Seats and cushion pads

Abstract

To provide a seat having a thin cushion pad while improving bottoming out feeling, and a thin cushion pad while improving bottoming out feeling. [Solution] The seat is equipped with a cushion pad 100 that supports a seated user, and the cushion pad 100 has a first sheet material 21 formed of resin and a second sheet material 22 also formed of resin and laminated on the underside of the first sheet material 21, the second sheet material 22 being thinner than the first sheet material 21 and having a lower hardness than the first sheet material 21.

Description

[Technical field]

[0001] The present disclosure relates to a seat and a cushion pad. [Background technology]

[0002] Patent Document 1 discloses a flexible polyurethane foam for automobile seat cushions and a method for producing the same. This flexible polyurethane foam for automobile seat cushions is produced by mixing a diphenylmethane diisocyanate-based polyisocyanate and a polyol component in the presence of a catalyst, a foam stabilizer and a blowing agent, and injecting the mixture into a mold to form the foam. In this flexible polyurethane foam for automobile seat cushions, the difference between the core density and the total density of the foam is 5 kg / m 3 The following is the description: Patent Document 1 describes that this flexible polyurethane foam for automobile seat cushions is excellent in productivity and working environment, and also eliminates the bottoming-out feeling that occurs when automobile seat cushion pads are made thin, resulting in excellent ride comfort.

[0003] Patent Document 2 discloses a layered differential hardness pad for a vehicle seat. This layered differential hardness pad is composed of upper and lower foam layers, with the upper layer being made of polyurethane foam and the lower layer being made of polystyrene foam. The upper and lower layers are integrally bonded. It is considered preferable that the lower layer forms 20% to 50% of the product thickness of the layered differential hardness pad. This layered differential hardness pad is considered to have better cushioning performance than conventional products. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP2010-280855A [Patent Document 2] Japanese Patent Application Publication No. 09-070330 Summary of the Invention [Problem to be solved by the invention]

[0005] In vehicles such as automobiles, it is necessary to ensure sufficient interior space for the user to sit in. In addition, in vehicles equipped with storage batteries, such as electric vehicles (EVs) and hybrid cars (HVs), it is necessary to ensure space to accommodate the storage batteries. If the cushion pads (seat pads) in vehicle seats can be made thinner, it will be possible to ensure sufficient interior space for the user to sit in. In addition, if the cushion pads can be made thinner, it will also be possible to ensure space to install storage batteries under the seats. For this reason, there is a demand for increasingly thinner cushion pads.

[0006] However, when the cushion pad is made thinner, it is more likely that the user sitting on it will feel like they are hitting the bottom. Therefore, in the conventional technologies such as those exemplified in the above Patent Documents 1 and 2, it has not been possible to sufficiently achieve both further thinning and an improvement in the feeling of hitting the bottom (to prevent the feeling of hitting the bottom). Therefore, it is desired to provide a seat with a thinner cushion pad while improving the feeling of hitting the bottom, and a thinner cushion pad while improving the feeling of hitting the bottom.

[0007] The present disclosure has been made in consideration of the above-mentioned circumstances, and has an object to provide a seat having a thin cushion pad while improving the feeling of bottoming out, and a thin cushion pad while improving the feeling of bottoming out. [Means for solving the problem]

[0008] The seat according to the present disclosure for achieving the above object comprises: A cushion pad is provided to support a seated user, The cushion pad is A first sheet material formed of a resin; a second sheet material formed of a resin and laminated on a lower surface side of the first sheet material, The second sheet material is a thickness smaller than that of the first sheet material, The hardness is less than that of the first sheet material.

[0009] The seat according to the present disclosure for achieving the above object comprises: A cushion pad is provided to support a seated user, The cushion pad has a sheet material formed of a resin, The sheet material is a rectangular plate material with sides of 50 mm and a thickness of 40 mm used as a test piece, and the loss spring constant determined by a dynamic spring test in which the test piece is vibrated at a frequency of 0.5 Hz to 10 Hz with an amplitude of 2.5 mm up and down in the thickness direction from a state in which the thickness of the test piece is compressed by 30% is 0.2 N / mm or more and 0.5 N / mm or less.

[0010] In order to achieve the above object, the cushion pad according to the present disclosure comprises: A first sheet material formed of a resin; a second sheet material formed of a resin and laminated on a lower surface side of the first sheet material, The second sheet material is a thickness smaller than that of the first sheet material, The hardness is less than that of the first sheet material. Effect of the Invention

[0011] According to the present disclosure, it is possible to provide a seat having a thinner cushion pad while improving the feeling of bottoming out, and a thinner cushion pad while improving the feeling of bottoming out. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a perspective view of a seat according to the present embodiment. [Diagram 2] FIG. 2 is a perspective view of the cushion pad according to the embodiment. [Diagram 3] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2. [Figure 4] 1 is an explanatory diagram of a vehicle equipped with a seat according to an embodiment of the present invention; [Diagram 5] FIG. 2 is an explanatory diagram of a test piece in the examples. [Figure 6] FIG. 1 is an explanatory diagram of how an FS curve is obtained using a test piece. [Figure 7] FS curves of the test pieces in each experimental example. [Figure 8] 4 shows the measurement results of the loss spring constant of each substrate. [Figure 9] 4 shows the results of a drop weight test for each substrate. [Figure 10] FIG. 11 is an explanatory diagram of another seat pad. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] (Description of the embodiment) A seat and a cushion pad according to an embodiment of the present disclosure will be described with reference to the drawings.

[0014] As shown in Fig. 1, a seat 200 according to this embodiment includes a cushion pad 100 for supporting a seated user. Fig. 1 is a perspective view of the seat 200 as viewed obliquely from the front.

[0015] In FIG. 1, the width direction (left-right direction) as seen by a user when seated on seat 200 is indicated as direction X, the front-rear direction is indicated as direction Y, and the up-down direction is indicated as direction Z. Note that the up-down direction is the same as the vertical direction in this embodiment. The up-down direction, width direction, and front-rear direction are all perpendicular to each other. In the following explanation, the positional relationship of each part will be explained based on the directions shown in FIG. 1.

[0016] 2 and 3, the cushion pad 100 has a first sheet material 21 made of resin and a second sheet material 22 made of resin and laminated on the lower surface side of the first sheet material 21, and the second sheet material 22 is thinner and has a lower hardness than the first sheet material 21. Note that Fig. 2 is a perspective view of the cushion pad 100 as viewed from an oblique front. Also, Fig. 3 is a cross-sectional view taken along the line III-III shown in Fig. 2.

[0017] The cushion pad 100 can achieve both an improvement in the bottoming out feeling in the seat 200 and a reduction in thickness. The bottoming out feeling refers to a sensation that occurs when the cushion pad 100 is unable to fully support the weight of the user when the user sits on the seat 200 (see FIG. 1), and the user is unable to feel the cushioning properties of the cushion pad 100 and feels hardness. The state in which the user feels the bottoming out feeling is usually not a comfortable state.

[0018] The seat 200 and the cushion pad 100 will be described in detail below.

[0019] 1 is installed in the interior of a vehicle such as an automobile, and a user sits on it. The seat 200 may, for example, include a seat portion 91 on which the user sits with his or her buttocks placed, a backrest portion 92 against which the user leans back, and a headrest 93 (headrest) against which the head is rested. In this embodiment, in the front-to-rear direction, the side of the seat portion 91 as viewed from the backrest portion 92 is the front (front, forward direction), and the side of the backrest portion 92 as viewed from the seat portion 91 is the rear (rear, rear direction). The front-to-rear direction in the following description will be described based on this positional relationship.

[0020] The seat 200 may have, inside its cover, a member (seat pad) that serves as a cushion conforming to the shape of the seat 200. The seat 200 in this embodiment has a cushion pad 100 as this seat pad inside the seat portion 91 (inside the cover of the seat 200). The cushion pad 100 is a cushion member inside the seat portion 91 that supports a user seated on the seat portion 91.

[0021] As shown in Figs. 2 and 3, the cushion pad 100 includes a first pad 10 and a second sheet material 22 serving as a second pad.

[0022] The first pad 10 may have a seat pad 11 having a first sheet material 21, side pad portions 12, 12 arranged on both sides (both ends in the width direction) of the seat pad 11, and a back pad portion 13 arranged at the rear end of the seat pad 11 in the front-to-rear direction.

[0023] The seat pad 11 is disposed below the portion of the seat 200 where the user's buttocks are located. The seat pad 11 may be a plate having a thickness in the vertical direction. The thickness of the seat pad 11 is, for example, 50 mm or more and 120 mm or less. The upper surfaces of the side pad portions 12 and the back pad portion 13 may be located at a position higher than the upper surface of the seat pad 11.

[0024] The first pad 10, i.e., the seat pad 11, the side pad portions 12, 12 and the back pad portion 13, may be integrally molded from the same base material, for example. An example of the base material forming the first pad 10 is a resin foam. The resin foam is preferably polyurethane, but may be formed from other resins. The first pad 10 may be formed by, for example, injection foam molding.

[0025] The first sheet material 21 is a part of the central portion of the plate-shaped seat pad 11 or the entire seat pad 11. The thickness of the first sheet material 21 is, for example, 30 mm or more and 60 mm or less.

[0026] The hardness of the first sheet material 21 is preferably 170N or more and 240N or less. In this embodiment, the "hardness" refers to a value measured in accordance with the JASO B408-89 method, which is a method of compressing a sample by a constant 25% of its original thickness and determining the force after 20 seconds. It is more preferable that the hardness of the first sheet material 21 is 170N or more and 240N or less when the thickness is 50 mm.

[0027] The second sheet material 22 is a plate-like member laminated with the first sheet material 21 in the cushion pad 100. An example of a base material forming the second sheet material 22 is a resin foam or a gel-like sheet material. When the base material forming the second sheet material 22 is a resin foam, the resin foam is preferably polyurethane, but may be formed of other resins.

[0028] The second sheet material 22 overlaps with the first sheet material 21 in the up-down direction. It is preferable that the entire plate surface of the second sheet material 22 overlaps with the first sheet material 21 in the up-down direction. The second sheet material 22 is disposed below the first sheet material 21. FIG. 3 and the like illustrate a case in which the second sheet material 22 is disposed in contact with the lower surface of the first sheet material 21.

[0029] The second sheet material 22 may be fixed to the first sheet material 21 by adhesion or the like, or may simply be in a state of being overlapped. In addition, the second sheet material 22 may be fixed to the first sheet material 21 while molding the first sheet material 21 (so-called mold molding) by first forming the second sheet material 22 into a plate shape, and then loading the plate into a mold for injection foam molding the first sheet material 21 (cushion pad 100).

[0030] The second sheet material 22 is thinner than the first sheet material 21. The thickness of the second sheet material 22 may be 0.10 to 0.40 times the thickness of the first sheet material, preferably 0.10 to 0.35 times, and more preferably 0.15 to 0.25 times. The thickness of the second sheet material is preferably 5 mm to 15 mm.

[0031] The second sheet material 22 has a hardness smaller than that of the first sheet material 21. By adjusting the balance between the hardness of the second sheet material 22 and the hardness of the first sheet material 21 in this way, it is possible to improve the bottoming out feeling in the seat 200 (see FIG. 1) and reduce the total thickness of the cushion pad 100 (see FIG. 2), particularly the seat pad 11 and the second sheet material 22. The hardness of the second sheet material 22 is, for example, 150N or more and 230N or less. That is, the second sheet material 22 is preferably cut into a rectangular (square) shape with one side of 300 mm and a plate shape with a thickness of 50 mm as a test piece (test piece for hardness measurement), and the hardness of the test piece is preferably 150N or more and 230N or less when the test piece is compressed by 25% of its thickness using a circular plate material with a diameter of 200 mm as a loader.

[0032] In the following, the improvement of the bottoming out feeling of the seat 200 will be simply referred to as the improvement of the bottoming out feeling and will be described. Also, the reduction in the total thickness of the seat pad 11 and the second sheet material 22 will be simply referred to as the reduction in thickness and will be described.

[0033] The hardness of the second sheet material 22 is preferably 0.75 to 0.98 times the hardness of the first sheet material 21. If the hardness of the second sheet material 22 is such, it is possible to better achieve both an improvement in the bottoming out feeling and a thinner material. If the difference in hardness between the second sheet material 22 and the first sheet material 21 is too large, that is, if the hardness of the second sheet material 22 is too small compared to the hardness of the first sheet material 21, the second sheet material 22 may be crushed too much (completely compressed) when the user sits on the cushion pad 100 (seat 200), and the user may feel the bottoming out.

[0034] The hardness of the second sheet material 22 is preferably 5 N or more less than the hardness of the first sheet material 21. By making the second sheet material 22 have such a hardness, it is possible to more effectively achieve both an improvement in the bottoming out feeling and a thinner material.

[0035] The total thickness of the second sheet material 22 and the first sheet material 21 is sufficient if it is 70 mm or less. This total thickness is preferably 60 mm or less. As a result, in the cushion pad 100, due to the effect of improving the bottoming out feeling, even if the thickness of the cushion pad 100, i.e., the total thickness of the thickness of the seat pad 11 and the thickness of the second sheet material 22, is made thinner, the user will not feel the bottoming out feeling.

[0036] The second sheet material 22 preferably has a moderately small loss spring constant. Specifically, the second sheet material 22 is a test piece (dynamic spring test piece) made of a rectangular (square) plate material with a thickness of 40 mm and a side length of 50 mm, and the loss spring constant determined by a dynamic spring test in which the test piece is vibrated at a frequency (frequency) of 0.5 Hz to 10 Hz with an amplitude of 2.5 mm up and down in the thickness direction of the test piece, with the center (center of amplitude) being a state in which the test piece is compressed by 30% (in this example, compressed by 12 mm), is preferably 0.2 N / mm or more and 0.5 N / mm or less. This may further improve the bottoming out feeling.

[0037] The air permeability in the thickness direction of the second sheet material 22 is 50 cm when measured in accordance with the air permeability test specified in JIS L 1096. 3 / cm 2 / s or more 300cm 3 / cm 2 It is sufficient, and preferably 100 cm 3 / cm 2 / s or more 300cm 3 / cm 2 , and more preferably 125 cm 3 / cm 2 / s or more 180cm 3 / cm 2 , most preferably 125 cm 3 / cm 2 / s or more 150cm 3 / cm 2 / s or less. This may weaken the damping property in the thickness direction of the cushion pad 100 (second sheet material 22), improving the sitting comfort.

[0038] FIG. 4 shows a vehicle C equipped with a seat 200 equipped with a cushion pad 100. FIG. 4 illustrates an example in which the traveling direction of the vehicle C is the forward direction in the front-rear direction based on the seat 200. In the vehicle C, the cushion pad 100 is thinned, and therefore, by reducing the thickness of the seat 200 in the vertical direction, it is possible to sufficiently ensure the size of the interior space S (the height of the interior space S) even in the case of lowering the vehicle height, for example. In addition, in the vehicle C, the cushion pad 100 is thinned, and therefore, it is possible to ensure a large accommodation space Sb of the accommodation container M that accommodates the storage battery B, which is disposed below the seat 200.

[0039] (Example) The following describes the improvement of the bottoming out feeling and the thinning of the seat and the cushion pad based on the examples.

[0040] In this example, a test piece (test piece for obtaining F-S curve) was used in which a first plate material corresponding to the first sheet material described in the above embodiment and a second plate material corresponding to the second sheet material were laminated, and an evaluation was performed on the improvement of the bottoming out feeling. The evaluation of the bottoming out feeling was performed based on the relationship between the load and the amount of deformation (F-S curve) obtained by applying a load to the entire plate surface of the test piece and measuring the amount of deformation (deflection) corresponding to the load. The F-S curve was obtained by increasing and then decreasing the load back and forth.

[0041] 5 and 6 show the test piece and an explanatory diagram of how the F-S curve was obtained using the test piece. The laminated plate material 5 as the test piece is formed by laminating a slab 51, which is a first plate material, and a slab 52, which is a second plate material. Although the shape is not shown in FIGS. 5 and 6, the outer shape of the laminated plate material 5 is the shape of an actual product rear cushion, and the target portion for obtaining the F-S curve (target portion for measurement) is in the laminated state shown in FIGS. 5 and 6. In FIG. 5, the thickness of the laminated plate material 5 is shown as plate thickness t, the thickness of the slab 51 as plate thickness t1, and the thickness of the slab 52 as plate thickness t2.

[0042] When obtaining the F-S curve, as shown in Fig. 6, a load F is evenly applied to the entire surface of the laminated plate material 5 to compress the laminated plate material 5, and the amount of reduction in thickness x is obtained and used as the amount of deflection. The amount of reduction x is the thickness obtained by subtracting the thickness of the laminated plate material 5 in a state where the load F is applied to the laminated plate material 5 (plate thickness ta) from the thickness of the laminated plate material 5 in a state where the load F is not applied to the laminated plate material 5 (plate thickness t).

[0043] In this embodiment, the combination of the first plate material and the second plate material was changed as in each of the experimental examples described below to manufacture test pieces, and the F-S curves of these test pieces were obtained. The F-S curves were obtained based on the JASO B408-89 method. The test piece was a 60 mm thick, real-life rear cushion (a plate-shaped part to be measured having a thickness of 60 mm) as described below. The load element used for the measurement was an iron grinding plate of the iron grinding type defined in JASO B 407 (a cushioning test method for automobile seats). The size of the load element (iron grinding plate) was a rectangle of 300 mm x 250 mm. The base material of the first plate material was used to mold a test piece (simulated cushion pad, test piece for drop weight test) of a 60 mm thick, real-life rear cushion (a plate-shaped part to be measured having a thickness of 60 mm), and this simulated cushion pad was used as the test piece of Experimental Example 1. Furthermore, a rectangular recess measuring 280 mm in the width direction, 220 mm in the front-to-back direction, and 10 mm in thickness was formed on the back side of the simulated cushion pad directly below the buttocks, and a second plate material with a plate shape and thickness that matched this recess was fitted into it to create the test specimens for Experimental Examples 2 to 5.

[0044] Table 1 shows the thickness of the first plate (plate thickness t1, unit: mm) and the thickness of the second plate (plate thickness t2, unit: mm) of the measurement target portion in the experimental examples (Experimental Examples 1 to 5) verified in this embodiment, the type and hardness (N) of the base material of the second plate, and the air permeability (unit: cm 3 / cm 2 / s). In Table 1, A, B, C, and D, which are the base materials of the second plate material, are polyurethane resin foams with different specifications. Each base material has a different resin skeleton, degree of polymerization, molecular weight, density, etc. The first plate material forming the first sheet material is a polyurethane resin foam, and its hardness is 205N when the plate thickness is 60mm and 224N when the plate thickness is 50mm. The hardness of the second plate material forming the second sheet material is the hardness when it is a rectangle with one side of 300mm and a plate thickness of 50mm. Figure 7 shows the F-S curves of the test pieces in these experimental examples. In Figure 7, the horizontal axis is deflection (mm) and the vertical axis is load (N).

[0045] [Table 1]

[0046] In the F-S curve shown in FIG. 7, the slope of the graph corresponds to the spring constant of the test piece for each experimental example.

[0047] The state in which a user sitting in a seat feels a stronger bottoming out can be said to be a state in which the spring constant of the seat pad becomes larger (for example, larger than a predetermined spring constant) when the user sits in the seat, i.e., when a load corresponding to the user's weight is applied to the seat. In other words, the state in which the spring constant of the seat pad becomes larger is a state in which the user's body (buttocks, etc.) is less likely to sink as the user applies more weight to the seat. In such a state, the user feels that the seat is hard (poorly cushioned) (i.e., feels a bottoming out sensation).

[0048] Now, when a user sits on the seat, the typical range of the load applied to the seat pad is 400N or more and 600N or less. Therefore, if the spring constant of the seat pad is not too large when the load applied to the cushion pad is in the range of 400N or more and 600N or less, the user is less likely to feel the bottoming out. Also, if the fluctuation of the spring constant is small in the range of 400N or more and 600N or less, the user will not feel the seat pad becoming harder as the user applies his / her weight to the seat, and the user will be less likely to feel the bottoming out. Therefore, in the following, the smaller the spring constant is in the range of 400N or more and 600N or less, and the smaller the fluctuation of the spring constant in this range, the better it is judged to be. Note that a state in which the spring constant of the cushion pad is large in the F-S curve is synonymous with a state in which the slope of the curve is large. In other words, the derivative value of the F-S curve is the spring constant of the cushion pad.

[0049] Experimental example 1 has a single layer cushion pad, which corresponds to the prior art. Therefore, in the following, the magnitude of the spring constant and the magnitude of the fluctuation in the spring constant are judged based on the results of Experimental example 1. In other words, the smaller the spring constant is than the results of Experimental example 1 in the range of 400N to 600N, and the smaller the fluctuation in the spring constant is in this range than the results of Experimental example 1, the better the product is judged to be.

[0050] Judging based on Experimental Example 1, the experimental examples that have a smaller spring constant than the result of Experimental Example 1 in the range of 400N or more and 600N or less, and also have a smaller fluctuation in the spring constant in this range than the result of Experimental Example 1, i.e., the good experimental examples, are Experimental Example 2 and Experimental Example 5. That is, in Experimental Example 2 and Experimental Example 5, a thinner wall is achieved while improving the bottoming out feeling.

[0051] Experimental Examples 3 and 4 are not good because the spring constants are larger than the results of Experimental Example 1 in the range of 400N to 600N and the fluctuation in the spring constant in this range is larger than the results of Experimental Example 1.

[0052] Therefore, in Table 2, Experimental Examples 1, 3, and 4 are referred to as Comparative Examples 1, 2, and 3, and Experimental Examples 2 and 5 are referred to as Example 1 and Example 2.

[0053] A closer look at Experimental Examples 2 and 5 (Examples 1 and 2) reveals the following: It is believed that when the hardness of the second plate material is greater than that of the first plate material, as in Experimental Examples 3 and 4 (Comparative Examples 2 and 3), a bottoming-out sensation is felt. In contrast, when the hardness of the second plate material is moderately smaller than that of the first plate material, as in Experimental Examples 2 and 5, it is believed that the bottoming-out sensation is less felt.

[0054] Based on the results of Experimental Examples 2 and 5, it is preferable that the hardness of the second plate be 0.75 to 0.98 times that of the first plate, and that the hardness of the second plate be 150 N or more, which is 5 N or more less than that of the first plate.

[0055] When the plate material is a resin foam, the hardness and air permeability of the plate material do not necessarily have a certain relationship. However, within the range confirmed in this example, the air permeability is 125 cm 3 / cm 2 / s or more 150cm 3 / cm 2 It seems that it is best to keep it below / s.

[0056] Furthermore, when the loss spring constant of the base material of the plate material used in each experimental example was confirmed, it was found that the loss spring constant should be at least 0.2 N / mm or more and 0.5 N / mm or less. Figure 8 shows the measurement results of the loss spring constant of the plate material used in each experimental example. In Figure 8, the base materials A to D of the second plate material used in Experimental Examples 2 to 5 are shown as base materials A to D. Also, the base material of the first plate material used in Experimental Examples 1 to 5 is shown as REF. The loss spring constant shown in Figure 8 is a value obtained by a dynamic spring test in which each base material is a rectangular (square) 50 mm on a side and a plate material test piece with a thickness of 40 mm, and the test piece is vibrated at a frequency (frequency) of 0.5 Hz to 10 Hz with an amplitude of 2.5 mm up and down in the thickness direction of the test piece centered on a state in which the thickness of the test piece is compressed by 30%. 8, the loss spring constants of the substrates A and D used in Experimental Examples 2 and 5 (Examples 1 and 2) are smaller than that of the substrate used as the REF, and are at least 0.2 N / mm to 0.5 N / mm. It is estimated that the loss spring constant is more preferably 0.2 N / mm to 0.3 N / mm.

[0057] With reference to the above-mentioned loss spring constant confirmation result, the following drop weight test was further performed to confirm the characteristics of the base material of the plate material used in each experimental example. First, a test piece (simulated cushion pad, test piece for drop weight test) of a real rear cushion (a plate-like part to be measured having a thickness of 60 mm) was molded using the base material of the first plate material. Then, this simulated cushion pad was used as the test piece of REF. Furthermore, a rectangular parallelepiped recess of 280 mm in width, 220 mm in front-rear direction, and 10 mm in thickness was formed on the back side directly below the buttocks of this molded product, and base materials A to D cut into a plate shape that matches this recess were fitted, and the simulated cushion pads into which these base materials A to D were fitted were used as test pieces A to D.

[0058] A 50 kg weight was then allowed to freely fall from a position 10 mm above the top surface (seat surface) of these test pieces, and the acceleration of the weight was measured while it was falling and while it was bouncing back after hitting the seat surface. The free fall of the weight simulated the motion of a user sitting down on a seat. Based on this acceleration and the mass of the weight (acceleration multiplied by the mass of the weight), the change over time in the load (N) applied to the test pieces by the fall of the weight was calculated.

[0059] The results of these drop weight tests are shown in Fig. 9. As shown in Fig. 9, in the test pieces of the substrate A and substrate D used in Experimental Example 2 and Experimental Example 5 (Example 1 and Example 2), the time (msec) elapsed from when the load applied to the test piece reached 400N to when it reached 600N was longer than that of the REF test piece (i.e., the slope of the graph was gentler), and it can be seen that when such substrates are laminated and used in a seat pad, the cushion pad is unlikely to give the user a feeling of bottoming out. Therefore, it is considered that by laminating substrates with a loss spring constant of at least 0.2N / mm or more and 0.5N / mm or less and using them in a cushion pad, it is possible to provide a cushion pad and seat that are thin but unlikely to give the user a feeling of bottoming out.

[0060] In this manner, it is possible to provide a seat having a thinner cushion pad while improving the feeling of bottoming out, and a thinner cushion pad while improving the feeling of bottoming out.

[0061] [Another embodiment] (1) In the above embodiment, the second sheet material 22 is disposed in contact with the lower surface of the first sheet material 21 in the cushion pad 100 (see FIG. 3). However, the second sheet material 22 is not limited to being disposed in contact with the lower surface of the first sheet material 21 in the cushion pad 100. As shown in FIG. 10, the cushion pad 100 may have another plate material 4 that does not have cushioning properties, such as a metal plate material (e.g., an iron plate), disposed between the first sheet material 21 and the second sheet material 22. FIG. 10 illustrates an example in which the plate material 4 is disposed in contact with the lower surface of the first sheet material 21, and the second sheet material 22 is disposed in contact with the lower surface of the plate material 4. FIG. 10 illustrates a cross section corresponding to FIG. 3 in another cushion pad 100 in which the second sheet material 22 is disposed differently as described above.

[0062] (2) In the above embodiment, the traveling direction of the vehicle C is described as being forward in the fore-and-aft direction when the seat 200 is used as a reference (see FIG. 4). However, the relationship between the traveling direction of the vehicle C and the fore-and-aft direction and their orientation when the seat 200 is used as a reference is not limited to this. The traveling direction of the vehicle C may be rearward in the fore-and-aft direction when the seat 200 is used as a reference, or the traveling direction of the vehicle C may be along the width direction when the seat 200 is used as a reference.

[0063] The configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, unless a contradiction occurs. In addition, the embodiments disclosed in this specification are merely examples, and the embodiments of the present disclosure are not limited thereto, and can be appropriately modified within the scope of the purpose of the present disclosure. [Industrial Applicability]

[0064] The present disclosure is applicable to seats and cushion pads. [Explanation of symbols]

[0065] 10: First pad 100: Cushion pad 11: Seat pad 12: Side pad section 13: Back pad 200: Seats 21: First sheet material 22: Second sheet material 4: Plate material 5: Laminated board material 51: Slab 52: Slab 91: Seat part 92: Backrest 93: Head rest B: Storage battery C: Vehicle F: Load M: Storage container S:Indoor space Sb: Storage space X: Direction Y : Direction Z: Direction t: plate thickness t1: Plate thickness t2: plate thickness ta: plate thickness x :Decrease amount

Claims

1. A cushion pad is provided to support a seated user, The cushion pad is A first sheet material formed of a resin; a second sheet material formed of a resin and laminated on a lower surface side of the first sheet material, The second sheet material is a thickness smaller than that of the first sheet material, The hardness is smaller than that of the first sheet material, A seat in which a loss spring constant is determined to be 0.2 N / mm or more and 0.3 N / mm or less, using a rectangular plate material with a thickness of 40 mm as a test piece, and vibrating the test piece at a frequency of 0.5 Hz to 10 Hz with an amplitude of 2.5 mm up and down in the thickness direction from a state in which the thickness of the test piece is compressed by 30% as the center.

2. A cushion pad is provided to support a seated user, The cushion pad is A first sheet material formed of a resin; a second sheet material formed of a resin and laminated on a lower surface side of the first sheet material, The second sheet material is a thickness smaller than that of the first sheet material, The hardness is smaller than that of the first sheet material, The seat, wherein the second sheet material has an air permeability in a thickness direction thereof, when measured in accordance with an air permeability test specified in JIS L 1096, of 130 cm 3 / cm 2 / s or more and 144 cm 3 / cm 2 / s or less.

3. 3. The seat according to claim 1, wherein the hardness of the second sheet material is 0.75 to 0.98 times the hardness of the first sheet material.

4. The first sheet material has a hardness of 170N or more and 240N or less, as measured in accordance with JASO B408-89 method; The seat according to claim 3, wherein the second sheet material has a hardness of 150N or more and 230N or less, as determined in accordance with JASO B408-89 method.

5. The seat according to claim 4, wherein the hardness of the second sheet material is at least 5 N smaller than the hardness of the first sheet material.

6. The seat according to claim 5 , wherein the thickness of the second sheet material is 0.10 to 0.40 times the thickness of the first sheet material.

7. The thickness of the first sheet material is 30 mm or more and 60 mm or less, The seat according to claim 6, wherein the second sheet material has a thickness of 5 mm or more and 15 mm or less.

8. The seat according to claim 7 , wherein the first sheet material and the second sheet material are made of a resin foam.

9. The second sheet material has a thickness direction air permeability of 130 cm when measured in accordance with the air permeability test specified in JIS L 1096. ３ / cm ２ / s or more 144cm ３ / cm ２ 2. The seat of claim 1, wherein the seat width is equal to or less than 1 / s.

10. A first sheet material formed of a resin; a second sheet material formed of a resin and laminated on a lower surface side of the first sheet material, The second sheet material is a thickness smaller than that of the first sheet material, The hardness is smaller than that of the first sheet material, The cushion pad has a loss spring constant of 0.2 N / mm or more and 0.3 N / mm or less, as determined by a dynamic spring test in which a test piece is made of a rectangular plate material with a thickness of 40 mm and a center of the thickness of the test piece compressed by 30%, and is vibrated with an amplitude of 2.5 mm up and down in the thickness direction at a frequency of 0.5 Hz to 10 Hz.

11. A first sheet material formed of a resin; a second sheet material formed of a resin and laminated on a lower surface side of the first sheet material, The second sheet material is a thickness smaller than that of the first sheet material, The hardness is smaller than that of the first sheet material, The second sheet material has an air permeability in a thickness direction thereof, which is measured in accordance with the air permeability test specified in JIS L 1096 and is 130 cm 3 / cm 2 / s or more and 144 cm 3 / cm 2 / s or less.

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