can be done. As a result, even if a molding defect occurs on the back surface 12 of the pad body 11, the load from the pad body 11 can be transmitted from the pressure receiving surface 13 of the expansion / contraction member 15 at the molding defect portion to the seating sensor 7. As a result, it is possible to suppress variations in the load applied to the seating sensor 7 from the pad body 11 via the pressure receiving surface 13, so that the detection accuracy of the seating sensor 7 can be ensured. Further, by ensuring the detection accuracy of the seating sensor 7, it is possible to appropriately set a predetermined value of the load that the seating sensor 7 determines that the occupant has been seated. Can reliably detect the seating of.

Here, when the occupant is seated on the seat cushion 2, the distribution of the load applied from the occupant to the seat cushion 2 is roughly determined, so that the occupant is seated based on the load distribution and the position of the seating sensor 7. A predetermined value of the load determined by the seating sensor 7 is set. For example, a seating sensor 7 is provided near the buttocks where a large load is easily applied by the occupant, and a predetermined value is set large. On the other hand, the load distribution other than the seating of the occupant (for example, when a luggage or the like is placed on the seat cushion 2) is basically different from the load distribution when the occupant is seated.

When the pressure receiving surface 13 is formed of the back surface material 14, the pressure receiving surface 13 can be made flat. However, the pressure receiving surface 13 becomes hard and difficult to stretch, and when a load is applied to the pad body 11, the circumference of the pressure receiving surface 13 behaves like a rigid body. In this case, when a relatively large load is applied to a position horizontally separated from the seating sensor 7 by placing a load on the seat cushion 2, pressure is received from the pad body 11 due to the deformation of the pad body 11 due to the load. The downward load is easily transmitted to the surface 13. As a result, even if the load distribution is different from the load distribution when the seat cushion 2 is seated, the seating sensor 7 is likely to erroneously detect that the occupant is seated.

On the other hand, in the present embodiment, the pressure receiving surface 13 is formed by the stretchable member 15. FIG. 5 shows a tension-load curve of the back surface material 14 and the expansion / contraction member 15 in which the soft foam is cured in a state where the foamed stock solution has penetrated between the fibers. The tension amount of the back surface member 14 and the expansion / contraction member 15 is on the horizontal axis, and the tensile load is on the vertical axis. The same test piece was performed on the back surface material 14 and the expansion / contraction member 15 with the same test contents. In FIG. 5, the test result A on the expansion / contraction member 15 is shown by a solid line, and the test result B on the back surface material 14 is shown by a broken line. ing.

Comparing the test results A and B, the telescopic member 15 is stretched about three times with about half the force of the back surface material 14. Therefore, when a relatively large load is applied to a position horizontally separated from the seating sensor 7, the elastic member 15 expands while being deformed in a gentle manner, so that the deformation of the pad body 11 can be absorbed. As a result, when a load is applied to a position horizontally separated from the seating sensor 7, it is possible to suppress the transmission of the load from the pad body 11 to the pressure receiving surface 13, so that it is difficult to transmit the load from the pressure receiving surface 13 to the seating sensor 7. can. As a result, if the load distribution is different from the load distribution when seated on the seat cushion 2, erroneous detection of the seating sensor 7 can be suppressed.

Further, since the back surface material 14 is attached to the back surface 12 of the pad body 11 other than the portion where the elastic member 15 is arranged, the back surface 12 of the pad body 11 can be reinforced. Further, the contact portion 15a (seating sensor 7) and the back surface material 14 are at least the shortest distance L3 or more by the connecting portion 15b that connects the contact portion 15a to which the seating sensor 7 is attached and the inner peripheral edge of the opening 17 of the back surface material 14. Placed apart.

Here, when a load is applied from the pad body 11 to the back surface material 14, the back surface material 14 is displaced downward, or the back surface material 14 is pulled on both sides of the contact portion 15a, and the bottom surface of the recess 16 is displaced downward. It may happen. At this time, if the contact portion 15a (seating sensor 7) and the back surface material 14 are not separated in the horizontal direction, the load is easily transmitted from the contact portion 15a to the seating sensor 7 as the back surface material 14 is displaced. , The seating sensor 7 is likely to be erroneously detected.

On the other hand, in the present embodiment, since the contact portion 15a and the back surface material 14 are separated by the shortest distance L3 or more, a load is applied to a position horizontally separated from the seating sensor 7 and the back surface material 14 is displaced. Also, the displacement of the back surface material 14 can be absorbed by the expansion and contraction of the connecting portion 15b. As a result, it is difficult to transmit the load applied to the seating sensor 7 at a position horizontally separated from the seating sensor 7 from the back surface member 14 to the seating sensor 7 via the contact portion 15a, so that erroneous detection of the seating sensor 7 can be further suppressed.

Further, since the shortest distance L3 is set larger than the thickness L2 of the seating sensor 7, the shortest distance L3 can be sufficiently secured, and the displacement of the back surface material 14 can be easily absorbed by the expansion and contraction of the connecting portion 15b. Further, since the shortest distance L3 is set larger than the depth L1 of the recess 16 larger than the thickness L2, the shortest distance L3 can be made larger, and the displacement of the back surface material 14 can be more easily absorbed by the expansion and contraction of the connecting portion 15b. can. As a result, erroneous detection of the seating sensor 7 can be further suppressed.

Since the connecting portion 15b is overlapped on the pad body 11 side of the back surface material 14, it is difficult for the foamed stock solution to enter between the fibers of the back surface material 14 at the portion overlapping the connecting portion 15b during molding of the pad body 11. The portion of the back surface material 14 that overlaps with the connecting portion 15b is softer and more easily stretched than the back surface material 14 of the portion where the hardened soft foam exists between the fibers (other than the portion that overlaps with the connecting portion 15b). As a result, the load applied to the position laterally separated from the seating sensor 7 can be absorbed by the expansion and contraction of a part of the back surface material 14, so that the false detection of the seating sensor 7 can be further suppressed.

Since the seating sensor 7 is fixed to the pressure receiving surface 13 with an adhesive, a pin, or the like, the pressure receiving surface 13 of the portion where the seating sensor 7 is fixed (contact portion 15a) is bent, or the seating sensor 7 is fixed. It is possible to prevent wrinkles from being formed on the pressure receiving surface 13. As a result, it is possible to suppress variations in the load applied to the seating sensor 7 from the pressure receiving surface 13, so that the detection accuracy of the seating sensor 7 can be improved.

Further, since the elastic member 15 forming the pressure receiving surface 13 is integrated with the back surface 12 of the pad body 11, it is possible to prevent the pressure receiving surface 13 from bending or wrinkling on the pressure receiving surface 13. As a result, it is possible to suppress variations in the load applied to the seating sensor 7 from the pressure receiving surface 13, so that the detection accuracy of the seating sensor 7 can be further improved.

The stretchable member 15 made of the stretchable non-woven fabric is joined to the pad body 11 by a part of the soft foam that has been cured while penetrating between the fibers of the stretchable non-woven fabric. As a result, when the pad body 11 is molded, air near the pressure receiving surface 13 is easily released through the stretchable non-woven fabric, and the soft foam (foam undiluted solution) is easily spread along the stretchable non-woven fabric. Molding defects on the back surface 12 of 11 can be suppressed. As a result, the variation in the load applied to the seating sensor 7 from the pad body 11 via the pressure receiving surface 13 can be further suppressed, so that the detection accuracy of the seating sensor 7 can be further improved.

Next, a second embodiment will be described with reference to FIGS. 6 and 7. In the first embodiment, the case where the elastic member 15 is sewn around the entire inner peripheral edge of the opening 17 has been described. On the other hand, in the second embodiment, a case where the expansion / contraction member 21 is laid over and sewn to the opposite portion of the inner peripheral edge of the opening 17 will be described. The same parts as those in the first embodiment are designated by the same reference numerals, and the following description will be omitted. FIG. 6 is a bottom view of the cushion pad 20 according to the second embodiment, and FIG. 7 is a cross-sectional view of the cushion pad 20 along the line VII-VII of FIG.

As shown in FIGS. 6 and 7, the cushion pad 20 of the seat cushion includes a pad body 11 made of a soft foam such as a flexible polyurethane foam, a sheet-shaped back material 14 and an elastic member attached to the back surface 12 of the pad body 11. 21 and. The stretchable member 21 is made of a stretchable non-woven fabric having a higher elongation rate than the back surface material 14, like the stretchable member 15 in the first embodiment.

The telescopic member 21 is arranged so as to be bridged in the left-right direction to the facing portion of the inner peripheral edge of the opening 17 of the back surface member 14, and the pressure receiving surface 13 is formed inside the opening 17. Therefore, the elastic member 21 and the back surface member 14 are partially separated from each other.

The telescopic member 21 includes a contact portion 22 to which the seating sensor 7 is attached, and a pair of connecting portions 23 that connect the contact portion 22 and the inner peripheral edge of the opening 17. The connecting portion 23 is overlapped with the pad body 11 side of the back surface material 14 outside the opening 17. The overlapped portion is sewn with a thread 19 along the inner peripheral edge of the opening 17, and the elastic member 21 is joined to the back surface material 14.

In the connecting portion 23, the shortest distance L3 for connecting the inner peripheral edge of the opening 17 and the contact portion 22 is set to be larger than the depth L1 of the recess 16 and the thickness L2 of the seating sensor 7. That is, the seating sensor 7 attached to the contact portion 22 and the back surface material 14 are arranged at a distance of L3 or more, which is the shortest distance.

According to the cushion pad 20, the pressure receiving surface 13 is formed by the elastic member 21 as in the first embodiment. As a result, even if molding defects occur on the back surface 12 of the pad body 11, it is possible to suppress variations in the load applied to the seating sensor 7 from the pressure receiving surface 13, and the seating sensor is applied by applying a load horizontally away from the seating sensor 7. False detection of 7 can be suppressed. As a result, the detection accuracy of the seating sensor 7 can be improved.

Since the back surface material 14 and the contact portion 22 are connected by the connecting portion 23 so as to be bridged over the facing portions of the inner peripheral edge of the opening portion 17, the back surface material 14 around the portion connected to the connecting portion 23 The displacement can be absorbed by the expansion and contraction of the connecting portion 23. As a result, it is difficult to transmit the load applied to the seating sensor 7 at a position horizontally separated from the seating sensor 7 from the back surface member 14 to the seating sensor 7 via the contact portion 22, so that false detection of the seating sensor 7 can be further suppressed.

Further, since a part of the contact portion 22 (expandable member 21) and a part of the inner peripheral edge of the opening 17 are separated from each other, it is possible to prevent the load from being transmitted from the back surface member 14 to the contact portion 22 at the separated portion. As a result, it is possible to make it more difficult to transmit the load applied to the seating sensor 7 at a position horizontally separated from the seating sensor 7 from the back surface material 14 to the seating sensor 7 via the contact portion 22, so that false detection of the seating sensor 7 is further suppressed. can.

Further, since the telescopic member 21 to which the seating sensor 7 is attached is located at the center of the cushion pad 20 in the left-right direction, the load distribution when the occupant is seated is large on both sides of the telescopic member 21, and is large on the back surface materials 14 on both sides thereof. A load is applied. Since the telescopic member 21 is bridged to the left and right on a part of the inner peripheral edge of the opening 17, the load applied to the back surface member 14 by the seating of the occupant can be easily transmitted to the seating sensor 7 via the telescopic member 21. As a result, the accuracy of detecting the seating of the occupant by the seating sensor 7 can be improved.

Next, a third embodiment will be described with reference to FIGS. 8 and 9. In the first embodiment, the seat cushion 2 having the back surface material 14 has been described. On the other hand, in the third embodiment, the seat cushion 30 having no back surface material 14 will be described. The same parts as those in the first embodiment are designated by the same reference numerals, and the following description will be omitted. FIG. 8 is a cross-sectional view of the seat cushion 30 according to the third embodiment, and FIG. 9 is a bottom view of the cushion pad 31.

As shown in FIG. 8, the seat cushion 30 includes a frame 5 made of a rigid material such as metal or synthetic resin, a cushion pad 31 supported by the frame 5, and a cover 6 covering the surface of the cushion pad 31. A seating sensor 7 is attached to the frame 5 at a position facing the back surface of the cushion pad 31. The pressure receiving surface 32 is a predetermined region on the back surface of the cushion pad 31 facing the seating sensor 7.

When the occupant sits on the seat cushion 30 and the cushion pad 31 bends, the seating sensor 7 comes into contact with the pressure receiving surface 32. Then, when a load equal to or higher than a predetermined value is applied to the seating sensor 7 between the pressure receiving surface 32 and the frame 5, the seating sensor 7 detects that the occupant is seated on the seat cushion 30. Since the position where the seating sensor 7 and the cushion pad 31 come into contact with each other changes depending on how the cushion pad 31 bends, the pressure receiving surface 32 is set large in the front-rear and left-right directions with respect to the seating sensor 7.

The cushion pad 31 includes a pad body 11 made of a soft foam such as a flexible polyurethane foam, and a sheet-shaped elastic member 15 attached to the back surface 12 of the pad body 11. The back surface 12 of the pad body 11 includes a recess 16 recessed upward with the pressure receiving surface 32 as the bottom surface. The elastic member 15 is adhered to the entire bottom surface of the recess 16 by the adhesive 33, and the entire surface of the bottom surface of the recess 16 is the pressure receiving surface 32.

According to the seat cushion 30, the pressure receiving surface 32 is formed by the elastic member 15 as in the first embodiment. As a result, even if molding defects occur on the back surface 12 of the pad body 11, it is possible to suppress variations in the load applied to the seating sensor 7 from the pressure receiving surface 32, and the seating sensor is applied by applying a load horizontally away from the seating sensor 7. False detection of 7 can be suppressed. As a result, the detection accuracy of the seating sensor 7 can be improved.

Since the back surface 12 of the pad body 11 is not provided with the back surface material 14 (see FIG. 1) other than the portion where the telescopic member 15 is arranged, the load applied to the position horizontally separated from the seating sensor 7 is applied. , It can be done without transmitting from the back surface member 14 to the seating sensor 7 via the telescopic member 15. As a result, erroneous detection of the seating sensor 7 can be further suppressed.

Further, for example, by forming the adhesive 33 with an adhesive and imparting elasticity to the adhesive 33, the elongation rate of the elastic member 15 joined to the pad body 11 by the adhesive 33 can be increased by the elastic member 15 (expansion and contraction). It can be made larger than the elongation rate of the elastic member 15 bonded to the pad body 11 by a part of the soft foam cured in a state of penetrating between the fibers of the (sexual non-woven fabric). As a result, the load applied to a position horizontally separated from the seating sensor 7 can be easily absorbed by the expansion and contraction of the expansion / contraction member 15. As a result, it is possible to make it more difficult for the load applied to the seating sensor 7 at a position horizontally separated from the seating sensor 7 to be transmitted from the pad body 11 to the seating sensor 7 via the pressure receiving surface 32 (expandable member 15). Detection can be further suppressed.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily inferred. For example, the size, shape, and the like of the pad body 11, the back surface material 14, the telescopic members 15, 21, the seating sensor 7, and the like can be appropriately set.

In the first embodiment described above, the case where the vehicle seat 1 is a seat mounted on an automobile has been described, but the present invention is not necessarily limited to this. Of course, it is possible to apply the present invention to a seat mounted on a vehicle such as another vehicle (for example, a railroad vehicle), a ship, or an aircraft.

In the first and second embodiments, the case where the elastic members 15 and 21 are joined to the back surface material 14 by suturing has been described, but the present invention is not necessarily limited to this. As a means for joining the elastic member 15 to the back surface material 14, known means such as adhesion, fusion, binding using a stapler or a pin (tag pin) can be appropriately adopted.

In the first and second embodiments, the case where the back surface material 14 and the elastic members 15 and 21 joined to each other are fixed to the molding die and the foaming stock solution is foamed and cured to mold the pad body 11 has been described. It is not necessarily limited to this. The pad body 11 may be molded by fixing only the back surface material 14 to the molding die, and after joining the pad body 11 and the back surface material 14, the elastic members 15 and 21 may be joined to the back surface material 14 and the pad body 11. .. As a means for joining the elastic members 15 and 21 to the back surface material 14 and the pad body 11, known means such as stitching, adhesion, fusion, and binding using a stapler or a pin (tag pin) can be appropriately adopted.

In each of the above embodiments, the case where the elastic members 15 and 21 are elastic non-woven fabrics has been described, but the present invention is not necessarily limited to this. The elastic members 15 and 21 may be any sheet-like members having elasticity (particularly, the elongation rate is 150% or more). Examples of the elastic sheet-like member include a single-layer or multi-layer film having a thermoplastic elastomer layer (for example, urethane film), a slab urethane processed into a sheet shape, and a rubber sheet. ..

When using elastic members 15 and 21 made of urethane film or the like in which the foamed stock solution does not enter between the fibers, or when joining the elastic members 15 and 21 made of elastic non-woven fabric to the molded pad body 11, the elastic member 15 The elongation rate of the elastic members 15 and 21 can be increased as compared with the case where the hardened soft foam is present between the fibers of, 21. As a result, the load applied to a position horizontally separated from the seating sensor 7 can be easily absorbed by the expansion and contraction of the expansion and contraction members 15 and 21. As a result, the load applied to the position laterally separated from the seating sensor 7 can be more difficult to be transmitted from the pad body 11 to the seating sensor 7 via the telescopic members 15 and 21, so that the false detection of the seating sensor 7 can be further prevented. Can be suppressed.

In the second embodiment, the case where the telescopic member 21 is bridged to the left and right on a part of the inner peripheral edge of the opening 17 has been described, but the present invention is not necessarily limited to this. Of course, it is possible to bridge the telescopic member 21 to a part of the inner peripheral edge of the opening 17 other than the left and right (for example, front and back). Further, the expansion / contraction member 21 is not bridged over the opening 17, and the expansion / contraction member is fixed to a part of the inner peripheral edge of the opening 17 in a cantilever shape, or the expansion / contraction member is fixed over half the circumference of the inner peripheral edge of the opening 17. Of course it is possible to do it.

It is possible to combine some or all of any of the above embodiments with some or all of the other embodiments. It is also possible to omit some configurations of each of the above embodiments. For example, it is naturally possible to combine the cushion pads 10 and 20 in the first and second embodiments with the frame 5 to which the seating sensor 7 in the third embodiment is attached. In this case, the contact portions 15a and 22 with which the seating sensor 7 contacts are a part of the telescopic members 15 and 21 facing the seating sensor 7 in a no-load state.

2,30 Seat cushion 5 Frame 7 Seating sensor 10, 20, 31 Cushion pad 11 Pad body 12 Back surface 13, 32 Pressure receiving surface 14 Back surface material 15, 21 Telescopic member 15a, 22 Contact part 15b, 23 Connecting part 17 Opening L1 Deep L3 shortest distance

Claims (4)

A cushion pad having a pressure receiving surface on which a seating sensor is arranged between the frame and the cushion pad.
The pad body made of soft foam and
A sheet-like elastic member attached to the back surface of the pad body and at least partially forming the pressure receiving surface and having elasticity .
It is provided with a back surface material attached to the back surface of the pad body other than the portion where the expansion / contraction member is arranged.
The back surface material is a cushion pad characterized in that the elongation rate is smaller than the elongation rate of the expansion / contraction member. The cushion pad according to claim 1, wherein the elastic member is integrated with the back surface of the pad body. The cushion according to claim 2, wherein the stretchable member is made of a stretchable non-woven fabric and is joined to the pad body by a part of the soft foam cured while invading between the fibers of the stretchable non-woven fabric. pad. A seating sensor that contacts the pressure receiving surface is provided.
The back surface material has an opening in which the pressure receiving surface is arranged inside.
The telescopic member includes a contact portion with which the seating sensor contacts.
A connecting portion for connecting the contact portion and the inner peripheral edge of the opening is provided.
The connection portion according to any one of claims 1 to 3 , wherein the shortest distance for connecting the contact portion and the inner peripheral edge of the opening portion is set to be larger than the thickness of the seating sensor. Cushion pad.

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