Seat cushion, vehicular seat and suppression method for erroneous pedalling

Abstract

To provide a seat cushion enabling suppression of confusion of an accelerator with a brake, and to provide a vehicular seat including the seat cushion.SOLUTION: A seat cushion 10 comprises: a seat cushion pad 18 which can support the hip and thigh part of a driver; a variable elastic soft material 26 disposed in a seat front part of the seat cushion pad 18, and at an accelerator side in a seat right-left direction, and varied in an elastic modulus according to the strength of a magnetic field; and an electric magnet 28 applying a magnetic field to the variable elastic soft material 26 at one of timings of retreat of a vehicle, and continuation for a fixed time of slow speed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a seat cushion, a vehicle seat, and a method for preventing misstepping. [Background technology]

[0002] The following Patent Document 1 discloses a variable elasticity soft material whose elastic modulus changes in response to a magnetic field. The variable elasticity soft material changes its elastic modulus from a soft state to a hard state by adjusting the strength of the magnetic field. The following Patent Document 1 describes the molecular structural formula, the type of magnetic particles, etc., but does not disclose a specific method of use. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-210311 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in vehicles, people sometimes mistakenly step on the accelerator instead of the brake. In particular, as people age, their hip joints tend to open up, so they may mistakenly step on the accelerator when they should be stepping on the brake.

[0005] In consideration of the above, an object of the present invention is to provide a seat cushion, a vehicle seat, and a method for preventing misapplication of the accelerator and brake pedals. [Means for solving the problem]

[0006] The seat cushion of the present invention described in claim 1 comprises a seat cushion pad configured to support the driver's buttocks and thighs, a variable elastic portion arranged at the front of the seat cushion pad and on the accelerator side in the left-right direction of the seat, the variable elastic portion having an elastic modulus that changes depending on the strength of any of an applied magnetic field, voltage or air pressure, and an addition portion configured to be able to add any of the magnetic field, voltage or air pressure to the variable elastic portion at least one of the timings when the vehicle is reversing or when slowing down for a certain period of time.

[0007] According to the present invention described in claim 1, the additional portion applies either a magnetic field, voltage or air pressure to the variable elastic portion at least when the vehicle is reversing or when the vehicle continues to move slowly for a certain period of time, thereby hardening the variable elastic portion.

[0008] In general, drivers are likely to mistake the accelerator for the brake when driving backward or when the vehicle has been moving slowly for a certain period of time. When the driver depresses the accelerator, a load is applied to the seat cushion pad from the front of the thigh on the accelerator side in the left-right direction of the seat.

[0009] The variable elasticity soft material is disposed in the front part of the seat cushion pad and on the accelerator side in the left-right direction of the seat. In other words, the variable elasticity soft material is disposed on the outer side and lower side in the left-right direction of the seat with respect to the front part of the thigh of the driver's leg on the accelerator side when the driver is naturally seated on the seat cushion. When the variable elasticity soft material becomes hard, the repulsive force transmitted to the driver's leg on the accelerator side via the seat cushion becomes stronger in that part. This makes it difficult for the driver to open the leg on the accelerator side and press the accelerator. Therefore, there is no foreign body sensation in the leg during normal driving, and the variable elasticity soft material becomes hard in a situation where there is a possibility of mis-pressing the accelerator, thereby achieving both driving operability and suppression of mis-pressing.

[0010] The seat cushion of the present invention described in claim 2 is the invention described in claim 1, in which the variable elasticity portion is a variable elasticity soft material whose elastic modulus changes depending on the strength of the applied magnetic field, and the additional portion is an electromagnet configured to be able to apply a magnetic field to the variable elasticity soft material.

[0011] According to the seat cushion of the present invention described in claim 2, a magnetic field is applied to the variable elasticity soft material by the electromagnet at least when the vehicle is moving backwards or slowly for a certain period of time, causing the variable elasticity soft material to become hard. This makes it possible to prevent the driver from accidentally stepping on the accelerator instead of the brake with a simple structure.

[0012] The seat cushion according to the present invention as set forth in claim 3 is the invention as set forth in claim 2, wherein the variable elasticity soft material is formed in a sheet shape.

[0013] According to the present invention as set forth in claim 3, a wide surface can be secured using a small amount of material, and therefore a repulsive force can be applied widely to the thighs of the driver on the accelerator side in the left-right direction of the seat using a small amount of material.

[0014] The seat cushion of the present invention as described in claim 4 is the invention as described in claim 2, in which the variable elastic soft material is arranged at an incline so as to have an upward gradient as it moves toward the outside in the seat width direction when viewed from the front-to-rear direction of the seat.

[0015] According to the present invention described in claim 4, the variable elasticity soft material arranged at an angle causes the driver's thighs on the accelerator side in the left-right direction of the seat to receive a repulsive force from the seat cushion in the seat upward and inward in the seat width direction. This makes it even more difficult for the driver's legs on the accelerator side in the left-right direction of the seat to open, making it difficult for the driver to depress the accelerator.

[0016] The seat cushion of the present invention described in claim 5 is the invention described in claim 2, and comprises a seating portion located in the center of the seat width direction, and a pair of left and right side support portions located on both sides of the seating portion in the seat width direction and formed to protrude above the seating portion, and the variable elastic soft material is arranged across the seating portion and the side support portions on the accelerator side in the left-right direction of the seat when viewed from above the seat.

[0017] According to the present invention described in claim 5, the pair of left and right side support parts are raised higher than the seating part. Therefore, when the driver is naturally seated, the driver's legs on the accelerator side in the left and right direction of the seat are arranged inside the seat width direction of the side support parts on the accelerator side in the left and right direction of the seat and above the seating part. Here, the variable elastic soft material is arranged across the seating part and the side support parts on the accelerator side in the left and right direction of the seat when viewed from the upper side of the seat. Therefore, when the variable elastic soft material becomes hard, a repulsive force acts on the driver's thighs on the accelerator side in the left and right direction of the seat from the seating part and the side support parts on the accelerator side in the left and right direction of the seat toward the inside and upper side in the seat width direction. As a result, the driver's legs on the accelerator side in the left and right direction of the seat are less likely to open outward in the seat width direction and to sink toward the lower side of the seat. Therefore, it becomes even more difficult for the driver to step on the accelerator.

[0018] The seat cushion according to the present invention as set forth in claim 6 is the invention as set forth in claim 2, in which a plurality of the electromagnets are disposed on the seat lower side of the variable elasticity soft material.

[0019] According to the present invention as set forth in claim 6, a wide range and strong magnetic field can be applied to the variable elasticity soft material by using a plurality of electromagnets. In addition, since the electromagnets are disposed below the variable elasticity soft material, it is possible to prevent the electromagnets from giving a foreign body sensation to the driver.

[0020] The vehicle seat of the present invention described in claim 7 has a seat back configured to support the back of a driver, and a seat cushion described in any one of claims 1 to 6, the rear end of which is connected to a lower end of the seat back.

[0021] According to the present invention as set forth in claim 7, the driver's back is supported by the seat back. The driver's buttocks and thighs are supported by the seat cushion. In this case, in the seat cushion, at least one of the timings when the vehicle is moving backwards and when slowing down continues for a certain period of time, one of a magnetic field, a voltage, and air pressure is applied to the variable elastic portion, and the variable elastic portion becomes hard. When the variable elastic portion becomes hard, the repulsive force from the seat cushion to the driver's thighs on the accelerator side in the left-right direction of the seat becomes stronger. This makes it difficult for the driver's legs on the accelerator side in the left-right direction of the seat to open outward in the seat width direction, making it difficult for the driver to step on the accelerator.

[0022] The method for preventing pedal misapplication according to the present invention, described in claim 8, applies any one of the magnetic field, voltage, and air pressure to the variable elastic portion of the seat cushion described in any one of claims 1 to 6 at at least one of the timings when the vehicle is reversing and when slowing down continues for a certain period of time.

[0023] According to the present invention described in claim 8, at least one of the timings when the vehicle is moving backward and when the vehicle is moving slowly for a certain period of time, a magnetic field, a voltage, or air pressure is applied to the variable elasticity part of the seat cushion, and the variable elasticity part becomes hard. When the variable elasticity part becomes hard, the repulsive force from the seat cushion to the thighs of the driver on the accelerator side in the left-right direction of the seat becomes stronger. This makes it difficult for the driver's legs on the accelerator side in the left-right direction of the seat to open outward in the seat width direction, making it difficult for the driver to step on the accelerator. Effect of the Invention

[0024] As described above, the seat cushion according to the present invention as set forth in claim 1 has an excellent effect of preventing the driver from accidentally stepping on the accelerator instead of the brake.

[0025] The seat cushion of the present invention described in claim 2 has the excellent effect of preventing mistaken application of the accelerator instead of the brake by using a variable elasticity soft material whose elastic modulus changes according to the strength of the magnetic field.

[0026] The seat cushion according to the present invention as set forth in claim 3 has an excellent effect of being able to effectively prevent the driver's right leg from opening at low cost.

[0027] The seat cushion according to the present invention as set forth in claim 4 has the excellent effect of being able to more effectively prevent the driver's right leg from opening wide.

[0028] The seat cushion according to the present invention as set forth in claim 4 has the excellent effect of preventing the driver's right leg from spreading out, while preventing the driver's right leg from sinking toward the accelerator.

[0029] The seat cushion according to the present invention as set forth in claim 6 has an excellent effect of being able to apply a wide range and strong magnetic field while suppressing the driver from feeling a foreign body sensation.

[0030] The vehicle seat according to the present invention as set forth in claim 7 has an excellent effect of preventing the driver from mistaking the accelerator for the brake.

[0031] The method for preventing misapplication of the present invention as set forth in claim 8 has the excellent effect of preventing the misapplication of the accelerator and the brake. [Brief description of the drawings]

[0032] [Figure 1] 1 is a front perspective view of a vehicle seat including a seat cushion according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a front view of the seat cushion shown in FIG. [Diagram 3]FIG. 2 is a plan view of the seat cushion shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] A seat cushion 10 according to one embodiment of the present invention and a vehicle seat 12 including the seat cushion will be described below with reference to Figures 1 to 3. Note that arrows FR, UP, LH, and RH shown as appropriate in each figure indicate the seat front side, seat upper side, seat width direction left side, and seat width direction right side of the vehicle seat 12. Furthermore, when the front-rear, up-down, and left-right directions are used in the following description unless otherwise specified, they respectively indicate front-rear in the seat front-rear direction, up-down in the seat up-down direction, and left-right in the seat left-right direction (width direction).

[0034] FIG. 1 shows a perspective view of a vehicle seat 12 as viewed from the left front side of the seat. The vehicle seat 12 is mounted on a driver's seat of a vehicle (not shown). The vehicle seat 12 includes a seat cushion 10 capable of supporting the buttocks H and thighs T of a driver D (see FIG. 3), a seat back 14 capable of supporting the back (not shown) of the driver D, and a headrest 16 capable of supporting the head (not shown) of the driver D. The seat back 14 is connected to a rear end of the seat cushion 10 so as to be able to tilt. The headrest 16 is connected to an upper end of the seat back 14.

[0035] The seat cushion 10 includes a seat cushion frame (not shown) that forms the framework, and a seat cushion pad 18 that is attached to the seat cushion frame and is made of elastic foamed resin, such as urethane foam.

[0036] The seat cushion pad 18 is fitted with a cover 20 which is constructed by sewing together a plurality of cover pieces made of cloth material, knit material, synthetic leather, leather, or the like.

[0037] The seat cushion pad 18 is configured to include a seating portion 22 formed in the center in the seat width direction, and a pair of left and right side support portions 24 formed on both the left and right sides of the seating portion 22 and protruding upward from the seating portion 22. The seating portion 22 includes a buttocks support portion 22A formed on the rear side of the seat capable of supporting the buttocks H of a driver D (see FIG. 3), and a thigh support portion 22B formed on the front side of the seat capable of supporting the thighs T of the driver D.

[0038] A variable elastic soft material 26 (hereinafter referred to as "soft material 26") whose elastic modulus changes according to the strength of a magnetic field is disposed on the front and right side of the seat cushion pad 18. As an example, the soft material 26 is suitably a highly elastic magnetic field responsive soft material made of a polyurethane elastomer composition disclosed in JP 2019-210311 A. Note that the variable elastic soft material is not limited to the above material, and may be any material whose elastic modulus changes according to the strength of a magnetic field.

[0039] As an example, the soft material 26 is formed in a rectangular sheet shape with the longitudinal direction being the front-rear direction of the seat. The soft material 26 is inserted into a groove (not shown) formed in the seat cushion pad 18 at a position spanning between the thigh support portion 22B of the seating portion 22 and the right side support portion 24 when viewed from above the seat. In this way, the soft material 26 is embedded in the seat cushion pad 18. Note that the variable elasticity soft material does not have to be embedded in the seat cushion pad. For example, it may be disposed between the seat cushion pad and the skin on the front surface side.

[0040] 2, the soft material 26 is disposed at an incline that increases toward the outside in the seat width direction when viewed from the seat front-rear direction. Two electromagnets 28 are disposed side by side in the approximately seat width direction below the soft material 26. The two electromagnets 28 are electrically connected to a control unit 30 provided in the seat cushion 10 by electric wires 32, respectively. The two electromagnets 28 and the electric wires 32 are inserted into grooves (not shown) formed in the seat cushion pad 18 together with the soft material 26 after the seat cushion pad 18 is molded.

[0041] The control unit 30 supplies electricity to the electromagnet 28 when the vehicle is moving backward or slowly for a certain period of time. As a result, a magnetic field is applied to the soft material 26 when the vehicle is moving backward or slowly for a certain period of time, and the soft material 26 becomes hard. In the present embodiment, the supply of electricity to the electromagnet 28 is controlled by the control unit 30 provided in the seat cushion, but this is not limiting. For example, the control unit may be provided in the seat back. Also, the control unit may be provided outside the vehicle seat. For example, the supply of electricity to the electromagnet may be controlled by an ECU (Electronic Control Unit) of the vehicle (not shown).

[0042] 3, a driver D seated on the seat cushion pad 18 is shown by a two-dot chain line. As shown in FIG. 3, the variable elasticity soft material 26 is disposed diagonally downward to the right with respect to the front part of the right thigh T of the driver D seated naturally on the seat cushion 10.

[0043] (Action of this embodiment) Next, the operation of the seat cushion 10 according to this embodiment and the vehicle seat 12 including the same will be described.

[0044] In the seat cushion 10 according to the present embodiment and the vehicle seat 12 equipped with the same, when the two electromagnets 28 are each energized, a magnetic field is applied to the variable elasticity soft material 26, and the variable elasticity soft material 26 becomes hard. As shown in FIG. 3, the variable elasticity soft material 26 is disposed diagonally downward to the right with respect to the front part of the right thigh T of the driver D who is naturally seated on the seat cushion 10. Therefore, when the variable elasticity soft material 26 becomes hard, the repulsive force transmitted to the right thigh T of the driver D via the seat cushion 10 becomes stronger in that part. For this reason, it becomes difficult for the driver D to open his right leg including the right thigh T and press the accelerator.

[0045] Furthermore, according to the seat cushion 10 of this embodiment and the vehicle seat 12 equipped with the same, a magnetic field is applied to the soft material 26 by the electromagnet 28 when a vehicle (not shown) in which the vehicle seat 12 is mounted on the driver's seat moves backward and slowly for a certain period of time. In general, drivers are likely to mistake the accelerator for the brake when the vehicle moves backward and slowly for a certain period of time. According to the seat cushion 10 of this embodiment and the vehicle seat 12 equipped with the same, the soft material 26 becomes hard in situations where the above-mentioned mistake is likely to occur, thereby effectively suppressing the mistake.

[0046] On the other hand, during normal driving, since no magnetic field is applied to the soft material 26, the soft material 26 is in a soft state. Therefore, compared with a configuration in which the seat cushion around the right thigh T is always hard or a configuration in which the seat cushion around the right thigh T is always inflated, the driver D does not feel a foreign body sensation around the right thigh T during normal driving, so that it is possible to achieve both driving operability and suppression of pedal misapplication.

[0047] Furthermore, in the seat cushion 10 according to the present embodiment and the vehicle seat 12 equipped with the same, the soft material 26 is formed in a sheet shape, so that a wide surface can be secured with a small amount of material. Therefore, a repulsive force can be applied widely to the right thigh T of the driver D with a small amount of material.

[0048] Furthermore, with the seat cushion 10 according to this embodiment and the vehicle seat 12 equipped with the same, as shown in Fig. 2, the soft material 26 arranged at an angle causes the right thigh T (see Fig. 3) of the driver D to receive a repulsive force from the seat cushion 10 in an upward and inward direction in the seat width direction (the direction of the arrow in Fig. 2). This makes it even more difficult for the driver D to open his right leg, making it more difficult for the driver D to depress the accelerator.

[0049] In addition, according to the seat cushion 10 and the vehicle seat 12 including the seat cushion 10 according to the present embodiment, the pair of left and right side support parts 24 are formed to be raised higher than the seating part 22. Therefore, when the driver D is naturally seated, the right thigh T of the driver D is disposed inside the right side support part 24 in the seat width direction and above the seating part. Here, the soft material 26 is disposed across the seating part 22 and the right side support part 24 when viewed from the upper side of the seat. Therefore, when the soft material 26 becomes hard, a repulsive force acts on the right thigh T of the driver D from the seating part 22 and the right side support part 24 toward the upper left side of the seat. As a result, the right leg including the right thigh T of the driver is less likely to open toward the right side of the seat and is less likely to sink toward the lower side of the seat. Therefore, it becomes even more difficult for the driver D to depress the accelerator.

[0050] Furthermore, according to the seat cushion 10 according to this embodiment and the vehicle seat 12 including the same, the two electromagnets 28 can apply a wide-range and strong magnetic field to the soft material 26. In addition, since the two electromagnets 28 are disposed below the soft material 26, it is possible to prevent the electromagnets 28 from giving a foreign body sensation to the driver.

[0051] In particular, the seat cushion 10 according to this embodiment and the vehicle seat 12 equipped with the same electrically change the hardness of the seat cushion 10, and therefore, compared to a configuration in which a physical push-up mechanism or a mechanism that inflates air like an air cushion is used to push back the right thigh T of the driver D inward, the seat cushion 10 has superior responsiveness and can be arranged space-efficiently. Also, compared to a physical push-up mechanism, the soft material 26 is soft during normal driving, and therefore it is possible to suppress the driver from feeling a foreign body sensation during normal driving.

[0052] [Supplementary explanation of the above embodiment] In the above embodiment, the variable elastic portion is a soft material 26 whose elastic modulus changes according to the strength of the applied magnetic field, and the magnetic field is applied by the electromagnet 28, but the present invention is not limited to this. For example, the variable elastic portion may be a member whose elastic modulus changes according to the strength of the voltage. In this case, the variable elastic portion becomes hard by the addition portion applying a voltage to the variable elastic portion at least one of the timings when the vehicle is reversing and when the vehicle is slowly moving for a certain period of time. Also, for example, the variable elastic portion may be an airbag whose elastic modulus changes according to the strength of the air pressure. In this case, the variable elastic portion becomes hard by the addition portion injecting air into the airbag to increase the air pressure at least one of the timings when the vehicle is reversing and when the vehicle is slowly moving for a certain period of time.

[0053] In the above embodiment, the control unit 30 has been described as controlling the electromagnet 28 so that the electromagnet 28 applies a magnetic field to the soft material 26 when the vehicle is moving backward and when slow driving has continued for a certain period of time, but this is not limited to the above. For example, the electromagnet 28 may apply a magnetic field to the soft material 26 only when the vehicle is moving backward. Also, the electromagnet 28 may apply a magnetic field to the soft material 26 only when slow driving has continued for a certain period of time. Furthermore, the electromagnet 28 may apply a magnetic field to the soft material 26 at other times when there are many cases of people mistaking the accelerator for the brake.

[0054] Furthermore, in the above embodiment, the soft material 26 is described as being formed in a sheet shape, but the shape of the variable elastic soft material is not limited to this. For example, the variable elastic soft material may be formed in a block shape having a thickness from the seat cushion frame to the back surface of the skin. In this case, it becomes easier to obtain a reaction force from the seat cushion frame, and the driver becomes easier to feel a change in hardness. Also, for example, the variable elastic soft material may be provided with legs that extend downward from the main body portion formed in a sheet shape and abut against the seat cushion frame. For example, the variable elastic soft material may be formed in a substantially U-shape with an open lower side when viewed from the horizontal direction. Also, for example, the variable elastic soft material may be formed in a bottomed cylindrical shape with a closed upper surface. Even when the variable elastic soft material is provided with legs in this way, it becomes easier to obtain a reaction force from the seat cushion frame, and the driver becomes easier to feel a change in hardness.

[0055] Furthermore, in the above embodiment, the soft material 26 is described as being arranged so as to be inclined upwards toward the outer side in the seat width direction when viewed from the seat front-rear direction, but this is not limited thereto. For example, the variable elasticity soft material may be arranged so as to be in a generally L-shape with the outer side in the seat width direction rising when viewed from the seat front-rear direction.

[0056] In addition, the soft material 26 has been described as being disposed across the seating portion 22 and the right side support portion 24 when viewed from above the seat, but this is not limited thereto. For example, the variable elasticity soft material may be disposed only in the side support portion.

[0057] Furthermore, although the two electromagnets 28 are described as being arranged side by side in the substantially width direction of the seat below the seat side of the soft material 26, the number and arrangement of the electromagnets are not limited to the above. For example, the number of electromagnets 28 may be one. Also, for example, the multiple electromagnets 28 may be arranged side by side in the front-rear direction of the seat.

[0058] Regarding the above embodiment, the following supplementary notes are further disclosed.

[0059] (Appendix 1) A seat cushion pad configured to be able to support the driver's buttocks and thighs; a variable elastic portion disposed on a front portion of the seat cushion pad on an accelerator side in a left-right direction of the seat, the variable elastic portion having an elastic modulus that changes in response to the strength of any one of an applied magnetic field, an applied voltage, and an applied air pressure; an application unit configured to apply any one of the magnetic field, the voltage, and the air pressure to the variable elastic unit at at least one of the timings when the vehicle is moving backward and when the vehicle is moving slowly for a certain period of time; A seat cushion having (Appendix 2) The variable elasticity portion is a variable elasticity soft material whose elastic modulus changes according to the strength of the applied magnetic field, The additional portion is an electromagnet configured to be able to apply a magnetic field to the variable elastic soft material. 2. A seat cushion as described in claim 1. (Appendix 3) The variable elastic soft material is formed in a sheet shape. 2. A seat cushion as described in Appendix 2. (Appendix 4) The variable elasticity soft material is arranged so as to have an upward gradient as it moves outward in the seat width direction when viewed from the seat front-rear direction, 4. A seat cushion according to claim 2 or 3. (Appendix 5) A seating portion disposed at a center portion in a width direction of the seat; A pair of left and right side support parts are arranged on both sides of the seating part in the seat width direction and are formed to protrude upward from the seating part, The variable elasticity soft material is disposed across the seating portion and the side support portion on the accelerator side in the left-right direction of the seat when viewed from above the seat. A seat cushion as described in any one of Supplementary Note 2 to Supplementary Note 4. (Appendix 6) The electromagnets are arranged in plurality on the lower side of the sheet of the variable elasticity soft material. A seat cushion according to any one of Supplementary Note 2 to Supplementary Note 5. (Appendix 7) A seat back configured to support the back of a driver; A seat cushion according to any one of claims 1 to 6, the seat cushion having a rear end connected to a lower end of the seat back; A vehicle seat having: (Appendix 8) At least one of the timings when the vehicle is reversing and when the vehicle is moving slowly for a certain period of time, Any one of the magnetic field, voltage, and air pressure is applied to the variable elastic portion of the seat cushion according to any one of claims 1 to 6. How to prevent missteps. [Explanation of symbols]

[0060] 10 Seat cushion 12 Vehicle seats 14 Seat back 18 Seat cushion pad 22 Seating area 24 Side support part 26 Variable elasticity soft material (variable elasticity part) 28 Electromagnet (additional part) D. Driver H Buttocks T Thigh

Claims

1. A seat cushion pad configured to be able to support the driver's buttocks and thighs; a variable elastic portion disposed on a front portion of the seat cushion pad on an accelerator side in a left-right direction of the seat, the variable elastic portion having an elastic modulus that changes in response to the strength of any one of an applied magnetic field, an applied voltage, and an applied air pressure; an application unit configured to apply any one of the magnetic field, the voltage, and the air pressure to the variable elastic unit at at least one of the timings when the vehicle is moving backward and when the vehicle is moving slowly for a certain period of time; A seat cushion having

2. The variable elasticity portion is a variable elasticity soft material whose elastic modulus changes according to the strength of the applied magnetic field, The additional portion is an electromagnet configured to be able to apply a magnetic field to the variable elastic soft material. The seat cushion according to claim 1 .

3. The variable elastic soft material is formed in a sheet shape. The seat cushion according to claim 2.

4. The variable elasticity soft material is arranged so as to have an upward gradient as it moves outward in the seat width direction when viewed from the seat front-rear direction, The seat cushion according to claim 2.

5. A seating portion disposed at a center portion in a width direction of the seat; A pair of left and right side support parts are arranged on both sides of the seating part in the seat width direction and are formed to protrude upward from the seating part, The variable elasticity soft material is disposed across the seating portion and the side support portion on the accelerator side in the left-right direction of the seat when viewed from above the seat. The seat cushion according to claim 2.

6. The electromagnets are arranged in plurality on the lower side of the sheet of the variable elasticity soft material. The seat cushion according to claim 2.

7. A seat back configured to support the back of a driver; The seat cushion according to any one of claims 1 to 6, wherein a lower end of the seat back is connected to a rear end of the seat cushion; A vehicle seat having:

8. At least one of the timings when the vehicle is reversing and when the vehicle is moving slowly for a certain period of time, Any one of the magnetic field, voltage, and air pressure is applied to the variable elastic portion of the seat cushion according to any one of claims 1 to 6. How to prevent missteps.

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