Seat and cushion

Abstract

A seat is provided having a cushioning pad with reduced thickness while improving ground contact feel, and a cushioning pad with reduced thickness is provided. The seat includes a cushioning pad for supporting a seated user. The cushioning pad includes a first seat material formed of resin and a second seat material formed of resin and stacked on the lower surface side of the first seat material. The second seat material is thinner and softer than the first seat material.

Description

Technical Field

[0001] This disclosure relates to seats and cushioning pads. Background Technology

[0002] Patent Document 1 describes a flexible polyurethane foam for automotive seat cushioning and a method for its production. This flexible polyurethane foam for automotive seat cushioning is molded 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 then injecting the mixture into a mold. In this flexible polyurethane foam for automotive seat cushioning, the difference between the core density and the overall density is 5 kg / m³. 3 Or smaller. According to Patent Document 1, this soft polyurethane foam used for automotive seat cushioning provides excellent manufacturability and processability, and eliminates the bottoming sensation that occurs when automotive seat cushioning is made thinner, thus providing excellent ride comfort.

[0003] Patent document 2 describes a pad for a vehicle seat, the pad having layers of different hardness. This pad with layers of different hardness consists of two foam layers, namely, an upper layer and a lower layer, wherein the upper layer is formed of polyurethane foam and the lower layer is formed of polystyrene foam. The upper and lower layers are combined as a single unit. It is described as a preferred embodiment where the lower layer constitutes 20% to 50% of the product thickness of the pad with layers of different hardness. This pad with layers of different hardness is described as providing superior cushioning performance compared to conventional products.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-280855

[0007] Patent Document 2: Japanese Patent Application Publication No. 09-070330 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] In vehicles such as automobiles, it is essential to ensure sufficient interior space for occupants. Furthermore, for vehicles equipped with batteries, such as electric vehicles (EVs) and hybrid vehicles (HVs), it is necessary to ensure sufficient interior space to accommodate the battery. Sufficient interior space for occupants can be ensured when the cushioning pads (seat cushions) of vehicle seats can be manufactured thinner. Additionally, thinner cushioning pads also ensure space for the battery located under the seat. Therefore, it is necessary to further thin the cushioning pads.

[0010] However, reducing the thickness of the cushioning pad makes it more likely that the seated user will experience a bottoming sensation. Therefore, it is not possible to adequately balance achieving further thinning and improved bottoming sensation (i.e., eliminating the bottoming sensation) using conventional techniques such as those in Patent Documents 1 and 2. Therefore, there is a need for a seat with a thinner cushioning pad and improved bottoming sensation, and a thinner cushioning pad with improved bottoming sensation.

[0011] This disclosure was made in light of this situation, and it would be helpful to provide a seat with a thinner cushioning pad and a thinner cushioning pad with an improved bottoming feel.

[0012] Solution for solving the problem

[0013] The seats according to this disclosure include:

[0014] A cushioning pad, configured to support the seated user.

[0015] The cushioning pad includes:

[0016] A first seat material, the first seat material being formed of resin; and

[0017] The second seat material is formed of resin and stacked on the lower surface side of the first seat material.

[0018] The material of the second seat

[0019] It has a smaller thickness than the material of the first seat, and

[0020] It has a lower hardness than the first seat material.

[0021] The seats according to this disclosure include:

[0022] A cushioning pad, configured to support the seated user.

[0023] The cushioning pad includes a seat material formed from resin.

[0024] The seat material has a loss spring constant of 0.2 N / mm or greater and 0.5 N / mm or less, determined by a dynamic spring test. In this dynamic spring test, a rectangular test piece with a side length of 50 mm and a thickness of 40 mm vibrates in the thickness direction with an amplitude of ±2.5 mm at a frequency of 0.5 Hz or greater and 10 Hz or less, centered on the test piece being compressed to 30% of its thickness.

[0025] The cushioning pads according to this disclosure include:

[0026] A first seat material, the first seat material being formed of resin; and

[0027] The second seat material is formed of resin and stacked on the lower surface side of the first seat material.

[0028] The material of the second seat

[0029] It has a smaller thickness than the material of the first seat, and

[0030] It has a lower hardness than the first seat material.

[0031] The effects of the invention

[0032] According to this disclosure, a seat may be provided having a thinner cushioning pad and improved bottoming feel, and a thinner cushioning pad with improved bottoming feel may be provided. Attached Figure Description

[0033] [ Figure 1 ] Figure 1 This is a perspective view of the seat according to the implementation method.

[0034] [ Figure 2 ] Figure 2 This is a perspective view of the cushioning pad according to the embodiment.

[0035] [ Figure 3 ] Figure 3 It is along Figure 2 The diagram shows a cross-sectional view taken from line III-III.

[0036] [ Figure 4 ] Figure 4 This is an explanatory diagram of a vehicle equipped with a seat according to an embodiment.

[0037] [ Figure 5 ] Figure 5 This is an explanatory diagram of the test piece based on the experimental example.

[0038] [ Figure 6 ] Figure 6 This is an explanatory diagram for obtaining the FS curve using test pieces.

[0039] [ Figure 7 ] Figure 7 The figure shows the FS curve of the test piece in the experimental example.

[0040] [ Figure 8 ] Figure 8 The figure shows the measurement results of the loss spring constant of the substrate.

[0041] [ Figure 9 ] Figure 9 The figure shows the results of the drop-weight test on the substrate.

[0042] [ Figure 10 ] Figure 10 These are illustrations of other seat cushions. Detailed Implementation

[0043] (Description of the implementation method)

[0044] The accompanying drawings illustrate a seat and cushioning pad according to an embodiment of the present disclosure.

[0045] like Figure 1 As illustrated, the seat 200 according to this embodiment includes a cushioning pad 100 configured to support a seated user. Figure 1 This is a 3D view of seat 200 as seen from the front at a certain angle.

[0046] exist Figure 1 In this embodiment, the width direction (left-right direction) observed by a user seated in seat 200 is indicated by direction X, the front-back direction by direction Y, and the vertical direction by direction Z. According to this embodiment, the vertical direction is the same as the vertical direction. The vertical, width, and front-back directions are orthogonal to each other. In the following description, based on... Figure 1 The directions shown in the diagram are used to explain the positional relationships of the components.

[0047] like Figure 2 and Figure 3 As illustrated, the cushioning pad 100 includes a first seat material 21 formed of resin and a second seat material 22 formed of resin and stacked on the lower surface side of the first seat material 21. The second seat material 22 is thinner than the first seat material 21 and has a lower hardness than the first seat material 21. Figure 2 This is a three-dimensional view of the buffer pad 100 viewed from the front at a certain angle. Figure 3 It is along Figure 2 The diagram shows a cross-sectional view taken from line III-III.

[0048] The cushioning pad 100 improves the bottoming sensation and reduces the thickness of the seat 200. The term "bottoming sensation" refers to the sensation felt when a user sits on the seat 200 (see [link to seat 200]). Figure 1 When the cushioning pad 100 fails to adequately support the user's weight, resulting in the user experiencing a feeling of hardness rather than the cushioning properties of the cushioning pad 100, the feeling of bottoming out is generally not a pleasant experience.

[0049] The seat 200 and the cushioning pad 100 are described in detail below.

[0050] Figure 1The illustrated seat 200 is installed inside a vehicle such as a car and is configured for a user to sit on. As an embodiment, the seat 200 may include a seat 91 for a user to place their buttocks on the seat 91 to sit; a backrest 92 for a user to lean their back against; and a headrest 93 for a user to lean their head against. According to this embodiment, regarding the fore-aft direction, one side of the seat 91 when viewed from the backrest 92 is the forward direction (front, forward direction), while one side of the backrest 92 when viewed from the seat 91 is the rearward direction (rear, backward direction). The fore-aft direction in the following description is defined based on this positional relationship.

[0051] The seat 200 may include a cushioning member (seat cushion) within its cover, which serves as a buffer portion conforming to the shape of the seat 200. According to this embodiment, the seat 200 is provided with a cushioning pad 100 as a seat cushion within the seat portion 91 (within the cover of the seat 200). The cushioning pad 100 is a buffering member within the seat portion 91 that supports the user sitting on the seat portion 91.

[0052] like Figure 2 and Figure 3 As illustrated, the cushioning pad 100 includes a first pad 10 and a second seat material 22 used as a second pad.

[0053] The first cushion 10 may include a seat cushion 11 having a first seat material 21, side cushion portions 12, 12 arranged on the sides (two end portions in the width direction) of the seat cushion 11, and a back side cushion portion 13 arranged in the front-rear direction at the rear end of the seat cushion 11.

[0054] The seat cushion 11 is positioned below the portion of the seat 200 where the user's buttocks are located. The seat cushion 11 may be in the form of a plate with thickness in the vertical direction. The thickness of the seat cushion 11 may be, for example, 50 mm or more and 120 mm or less. The upper surface of the side pad portion 12 or the upper surface of the back side pad portion 13 may be positioned higher than the upper surface of the seat cushion 11.

[0055] The first pad 10 (i.e., seat cushion 11, side pad portions 12, 12 and back pad portion 13) can be integrally molded, for example, from the same substrate. An embodiment of the substrate forming the first pad 10 is resin foam. The resin foam is preferably polyurethane, but other resins may also be used. The first pad 10 can be molded, for example, by injection molding.

[0056] The first seat material 21 is part of or the entire central portion of the plate-shaped seat cushion 11. The thickness of the first seat material 21 is, for example, 30 mm or more and 60 mm or less.

[0057] The hardness of the first seat material 21 is preferably 170 N or greater and 240 N or less. According to this embodiment, "hardness" refers to a value measured according to the JASO B408-89 method, which involves determining the force applied 20 seconds after the sample has been compressed to a fixed 25% of its original thickness. When the thickness is 50 mm, the first seat material 21 more preferably has a hardness of 170 N or greater and 240 N or less.

[0058] The second seat material 22 is a plate-like member stacked with the first seat material 21 in the cushioning pad 100. Examples of substrates forming the second seat material 22 include resin foam and gel-like seat materials. When the substrate forming the second seat material 22 is resin foam, the resin foam is preferably polyurethane, but the second seat material 22 can be formed from other resins.

[0059] The second seat material 22 overlaps with the first seat material 21 in the vertical direction. Preferably, the entire surface of the second seat material 22 overlaps with the first seat material 21 in the vertical direction. The second seat material 22 is disposed below the first seat material 21. Figure 3 The illustration shows the second seat material 22 being arranged to contact the lower surface of the first seat material 21.

[0060] The second seat material 22 can be fixed to the first seat material 21 by adhesion or the like, or it can be simply stacked. Alternatively, the second seat material 22 can be fixed to the first seat material 21 by first molding the second seat material 22 into a plate shape, placing it in a mold (buffer pad 100) for injection foaming the first seat material 21, and fixing it to the first seat material 21 during molding (so-called molding).

[0061] The second seat material 22 is thinner than the first seat material 21. It is sufficient for the thickness of the second seat material 22 to be 0.10 to 0.40 times the thickness of the first seat material, but preferably 0.10 to 0.35 times, and more preferably 0.15 to 0.25 times. The thickness of the second seat material is preferably 5 mm or more and 15 mm or less.

[0062] The second seat material 22 has a lower hardness than the first seat material 21. By adjusting the balance between the hardness of the second seat material 22 and the hardness of the first seat material 21 in this way, the seat 200 (see...) can be achieved. Figure 1 Improved bottoming feel and cushioning pad 100 in ) (see) Figure 2The reduction in the total thickness of the seat cushion 11, specifically the reduction in the combined thickness of the seat cushion 11 and the second seat material 22. The hardness of the second seat material 22 is, for example, 150 N or greater and 230 N or less. Specifically, regarding the second seat material 22, it is preferable that the hardness is determined to be 150 N or greater and 230 N or less by using a test piece (for hardness measurement) cut into a 300 mm square shape and 50 mm thick and a circular plate with a diameter of 200 mm as loading members, and by measuring the force when the test piece is compressed to 25% of its thickness.

[0063] In the following description, the improved bottoming sensation in seat 200 is referred to simply as bottoming improvement. Furthermore, the reduction in the combined thickness of seat cushion 11 and the second seat material 22 is referred to simply as thinning in the following description.

[0064] The hardness of the second seat material 22 is preferably 0.75 to 0.98 times that of the first seat material 21. Setting the hardness of the second seat material 22 in this manner allows for better bottoming-out and thinning. However, when the hardness difference between the second seat material 22 and the first seat material 21 is too large—specifically, when the hardness of the second seat material 22 is too low compared to the hardness of the first seat material 21—the second seat material 22 may become over-compressed (fully compressed) when the user sits on the cushioning pad 100 (seat 200), potentially leading to a bottoming-out sensation.

[0065] The hardness of the second seat material 22 is preferably at least 5 N lower than that of the first seat material 21. By setting the hardness of the second seat material 22 in this way, better bottoming-out and thinning can be achieved.

[0066] The total thickness of the second seat material 22 and the first seat material 21 only needs to be 70 mm or less. The total thickness is preferably 60 mm or less. As a result, the cushioning pad 100 benefits from improved bottom contact. Therefore, even when the thickness of the cushioning pad 100 (specifically, the combined thickness of the seat cushion 11 and the second seat material 22) is reduced, the user will not experience a bottom contact sensation.

[0067] The second seat material 22 preferably has a suitable low-loss spring constant. Specifically, it is preferred that the second seat material 22 has a loss spring constant of 0.2 N / mm to 0.5 N / mm, determined by a dynamic spring test. In this dynamic spring test, a rectangular (square) test piece (the test piece used for the dynamic spring test) with a side length of 50 mm and a thickness of 40 mm vibrates in the thickness direction at a frequency of 0.5 Hz to 10 Hz with an amplitude of ±2.5 mm, centered on a state where the test piece is compressed to 30% of its thickness (12 mm in this embodiment). This can further improve bottoming-out performance.

[0068] When measured according to the air permeability test specified in JIS L 1096, the air permeability of the second seat material 22 in the thickness direction is 50 cm. 3 / cm 2 / s or greater and 300cm 3 / cm 2 / s or less, preferably 100cm 3 / cm 2 / s or greater and 300cm 3 / cm 2 / s or less, more preferably 125cm 3 / cm 2 / s or larger and 180cm 3 / cm 2 / s or less, and most preferably 125cm 3 / cm 2 / s or larger and 150cm 3 / cm 2 / s or less is sufficient. This reduces the damping characteristics of the cushioning pad 100 (second seat material 22) in the thickness direction, thereby improving seat comfort.

[0069] Figure 4 The illustration shows a vehicle C equipped with a seat 200 including a cushioning pad 100. Figure 4 The illustration shows the vehicle C traveling in a forward direction relative to the seat 200. In vehicle C, the cushioning pad 100 is made thinner, thus reducing the vertical thickness of the seat 200. Therefore, even when the vehicle height is lowered, for example, sufficient spaciousness of the interior space S (the height of the interior space S) can be ensured. Furthermore, the thinner cushioning pad 100 in vehicle C allows for a larger storage space Sb in the storage container M located below the seat 200 and housing the battery B.

[0070] Example

[0071] The following describes the bottoming-out improvement and thinning of seats and cushioning pads based on test cases.

[0072] In these test examples, evaluations of bottoming-out improvement were performed using test pieces (test pieces for obtaining FS curves) formed by stacking a first plate corresponding to the first seat material described in the above embodiments and a second plate corresponding to the second seat material. Each evaluation of bottoming-out feel was based on the relationship between load and deformation (FS curve), which was obtained by applying a load to the entire surface of the test piece and measuring the amount of deformation (deflection) corresponding to that load. The FS curve was obtained through a load-unload cycle of increasing and then decreasing the load.

[0073] Figure 5 and Figure 6 This is an illustration of the test piece and the FS curve obtained using the test piece. The stacked sheet 5 used as the test piece is formed by stacking a blank 51 as the first sheet and a blank 52 as the second sheet. Although in Figure 5 and Figure 6 The shape illustration is omitted, but the shape of the stacked plates 5 corresponds to the actual shape of the rear cushioning product, and the part that is the target for obtaining the FS curve (the measurement target part) is located in Figure 5 and Figure 6 The stacking state is illustrated. Figure 5 In the diagram, the thickness of the stacked plate 5 is denoted as plate thickness t, the thickness of the slab 51 is denoted as plate thickness t1, and the thickness of the slab 52 is denoted as plate thickness t2.

[0074] When obtaining the FS curve, such as Figure 6 As illustrated, a load F is uniformly applied across the entire surface of the stacked plates 5 to compress them, and then the reduction in thickness x is measured and taken as the amount of deflection. Note that the reduction in thickness x is obtained by subtracting the thickness of the stacked plates 5 under load F (plate thickness ta) from the thickness of the stacked plates 5 under load F (plate thickness t) when no load F is applied.

[0075] In these test examples, test pieces were produced by varying the combination of the first and second plates, as described in the following test examples, and the FS curves of these test pieces were obtained. These FS curves were obtained based on the JASO B408-89 method. Each test piece used was an actual rear cushioning product (plate-shaped with a 60mm target measurement portion thickness) with a thickness of 60mm, as described later. The loading member used for measurement was a "Tekken" type pressure plate, as specified in JASO B407 (Test Code for Seat Comfort of Automobile Seats). The loading member (pressure plate) was a rectangle measuring 300mm × 250mm. A test piece (simulated cushioning pad; test piece for drop weight test) in the form of an actual rear cushioning product (plate-shaped with a 60mm target measurement portion thickness) with a thickness of 60mm was molded from the substrate of the first plate, and this simulated cushioning pad was used as the test piece for Test Example 1. In addition, a rectangular recess measuring 280 mm in width, 220 mm in front-to-back direction, and 10 mm in thickness was formed on the opposite side of the simulated cushioning pad, which was located directly below the position where the buttocks would rest. Then, a second plate with a thickness matching that of the recess was assembled into the recess to produce test pieces for Experimental Examples 2 to 5.

[0076] Table 1 lists the thickness of the first plate (plate thickness t1, in mm) and the thickness of the second plate (plate thickness t2, in mm) at the target measurement location, the type and hardness (N) of the second plate substrate, and the air permeability (in cm) of the second plate component. 3 / cm 2 / s), used in the experimental examples studied in this test case (Experiments 1 to 5). In Table 1, A, B, C, and D, representing the substrates of the second board, are polyurethane resin foams of different specifications. Each substrate differs in resin backbone, degree of polymerization, molecular weight, density, etc. The first board forming the first seat material is polyurethane resin foam, and has a hardness of 205 N when the board thickness is 60 mm, and a hardness of 224 N when the board thickness is 50 mm. The hardness of the second board forming the second seat material is measured for a rectangular shape with a side length of 300 mm and a board thickness of 50 mm. Furthermore, Figure 7 The FS curves of the test pieces in these experimental examples are illustrated. Figure 7 In the diagram, the horizontal axis represents deflection in mm, while the vertical axis represents load in N.

[0077] [Table 1]

[0078]

[0079] exist Figure 7In the illustrated FS curve, the slope of the graph corresponds to the spring constant of the test piece in each experimental example.

[0080] The state in which a user sitting in a seat perceives a stronger bottoming sensation can be reformulated as a state in which the spring constant of the seat cushion has increased (e.g., increased beyond a predetermined spring constant value) when the user sits down, i.e., when a load corresponding to the user's weight is applied to the seat. In other words, a high spring constant in the seat cushion means that the body (such as the hips) is less likely to sink when the user applies their weight to the seat. In this state, the user feels the seat is hard (lacking cushioning), i.e., feels bottoming out.

[0081] When a user is seated, the typical range of load applied to the seat cushion is 400N to 600N. Therefore, when the spring constant of the seat cushion does not become excessively high within the 400N to 600N range, the user is unlikely to experience a bottoming-out sensation. Furthermore, when the spring constant varies little within the 400N to 600N range, the user will not feel the seat cushion become harder as they apply their weight to the seat, and is unlikely to experience a bottoming-out sensation. Therefore, in the following description, a lower spring constant within the 400N to 600N range and a smaller variation in the spring constant within this range are considered advantageous. In the FS curve, a high spring constant of the cushion is synonymous with a steep slope. That is, the derivative of the FS curve is the spring constant of the cushion.

[0082] Experimental Example 1 has a construction corresponding to conventional technology, wherein the buffer pad is composed of a single layer. Therefore, in the following sections, the magnitude of the spring constant and the magnitude of the variation of the spring constant are determined with reference to the results of Experimental Example 1. That is, in the range of 400N to 600N, when the spring constant is lower than that of Experimental Example 1 and the variation of the spring constant within this range is less than that of the spring constant of Experimental Example 1, the result is judged to be advantageous.

[0083] Based on the judgment of Experimental Example 1, Experimental Examples 2 and 5 are advantageous because they exhibit a lower spring constant in the range of 400N to 600N compared to Experimental Example 1, as well as a smaller variation in the spring constant within this range. In other words, Experimental Examples 2 and 5 achieve thinning and improved bottoming-out.

[0084] Experiments 3 and 4 are disadvantageous because the spring constant is higher than that of Experiment 1 in the range of 400N to 600N, and the change in the spring constant in this range is greater than the change in the spring constant of Experiment 1.

[0085] Therefore, in Table 1, Experimental Example 1, Experimental Example 3 and Experimental Example 4 are referred to as Comparative Example 1, Comparative Example 2 and Comparative Example 3, respectively, while Experimental Example 2 and Experimental Example 5 are referred to as Example 1 and Example 2, respectively.

[0086] More detailed observations of Experimental Examples 2 and 5 (Examples 1 and 2) revealed the following additional information. It can be considered that when the hardness of the second board is greater than the hardness of the first board, as in Experimental Examples 3 and 4 (Comparative Examples 2 and 3), a bottoming sensation is perceived. In contrast, it can be considered that when the hardness of the second board is appropriately lower than the hardness of the first board, as in Experimental Examples 2 and 5, a bottoming sensation is unlikely to be perceived.

[0087] Specifically, based on the results of Experimental Examples 2 and 5, it is preferable that the hardness of the second plate is 0.75 to 0.98 times that of the first plate. It is also preferable that the hardness of the second plate is 150 N or higher, and at least 5 N lower than the hardness of the first plate.

[0088] When the board is made of resin foam, the material's hardness and air permeability do not necessarily have a fixed relationship. However, within the range examined in these test examples, an air permeability of 125 cm⁻¹ is preferred. 3 / cm 2 / s or larger and 150cm 3 / cm 2 / s or less.

[0089] Furthermore, examination of the loss spring constant of the substrate material used in each experimental example showed that a loss spring constant of at least 0.2 N / mm or greater and 0.5 N / mm or less was sufficient. Figure 8 The diagram illustrates the measurement results of the loss spring constant of the sheet metal used in each experimental example. Figure 8 In the examples, A to D are the substrates of the second sheet used in Examples 2 to 5, denoted as substrate A to substrate D. Furthermore, the substrate of the first sheet used in Examples 1 to 5 is denoted as REF. Figure 8 The loss spring constant indicated is a value determined by dynamic spring testing, where each substrate is a rectangular (square) test piece with a side length of 50 mm and a thickness of 40 mm, and the test piece vibrates in the thickness direction with an amplitude of ±2.5 mm at a frequency of 0.5 Hz to 10 Hz, centered on a state where the test piece is compressed to 30% of its thickness. Figure 8 As illustrated, the loss spring constants of substrates A and D used in Experimental Examples 2 and 5 (Examples 1 and 2) are smaller than the loss spring constant of the substrate designated REF, and are at least 0.2 N / mm or greater and 0.5 N / mm or less. It is estimated that the loss spring constant is more preferably 0.2 N / mm or greater and 0.3 N / mm or less.

[0090] Based on the results confirming the spring loss constant, further drop tests were conducted to verify the characteristics of the substrate material of the sheet material used in each experimental example. First, a test piece (a simulated cushioning pad for the drop test) in the form of an actual rear cushioning product with a thickness of 60 mm (sheet shape and the thickness of the target portion is 60 mm) was molded from the substrate material of the first sheet material. Then, one of these simulated cushioning pads was used as a REF test piece. In addition, a cuboid 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 opposite side of the molded product directly below the buttocks. Substrate material A to substrate material D, cut into the shape of a sheet matching the recess, were assembled therein, and the resulting simulated cushioning pads containing substrate material A to substrate material D were designated as test pieces A to test pieces D.

[0091] A 50 kg weight was dropped freely from a height of 10 mm above the top surface (sitting surface) of these test pieces, and the acceleration of the weight was measured during the fall, as well as throughout the impact with the seating surface and the subsequent rebound. The free fall of the weight simulated the action of a user sitting in the seat. Based on this acceleration and the mass of the weight (by multiplying the acceleration by the mass of the weight), the change of the load (N) applied to the test piece by the falling weight over time was determined.

[0092] Figure 9 The results of these drop tests are illustrated. For example... Figure 9 As illustrated, for the test pieces of substrates A and D used in Experimental Examples 2 and 5 (Examples 1 and 2), the time (in milliseconds) for the applied load to the sample to increase from 400 N to 600 N was longer than that of the REF test piece (meaning a gentler slope in the graph), and this indicates that when such substrates are stacked and used in seat cushions, the resulting cushioning pad is less likely to give the user a bottoming sensation. Therefore, it can be considered that by stacking substrates with a loss spring constant of at least 0.2 N / mm or greater and 0.5 N / mm or less used in cushioning pads, a thinner cushioning pad or seat can be provided to the user, while also being less likely to result in a bottoming sensation.

[0093] Therefore, seats with thinner cushioning and improved bottom contact can be provided.

[0094] [Other Implementation Methods]

[0095] (1) According to the above embodiment, the cushioning pad 100 is described using an example in which the second seat material 22 is arranged to contact the lower surface of the first seat material 21 (see Figure 3However, in the cushioning pad 100, the second seat material 22 is not limited to being arranged to contact the lower surface of the first seat material 21. For example... Figure 10 As illustrated, in the cushioning pad 100, other sheet materials 4 that do not have cushioning properties, such as metal plates (e.g., iron plates), can be arranged between the first seat material 21 and the second seat material 22. Figure 10 The illustration shows a configuration where plate 4 is arranged to contact the lower surface of the first seat material 21 and a second seat material 22 is further arranged to contact the lower surface of plate 4. Figure 10 The diagram shows the corresponding Figure 3 The cross-section of another cushioning pad 100, wherein the configuration of the second seat material 22 is different from that described above.

[0096] (2) According to the above embodiments, the case in which the direction of travel of the vehicle C is forward relative to the seat 200 in the longitudinal direction is described by means of the example (see Figure 4 However, the relationship between the travel direction of the vehicle C and the fore-and-aft direction or orientation based on the seat 200 is not limited to this embodiment. The travel direction of the vehicle C may be a rearward direction relative to the seat 200 in the fore-and-aft direction, or the travel direction of the vehicle C may be along the width direction relative to the seat 200.

[0097] Note that, without contradiction, the structures disclosed as embodiments described above can be applied in conjunction with those disclosed as other embodiments (including other embodiments, which also apply hereinafter). The embodiments disclosed herein are illustrative, and appropriate variations can be made within the scope of this disclosure, without being limited to the disclosed embodiments.

[0098] Industrial availability

[0099] This disclosure applies to seats and cushioning pads.

[0100] Explanation of reference numerals in the attached figures

[0101] 10: First pad

[0102] 100: Cushioning Pad

[0103] 11: Seat Cushion

[0104] 12: Side padding

[0105] 13: Back side padding

[0106] 200: Seats

[0107] 21: First Seat Material

[0108] 22: Second Seat Material

[0109] 4: Board material

[0110] 5: Stacked boards

[0111] 51: Slab

[0112] 52: Slab

[0113] 91: Seat

[0114] 92: Backrest

[0115] 93: Headrest

[0116] B: Storage battery

[0117] C: Vehicle

[0118] F: Load

[0119] M: Containment Container

[0120] S: Interior space

[0121] Sb: Containment space

[0122] X: Direction

[0123] Y: direction

[0124] Z: Direction

[0125] t: Plate thickness

[0126] t1: Plate thickness

[0127] t2: Plate thickness

[0128] ta: Plate thickness

[0129] x: Decrease amount

Claims

1. A seat, comprising: A cushioning pad, configured to support the seated user. The cushioning pad includes: A first seat material, the first seat material being formed of resin; and The second seat material is formed of resin and is stacked on the lower surface side of the first seat material. The second seat material It has a smaller thickness than the first seat material, and It has a lower hardness than the first seat material.

2. The seat according to claim 1, wherein the hardness of the second seat material is 0.75 times or greater and 0.98 times or less than the hardness of the first seat material.

3. The seat according to claim 2, wherein the first seat material has a hardness of 170 N or greater and 240 N or less as determined according to the JASO B408-89 method. The second seat material has a hardness of 150 N or greater and 230 N or less, as determined by the method of JASO B408-89.

4. The seat according to claim 3, wherein the hardness of the second seat material is 5N or more lower than the hardness of the first seat material.

5. The seat according to claim 4, wherein the thickness of the second seat material is 0.10 to 0.40 times the thickness of the first seat material.

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

7. The seat according to claim 6, wherein the first seat material and the second seat material are resin foam.

8. The seat according to any one of claims 1 to 7, wherein, The second seat material has a loss spring constant of 0.2 N / mm or greater and 0.5 N / mm or less, determined by a dynamic spring test in which a rectangular test piece with a side length of 50 mm and a thickness of 40 mm vibrates in the thickness direction at a frequency of 0.5 Hz or greater and 10 Hz or less, centered on the test piece being compressed to 30% of its thickness, with an amplitude of ±2.5 mm.

9. The seat according to any one of claims 1 to 7, wherein the air permeability of the second seat material in the thickness direction is 125 cm when measured according to the air permeability test specified in JIS L 1096. 3 / cm 2 / s or larger and 150cm 3 / cm 2 / s or less.

10. A seat, comprising: A cushioning pad, configured to support the seated user. The cushioning pad comprises a seat material formed of resin, and The seat material has a loss spring constant of 0.2 N / mm or greater and 0.5 N / mm or less, determined by a dynamic spring test in which a rectangular test piece with a side length of 50 mm and a thickness of 40 mm vibrates in the thickness direction at a frequency of 0.5 Hz or greater and 10 Hz or less, with an amplitude of ±2.5 mm, centered on the test piece being compressed to 30% of its thickness.

11. A cushioning pad, comprising: A first seat material, wherein the first seat material is formed of resin; as well as The second seat material is formed of resin and is stacked on the lower surface side of the first seat material. The second seat material It has a smaller thickness than the first seat material, and It has a lower hardness than the first seat material.

Images