Seat cushion

Abstract

A seat cushion (10) is provided with a cushion pad (11) serving as a seat part when seated, in which a highly breathable member (12) having higher air permeability than a cushion pad member forming the cushion pad (11) is embedded in a portion of the cushion pad (11) other than a hip lower part located below the hip part when seated, and is exposed only on the bottom surface side of the cushion pad.

Description

[0001] This application is a divisional application of an application with an application date of November 22, 2017, an application number of 201780072624.6, and an invention title of Seat Cushion. Technical Field

[0002] The present disclosure relates to a seat cushion. Background Art

[0003] As a seat cushion forming a structure of a seat, for example, a seat cushion for a motor vehicle seat is known. A seat cushion for a motor vehicle seat needs to have an appropriate hardness and softness to stably maintain the sitting posture of a seated passenger while ensuring comfortable sitting, and thus is made of, for example, a foam such as soft polyurethane foam.

[0004] The body temperature of a passenger seated on a motor vehicle seat is transferred to the motor vehicle seat. In a case where heat dissipation of the seat cushion is insufficient, the transferred body temperature inevitably heats the seat cushion. Further, in a case where the motor vehicle is parked at a high outdoor temperature such as in a hot climate or the like, the motor vehicle seat reaches a high temperature as the temperature inside the motor vehicle increases, which inevitably heats the seat cushion.

[0005] When the seat cushion of a motor vehicle seat is hot, a passenger seated on the motor vehicle seat is continuously exposed to the heat of the seat cushion and feels discomfort. As a result, the riding comfort of the passenger decreases.

[0006] To solve such a situation where the foam becomes hot, for example, a pillow made of a foam and having heat dissipation cavities has been proposed (see PTL 1).

[0007] Citation List

[0008] Patent Document

[0009] PTL 1: JP 3174096 U Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] However, for example, in a case where heat dissipation cavities are formed to reduce heat in a seat cushion made of a foam, the space constructed inside the seat cushion makes it difficult to stably maintain the sitting posture of a seated passenger while ensuring comfortable sitting. In particular, the comfortable sitting inevitably decreases.

[0012] Therefore, an object of the present disclosure is to provide a seat cushion that can effectively dissipate heat without reducing the riding comfort of a seated passenger.

[0013] Solution to the Problem

[0014] The seat cushion according to the present disclosure is a seat cushion including a cushion pad configured as a seat portion when sitting, wherein a highly breathable member having higher breathability than the cushion pad member forming the cushion pad is embedded in a portion of the cushion pad other than a lower buttock portion configured to be under the buttocks when sitting, in a state of being exposed only on the back side of the cushion pad.

[0015] Effect of the Invention

[0016] Therefore, according to the present invention, a seat cushion can be provided that can effectively dissipate heat without reducing the riding comfort of the seated passenger. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In the drawings:

[0018] Figure 1 A is a perspective view schematically showing the structure of a cushion pad in a seat cushion according to one of the disclosed embodiments, cut along a front-rear direction line substantially at the center in the width direction of the cushion pad;

[0019] Figure 1 B is a cross-sectional view schematically showing the structure of a cushion pad in a seat cushion according to one of the disclosed embodiments, along the Figure 1 front-rear direction line of the cushion pad in A;

[0020] Figure 2 To show the Figure 1 temperature change over time of the cushion pads in A and 1B for the examples and comparative examples;

[0021] Figure 3A To show the Figure 1 temperature change of the cushion pads in A and 1B in the case of a change in the number of cells of the highly breathable member; and

[0022] Figure 3B To show the Figure 1 temperature change of the cushion pads in A and 1B in the case of a change in the thickness of the highly breathable member.

[0023] Explanation of Reference Signs

[0024] 10 Seat cushion; 11 Cushion pad; 11a Flat surface portion; 12 Highly breathable member; 13 Concave-shaped space DETAILED DESCRIPTION

[0025] Referring to the drawings, one of the disclosed embodiments will be described below.

[0026] As Figure 1As shown in Figures 1A and 1B, the seat cushion 10 in this embodiment includes a cushion pad 11 configured as a seat portion for a passenger to sit on and a backrest cushion (not shown) configured as a backrest for supporting the passenger's back when sitting. The seat cushion 10 is connected to a seat frame (not shown), covered with a covering material (not shown), and is installed in a vehicle such as a motor vehicle as a seat for a passenger to sit on.

[0027] In this embodiment, the high ventilation member 12 having higher air permeability than the cushion member forming the cushion 11 is embedded in the cushion 11 except for the lower buttocks portion located below the buttocks when the user sits down, while being exposed only on the back side of the cushion 11 .

[0028] The lower buttocks portion of the cushion pad 11 is the portion that supports the load on the cushion pad 11. For example, in the case where the cushion pad 11 in this embodiment is included in a seat cushion 10 installed in a motor vehicle as a seat for a passenger, the lower buttocks portion of the cushion pad 11 is the portion of the cushion pad 11 where the seated passenger's buttocks are located and includes at least the area between the portions where the seated passenger's ischial tuberosities are located. The weight of the seated passenger on the seat cushion 10 is primarily supported by the ischial tuberosities located on the flat surface portion 11a, which occupies the widthwise center portion of the cushion pad 11 and serves as the seat surface.

[0029] Herein, the “width direction” is the direction of the seat cushion 10 installed in the motor vehicle along the width direction of the motor vehicle, the “front-rear direction” is the direction of the seat cushion 10 installed in the motor vehicle along the front-rear direction of the motor vehicle, and the “up-down direction” is the direction of the seat cushion 10 installed in the motor vehicle along the up-down direction of the motor vehicle.

[0030] The cushion member forming the cushion pad 11 in this embodiment is made of a foamed synthetic resin such as polyurethane foam, for example, with a density of 45 kg / m 3 Up to 75kg / m 3 The polyurethane foam is formed without undergoing film removal treatment and has, for example, a 25% hardness of 200N / 200φ to 300N / 200φ (according to JIS K 6400-2) and an air permeability of 100cc / cm 2 / sec or less.

[0031] The high ventilation member 12 in this embodiment is formed in, for example, a transversely rectangular parallelepiped shape that substantially spans the entire width of the flat surface portion 11 a of the cushion pad 11 , and is housed in a recessed space 13 formed in the cushion pad 11 corresponding to the high ventilation member 12 .

[0032] The high ventilation member 12 in this embodiment is made of a foamed synthetic resin such as polyurethane foam, for example, with a density of 20 kg / m 3 Up to 40kg / m 3, more preferably 20 kg / m 3 to 30 kg / m 3 and is formed of a polyurethane foam having 45 cells / 25 mm or less, more preferably 25 cells / 25 mm or less, and preferably 5 cells / 25 mm or more and more preferably 10 cells / 25 mm or more. For example, the 25% hardness of the polyurethane foam is 50 N / 200φ to 90 N / 200φ (in accordance with JIS K 6400-2) and the air permeability is 150 cc / cm 2 / sec to 1000 cc / cm 2 / sec. These are the values when the highly breathable member 12 is not inserted into the cushion 11 (i.e., in its natural state and not in the following compressed state).

[0033] Since the density of the polyurethane foam is 20 kg / m 3 to 40 kg / m 3 , the heat capacity can be reduced while maintaining seating comfort and riding comfort. Since the number of cells of the polyurethane foam is 45 cells / 25 mm or less, sufficient air permeability is ensured and heat can be effectively dissipated from the seat cushion. If the density of the polyurethane foam is less than 20 kg / m 3 , the seating comfort and riding comfort are negatively affected. If the density is greater than 40 kg / m 3 , the higher heat capacity hinders heat dissipation compared to the case of using a conventional polyurethane foam. If the number of cells is greater than 45 cells / 25 mm, sufficient air permeability for heat dissipation cannot be ensured.

[0034] The polyurethane foam used as the highly breathable member 12 in this embodiment is a polyurethane foam that has undergone a defoaming treatment to remove the foaming film, that is, a polyurethane foam having only a skeleton. Such a polyurethane foam that has undergone a defoaming treatment promotes the replacement of air in the natural ventilation state compared to a polyurethane foam that has not undergone a defoaming treatment, and thus can effectively ventilate. Therefore, high air permeability of the seat cushion 10 in a typical use environment can be ensured.

[0035] The polyurethane foam used as the highly breathable member 12 in this embodiment has higher air permeability than the polyurethane foam used as the cushion member forming the cushion 11.

[0036] In this embodiment, the thickness of the high ventilation member 12 in the up-and-down direction is preferably 20% or more of the total thickness of the cushion 11 and the high ventilation member 12 at the position where the high ventilation member 12 is buried, more preferably 30% to 90% of the total thickness, and still more preferably 70% to 90% of the total thickness. The thickness of the high ventilation member 12 in the up-and-down direction in this embodiment is the thickness when no passenger is seated on the cushion 11. For example, when the thickness of the high ventilation member 12 is 50 mm, the thickness of the cushion 11 covering the high ventilation member 12, that is, the distance h from the upper surface of the high ventilation member 12 to the upper surface of the cushion 11 (see Figure 1 B) is preferably at least about 5.6 mm.

[0037] The concave-shaped space 13 in this embodiment is formed in the cushion 11 in a rectangular parallelepiped shape in the lateral direction that roughly spans the entire width of the flat surface portion 11a corresponding to the shape of the high ventilation member 12, and has an opening only on the back side of the cushion 11. The high ventilation member 12 in this embodiment is inserted into the concave-shaped space 13 of the seat cushion 10 (the cushion 11 in this embodiment) in a state compressed in the lateral direction of the top view of the high ventilation member 12. Thus, the high ventilation member 12 in this embodiment is buried in the seat cushion 10 in a state of being exposed only on the back side of the seat cushion 10.

[0038] Herein, the lateral direction of the top view of the high ventilation member 12 is the direction perpendicular to the length direction of the high ventilation member 12 in the top view. In Figure 1 B, the lateral direction of the top view of the high ventilation member 12 is the left-right direction of the drawing.

[0039] The compression ratio when compressing the high ventilation member 12 in this embodiment is preferably 20% or less of the entire length in the lateral direction of the top view of the high ventilation member 12, and more preferably 5% to 10% of the entire length.

[0040] In this embodiment, by compressing the high ventilation member 12 in the lateral direction of the top view of the high ventilation member 12 when inserting the high ventilation member 12 into the concave-shaped space 13 of the seat cushion 10 (the cushion 11 in this embodiment), deformation of the high ventilation member 12 is prevented, and it is also prevented from falling off from the concave-shaped space 13 of the seat cushion 10.

[0041] The concave-shaped space 13 in this embodiment is formed at the front end side of the portion of the thigh of the seated passenger on the flat surface portion 11a that is the seat surface (the lower leg portion of the cushion 11), that is, in the area on the front end side of the flat surface portion 11a other than the hip lower portion of the passenger.

[0042] Therefore, in the present embodiment, the highly breathable member 12 inserted into the concave portion-shaped space 13 and embedded in the cushion 11 is located on the front end side of the portion of the thigh of the seated passenger on the flat surface portion 11a serving as the seat surface (the lower leg portion of the cushion 11), that is, in the area on the front end side of the flat surface portion 11a other than the lower buttocks portion of the passenger. The lower buttocks portion, particularly the portion where the ischial tuberosity of the seated passenger is located, is the portion for supporting the weight of the passenger and is an area that affects the riding comfort of the passenger. Therefore, by arranging the highly breathable member 12 within the range of the flat surface portion 11a other than the portion where the ischial tuberosity of the passenger is located, the riding comfort of the passenger is minimally affected.

[0043] More specifically, the position of the highly breathable member 12 is preferably within the area extending from the front end of the cushion 11 and having a length of 40% of the length L in the front-rear direction of the cushion 11 (see Figure 1 B), and more preferably within the area extending from the front end of the cushion 11 and having a length of 35% of the length L. Such an area is far from the area that affects the riding comfort of the seated passenger, and thus minimally affects the riding comfort of the passenger.

[0044] The number of the highly breathable members 12 may be two or more.

[0045] Thus, in the seat cushion 10 in the present embodiment, the highly breathable member 12 having higher breathability than the cushion member forming the cushion 11 is buried only on the back side of the cushion 11 in a state of being exposed only on the front end side of the portion of the thigh of the seated passenger (the lower leg portion) on the flat surface portion 11a serving as the seat surface of the cushion 11.

[0046] Even when the temperature of the passenger sitting on the seat cushion 10 is transferred to the seat cushion 10 or when the vehicle seat reaches a high temperature as the internal temperature of the vehicle rises when the vehicle is parked in a high outdoor temperature, such as in a hot climate, the seat cushion 10 in the present embodiment having such a structure can effectively dissipate heat from the back side of the cushion 11. That is, the seat cushion 10 in the present embodiment can effectively dissipate the heat in the seat cushion 10 made of polyurethane foam, which is a material that is difficult to cool and easy to get hot, through the highly breathable member 12 of the cushion 11.

[0047] Since the thickness of the highly breathable member 12 is more than 20% of the total thickness of the cushion 11 and the highly breathable member 12 at the position where the highly breathable member 12 is buried, the heat in the cushion 11 can be effectively dissipated while ensuring the riding comfort. Therefore, heat can be further effectively dissipated from the seat cushion.

[0048] In the present embodiment, the high-ventilation member 12 is located at the front end side of the portion (lower leg) of the thigh of the seated passenger on the flat surface portion 11a that serves as the seat surface. For example, during driving, the lower leg of the flat surface portion 11a moves more than the lower buttock portion. Because of the high frequency of compression and release of the cushion 11, the pumping effect is promoted. This contributes to a significant effect of discharging the hot air inside the cushion 11 including the high-ventilation member 12 to the outside. Therefore, heat can be effectively dissipated from the cushion 11, which can make the cushion 11 easily cooled. In other words, since the high-ventilation member 12 is only embedded in the lower leg portion of the cushion 11 located under the thigh of the seated passenger, heat can be effectively dissipated from the cushion 11.

[0049] Thus, the cushion 11 in the seat cushion 10 in the present embodiment is easily cooled, and thus the seat cushion 10 can be kept from getting hot. This prevents the situation where the seated passenger feels uncomfortable due to the seat cushion 10 getting hot, so that the seating comfort of the passenger and the riding comfort of the passenger are reduced. Especially when the inside of the motor vehicle is cooled by air conditioning, the inside of the motor vehicle can be effectively cooled, and the cooling effect can be improved. The seat cushion 10 in the present embodiment is therefore more effective when the motor vehicle is parked in a hot climate or the like and the motor vehicle seat reaches a high temperature.

[0050] In addition, the high-ventilation member 12 is embedded in the cushion 11 on the front end side of the portion (lower leg) of the thigh of the passenger on the flat surface portion 11a. In the lower buttock portion, especially in the portion where the ischial tuberosity of the seated passenger is located, there is no space inside the cushion 11 made of foam, and the polyurethane foam is provided in the entire portion (lower leg) of the thigh of the passenger and the lower buttock portion of the flat surface portion 11a that serves as the seat surface. This prevents the situation where it is difficult to stably maintain the sitting posture of the seated passenger while ensuring the seating comfort due to the space formed inside the cushion 11. The seating comfort of the passenger and the riding comfort of the passenger are therefore not impaired.

[0051] Although the high-ventilation member 12 embedded in the cushion 11 is only exposed on the back side of the cushion 11 in the present embodiment, the high-ventilation member 12 can communicate with the front side (upper surface) of the cushion 11 via one or more thin communication holes.

[0052] Embodiment

[0053] Experimentally produce the cushions (examples) of the seat cushion according to the present disclosure, and compare their temperature changes over time with the comparative examples.

[0054] The cushion of the example has a structure in which the high-ventilation member 12 is embedded in the lower leg portion of the cushion (see Figure 1A and 1B). Various properties of the highly breathable member 12 are listed in Table 1. In Table 1, the total thickness represents the total thickness of the cushion 11 and the highly breathable member 12 at the position where the highly breathable member 12 is buried. For example, when the thickness of the cushion 11 is 1.5 cm and the thickness of the highly breathable member 12 is 3.5 cm, it is 5.0 cm. The measurement method for the 25% hardness refers to JIS K 6400-2, and the thickness is 50 mm.

[0055] In Example a, the highly breathable member 12 buried in the cushion is exposed only on the back side of the cushion (see Figure 1 A and 1B). Similarly, in Example b, Example c, and Comparative Example G described below, the highly breathable member 12 is exposed only on the back side of the cushion.

[0056] [Table 1]

[0057] Thickness Approximately 70% of the Total Thickness Density <![CDATA[30kg / m 3 > 25% Hardness 70N / 200φ Number of Foam Cells 16 per 25 mm Air Permeability <![CDATA[492 cc / cm 2 / sec]]>

[0058] The cushion of Comparative Example X is made only of polyurethane foam as a cushion member without the highly breathable member of the examples.

[0059] Example a (density: 30 kg / m 3 ), Example b (density: 21 kg / m 3 ), Example c (density: 40 kg / m 3 ), and the temperature (°C) change over time (minutes) inside the cushions of Comparative Example X are shown in the figure ( Figure 2 ) and listed in the table (Table 2). In Example b, the number of cells is 16 cells / 25 mm, and the thickness is about 70% of the total thickness. In Example c, the number of cells is 16 cells / 25 mm, and the thickness is about 70% of the total thickness. Examples a, b, and c have the same number of cells and the same thickness but differ in density.

[0060] [Table 2]

[0061]

[0062] As can be seen from Figure 2As can be seen from Table 2, the temperature drop of the cushion pad was 10.9 (°C) in Example a over the elapsed time of 0 to 10 (minutes) and 4.3 (°C) over the elapsed time of 10 to 15 (minutes), 7.6 (°C) in Comparative Example X over the elapsed time of 0 to 10 (minutes) and 4.0 (°C) over the elapsed time of 10 to 15 (minutes). As can be seen from Table 2, the temperature drop of the cushion pad over the elapsed time of 0 to 10 (minutes) was 12.1 (°C) in Example b and 9.0 (°C) in Example c, and the temperature drop of the cushion pad over the elapsed time of 10 to 15 (minutes) was 3.0 (°C) in Example b and 3.8 (°C) in Example c. The temperature drop after 15 (minutes) was 15.2 (°C) in Example a, 15.1 (°C) in Example b, and 12.8 (°C) in Example c, while the temperature drop after 15 (minutes) was 11.6 (°C) in Comparative Example X.

[0063] Thus, Example a using the highly breathable member 12 with a density of 30 kg / m 3 , Example b using the highly breathable member 12 with a density of 21 kg / m 3 , and Example c using the highly breathable member 12 with a density of 40 kg / m 3 of the cushion pads each achieved a lower temperature compared to the cushion pad of Comparative Example X without the highly breathable member (Example a: 41.4 °C, Example b: 41.1 °C, Example c: 43.1 °C, compared to Comparative Example X: 46.6 °C), involving an initial sharp temperature drop (Example a: 10.9 °C, Example b: 12.1 °C, Example c: 9.0 °C, compared to Comparative Example X: 7.6 °C). In particular, Example a with a density of 30 kg / m 3 and Example b with a density of 21 kg / m 3 achieved a remarkable temperature drop of more than 15 °C from the initial temperature.

[0064] Next, in the case of the change in the number of cells of the highly breathable member 12 (see ​ ) and in the case of the change in the thickness of the highly breathable member 12 (see ​ ), the temperature change of the cushion pad 11 of the seat cushion 10 according to the present disclosure (the highly breathable member 12 is buried in a portion other than the lower buttocks portion so as to be exposed only on the back side of the cushion pad) was detected (initial temperature: 60 (°C), after 15 minutes). Each value given below indicating the thickness of the highly breathable member 12 is the ratio (%) with respect to the total thickness of the cushion pad 11 and the highly breathable member 12 at the position where the highly breathable member 12 is buried.

[0065] In ​ , A is the number of cells of 20 cells / 25 mm, density of 30 kg / m3 and a sample with a thickness of about 70% of the total thickness, where B has 45 cells / 25 mm and a density of 31 kg / m 3 and a sample with a thickness of about 70% of the total thickness, and C is a seat cushion of a conventional product (molded polyurethane) without a high ventilation member.

[0066] As ​ shown, when the number of cells of the high ventilation member 12 in the buffer pad 11 is 45 cells / 25 mm or less (Samples A and B), a significant difference indicating a temperature drop of at least about 1 degree is observed compared to a conventional product (C) without a high ventilation member.

[0067] In ​ , D is a sample with a thickness of about 30% of the total thickness, 20 cells / 25 mm and a density of 29 kg / m 3 and E is a sample with a thickness of about 70% of the total thickness, 20 cells / 25 mm and a density of 29 kg / m 3 and F is a seat cushion of a conventional product (molded polyurethane) without a high ventilation member.

[0068] As ​ shown, when the thickness of the high ventilation member 12 is 20% or more of the total thickness of the buffer pad 11 and the high ventilation member 12 at the position where the high ventilation member 12 is embedded (Samples D and E), a significant difference indicating a temperature drop of at least about 2 degrees is observed compared to a seat cushion (F) of a conventional product (molded polyurethane) without a high ventilation member.

[0069] As a comparative example, a sample with a thickness of about 70% of the total thickness, 63 cells / 25 mm and a density of 45 kg / m 3 (Comparative Example G) and a sample that includes the same high ventilation member 12 as in Example a but is not exposed on the back side of the buffer pad 11, i.e., is accommodated within the buffer pad 11 (molded polyurethane) (Comparative Example H) are used to detect the change in temperature (°C) inside the buffer pad 11 over time (minutes).

[0070] [Table 3]

[0071]

[0072] As can be seen from Table 3, the temperature decrease of the cushion 11 was 6.2 (°C) in Comparative Example G from elapsed time 0 to 10 (minutes) and 2.5 (°C) from elapsed time 10 to 15 (minutes), and was 7.2 (°C) in Comparative Example H from elapsed time 0 to 10 (minutes) and 3.8 (°C) from elapsed time 10 to 15 (minutes). The temperature decrease after 15 (minutes) was 8.7 (°C) in Comparative Example G and 11.0 (°C) in Comparative Example H.

[0073] That is, in the case where the number of cells is greater than 45 cells / 25 mm and the density is greater than 40 kg / m 3 (the number of cells in Comparative Example G was 63 cells / 25 mm and the density was 45 kg / m 3 ), the temperature decrease of the cushion 11 after 15 minutes was about 8.7 (°C). This shows that in Example a where the temperature decrease after 15 minutes was about 15.2 (°C), Example b where the temperature decrease after 15 minutes was about 15.1 (°C), Example c where the temperature decrease after 15 minutes was about 12.8 (°C), Sample A where the temperature decrease after 15 minutes was about 15 (°C), Sample B where the temperature decrease after 15 minutes was about 13 (°C), Sample D where the temperature decrease after 15 minutes was about 13 (°C), and Sample E where the temperature decrease after 15 minutes was about 18 (°C), the temperature decreased significantly.

[0074] In the case where the highly ventilated member 12 was not exposed on the back side of the cushion 11 (Comparative Example H), the temperature decrease of the cushion 11 after 15 minutes was about 11.0 (°C). This shows that in Example a where the temperature decrease after 15 minutes was about 15.2 (°C), Example b where the temperature decrease after 15 minutes was about 15.1 (°C), Example c where the temperature decrease after 15 minutes was about 12.8 (°C), Sample A where the temperature decrease after 15 minutes was about 15 (°C), Sample B where the temperature decrease after 15 minutes was about 13 (°C), Sample D where the temperature decrease after 15 minutes was about 13 (°C), and Sample E where the temperature decrease after 15 minutes was about 18 (°C), the temperature decreased significantly.

[0075] Next, examples of measuring the rocking angle in the case of changing the position of the highly ventilated member 12 in the present embodiment are given in Table 4. The rocking angle is the angle at which the load element placed on the seat rocks when the seat vibrates. The smaller the rocking angle, the more comfortable the ride. In the measurement of the rocking angle, a highly ventilated member 12 with a density of 35 kg / m 3 , a number of cells of 30 cells / 25 mm, a 25% hardness of 402 N / 200φ (in accordance with JIS K6400-2), and a thickness of about 70% of the total thickness of both under the legs and under the buttocks was used.

[0076] In Table 4, under the legs (penetrating the front and back) corresponds to the following situation: the high-ventilation member is configured to extend through the cushion 11 to the front and back, and the density of the high-ventilation member located under the legs (penetrating the front and back) is 35 kg / m 3 , the number of pores is 30 per 25 mm and the 25% hardness is 514.5 N / 200φ (in accordance with JIS K 6400-2).

[0077] [Table 4]

[0078]

[0079] As can be seen from Table 4, in the case where the high-ventilation member is located under the legs in a manner that it is only exposed on the back side of the cushion, the rocking angle closer to that of Comparative Example X is maintained, and the decrease in riding stability is suppressed. In the case where the high-ventilation member is positioned to extend through the cushion to the front and back or in the case where the high-ventilation member is located under the buttocks, the rocking angle is larger and the riding stability decreases. Compared with when the high-ventilation member 12 is located under the buttocks, it is more comfortable to ride when the high-ventilation member 12 is located under the legs. Even if inserting the high-ventilation member 12 into the cushion 11 causes an uncomfortable feeling that affects the riding stability, such an uncomfortable feeling can be reduced according to the position where the high-ventilation member 12 is inserted (for example, under the legs is more desirable compared to under the buttocks).

Claims

1. A seat cushion, comprising: A cushion pad configured as a seat portion when sitting; A high-ventilation member having higher ventilation than the cushion pad member forming the cushion pad is buried only in a portion of the flat surface portion of the cushion pad serving as a seat surface, except for the lower buttock portion configured to be located under the buttocks when sitting, in a state of being exposed only on the back side of the cushion pad; No communication hole is provided to communicate the surface of the cushion pad and the high-ventilation member; The 25% hardness of the cushion pad member forming the cushion pad is 200 N / 200φ to 300 N / 200φ; The high-ventilation member is buried only in the lower leg portion of the cushion pad configured to be located under the thigh when sitting, and the high-ventilation member is formed of a polyurethane foam having a 25% hardness of 50 N / 200φ to 90 N / 200φ; The thickness of the high-ventilation member is 30% to 90% of the total thickness of the cushion pad and the high-ventilation member at the position where the high-ventilation member is buried; The high-ventilation member substantially spans the entire width of the flat surface portion of the surface of the cushion pad.

2. The seat cushion according to claim 1, wherein the high-ventilation member is inserted into the cushion pad in a state of being laterally compressed in a top view of the high-ventilation member.

3. The seat cushion according to claim 1 or 2, wherein the high-ventilation member is a polyurethane foam that has undergone a defoaming treatment.

4. The seat cushion according to claim 3, wherein the density of the polyurethane foam is 20 kg / m 3 to 40 kg / m 3 and the number of pores is 45 or less per 25 mm.

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