Seat frame

The present disclosure describes a seat frame including a waist portion supporting member having a smaller size while stably supporting a waist portion of an occupant. A vehicle seat frame serving as a frame for a vehicle seat includes a seat cushion frame forming a frame of a sitting part of the vehicle seat, a seatback frame forming a frame of a backrest part of the vehicle seat, and a waist portion supporting member coupled to a lower frame which is included in the seatback frame. The waist portion supporting member has a coupling region extending in the seat width direction, the coupling region being coupled to the lower frame, and a waist portion supporting region extending from the coupling region toward the seat cushion frame and supporting a waist portion of an occupant. The waist portion supporting region is longer in the seat width direction than the coupling region.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Stage Entry application of PCT Application No. PCT/JP2015/080829, filed Oct. 30, 2015, which claims the priority benefit of Japanese Patent Application No. JP 2015-197156, filed Oct. 2, 2015, the contents being incorporated herein by reference.

BACKGROUND

The present disclosure relates to a seat frame. In particular, the present disclosure relates to a seat frame including a waist portion supporting member that supports a waist portion of an occupant seated in a conveyance seat.

At the time of a rear surface collision where a vehicle collides with a rear portion of another vehicle such as an automobile or a vehicle collides with an obstacle, etc. at the time of driving backwards, an occupant seated in a conveyance seat radically tilts back due to inertia force, and a neck portion of the occupant may receive a great shock.

For example, Japanese Patent Publication JP 2011-173515 discloses a conveyance seat in which a waist portion supporting member that supports a waist portion of an occupant is provided in a seatback frame serving as a framework of a backrest part of the conveyance seat. In the conveyance seat in which the waist portion supporting member is provided in such a way, by suppressing the waist portion of the occupant from coming in backward by the waist portion supporting member at the time of rear surface collision and facilitating backward tilt of an upper body of the occupant, the upper body of the occupant sinks into the conveyance seat and a shock on a neck portion is effectively absorbed.

Due to a demand to improve fuel consumption of a vehicle, etc., a seat frame is desired to have a reduced weight. Even in a seat frame in which a waist portion supporting member is provided, while maintaining a function of stably supporting a waist portion of an occupant by the waist portion supporting member, a challenge is to downsize the waist portion supporting member to further reduce the weight.

SUMMARY

The present disclosure is achieved in consideration with the above challenges and an embodiment of the present disclosure provides a seat frame including a waist portion supporting member which is capable of being downsized while stably supporting a waist portion of an occupant.

The challenge is solved in an embodiment of a seat frame for a conveyance seat, including a seat cushion frame that forms a frame of a sitting part of the conveyance seat, a seatback frame that forms a frame of a backrest part of the conveyance seat, and a waist portion supporting member coupled to a lower frame which is included in the seatback frame. The waist portion supporting member has a coupling region extending in a seat width direction, the coupling region being coupled to the lower frame, and a waist portion supporting region extending from the coupling region toward the seat cushion frame and supporting a waist portion of an occupant. The waist portion supporting region is longer in the seat width direction than the coupling region.

With the above seat frame, while ensuring the size of the waist portion supporting region supporting the waist portion of the occupant in the waist portion supporting member, the coupling region coupling the waist portion supporting member to the seatback frame can be downsized. That is, with the above seat frame, by providing the waist portion supporting member which is capable of being downsized while stably supporting the waist portion of the occupant by a wide surface, the seat frame having a high shock absorbing property for rear surface collision, the seat frame whose weight is reduced can be implemented.

In the above seat frame, the waist portion supporting member may have a bent portion formed by bending at least one of end portions of the waist portion supporting member in the seat width direction to an inner side in the seat width direction. By doing so, rigidity of the waist portion supporting region supporting the waist portion of the occupant in the waist portion supporting member can be improved. That is, with the above seat frame, by more stably supporting the waist portion of the occupant, the shock absorbing property for rear surface collision can be improved.

In the above seat frame, the bent portion may have an extending region that extends toward the lower frame. By doing so, in a case where a load is applied to the waist portion supporting region supporting the waist portion of the occupant in the waist portion supporting member, by abutting the extending region of the bent portion with the lower frame to deform the extending region, a shock can be absorbed by the bent portion. That is, with the above seat frame, by improving a shock absorbing property by the waist portion supporting member, the shock absorbing property for rear surface collision can be improved.

In the above seat frame, the waist portion supporting member may have a cutout portion formed around a connection portion between the waist portion supporting region and the bent portion. By doing so, at the time of forming the bent portion in the waist portion supporting member, deformation of the waist portion supporting region supporting the waist portion of the occupant can be suppressed. The bent portion can also be more precisely formed. That is, with the above seat frame, by the waist portion supporting region capable of more stably supporting the waist portion of the occupant and enhancing the rigidity more, the shock absorbing property for rear surface collision can be improved.

In the above seat frame, the connection portion may have a reinforcing region formed in a shape that projects toward the lower frame. By doing so, rigidity of the connection portion connecting the waist portion supporting region and the bent portion can be enhanced. Thereby, in a case where a load is applied to the waist portion supporting region, the extending region of the bent portion can be highly precisely abutted with the lower frame. Thus, a shock absorbing property of the bent portion can be improved.

In the above seat frame, the bent portion has a member attachment portion to which a member is attached. By doing so, a space in the seat outer side direction from the bent portion can be effectively utilized. Thereby, space utilization efficiency inside the conveyance seat is improved. Thus, a size increase in the conveyance seat can be suppressed.

In the above seat frame, the lower frame has a forward extending region that extends to face the extending region of the bent portion in a lower portion of the lower frame. By doing so, at the time of the waist portion supporting region receiving a load, the extending region of the bent portion extending on the seat rear side and the forward extending region of the lower frame extending on the seat front side are easily abutted with each other. Thus, the load received by the waist portion supporting region is easily transmitted to the lower frame.

In the above seat frame, the lower frame has a bead portion that extends in the seat width direction and projects toward the sitting part, the extending region of the bent portion has a recessed portion recessed toward the sitting part, and the recessed portion and the bead portion are arranged at positions to face each other. By doing so, contact between the bead portion of the lower frame projecting on the seat front side and the bent portion is suppressed. Thus, a size increase in the seat frame can be suppressed.

In the above seat frame, the waist portion supporting member is formed in a shape that spreads in the seat width direction from the coupling region toward the waist portion supporting region. By doing so, the load received by the waist portion supporting region can be efficiently divided to the coupling region. Since the waist portion supporting region and the coupling region are stably connected, the rigidity of the waist portion supporting region can be enhanced.

In the above seat frame, the waist portion supporting member has a region formed with a recessed and projected edge in a lower portion of the waist portion supporting region. By doing so, weight of the waist portion supporting member can be reduced, and the weight of the seat frame can also be reduced.

According to an embodiment of the present disclosure, the seat frame having a high shock absorbing property for rear surface collision, the seat frame whose weight is reduced can be implemented.

According to an embodiment of the present disclosure, the waist portion of the occupant is more stably supported, so that the shock absorbing property for rear surface collision can be improved.

According to an embodiment of the present disclosure, the shock absorbing property by the waist portion supporting member is improved, so that the shock absorbing property for rear surface collision can be improved.

According to an embodiment of the present disclosure, the waist portion supporting region is capable of more stably supporting the waist portion of the occupant and the rigidity is more enhanced. Thus, the shock absorbing property for rear surface collision can be improved.

According to an embodiment of the present disclosure, the extending region of the bent portion precisely abuts the lower frame, so that the shock absorbing property of the bent portion can be improved.

According to an embodiment of the present disclosure, the space utilization efficiency inside the conveyance seat is improved, so that the size increase in the conveyance seat can be suppressed.

According to an embodiment of the present disclosure, the load received by the waist portion supporting region is easily transmitted to the lower frame.

According to an embodiment of the present disclosure, the contact between the bead portion of the lower frame projecting on the seat front side and the bent portion is suppressed, so that the size increase in the seat frame can be suppressed.

According to an embodiment of the present disclosure, the load received by the waist portion supporting region is efficiently divided to the coupling region, so that the rigidity of the waist portion supporting region can be enhanced.

According to an embodiment of the present disclosure, the weight of the waist portion supporting member can be reduced, and the weight of the seat frame can also be reduced.

DETAILED DESCRIPTION

The present disclosure relates to an embodiment of a seat frame for a conveyance seat, including a seat cushion frame that forms a frame of a sitting part of the conveyance seat, a seatback frame that forms a frame of a backrest part of the conveyance seat, and a waist portion supporting member coupled to a lower frame which is included in the seatback frame. The waist portion supporting member has a coupling region that extends in the seat width direction, the coupling region being coupled to the lower frame, and a waist portion supporting region that extends from the coupling region toward the seat cushion frame and supports a waist portion of an occupant, and the waist portion supporting region is longer in the seat width direction than the coupling region. In the following embodiment, a case where the seat frame according to the present disclosure is applied to a seat frame for a vehicle (hereinafter, referred to as the vehicle seat frame) is described.

Hereinafter, a vehicle seat according to the embodiment of the present disclosure and a vehicle seat frame that forms a frame of the vehicle seat is described with reference toFIGS. 1 to 16.

In the following description, the “front to back direction” indicates the front to back direction when seen from a seated person of the vehicle seat, the direction matching with the driving direction of a vehicle. The “seat width direction” indicates the lateral direction of the vehicle seat, matching with the right and left direction when seen from the seated person of the vehicle seat. The “height” direction indicates the height direction of the vehicle seat, matching with the up and down direction when the vehicle seat is seen from the front.

Configuration of Vehicle Seat S

Firstly, based onFIG. 1, a basic configuration of a vehicle seat S according to a first embodiment is described. As shown inFIG. 1, the vehicle seat S has a seatback S1, a seat cushion S2, and a headrest S3. In a lower portion of the seat cushion S2, slide rail mechanisms30for slidingly moving a seat main body (major portion of the vehicle seat S) in the front to back direction are provided.

The vehicle seat S has a vehicle seat frame F1shown inFIG. 2as a framework thereof.FIG. 3shows a left side view of the vehicle seat frame F1, andFIG. 4shows a right side view of the vehicle seat frame F1. Hereinafter, with reference toFIGS. 2 to 4, a configuration of the vehicle seat frame F1is described.

Configuration of Vehicle Seat Frame F1

As shown inFIG. 2, the vehicle seat frame F1includes major constituent elements including a seatback frame10and a seat cushion frame20.

The seatback frame10has an inverted-U-shaped upper frame11, a seatback side frame12L serving as a left end portion in the seat width direction, a seatback side frame12R serving as a right end portion in the seat width direction, and a lower frame13bridged between lower end portions of the seatback side frame12L and the seatback side frame12R. Between the lower end portions of the seatback side frame12L and the seatback side frame12R, a reclining shaft14of a reclining mechanism50is set in a state of passing through the seatback side frame12L and the seatback side frame12R. By operating a reclining operation portion51, the reclining mechanism50is activated, so that an angle of the seatback frame10can be adjusted.

S springs17,18serving as pressure receiving members are respectively bridged between center portions and between lower portions of the seatback side frame12L and the seatback side frame12R. Right and left end portions of the lower S spring18are locked onto hook portions19B of S spring hook brackets19provided respectively in the seatback side frames12L,12R. Each of the S spring hook brackets19is fixed to the seatback side frame by a fixing portion19A, and a welding bead is formed from the fixing portion19A toward the hook portion19B, so that rigidity of the S spring hook bracket is enhanced. Right and left end portions of the center-side S spring17are locked onto locking portions17A provided respectively in the seatback side frames12L,12R.

A pressure receiving member15that supports the back of a seated person of the vehicle seat S from the rear side is provided between the seatback side frame12L and the seatback side frame12R. This pressure receiving member15is formed by a planar spring (Pullmaflex®) and held in a state where the pressure receiving member is hung onto an upper cross member16coupling both end portions of the upper frame11by wires, etc. Specifically speaking, the pressure receiving member15is formed by a pair of right and left side wires15A, plural cross wires15B extended between the side wires15A, and a center wire15C arranged in center portions of the cross wires15B in parallel to the side wires15A. Upper end portions of the side wires15A are attached to the upper cross member16, and lower end portions of the side wires15A are attached to and held by the S spring17.

By combining the pressure receiving member15to the S spring17as described above, a pressure receiving characteristic of the S spring17can be actively utilized over a wide range including the pressure receiving member15while reducing the number of parts.

As shown inFIG. 2, a waist portion supporting member100that supports a waist portion of an occupant seated in the vehicle seat S is attached to a center part of the lower frame13. By suppressing the waist portion of the occupant from coming in backward at the time of rear surface collision and facilitating backward tilt of an upper body of the occupant, this waist portion supporting member100performs a function of letting the upper body of the occupant sink into the vehicle seat S and effectively absorbing a shock on a neck portion. Details of a shape of the waist portion supporting member100and a configuration of coupling with the lower frame13are described below.

Next, the seat cushion frame20serving as a framework of a sitting part of the vehicle seat S is described. As shown inFIG. 2, the seat cushion frame20has an outer shape of a square frame when seen from the upper side, and includes major constituent elements of a cushion side frame21L positioned in a left end portion in the seat width direction, a cushion side frame21R positioned in a right end portion in the seat width direction, and a pan frame22forming a front end portion of the seat cushion frame20. An upper part of a rear end portion of the cushion side frame21L is attached to a lower end portion of the seatback side frame12L via a coupling bracket.

Lower parts of rear end portions of the cushion side frame21L and the cushion side frame21R are coupled to each other by a member extending along the seat width direction as shown inFIG. 2. This member is a coupling pipe24serving as a hollow member, specifically, a round pipe. Both end portions in the seat width direction of the coupling pipes24are supported by the cushion side frame21L and the cushion side frame21R via end portion sleeves serving as tubular members.

Plural S springs25serving as bottom portion supporting members are provided between the cushion side frame21L and the cushion side frame21R and placed side by side in the seat width direction. The S springs25are provided for supporting a bottom portion of the occupant which is a seated person, and extend along in the front to back direction. Front end portions of the S springs25are fixed to an upper end surface of the pan frame22. Rear end portions of the S springs25are secured to the above coupling pipe24by engagement hooks26and L-angle-shaped fixing brackets27arranged between the cushion side frame21L and the cushion side frame21R.

The vehicle seat S also includes a height adjustment mechanism40configured to adjust a height of the seat cushion S2. This height adjustment mechanism40is arranged between the seat cushion frame20and upper rails32of the slide rail mechanisms30. Each of the slide rail mechanisms30includes a lower rail31and the upper rail32. By the upper rails32to which the seat cushion frame20is coupled sliding with respect to the lower rails31, the vehicle seat frame F1is movable in the front to back direction. By the occupant operating a height adjustment operation portion46, height of the seat main body including the seat cushion S2is adjusted by the height adjustment mechanism40.

A left side surface shape of the vehicle seat frame F1is described based onFIG. 3. As shown inFIG. 3, a side surface of the seatback side frame12L is formed in a shape that extends to become wider from a coupling point to the upper frame11toward a coupling point to the seat cushion frame20. Plural holes including airbag attachment holes12aand stay cloth clip attachment holes12bare formed on the side surface of the seatback side frame12L.

An airbag module is fastened to the air bag attachment holes12aby bolts. Clips are attached to a stay cloth at two points in a lower portion on one side in the seat width direction at the time of attachment. By respectively attaching the two clips attached to the stay cloth to the stay cloth clip attachment holes12bat two points of the seatback side frame12L, the stay cloth is fixed to the seatback frame10. Since the airbag attachment holes12aand the stay cloth clip attachment holes12bare arranged close to each other, an airbag can be efficiently deployed in the stay cloth. Therefore, the airbag is promptly deployed in the direction guided by the stay cloth.

Plural fragile portions are formed around a lower side end portion of the seatback side frame12L. The fragile portions are points where strength is lowered in order to promote deformation of the frame. In the present embodiment, the fragile portions are made as holes formed in a bead-like shape recessed to the seat inner side from an outer peripheral surface of the seatback side frame12L or in a frame. By providing such fragile portions in the seatback side frame, the seatback side frame is deformed at points of the fragile portions at the time of rear surface collision, so that a shock is efficiently absorbed.

As shown inFIG. 3, a bead portion12cextending in the seat width direction from the side surface of the seatback side frame12L (12R) to a back surface, the bead portion being recessed to the seat inner side functions as the fragile portion. A hole provided on the seat upper side of the bead portion on the back surface of the seatback side frame12L (12R) also functions as the fragile portion. A hole12fprovided around a seat lower side end portion on the side surface of the seatback side frame12L (12R) also functions as the fragile portion.

The S spring hook bracket19is provided on the upper side of a bead portion12cfunctioning as the fragile portion. By applying a load of the occupant to the S spring hook bracket19at the time of rear surface collision, deformation easily occurs at the point of the bead portion12cfunctioning as the fragile portion. Thereby, a shock absorbing property can be improved.

Reinforcing portions for improving strength are formed in the seatback side frame12L (12R), so that strength of selected parts is ensured. For example, a substantially L-shaped bead portion12dprovided on the side surface of the seatback side frame12L (12R) functions as the reinforcing portion. A substantially I-shaped bead portion12eprovided on the seat front side of the bead portion12don the side surface of the seatback side frame12L (12R) also functions as the reinforcing portion.

As shown inFIG. 3, bead portions21a,21bextending from a center portion to a front portion (regions projected to the seat outer side) are provided respectively in an upper side end portion and in a lower side end portion on the side surface of the seatback side frame12L. The height adjustment operation portion46of the height adjustment mechanism40is arranged between the upper bead portion21aand the lower bead portion21b. In such a way, by effectively utilizing a space between the upper bead portion21aand the lower bead portion21b, the vehicle seat S can be compactly formed.

Next, a right side surface shape of the vehicle seat frame F1is described based onFIG. 4. Since a side surface of the seatback side frame12R is the same as the side surface of the seatback side frame12L, description thereof is omitted, and a side surface shape of the cushion side frame21R is described below.

As shown inFIG. 4, on the side surface of the cushion side frame21R, bead portions21c,21dextending from a center portion to a rear side portion are provided respectively in an upper side end portion and in a lower side end portion. A distance between the upper bead portion21cand the lower bead portion21dis gradually enlarged from the seat front side to the seat rear side. A bead portion21eformed in a shape of three connected holes is provided between the upper bead portion21cand the lower bead portion21d. The three holes provided in the bead portion21emay be used for attachment of members. In such a way, by forming the holes for attachment of members in the bead portion21e, rigidity of a member attachment part of the cushion side frame21R can be improved.

Configuration of Waist Portion Supporting Member100

Next, with reference toFIGS. 5 to 11, the details of the configuration of the waist portion supporting member100provided in the vehicle seat frame F1according to the present embodiment is described. In the following description, the directions of portions of the waist portion supporting member100corresponds to the direction at the time of attaching the waist portion supporting member100to the lower frame13.

FIG. 5is an enlarged view of major portions ofFIG. 2, showing a coupling point of the waist portion supporting member100and the lower frame13.FIG. 6is a back view of the coupling point of the waist portion supporting member100and the lower frame13.FIG. 7is a cross-sectional view taken along the line VII-VII inFIG. 6.FIG. 8is a perspective view of the waist portion supporting member100.FIG. 9is an upper surface view of the waist portion supporting member100.FIG. 10is a side view of the waist portion supporting member100.FIG. 11shows a configuration example in a case where a wire harness is attached to the waist portion supporting member100.

As shown inFIG. 5, the waist portion supporting member100is attached to the lower frame13in such a manner that a surface supporting the waist portion (waist portion supporting region120) is placed between the reclining shaft14and the lower frame13in the seat front to back direction. In such a way, by arranging the waist portion supporting member100on the rear side of the reclining shaft14, even in a case where the waist portion supporting member100is warped in a normal seating state, contact with the reclining shaft14can be prevented. Thus, generation of a contact sound can be suppressed.

As shown inFIG. 5, a flange portion13bof the lower frame13extends in the seat width direction from a part where the lower frame13is connected to the seatback side frame12L to a part where the lower frame13is connected to the seatback side frame12R. End portions of the flange portion13bare positioned respectively in the vicinity of upper portions of parts where the reclining shaft14passes through the lower frame13.

As shown inFIGS. 8 to 10, the waist portion supporting member100has a coupling region110coupled to the lower frame13(the coupling region110extending in the seat width direction), the waist portion supporting region120extending from the coupling region110to the seat front side and supporting the waist portion of the occupant, a rearward extending region130extending from the waist portion supporting region120to the seat rear side, bent portions140formed by bending end portions in the seat width direction of the waist portion supporting member100to the inner side in the seat width direction, and connection portions150connecting the waist portion supporting region120and the bent portions140. Hereinafter, details of the portions of the waist portion supporting member100are described.

Firstly, a configuration of the coupling region110in the waist portion supporting member100is described. As shown inFIG. 9, length W1in the seat width direction of the coupling region110is shorter than length W2in the seat width direction of the waist portion supporting region120. In other words, the length W2in the seat width direction of the waist portion supporting region120is longer than the length W1in the seat width direction of the coupling region110.

In such a way, by making the length in the seat width direction of the waist portion supporting region120longer than the length in the seat width direction of the coupling region110, the coupling region110can be downsized while sufficiently ensuring a surface of the waist portion supporting region120and stably supporting the waist portion of the occupant. That is, with the above configuration, while holding a waist portion supporting function of the waist portion supporting member100, the part attached to the lower frame13can be downsized, and thereby, the whole weight can be reduced.

As shown inFIG. 9, in a case where the waist portion supporting member100is seen from the seat upper side, the waist portion supporting member is formed in a shape of spreading widthwise (width in the seat width direction) from the coupling region110toward the waist portion supporting region120(for example, a flare shape). By forming the coupling region110and the waist portion supporting region120in such a shape, the coupling region110can stably support the waist portion supporting region120, and a load of the occupant received by the waist portion supporting region120can be divided in a well-balanced manner and transmitted to the coupling region110.

As shown inFIG. 10, the coupling region110is formed in a substantially L-like shape formed by bending a seat rear side portion to be bent to the seat lower side. As shown inFIGS. 6 and 7, the coupling region110is welded and fixed to the lower frame13in the lower side end portion bent to the seat lower side.

As shown inFIGS. 6 and 7, on the rear surface side of the coupling region110, projected portions111projected towards the seat lower side are formed in the seat lower side end portion at positions on both sides of a bead portion121projecting to the seat outer side of the lower frame13. Respectively for the projected portions111, positioning holes112for determining a coupling position of the coupling region110and the lower frame13are formed. The lower side end portion of the coupling region110is welded and fixed for example by arc welding at welded portions200positioned above bead portions201which are recessed to the seat inner side of the lower frame13. Welding is not limited to arc welding but other welding methods such as laser welding may be used. Further, as shown inFIG. 6, in the present embodiment, the welded portions200and the positioning holes112are provided to be positioned on the substantially straight line in the seat width direction.

Next, a configuration of the waist portion supporting region120in the waist portion supporting member100is described. As shown inFIG. 5, the waist portion supporting region120is a part which is the surface supporting the waist portion at the time of attaching the waist portion supporting member100to the lower frame13. As shown inFIG. 8, by forming plural circular and substantially oval holes in the waist portion supporting region120, weight of the waist portion supporting member100is reduced.

The bent portions140and the connection portions150are provided in end portions in the seat width direction of the waist portion supporting region120. As shown inFIG. 8, cutout portions160are provided around the connection portions150(that is, in the seat front to back direction). By providing the cutout portions160, deformation of the surface of the waist portion supporting region120is suppressed at the time of bending the bent portions140to the inner side in the seat width direction.

As shown inFIGS. 8 and 10, bead-shaped reinforcing portions151projected towards the inner side of the waist portion supporting member100, that is, toward the lower frame13, are provided in the connection portions150. By providing the reinforcing portions151, rigidity of the connection portions150is strengthened.

Next, a configuration of the bent portions140in the waist portion supporting member100is described. As shown inFIG. 9, the bent portions140are connected on the outer sides in the seat width direction of the connection portions150, and formed by bending connection points to the connection portions150substantially perpendicularly rearward. As shown inFIGS. 7 and 10, each of the bent portions140has a bent portion rearward extending region141extending toward the seat rear side, that is, toward the lower frame13.

As shown inFIG. 7, a lower frame lower end portion13aserving as an end portion of the lower frame13on the seat lower side is positioned on the seat lower side of a bent portion lower end portion142serving as an end portion of the bent portion140on the seat lower side in the bent portion rearward extending region141of the bent portion140, and extends toward the seat front side, that is, toward the waist portion supporting member100. In such a way, as shown inFIG. 7, the bent portion rearward extending region141and a forward extending region13cof a seat lower portion of the lower frame13are arranged to be separated from each other at positions to face each other.

In such a way, the bent portion rearward extending region141is arranged at a position where the region does not abut the forward extending region13cof the lower frame13at a normal time. However, at the time of rear surface collision, due to application of a load of the occupant to the waist portion supporting region120, the bent portion rearward extending region141abuts the forward extending region13cof the lower frame13, and the bent portion140is deformed. Thereby, a shock is absorbed by the bent portion140at the time of rear surface collision.

As shown inFIG. 7, along an edge on the seat rear side in the bent portion140, a recessed portion143recessed toward the seat front side and a bead portion201projecting to the seat front side of the lower frame13are arranged to face each other. Thereby, abutment of the bead portion201of the lower frame13with the bent portion140at the normal time is suppressed. By doing so, the waist portion supporting member100and the lower frame13can be compactly formed. Thus, a size increase in the seat frame can be suppressed.

As shown inFIG. 10, holes (member attachment holes145) for attaching some members forming the vehicle to the bent portion140are formed in the bent portion140. In the present embodiment, two member attachment holes145are provided in the bent portion140. However, the present disclosure is not limited to this but one or three or more member attachment holes145may be formed.

For example, as shown inFIG. 11, by engaging a clip for attaching a wire harness with the member attachment holes145, the wire harness can be attached to the bent portion140. In such a way, by providing the member attachment holes145capable of attaching the members to the bent portion140, a space from the waist portion supporting member100to the seatback side frame12L,12R can be effectively utilized.

Next, the rearward extending region130in the waist portion supporting member100is described. As shown inFIG. 8, an end portion on the seat rear side of the rearward extending region130is positioned on the seat front side of an end portion on the seat rear side of the bent portion140. At the normal time, the rearward extending portion130does not abut the lower frame13. However, in a case where a strong shock is received at the time of rear surface collision, a load of the occupant is applied to the waist portion supporting region120, and thereby, the bent portion140abuts the lower frame13and successively the rearward extending region130abuts the lower frame13. The rearward extending region130has a wider surface to abut the lower frame13than the bent portion140. Thus, by abutting the rearward extending region130with the lower frame13to support the waist portion supporting region120at the time of rear surface collision as described above, the waist portion of the occupant can be not coming into the rear side at the time of rear surface collision.

As shown inFIG. 8, by forming recessed portions131in an edge portion on the seat lower side of the rearward extending region130, a recessed and projected edge portion is formed. Further, plural circular- and substantially-oval-shaped holes are formed on a surface of the rearward extending region130. Thereby, weight of the waist portion supporting member100is reduced.

With the vehicle seat frame F1according to the present embodiment described above, while ensuring the size of the waist portion supporting region120that supports the waist portion of the occupant in the waist portion supporting member100, the coupling region110coupling the waist portion supporting member100to the seatback frame10can be downsized. That is, with the vehicle seat frame F1, by providing the waist portion supporting member100which is capable of being downsized while stably supporting the waist portion of the occupant on the wide surface, a seat frame having a high shock absorbing property for rear surface collision, the seat frame whose weight is reduced can be realized.

The bent portions140are provided in the end portions in the seat width direction of the waist portion supporting member100. Thereby, rigidity of the waist portion supporting region120that supports the waist portion of the occupant can be improved in the waist portion supporting member100. That is, with the vehicle seat frame F1, by more stably supporting the waist portion of the occupant, the shock absorbing property for rear surface collision can be improved.

The bent portion140has the bent portion rearward extending region141extending toward the lower frame13. Thereby, in a case where a load is applied to the waist portion supporting region120that supports the waist portion of the occupant in the waist portion supporting member100, the extending region of the bent portion140abuts the lower frame130and is deformed, so that a shock can be absorbed by the bent portion140. That is, with the vehicle seat frame F1, by improving a shock absorbing property by the waist portion supporting member100, the shock absorbing property for rear surface collision can be improved.

The cutout portion160is provided around the connection portion150between the waist portion supporting region120and the bent portion140. Thereby, at the time of forming the bent portion140in the waist portion supporting member100, deformation of the waist portion supporting region120that supports the waist portion of the occupant can be suppressed. The bent portion140can also be formed very precisely. That is, with the vehicle seat frame F1, by the waist portion supporting region capable of more stably supporting the waist portion of the occupant and enhancing the rigidity more, the shock absorbing property for rear surface collision can be improved.

The reinforcing regions (reinforcing portions151) projecting toward the lower frame13are provided in the connection portions150. Thereby, the rigidity of the connection portions150connecting the waist portion supporting region120and the bent portions140can be enhanced. Thereby, in a case where a load is applied to the waist portion supporting region120, the extending regions of the bent portions140can very precisely abut the lower frame13. Thus, a shock absorbing property of the bent portions140can be improved.

The member attachment portions (member attachment holes145), to which other members are attached, are formed in the bent portion140. Thereby, a space in the seat outer side direction from the bent portion140can be effectively utilized. Thereby, space utilization efficiency inside the seat is improved. Thus, a size increase in the seat can be suppressed.

The above embodiment does not limit the present disclosure but only suggests one example for facilitating understanding of the present disclosure. The present disclosure can be changed and improved without departing from the gist thereof, and the present disclosure includes equivalents thereof as a matter of course.

For example, the example in which the waist portion supporting member100according to the present embodiment is applied to the vehicle seat frame including the mechanism where the position adjustment mechanism (front and rear positions, upper and lower positions, and angles of the seatback) of the vehicle seat S is manually adjusted is described in the above embodiment. However, the above waist portion supporting member100can similarly be applied to a vehicle seat frame in which a position adjustment mechanism of a vehicle seat S is adjusted by using an electric actuator.

FIG. 12is a perspective view of a vehicle seat frame F2serving as a framework of the vehicle seat S whose position adjustment mechanism is electrically adjusted, andFIG. 13is a side view of the vehicle seat frame F2.FIG. 14is a directional view seen from the XIV direction ofFIG. 12, the partially enlarged view of attachment points of S springs17,18in the vehicle seat frame F2.FIG. 15is a directional view seen from the XV direction ofFIG. 12, the partially enlarged view of the inside of a cushion side frame21L in the vehicle seat frame F2.FIG. 16is a directional view seen from the XVI direction ofFIG. 12, the partially enlarged view of a back surface of a lower rail31in the vehicle seat frame F2.

As shown inFIGS. 12 and 13, a configuration of a seatback frame10of the vehicle seat frame F2is generally the same as that of the vehicle seat frame F1. Thus, different points are described below.

As shown inFIGS. 12 and 14, in the vehicle seat frame F2, an actuator300that generates a drive force for adjusting an angle of a reclining mechanism50is attached to a portion around a bonded part between a lower frame13and a seatback side frame12R. The actuator300includes a connector301to which a cable is connected. Drive power, control signals, etc. are inputted to the actuator300via the cable and the connector301.

The connector301is arranged at a position overlapping with an S spring hook bracket19provided in the side of the seatback side frame12R in the seat front-to-back direction. By arranging the connector301and the S spring hook bracket19in such a way, an inner space of the vehicle seat frame F2can be effectively utilized, and at the time of receiving a shock from the rear side, the connector301can be protected.

As shown inFIG. 14, a locking portion17A that locks the S spring17is provided between upper and lower stay cloth clip attachment holes12bof the seatback side frame12R. By arranging the locking portion17A between the stay cloth clip attachment holes12bin such a way, a part onto which force is applied at the time of deploying the airbag can be reinforced. A locking portion17A is also provided between stay cloth clip attachment holes12bin a seatback side frame12L.

As shown inFIG. 13, on a side surface of the cushion side frame21L on the seat outer side, bead portions21a,21bextending from a center portion to a front side portion are provided respectively in an upper side end portion and a lower side end portion. An actuator310that activates a movable portion of a height adjustment mechanism40is attached between the upper and lower bead portions21a,21b. By effectively utilizing a space between the upper and lower bead portions21a,21bin such a way, the vehicle seat S can be compactly formed.

The actuator310that activates the height adjustment mechanism40includes a connector311to which a cable is connected. Drive power, control signals, etc. are inputted to the actuator310via the cable and the connector311. As shown inFIGS. 12, 13, and 15, the connector311is arranged on the lower side of a wire320for fixing a cover of the vehicle seat S. By arranging the connector311on the lower side of the wire320in such a way, at the time of receiving a shock from the upper side, the connector311can be protected.

As shown inFIG. 13, an actuator350that activates a slide rail mechanism30is attached on the lower side of the lower rail31.

As shown inFIG. 15, a cut and upward-bent portion330, cut and bent upward to the seat upper side from a hole portion331, is provided between respective attachment parts of the wire310and a wire321of the cushion side frame21L on a side surface of the cushion side frame21L on the seat inner side. By fixing a harness to a part of this cut and upward-bent portion330extending in the seat width direction with a binding tool (binding band), movement in the seat width direction of the harness can be suppressed.

As shown inFIG. 16, a rail bottom bracket340, in which engagement holes341that engage claws of a foot cover of the vehicle seat S are formed, is attached on a bottom surface of the lower rail31on the seat rear side. By providing such a rail bottom bracket340, the foot cover can be stable fixed to the vehicle seat frame F2.

The above cut and upward-bent portion330and the rail bottom bracket340may also be provided in the vehicle seat frame F1as a matter of course.

Vehicle Seat Frame F1aIncluding Side Airbag Mechanism SA

Next, a vehicle seat frame F1aaccording to a modified example of the vehicle seat frame F1is described based onFIGS. 17 to 31. The vehicle seat frame F1adescribed below is different from the vehicle seat frame F1in a point that a side airbag mechanism SA is attached to the seatback side frame12L of the vehicle seat frame F1according to the first embodiment. However, the other points are common between the vehicle seat frames. Hereinafter, points that are different from the vehicle seat frame F1are described. First of all, outlines of the figures is briefly described.

FIG. 17is a perspective view of the vehicle seat frame F1a, andFIG. 18is an exploded perspective view of the side airbag mechanism SA attached to the vehicle seat frame F1a. Although details are described below, as shown inFIG. 18, the side airbag mechanism SA includes a support member60, an airbag module62, and a stay cloth attachment plate66.

FIG. 19is a side view showing a state where the support member60and the stay cloth attachment plate66are attached to a seatback side frame12L, andFIG. 20is a side view showing a state where the airbag module62is further attached inFIG. 19.

FIG. 21is a side view from the seat inner side of the seatback side frame12L to which the side airbag mechanism SA is attached.FIG. 22is a cross-sectional view taken along the line XXII-XXII ofFIG. 21, andFIG. 23is cross-sectional view taken along the line XXIII-XXIII ofFIG. 20.

FIG. 24is a perspective view of the side of an outer plate of the support member60,FIG. 25is a perspective view of the side of an inner plate of the support member60, andFIG. 26is a perspective view of the rear side of the support member60.FIG. 27is a view for illustrating a state of the support member when a shock is received from the seat outer side.

FIG. 28is a left side view of a seatback S1, andFIG. 29is a cross-sectional view taken along the line XXIX-XXIX ofFIG. 28.FIG. 30is a front view of the stay cloth attachment plate66, andFIG. 31shows a state where stay cloths are attached to the stay cloth attachment plate66.

As described above, the side airbag mechanism SA includes the support member60, the airbag module62, and the stay cloth attachment plate66. As shown inFIG. 19, the support member60and the stay cloth attachment plate66are attached side by side in the up and down direction to abut a surface of the seatback side frame12L on the seat outer side. As shown inFIG. 20, the airbag module62is arranged on the seat outer side of the support member60and the stay cloth attachment plate66, and the airbag module62is attached to the seatback side frame12L via the support member60and the stay cloth attachment plate66.

The support member60is provided for supporting the occupant in the seat width direction from external force applied to the vehicle. For example, the support member is made of elastomer resin such as thermo polyolefin (TPO) and thermoplastic polyurethane (TPU). The support member60is attached to at least one of the right seatback side frame12R and the left seatback side frame12L, in the present embodiment, to the left seatback side frame12L.

The airbag module62is a device that absorbs a shock at the time of collision of the vehicle and protects the occupant. In the present embodiment, the airbag module62is a caseless airbag module having no module case. However, the present disclosure is not limited to this but the airbag module may have a module case.

The airbag module62includes an airbag62A and an inflator62B. The airbag62A and the inflator62B are wrapped and held together by a wrapping material. The inflator62B is a device that generates a gas in accordance with an input signal from a harness64, and by inputting the gas generated by the inflator62B into the airbag62A, the airbag62A is opened and deployed.

Side surfaces of the airbag62A are covered by the stay cloths attached to the stay cloth attachment plate66and the developing direction is guided by the stay cloths.

Details of a configuration of the support member60are now described. As shown inFIGS. 24 to 26, the support member60includes an inner plate60A fixed to the seatback side frame12L on the inner side in the seat width direction, an outer plate60B fixed to the seatback side frame12L on the outer side in the seat width direction, and plural ribs60F coupling front portions of the inner side plate60A and the outer side plate60B.

Front side end portions of the inner side plate60A and the outer side plate60B are coupled to each other. The inner side plate60A and the outer side plate60B are provided in such a manner that a gap between both the plates increases from the front side end portions to the rear side.

As shown inFIG. 24, the outer plate60B is formed in a substantially flat plate shape, and a length of the outer plate in the up and down direction is substantially the same as that of the inner plate60A.

A first flange portion60C and a second flange portion60D are respectively provided in an upper side end portion and a rear side end portion of the outer plate60B. The first flange portion60C extends from the upper side end portion of the outer plate60B to the seat outer side, and the second flange portion60D extends from the rear side end portion of the outer plate60B to the seat outer side. The first flange portion60C and the second flange portion60D are connected to each other at an upper rear side corner portion of the outer plate60B. By providing the first flange portion60C and the second flange portion60D, an outer shape of a vehicle seat S is maintained.

The airbag module62is arranged to abut the outer plate60B. By the first flange portion60C and the second flange portion60D, an effect of preventing position displacement of the airbag module62to the upper side and the rear side is also provided.

As shown inFIG. 25, the inner plate60A is formed in a level difference structure having a level difference between the front side and the rear side in such a shape that the gap between the inner plate60A and the outer plate60B is more on the rear side than the front side.

As shown inFIG. 26, the ribs60F extend in the seat front to back direction and couple the inner plate60A and the outer plate60B. The plural ribs60F are provided, and the ribs60F are arranged at substantially equal intervals from the vicinity of upper ends to the vicinity of lower ends between the inner plate60A and the outer plate60B. A length of the ribs60F in the seat front to back direction is shorter than a corresponding length of the inner plate60A and the outer plate60B. A space is formed between the inner plate60A and the outer plate60B on the seat rear side of the ribs60F. In such a space, a coupling part of an upper frame11and the seatback side frame12L is arranged. As shown inFIG. 22, even at the time point when the occupant is not seated, the ribs60F and the seatback side frame12L at least partly abut each other.

By providing the ribs60F in such a way, rigidity of the inner plate60A and the outer plate60B is enhanced, so that a property of holding the occupant can be enhanced, and a shock absorbing property can also be enhanced. The length of the ribs60F in the seat front to back direction may reach the rear side of a level different part of the inner plate60A. By doing so, the rigidity of the inner plate60A and the outer plate60B can be more improved. As a matter of course, a shape of the ribs60F is not limited to the shape shown in the figures but may be for example a flat plate shape extending in the up and down direction.

Next, an attachment structure of the support member60is described. As shown inFIGS. 25 and 26, two screw attachment portions60E are provided in a rear side end portion of the inner plate60A.

Each of the screw attachment portions60E is formed by a screw through hole and a thick portion around the screw through hole. The screw through hole is a hole through which a screw61is inserted, and a through hole is provided in the inner plate60A at a corresponding position. In such a way, by providing the thick portion around the screw through hole in the screw attachment portion60E, rigidity of the screw attachment portion60E is improved.

As shown inFIG. 22, the coupling part of the upper frame11and the seatback side frame12L is arranged between the inner plate60A and the outer plate60B. Screw attachment holes are provided in the upper frame11at positions to face the screw attachment portions60E, and the screw attachment portions60E and the upper frame11are fastened to each other by the screws61. In such a way, the support member60is fixed to the coupling part of the upper frame11and the seatback side frame12L.

The inner plate60A of the support member60arranged on the seat inner side is fastened to the coupling part of the upper frame11and the seatback side frame12L, while the outer plate60B arranged on the seat outer side abuts, but is not fastened to a part of the seatback side frame12L on the seat outer side and hence serves as a free end.

By fixing the inner part of the support member60and making the outer part the free end in such a way, as shown inFIG. 27, in a case where a load is added to the support member60from the outside, the screw attachment portions60E serve as a fixed end to facilitate movement and deformation of the outer plate60B, so that the load can be released. That is, by the inner part of the support member60serving as the fixed end and the outer part serving as the free end, the property of absorbing a shock from the outside is improved. Against a load from the seat inner side, since the ribs60F of the support member60are supported by the seatback side frame12L, the property of holding the occupant can be enhanced.

Since only the inner part of the support member60serves as the fixed end, by providing the thick portions in the screw attachment portions60E serving as the fixed end, the rigidity of the screw attachment portions60E is improved, so that the support member60can stably hold.

Since the inner plate60A is arranged to overlap with a height of a chest portion of the occupant, ribs of the occupant can be properly protected by support of the inner plate60A.

As described above, the support member60is attached by arranging the inner plate60A and the outer plate60B over the inner side and the outer side in the seat width direction in the coupling part of the upper frame11and the seatback side frame12L. Therefore, the support member60is arranged more compactly than the one attached to the coupling part of the upper frame11and the seatback side frame12L by using a space only on the outer side in the seat width direction.

Next, a configuration of the stay cloth attachment plate66to which the stay cloths serving as a guide member that guides the deployment direction of the airbag62A of the airbag module62is attached, and an attachment structure of the stay cloth attachment plate is described.

The stay cloth attachment plate66is a thin-plate-shaped resin plate. For example, the stay cloth attachment plate66may be made of resin such as thermo polyolefin (TPO) and thermoplastic polyurethane (TPU).

As shown inFIG. 30, the stay cloth attachment plate66is formed by a substantially-rectangular-shaped rectangular region66A, and a substantially-arch-shaped arch region66B coupled to the rectangular region66A. In a center portion of the rectangular region66A, a first through hole66C, a second through hole66D, and a third through hole66E are formed along the longitudinal direction of the rectangular region66A. Washers67are provided for the first through hole66C and the third through hole66E.

As shown inFIG. 18, a first attachment portion62D and a second attachment portion62E of the airbag module62are respectively inserted through the first through hole66C and the second through hole66D. The first through hole66C and the second through hole66D are arranged at positions to face an airbag attachment hole12aand an airbag attachment hole12gof the seatback side frame12L. The first attachment portion62D and the second attachment portion62E are stud bolts projecting from the inflator62B to the seat inner side.

The first attachment portion62D of the airbag module62is inserted through the first through hole66C of the stay cloth attachment plate66and the airbag attachment hole12aof the seatback side frame12L from the seat outer side and fixed by using a fastening tool such as a nut. Similarly, the second attachment portion62E of the airbag module62is inserted through the second through hole66D of the stay cloth attachment plate66and the airbag attachment hole12gof the seatback side frame12L from the seat outer side and fixed by using a fastening tool such as a nut. Thereby, the stay cloth attachment plate66and the airbag module62are fixed to the seatback side frame12L.

A configuration relating to attachment of the stay cloths to the stay cloth attachment plate66is described. As shown inFIG. 30, in the stay cloth attachment plate66, a first sewing portion66F and a second sewing portion66G, to which the stay cloths are respectively sewn, are provided on the left side and the right side of the first through hole66C, the second through hole66D, and the third through hole66E.

Specifically, as shown inFIG. 31, the stay cloth attachment plate66is sewn to the inner stay cloth68at the first sewing portion66F and the second sewing portion66G. The inner stay cloth68and the outer stay cloth69are sewn to each other at a stay cloth sewing portion70. Thereby, the stay cloth attachment plate66, the inner stay cloth68, and the outer stay cloth69are integrated.

Holes are formed at two points of a first hole portion68A and a second hole portion68B of the inner stay cloth68. The first hole portion68A and the second hole portion68B are respectively arranged at positions overlapping with the first through hole66C and the second through hole66D of the stay cloth attachment plate66.

As shown inFIGS. 28 and 29, the side surface of the airbag module62on the seat inner side is covered by the inner stay cloth68, and the side surface on the seat outer side is covered by the outer stay cloth69. Respective end portions of the inner stay cloth68and the outer stay cloth69are sewn together with a skin73of a cushion material72at a split portion71. Thereby, in a case where the gas generated by the inflator62B is charged into the airbag62A, the bulging direction is guided by the inner stay cloth68and the outer stay cloth69, and the airbag62A is deployed while splitting the split portion71.

Hereinafter, a supplementary description is given to a relationship between attachment positions of the support member60, the stay cloth attachment plate66, and the airbag module62.

For example, as shown inFIGS. 19 and 20, a lower end of the stay cloth attachment plate66is positioned above a bead portion12c(fragile portion) formed in the seatback side frame12L. In such a way, by attaching the side airbag mechanism SA to the seatback side frame12L on the upper side of a deformed point at the time of rear surface collision, deformation of an attached point of the side airbag mechanism SA can be prevented. Thereby, a shock onto the side airbag mechanism SA can be eased.

As shown inFIG. 20, in a seat side surface view, the inflator62B is arranged to overlap with both the support member60and the stay cloth attachment plate66.

As shown inFIG. 23, part of the outer plate60B of the support member60(that is, on the side of the free end of the support member60) and the inflator62B are arranged at the positions overlapping with each other in a seat side surface view.

As shown inFIG. 23, the second flange portion60D serving as a rear wall of the support member60and at least part of the harness64are arranged at the positions overlapping with each other in a seat rear surface view. In such a way, by the second flange portion60D receiving a load from the rear side, the harness64can be protected.

As shown inFIG. 23, thickness of the outer plate60B of the support member60is greater than thickness of the stay cloth attachment plate66. By doing so, the rigidity of the support member60receiving a load in the seat width direction can be enhanced more than the stay cloth attachment plate66.

As shown inFIG. 23, at the time of a normal seating posture, at least part of the support member60and at least part of the stay cloth attachment plate66are positioned on the same horizontal plane. In other words, at least part of the support member60and at least part of the stay cloth attachment plate66overlap with each other in the up and down direction. Specifically, an upper end portion of the arch region66B of the stay cloth attachment plate66and a lower end portion of the outer plate60B and a lower end portion of the second flange portion60D of the support member are placed at positions overlapping with each other in the up and down direction.

As shown inFIG. 23, the upper frame11, the inflator62B, and the harness64respectively have parts positioned on the horizontal plane where part of the support member60and part of the stay cloth attachment plate66overlap with each other in the up and down direction.

In the present embodiment, the vehicle seat according to the present disclosure is mainly described. However, the above embodiment does not limit the present disclosure but only suggests one example for facilitating understanding of the present disclosure. The present disclosure can be changed and improved without departing from the gist thereof, and the present disclosure includes equivalents thereof as a matter of course.

For example, in the present embodiment, the configuration in which the support member is attached to only one of the right and left side frames is described. However, in order to enhance the property of holding the occupant on both the sides of the seat, symmetrically formed support members may be attached to both the side frames.

For example, the support member60and the stay cloth attachment plate66may be integrated. Specifically, the outer plate60B of the support member60and the stay cloth attachment plate66may be integrated.

For example, the support member60and the stay cloth attachment plate66may be coupled to each other by a coupling member. Specifically, the outer plate60B of the support member60and the stay cloth attachment plate66may be coupled to each other by a metal or resin coupling plate.

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