Vehicular seat

Abstract

SOLUTION: A vehicular seat 10 comprises a member 40A for a seat, that is constituted of a resin material containing a cellulose material. The member 40A for a seat integrally includes: a first extension part 122 and a second extension part 132 that extend by facing each other; and a reinforcement part 150. The reinforcement part 150 connects: a first intermediate section 129 from one end to the other end in an extension direction of the first extension part 122; and a second intermediate section 139 from one end to the other end in an extension direction of the second extension part 132.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle seat installed in a vehicle. [Background technology]

[0002] In response to the demand for lighter vehicles, attempts have been made to reduce the weight of various structures mounted on vehicles. For example, Japanese Patent Application Laid-Open No. 2019-38469 proposes a configuration for reducing the weight of an armrest, which is a part of a vehicle seat.

[0003] In addition, Japanese Patent Application Laid-Open Publication No. 2020-50038 discloses that sound-absorbing and insulating components installed in four-wheeled automobiles are made from cellulose material, which is lighter than metal or resin materials. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-38469 [Patent Document 2] Japanese Patent Application Publication No. 2020-50038 Summary of the Invention [Problem to be solved by the invention]

[0005] In JP 2019-38469 A, the weight of the main frame is reduced by forming a lightening hole (opening) in the main frame of the armrest. By increasing the area of ​​the opening, the main frame becomes even lighter. However, in this case, the rigidity of the main frame decreases. Furthermore, members made of lightweight materials generally have low rigidity. Therefore, if the main frame is made using a lightweight material, the rigidity of the main frame may decrease.

[0006] As can be seen from the above, there is a concern that attempts to reduce the weight of the armrest main frame will result in a decrease in the rigidity of the main frame. Similarly, there is a concern that attempts to reduce the weight of other seat components in a vehicle seat will result in a decrease in rigidity.

[0007] The present disclosure aims to solve the above-mentioned problems. [Means for solving the problem]

[0008] An aspect of the present disclosure is a vehicle seat to be mounted on a vehicle, comprising a seat component made of a resin material containing cellulose material, the seat component integrally having a first extension portion and a second extension portion extending toward each other, a first intermediate portion between one end and the other end in the extension direction of the first extension portion, and a reinforcing portion connecting a second intermediate portion between one end and the other end in the extension direction of the second extension portion. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a vehicle seat having a seat component that is lightweight yet has sufficient rigidity. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic perspective view of a vehicle seat according to this embodiment. [Figure 2] FIG. 2 is a schematic side view of the main frame (seat member) of the armrest. [Figure 3] FIG. 3 is a schematic perspective view of the main frame of the armrest. [Figure 4] FIG. 4 is a schematic plan view of the first extending portion of the main frame of the armrest as viewed from the short side direction perpendicular to the longitudinal direction. [Figure 5] FIG. 5 is an enlarged view of a main part of the main frame of the armrest. [Figure 6] FIG. 6 is a schematic side view of the base portion of the main frame of the armrest as viewed from the second surface. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] 8A and 8B are schematic side views of a main frame of an armrest according to a modified example. [Figure 9] 9A to 9C are explanatory diagrams showing the flow of the molding material in the cavity. [Figure 10] FIG. 10 is a cross-sectional view of a main part showing the flow of the molding material around the core for forming the recess. [Figure 11] 11A to 11C are explanatory diagrams showing the flow of the molding material when the gate position is different from that in FIGS. 9A to 9C. [Figure 12] FIG. 12 is a schematic side view of the operating lever (seat member) of the height brake. DETAILED DESCRIPTION OF THE INVENTION

[0011] In the following description, the "seat front-rear direction" is the same as the front-rear direction of a vehicle (for example, a four-wheeled automobile), and the "seat width direction" is the same as the left-right direction of the vehicle.

[0012] FIG. 1 is a schematic perspective view of a vehicle seat 10 according to this embodiment. In the illustrated example, the vehicle seat 10 constitutes a passenger seat of a four-wheeled automobile (right-hand drive vehicle) not shown. However, the vehicle seat 10 may be a seat other than a passenger seat. Furthermore, the vehicle seat 10 is not limited to an automobile seat installed in a four-wheeled automobile. The vehicle seat 10 may also be an aircraft seat or a railway car seat.

[0013] The vehicle seat 10 includes a seat cushion 20, a seat back 30, and an armrest 100. The armrest 100 is disposed on the right side of the seat back 30. When the vehicle seat 10 is used as a right-hand seat in a four-wheeled vehicle (a right-hand drive vehicle), the armrest 100 is disposed on the left side of the seat back 30. The armrest 100 is capable of rotating relative to the seat back 30 around a connecting shaft 90 as the center of rotation. The angle through which the armrest 100 can rotate is, for example, approximately 90° to approximately 100°.

[0014] The seat cushion 20, seat back 30, and armrest 100 support the buttocks, back, and arms of the occupant, respectively. The armrest 100 has a main frame 110A therein as an armrest frame. The seat cushion 20 is also provided with an operating lever 50 for adjusting the up and down position of the seat cushion 20.

[0015] The vehicle seat 10 includes seat members 40A and 40B made of a resin material containing a cellulose material. An embodiment in which the seat member 40A is a main frame 110A will be described below as an example.

[0016] Fig. 2 is a schematic side view of the main frame 110A, showing the main frame 110A in a position extending along the seat front-rear direction, as viewed from the right in the seat width direction.

[0017] As shown in FIG. 2, the main frame 110A integrally includes a shaft connecting portion 112 and a frame body 120 extending from the shaft connecting portion 112. In the illustrated example, the shaft connecting portion 112 and the frame body 120 are integrally formed from a resin material containing a cellulose material. The cellulose material is, for example, cellulose fiber. The cellulose fiber is, for example, short cellulose fiber such as cellulose microfiber or cellulose nanofiber. The main frame 110A is, for example, a fiber-reinforced resin molded product in which short cellulose fiber is dispersed as a reinforcing fiber in a matrix resin. The matrix resin is not particularly limited, but suitable examples include polypropylene, nylon, polylactic acid, and polybutylene terephthalate.

[0018] The illustrated example is one embodiment of the configuration of the main frame 110A. In another embodiment, the shaft connecting portion 112 is made of a metal material, and a frame main body 120 made of a resin material containing cellulose is connected to this shaft connecting portion 112. In yet another embodiment, the frame main body 120 is made of a fiber-reinforced resin material in which long cellulose fibers are impregnated with a matrix resin.

[0019] As described above, by forming at least the frame body 120 from a fiber-reinforced resin material, it is possible to ensure the rigidity of the main frame 110A while reducing its weight. Note that the main frame 110A in the illustrated example is manufactured by, for example, injection molding. The manufacturing (molding) method of the main frame 110A will be described later.

[0020] The shaft connecting portion 112 has a generally cylindrical shape with a diameter D. The shaft connecting portion 112 has an insertion hole 114 at its center. The shaft portion of the connecting shaft 90 shown in FIG. 1 passes through the insertion hole 114. The armrest 100 is rotatably attached to the seat back 30 via the shaft portion of the connecting shaft 90.

[0021] As shown in Figures 2 and 3, the frame main body 120 has a first extension portion 122, a second extension portion 132, and a reinforcing portion 150. In the illustrated example, the frame main body 120 further has a base portion 170. However, the base portion 170 is not essential. The frame main body 120 extends in a substantially linear manner from the outer peripheral surface of the shaft connecting portion 112 in a predetermined direction. Hereinafter, the extension direction of the frame main body 120 will be referred to as the "longitudinal direction," and the direction perpendicular to the longitudinal direction will be referred to as the "transverse direction." When an occupant places their forearm on the armrest 100, the longitudinal direction is, for example, substantially parallel to the front-to-rear direction of the seat.

[0022] As shown in FIG. 2, the base portion 170 has a first surface 172. As shown in FIG. 6, the base portion 170 has a second surface 174, which is the surface (back surface) opposite to the first surface 172. The base portion 170 has a plurality of openings 176. In the illustrated example, the plurality of openings 176 include a first opening 176a, a second opening 176b, a third opening 176c, a fourth opening 176d, and a fifth opening 176e. The number of openings 176 is not limited to five. Furthermore, it is not essential to form the openings 176 in the base portion 170.

[0023] The first opening 176a to the fifth opening 176e are aligned at intervals along the longitudinal direction of the frame main body 120. As shown in Fig. 2, the interval between the first opening 176a and the second opening 176b is V1, the interval between the second opening 176b and the third opening 176c is V2, the interval between the third opening 176c and the fourth opening 176d is V3, and the interval between the fourth opening 176d and the fifth opening 176e is V4. Of the intervals V1 to V4, the interval V2 is the smallest.

[0024] 3, the first extension portion 122, the second extension portion 132, and the reinforcing portion 150 are convex wall portions that start from the first surface 172 of the base portion 170 and protrude in a direction (protruding direction) away from the first surface 172. The first extension portion 122, the second extension portion 132, and the reinforcing portion 150 are integrally connected to the first surface 172. The protruding directions of the first extension portion 122, the second extension portion 132, and the reinforcing portion 150 are perpendicular to the longitudinal direction and the lateral direction.

[0025] 2 and 3, the first extension portion 122 and the second extension portion 132 extend opposite to each other. In the longitudinal direction of the first extension portion 122, one end connected to the shaft connecting portion 112 is referred to as a first base end 128, and the other end opposite the first base end 128 is referred to as a first tip end 130. In the longitudinal direction of the second extension portion 132, one end connected to the shaft connecting portion 112 is referred to as a second base end 138, and the other end opposite the second base end 138 is referred to as a second tip end 140.

[0026] The first base end 128 and the second base end 138 are continuous with the outer peripheral surface of the shaft connecting portion 112. As shown in FIG. 2, the distance T1 in the short direction from the outer edge of the first base end 128 to the outer edge of the second base end 138 (length in the short direction) is shorter than the diameter D of the shaft connecting portion 112.

[0027] The first extending portion 122 has a first curved portion 124 and a first straight portion 126. The first curved portion 124 starts at a first base end 128 and extends toward the reinforcing portion 150. The first curved portion 124 is curved so as to be convex toward the second extending portion 132. The first curved portion 124 is continuous with the first straight portion 126 at a position closer to the first base end 128 than the reinforcing portion 150.

[0028] The second extending portion 132 has a second curved portion 134 and a second straight portion 136. The second curved portion 134 faces the first curved portion 124. The second curved portion 134 starts at the second base end 138 and extends toward the reinforcing portion 150. The second curved portion 134 is curved so as to be convex toward the first extending portion 122. As described above, because the first curved portion 124 is curved so as to be convex toward the second extending portion 132, the distance between the first curved portion 124 and the second curved portion 134 increases as the distance from the reinforcing portion 150 increases. The second curved portion 134 is continuous with the second straight portion 136 at a position closer to the second base end 138 than the reinforcing portion 150. The second straight portion 136 is approximately parallel to the first straight portion 126.

[0029] The dimension in the direction perpendicular to the longitudinal direction and the protruding direction of each of the first curved portion 124, the first straight portion 126, the second curved portion 134, and the second straight portion 136 is referred to as the thickness. The thickness C1 of the first curved portion 124 (see FIG. 2) is greater than the thickness C2 of the first straight portion 126. The thickness C3 of the second curved portion 134 is greater than the thickness C4 of the second straight portion 136.

[0030] 2 and 3, the first tip 130 is connected to the second tip 140 via a bulging portion 180. The bulging portion 180 is an end portion of the frame main body 120 in the longitudinal direction, and has a shape that bulges out in an arc shape in a direction away from the shaft connecting portion 112. In the bulging portion 180, the portion that connects to the first tip 130 is also arc-shaped, and the portion that connects to the second tip 140 is also arc-shaped.

[0031] As shown in Fig. 4, the first extending portion 122 has a first inclined portion 182. At the first inclined portion 182, the protruding height of the first extending portion 122 from the first surface 172 decreases with increasing distance from the shaft connecting portion 112 along the longitudinal direction. As shown in Fig. 3, the second extending portion 132 similarly has a second inclined portion 184 at a position facing the first inclined portion 182. At the second inclined portion 184, the protruding height of the second extending portion 132 from the first surface 172 decreases with increasing distance from the shaft connecting portion 112 along the longitudinal direction.

[0032] As shown in FIGS. 2 and 3 , the frame main body 120 has a first recessed space 186 and a second recessed space 188. The first recessed space 186 is a space surrounded by a part of the outer circumferential surface of the shaft connecting portion 112, the inner surface of the first extending portion 122 (mainly the first curved portion 124), the inner surface of the second extending portion 132 (mainly the second curved portion 134), and the first side surface 158 of the reinforcing portion 150. The second recessed space 188 is a space surrounded by the inner surface of the first straight portion 126, the inner surface of the second straight portion 136, the second side surface 160 of the reinforcing portion 150, and the inner surface of the bulging portion 180. As can be seen from this, the reinforcing portion 150 divides the space between the first extending portion 122 and the second extending portion 132 into the first recessed space 186 and the second recessed space 188.

[0033] The reinforcing portion 150 connects the first intermediate region 129 of the first extending portion 122 and the second intermediate region 139 of the second extending portion 132. That is, the extending direction of the reinforcing portion 150 is the direction connecting the first intermediate region 129 and the second intermediate region 139. Note that FIGS. 2 and 3 illustrate an example in which the first intermediate region 129 and the second intermediate region 139 are located approximately in the longitudinal centers of the first extending portion 122 and the second extending portion 132, respectively. However, the first intermediate region 129 is a region between the first base end 128 and the first tip 130 and is not a specific region. Similarly, the second intermediate region 139 is a region between the second base end 138 and the second tip 140 and is not a specific region. For example, when the first extending portion 122 is divided into three regions of the same length along its extending direction, the first intermediate region 129 may be located in the middle region. Furthermore, for example, when the second extending portion 132 is divided into three regions of the same length along its extending direction, the second intermediate portion 139 can be located in the intermediate region.

[0034] 5 is an enlarged view of the reinforcing portion 150 and the surrounding essential parts. As shown in Fig. 5, the direction perpendicular to the extending direction of the reinforcing portion 150 is referred to as the width direction of the reinforcing portion 150. The width direction of the reinforcing portion 150 is approximately parallel to the longitudinal direction of the frame main body 120.

[0035] The reinforcing portion 150 has a first wide portion 154, a second wide portion 156, and a constricted portion 152. The first wide portion 154 is one end of the reinforcing portion 150 in the extension direction, and is a portion that continues to the first extending portion 122. The second wide portion 156 is the other end of the reinforcing portion 150 in the extension direction, and is a portion that continues to the second extending portion 132. The constricted portion 152 is located at an intermediate position in the extension direction of the reinforcing portion 150. Therefore, the constricted portion 152 is located between the first wide portion 154 and the second wide portion 156.

[0036] The constricted portion 152 is narrower than the first wide portion 154 and the second wide portion 156 in the width direction of the reinforcing portion 150. In other words, the reinforcing portion 150 gradually becomes wider from the constricted portion 152 toward the first extending portion 122. Furthermore, the reinforcing portion 150 gradually becomes wider from the constricted portion 152 toward the second extending portion 132. As a result, the section modulus of the reinforcing portion 150 is large at the first wide portion 154 and the second wide portion 156.

[0037] The reinforcing portion 150 has a first side surface 158 that forms the inner surface of the first recessed space 186, and a second side surface 160 that forms the inner surface of the second recessed space 188. The first side surface 158 is a curved surface that is recessed toward the second recessed space 188. The second side surface 160 is a curved surface that is recessed toward the first recessed space 186. Therefore, in the first wide portion 154, the first side surface 158 and the second side surface 160 are curved so that the distance between them widens as they move from the narrowed portion 152 toward the first extending portion 122. Similarly, in the second wide portion 156, the first side surface 158 and the second side surface 160 are curved so that the distance between them widens as they move from the narrowed portion 152 toward the second extending portion 132.

[0038] 6 is a schematic side view of the main frame 110A when viewed from the second surface 174 of the base portion 170. The second surface 174 of the base portion 170 is a flat surface with no protrusions. The main frame 110A has two recesses 190 on the second surface 174 of the base portion 170. However, there may be only one recess 190. Alternatively, there may be three or more recesses 190.

[0039] 7, the two recesses 190 each have an opening 192 in the second surface 174 of the base portion 170. In the illustrated example, the openings 192 of the two recesses 190 are located at positions corresponding to the first wide portion 154 and the second wide portion 156. In other words, the constricted portion 152 is located between the two recesses 190. Thus, in one aspect, the two recesses 190 are formed at positions that avoid the constricted portion 152. The two recesses 190 are tapered holes with a bottom that are recessed along the protruding direction and taper in diameter as they extend in the protruding direction.

[0040] The protruding direction and the direction opposite to the protruding direction are collectively referred to as the height direction. The recessed direction of the recess 190 is not limited to the protruding direction. Alternatively, the recessed direction of the recess 190 may be the direction opposite to the protruding direction. For example, the recess 190 may be recessed from the top of the reinforcing portion 150 toward the base portion 170. In this way, the recessed direction of the recess 190 is the height direction and is not limited to the protruding direction or the direction opposite to the protruding direction.

[0041] 8A and 8B show modified main frames 110B and 110C, respectively. The main frame 110B shown in FIG. 8A has two cross ribs 195 in addition to the reinforcing portion 150. The two cross ribs 195 are located between the first opening 176a and the second opening 176b and intersect with each other in an X-shape. One end of each of the two cross ribs 195 is connected to the first extension portion 122. One end of each of the two cross ribs 195 is connected to the second extension portion 132.

[0042] 8B, two intersecting ribs 196 extend from one end to the other end of the first recessed space 186 and intersect with each other in an X-shape. One end of each of the two intersecting ribs 196 is connected to the first extending portion 122. One end of each of the two intersecting ribs 196 is connected to the second extending portion 132.

[0043] Next, a molding method for the main frame 110A shown in Figures 2 to 7 will be briefly described. The main frame 110A is produced by, for example, injection molding. This embodiment will be described below, but the molding method for the entire main frame 110A or the frame main body 120 is not limited to injection molding. Other molding methods for the entire main frame 110A or the frame main body 120 include vacuum molding and press molding.

[0044] 9A to 9C schematically show a cavity 200 for obtaining the main frame 110A. The cavity 200 is formed by a molding die of an injection molding machine (not shown). The cavity 200 has a first space 210 for molding the base portion 170, a second space 212 for molding the shaft connecting portion 112, a third space 214 for molding the first extension portion 122, a fourth space 216 for molding the reinforcing portion 150, a fifth space 218 for molding the second extension portion 132, and a sixth space 220 for molding the bulge portion 180. The correspondence between the positions of the first space 210, the second space 212, the third space 214, the fourth space 216, the fifth space 218 and the sixth space 220 and the positions of the base portion 170, the shaft connecting portion 112, the first extension portion 122, the reinforcing portion 150, the second extension portion 132 and the bulge portion 180 is shown in Figure 9C.

[0045] A plurality of protrusions 226 for forming the plurality of openings 176 are arranged in the first space 210. Of the plurality of protrusions 226, protrusion 226b forms the second opening 176b, and of the plurality of protrusions 226, protrusion 226c forms the third opening 176c.

[0046] The fourth space 216 has a narrowed portion 222 corresponding to the constricted portion 152 of the reinforcing portion 150. Furthermore, two cores 224 for forming the two recesses 190 are disposed in the fourth space 216. As shown in Fig. 10, the two cores 224 extend along the protruding direction of the reinforcing portion 150, and taper in diameter as they move away from the first space 210. That is, the two cores 224 are frustum-shaped.

[0047] 9A shows the runner 230 and the gate 232. The gate 232 is connected to a portion of the first space 210 that is located below the third space 214.

[0048] In injection molding, the material MT for obtaining the main frame 110A is a molten resin containing a cellulose material. As described above, a suitable example of the cellulose material is cellulose fiber. A suitable example of the cellulose fiber is short cellulose fiber such as cellulose microfiber or cellulose nanofiber. The molten resin is obtained by softening the matrix resin to a degree that exhibits sufficient fluidity.

[0049] As shown in FIG. 9A, after passing through the gate 232, the material MT injected from the injection machine constituting the injection molding apparatus is divided into a first divided flow F1 flowing toward the second space 212 and a second divided flow F2 flowing toward the sixth space 220. As shown in FIG. 9B, the first divided flow F1 fully fills the second space 212. Meanwhile, a third divided flow F3 flows from the second space 212 toward the fifth space 218 in the first divided flow F1. Furthermore, a fourth divided flow F4 flows through the fourth space 216 in the second divided flow F2. After flowing through the fourth space 216, the fourth divided flow F4 is divided into a fifth divided flow F5 flowing toward the space in the fifth space 218 that molds the second curved portion 134, and a sixth divided flow F6 flowing toward the sixth space 220.

[0050] The second branch flow F2 shown in Fig. 9B results in the first straight portion 126 shown in Fig. 9C. The third branch flow F3 and the fifth branch flow F5 shown in Fig. 9B result in the second curved portion 134 shown in Fig. 9C. The second branch flow F2 and the sixth branch flow F6 shown in Fig. 9B result in the bulge portion 180 shown in Fig. 9C.

[0051] Because cellulose materials exhibit thixotropy, if the flow rate of the raw material MT is low, the raw material MT may dry out before filling the cavity 200, reducing the fluidity of the raw material MT. However, in the above embodiment, as shown in Figures 9B and 9C, the fourth branch flow F4 that passes through the fourth space 216 is branched into fifth branch flow F5 and sixth branch flow F6, and the fifth branch flow F5 and sixth branch flow F6 flow toward different spaces. This allows the raw material MT to be filled into the cavity 200 in a shorter time than when molding a main frame without the reinforcing portion 150.

[0052] The flow rate of the fourth diverted flow F4 is restricted by the constricted section 222. As a result, the pressure of the fourth diverted flow F4, which branches off from the second diverted flow F2 and flows into the constricted section 222, increases upstream of the constricted section 222. Due to the thixotropy of cellulose material, the material subjected to pressure tends to flow in the direction of the applied pressure. Therefore, the fourth diverted flow F4 flows easily through the constricted section 222 and fills the fourth space 216 in a short time. Furthermore, the increased pressure of the fourth diverted flow F4 causes a reaction on the first diverted flow F1, which tends to flow more easily toward the space in the second space 212 where the first straight portion 126 is formed.

[0053] The fourth diverged flow F4 contacts the two cores 224 in the fourth space 216. Because the two cores 224 taper in diameter along the protruding direction, the fourth diverged flow F4 easily flows along the cores 224. For this reason, the fourth diverged flow F4 easily fills the fourth space 216. Therefore, it is possible to easily form the reinforcing part 150 having the recess 190 that opens at the second surface 174 of the base part 170 and tapers in diameter along the protruding direction.

[0054] When the material MT filling the cavity 200 hardens, the main frame 110A having the appearance shown in Figures 2 to 7 is obtained. The armrest 100 (see Figure 1) is obtained by covering the main frame 110A with a pad and then covering the pad with a surface material.

[0055] 11A to 11C are explanatory diagrams showing the flow of the molding material when the position of the gate 232 is different from that shown in Figures 9A to 9C. Note that the correspondence between the positions of the first space 210, the second space 212, the third space 214, the fourth space 216, the fifth space 218, and the sixth space 220 and the positions of the base portion 170, the shaft connecting portion 112, the first extending portion 122, the reinforcing portion 150, the second extending portion 132, and the bulging portion 180 is shown in Figure 11C.

[0056] 11A to 11C, the gate 232 is disposed in a space that forms the portion of the base portion 170 between the shaft connecting portion 112 and the reinforcing portion 150. In this embodiment, as shown in Fig. 11A, the material MT spreads in a diffusive manner from the space that forms the portion between the shaft connecting portion 112 and the reinforcing portion 150 toward the second space 212, the space in the third space 214 that forms the first curved portion 124, the space in the fifth space 218 that forms the second curved portion 134, and the fourth space 216.

[0057] 11B, the raw material MT that has passed through the reinforcing portion 150 is divided into two streams: one that flows into the space that forms the first straight portion 126 and the other that flows into the space that forms the second straight portion 136. Meanwhile, the raw material MT that has passed through the space that forms the first curved portion 124 and the space that forms the second curved portion 134 flow into the second space 212. Thereafter, as shown in FIG. 11C, the entire cavity 200 is filled with the raw material MT.

[0058] 11A to 11C, the raw material MT is divided by the fourth space 216, resulting in branched flows. The branched flows flow through separate spaces. Therefore, the raw material MT can be filled into the cavity 200 in a shorter time than when molding a main frame without a reinforcing portion 150.

[0059] The effects of the vehicle seat 10 shown in FIG. 1 will be described mainly in relation to the main frame 110A.

[0060] 2 and 3, a main frame 110A, which is an example of a seat component 40A, has a frame body 120 made of a resin material containing cellulose. The frame body 120 integrally includes a first extending portion 122 and a second extending portion 132 that extend facing each other, and a reinforcing portion 150 that connects a first intermediate portion 129 of the first extending portion 122 and a second intermediate portion 139 of the second extending portion 132.

[0061] Because the frame body 120 is formed from a resin material containing cellulose, the weight of the main frame 110A can be reduced. This also reduces the weight of the armrest 100 and the vehicle seat 10. Furthermore, the reinforcing portion 150 provides the frame body 120 with sufficient rigidity. In other words, the main frame 110A is lightweight yet has excellent rigidity.

[0062] As shown in FIG. 5, the reinforcing portion 150 has a constricted portion 152 at a middle position in the extending direction of the reinforcing portion 150, which is narrower in the width direction intersecting the extending direction of the reinforcing portion 150 than the end portions in the extending direction.

[0063] When reinforcing portion 150 is formed by molding, the resin material containing cellulose (molding material MT shown in FIG. 9A) flows easily in the space where constricted portion 152 is molded. Therefore, molding defects in reinforcing portion 150 are less likely to occur.

[0064] As shown in FIG. 5 , the ends of the reinforcing portion 150 in the extension direction are a first wide portion 154 and a second wide portion 156, which gradually widen. In this case, the section modulus of the first wide portion 154 and the second wide portion 156 is large, and therefore the strength of the portions of the reinforcing portion 150 that are continuous with the first extending portion 122 and the second extending portion 132 is increased. The first side surface 158 and the second side surface 160 of the first wide portion 154 are curved so that the distance between them increases from the narrowed portion 152 toward the first extending portion 122. The first side surface 158 and the second side surface 160 of the second wide portion 156 are similarly curved so that the distance between them increases from the narrowed portion 152 toward the second extending portion 132. In this case, the section modulus can be increased compared to when the first side surface 158 and the second side surface 160 are flat.

[0065] As shown in Fig. 3, the main frame 110A has a base portion 170. The base portion 170 has a first surface 172 (see Fig. 3) and a second surface 174 (see Fig. 6) that is the surface opposite to the first surface 172. As can be seen from Fig. 3, the first extension portion 122, the second extension portion 132, and the reinforcing portion 150 are integrally connected to the first surface 172 of the base portion 170 and are convex wall portions that protrude in the same direction from the first surface 172.

[0066] The first extending portion 122, the second extending portion 132, and the reinforcing portion 150 protrude convexly from the base portion 170, and therefore act as ribs for the base portion 170. This further increases the rigidity of the main frame 110A. Furthermore, by forming the first extending portion 122, the second extending portion 132, and the reinforcing portion 150 in the above-described shapes, the material MT becomes more likely to flow when the main frame 110A is molded.

[0067] As shown in FIG. 7, the main frame 110A has a recess 190 recessed along the height direction parallel to the direction in which the first extending portion 122, the second extending portion 132, and the reinforcing portion 150 protrude.

[0068] The recess 190 allows the main frame 110A to be made even lighter.

[0069] As shown in Fig. 6, the second surface 174 of the base portion 170 is a flat surface. As shown in Fig. 7, the recess 190 has an opening 192 in the second surface 174 of the base portion 170, and is recessed along the protruding direction.

[0070] This allows the formation of a recess 190 with a large opening area and great depth. Furthermore, as shown in Fig. 10, when the flat second surface 174 is formed first in molding the main frame 110A, the material MT easily flows along the core 224 for forming the recess 190 toward the portion that will become the first surface 172.

[0071] The recess 190 is a tapered hole whose diameter tapers toward the protruding direction.

[0072] In this case, the core 224 for forming the recess 190 has a truncated cone shape that tapers in diameter from the portion that forms the second surface 174 toward the protruding direction. The material MT flows easily along the core 224 having such a shape. Therefore, the recess 190 can be easily formed.

[0073] 2 and 3, the base portion 170 has a plurality of openings 176 that are spaced apart along the extension direction of the first extension portion 122 and the second extension portion 132. The reinforcing portion 150 is located between two of the plurality of openings 176 that are adjacent to each other and have the shortest distance between them.

[0074] The reinforcing portion 150 is interposed between the two openings 176 that are spaced the shortest from each other, which prevents the rigidity of the base portion 170 from decreasing between the two openings 176. Furthermore, when the main frame 110A is molded, the material MT easily flows into the portion that will become the reinforcing portion 150.

[0075] The first extending portion 122 has a first curved portion 124 and a first straight portion 126. The second extending portion 132 has a second curved portion 134 and a second straight portion 136. The first curved portion 124 and the second curved portion 134 are each curved so that the distance between them increases as they move away from the reinforcing portion 150 and approach the shaft connecting portion 112. The first straight portion 126 and the second straight portion 136 extend linearly facing each other.

[0076] 2, in this configuration, the thickness C1 of the first curved portion 124 in a direction perpendicular to the extending direction and the protruding direction is greater than the thickness C2 of the first straight portion 126 in a direction perpendicular to the extending direction and the protruding direction. Similarly, the thickness C3 of the second curved portion 134 in a direction perpendicular to the extending direction and the protruding direction is greater than the thickness C4 of the second straight portion 136 in a direction perpendicular to the extending direction and the protruding direction.

[0077] Since the thickness of the first curved portion 124 and the second curved portion 134 connected to the shaft connecting portion 112 is sufficiently large, the joining strength between the shaft connecting portion 112 and the first extending portion 122 and the second extending portion 132 is ensured.

[0078] The first tip 130 of the first extending portion 122 and the second tip 140 of the second extending portion 132 are connected via an arc-shaped bulging portion 180. In this case, the rigidity of the frame main body 120 is greater than in a configuration in which the first tip 130 and the second tip 140 are connected by a straight portion. Also, since it is easy to give the tip of the armrest 100 a curved shape, the aesthetic appearance (design) of the armrest 100 is improved.

[0079] In one embodiment, the cellulose material is cellulose fiber, and the resin material is a fiber-reinforced resin material containing cellulose fiber as a reinforcing fiber.

[0080] In this case, the main frame 110A can be easily obtained by molding. The cellulose fibers are preferably short cellulose fibers, and more preferably cellulose microfibers or cellulose nanofibers. In particular, since cellulose nanofibers are very fine, they are easily dispersed in the matrix resin even when only a small amount of cellulose nanofiber is added to the matrix resin. This allows for a main frame 110A that exhibits sufficient rigidity.

[0081] Next, an embodiment will be described in which the seat member 40B shown in Fig. 1 is an operating lever 50. Fig. 12 is a schematic side view of the operating lever 50. Fig. 12 shows the operating lever 50 extending along the seat front-rear direction as viewed from the right in the seat width direction.

[0082] The operating lever 50 integrally includes an attachment portion 52 that is attached to a height brake (not shown), a grip portion 54 that is gripped by the occupant, and an intermediate portion 53 that is interposed between the attachment portion 52 and the grip portion 54. The intermediate portion 53 and the grip portion 54 integrally include a base portion 55, a first extending portion 56, a second extending portion 58, and a plurality of reinforcing portions 62. The first extending portion 56, the second extending portion 58, and the plurality of reinforcing portions 62 are convex wall portions that protrude in the same direction (protruding direction) from a first surface 64 of the base portion 55.

[0083] The first extending portion 56 and the second extending portion 58 extend facing each other. The multiple reinforcing portions 62 connect the first extending portion 56 between a first base end 66 and a first tip 68 (a first intermediate portion 67) and the second extending portion 58 between a second base end 70 and a second tip 72 (a second intermediate portion 71).

[0084] The operating lever 50 configured as described above is made of a resin material containing cellulose. The operating lever 50 is, for example, a fiber-reinforced resin molded product in which short cellulose fibers are dispersed as reinforcing fibers in a matrix resin. Therefore, the operating lever 50 is lightweight. Furthermore, the operating lever 50 exhibits excellent rigidity due to the reinforcing portion 150.

[0085] As described above, since the main frame 110A of the armrest 100 and the height brake operating lever 50 are lightweight, the vehicle seat 10 shown in FIG. 1 can be made lighter.

[0086] The following additional notes are further disclosed regarding the above embodiment.

[0087] (Appendix 1) The vehicle seat (10) of the present disclosure is a vehicle seat to be mounted on a vehicle, and includes seat members (40A, 40B) made of a resin material containing cellulose material, and the seat members integrally include a first extension portion (122, 56) and a second extension portion (132, 58) extending toward each other, a first intermediate portion (129, 67) extending from one end to the other in the extension direction of the first extension portion, and a reinforcing portion (150, 62) connecting a second intermediate portion (139, 71) extending from one end to the other in the extension direction of the second extension portion.

[0088] The reinforcing portion provides the seat member with sufficient rigidity. Furthermore, since the seat member is formed from a material containing cellulose, the seat member can be made lighter. That is, the seat member is lightweight yet has excellent rigidity. Because the seat member is lightweight, the vehicle seat can also be made lighter.

[0089] (Appendix 2) In the vehicle seat described in Appendix 1, the reinforcing portion may have a constricted portion (152) at an intermediate position in the extending direction of the reinforcing portion, the constricted portion being narrower in a width direction intersecting the extending direction of the reinforcing portion than the ends (154, 156) of the reinforcing portion in the extending direction.

[0090] When forming the reinforcing portion by molding, the resin material (molding material) containing cellulose material is more likely to flow in the space where the constricted portion is molded. This reduces molding defects in the reinforcing portion. Furthermore, the seat component is even lighter.

[0091] (Appendix 3) In the vehicle seat described in Appendix 1 or 2, the seat member has a base portion (170, 55) having a first surface (172, 64) and a second surface (174) opposite the first surface, and the first extension portion, the second extension portion and the reinforcing portion may be convex wall portions that are integrally connected to the first surface of the base portion and protrude in the same direction from the first surface.

[0092] By making the first extension portion, the second extension portion, and the reinforcing portion convex walls relative to the base portion, the material containing cellulose material can flow more easily when the sheet member is formed. Also, the first extension portion, the second extension portion, and the reinforcing portion act as ribs relative to the base portion, further increasing the rigidity of the sheet member.

[0093] (Appendix 4) In the vehicle seat described in Appendix 3, when the direction parallel to the protruding direction in which the first extension portion, the second extension portion, and the reinforcing portion protrude from the first surface is defined as the height direction, the seat member may have a recess (190) formed in the reinforcing portion and recessed along the height direction.

[0094] By forming the recess, the weight of the seat member can be further reduced.

[0095] (Appendix 5) In the vehicle seat described in Appendix 4, the second surface of the base portion may be a flat surface, and the recess may have an opening (192) on the second surface of the base portion and be recessed along the protruding direction.

[0096] This allows the formation of a recess with a large opening area and great depth. Furthermore, when molding the sheet member, if the flat second surface is molded first, the molding material will easily flow in the protruding direction along the core that forms the recess.

[0097] (Appendix 6) In the vehicle seat described in Supplementary Note 5, the recess may be a tapered hole whose diameter tapers toward the protruding direction.

[0098] The core for forming the recessed portion tapers in diameter from the portion forming the second surface toward the protruding direction, so that the material flows more easily along the core.

[0099] (Appendix 7) In the vehicle seat described in any one of Appendices 3 to 6, the base portion has a plurality of openings (176) spaced apart along the extension direction of the first extension portion and the extension direction of the second extension portion, and the reinforcing portion may be located between two of the plurality of openings that are adjacent to each other and have the shortest distance between them.

[0100] Since the reinforcing portion is located between the two openings with the shortest spacing among the multiple openings, the rigidity of the base portion between the two openings is prevented from decreasing. Furthermore, when molding the seat member, the material flows easily into the portion that will become the reinforcing portion.

[0101] (Appendix 8) In the vehicle seat described in any one of Supplementary Notes 3 to 7, the first extension portion has a first curved portion (124) and a first straight portion (126), the second extension portion has a second curved portion (134) and a second straight portion (136), the first curved portion and the second curved portion are each curved so that the distance between them increases as they move away from the reinforcing portion, the first straight portion and the second straight portion extend linearly facing each other, and a thickness (C1) of the first curved portion in a direction perpendicular to the extending direction and the protruding direction may be greater than a thickness (C2) of the first straight portion in a direction perpendicular to the extending direction and the protruding direction, and a thickness (C3) of the second curved portion in a direction perpendicular to the extending direction and the protruding direction may be greater than a thickness (C4) of the second straight portion in a direction perpendicular to the extending direction and the protruding direction.

[0102] (Appendix 9) In the vehicle seat according to any one of Supplementary Notes 1 to 8, the cellulose material may be cellulose fibers, and the resin material may be a fiber-reinforced resin material containing the cellulose fibers as reinforcing fibers.

[0103] In this case, the sheet member can be easily obtained by molding.

[0104] (Appendix 10) In the vehicle seat according to any one of Supplementary Notes 1 to 9, the seat member may be an armrest frame (110A, 110B, 110C) that constitutes an armrest (100).

[0105] This configuration makes it possible to construct an armrest that is lightweight yet has excellent rigidity.

[0106] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention. [Explanation of symbols]

[0107] 10... Vehicle seat 40A, 40B... Seat member 50...Operating lever 55, 170...Base part 56, 122...first extension part 58, 132...second extension part 62, 150...Reinforcement part 100...Armrest 110A~110C...Main frame 120...Frame body 152...Hanging part 176...Opening 190...recess 192...opening 200: Cavity 222: Throttle section 224… Core MT… Material

Claims

1. A vehicle seat to be mounted on a vehicle, A sheet member is provided which is made of a resin material containing a cellulose material, The sheet member includes a first extending portion and a second extending portion extending toward each other, a reinforcing portion connecting a first intermediate portion between one end and the other end of the first extending portion in the extending direction and a second intermediate portion between one end and the other end of the second extending portion in the extending direction; A vehicle seat integrally having the above.

2. 2. The vehicle seat according to claim 1, wherein the reinforcing portion has a narrowed portion at a middle position in the extension direction of the reinforcing portion, the narrowed portion being narrower in a width direction intersecting the extension direction of the reinforcing portion than an end portion of the reinforcing portion in the extension direction.

3. 3. The vehicle seat according to claim 2, wherein the seat member has a base portion having a first surface and a second surface opposite to the first surface, A vehicle seat, wherein the first extension portion, the second extension portion, and the reinforcing portion are convex wall portions that are integrally connected to the first surface of the base portion and protrude in the same direction from the first surface.

4. 4. The vehicle seat of claim 3, wherein when a direction parallel to the protruding direction in which the first extension portion, the second extension portion, and the reinforcing portion protrude from the first surface is defined as a height direction, the seat member has a recess formed in the reinforcing portion and recessed along the height direction.

5. 5. The vehicle seat according to claim 4, wherein the second surface of the base portion is a flat surface, and the recess has an opening in the second surface of the base portion and is recessed along the protruding direction.

6. 6. The vehicle seat according to claim 5, wherein the recess is a tapered hole whose diameter tapers toward the protruding direction.

7. 4. The vehicle seat according to claim 3, wherein the base portion has a plurality of openings arranged at intervals along the extension direction of the first extension portion and the extension direction of the second extension portion, The vehicle seat, wherein the reinforcing portion is located between two of the plurality of openings that are adjacent to each other and have the shortest distance between them.

8. 5. The vehicle seat according to claim 4, wherein the first extending portion has a first curved portion and a first straight portion, and the second extending portion has a second curved portion and a second straight portion, the first curved portion and the second curved portion are curved such that the distance between them increases as they move away from the reinforcing portion, and the first straight portion and the second straight portion extend linearly facing each other, A vehicle seat in which the thickness of the first curved portion in a direction perpendicular to the extending direction and the protruding direction is greater than the thickness of the first straight portion in a direction perpendicular to the extending direction and the protruding direction, and the thickness of the second curved portion in a direction perpendicular to the extending direction and the protruding direction is greater than the thickness of the second straight portion in a direction perpendicular to the extending direction and the protruding direction.

9. 2. The vehicle seat according to claim 1, wherein the cellulose material is cellulose fiber, and the resin material is a fiber-reinforced resin material containing the cellulose fiber as a reinforcing fiber.

10. 10. The vehicle seat according to claim 1, wherein the seat member is an armrest frame that constitutes an armrest.

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