Back frame

Abstract

An example of a back frame capable of suppressing deformation when an external force acts to twist the side frame of the back frame is disclosed. [Solution] The first joint W1 on the front side of the joint between the lower beam 6 and the first side frame 3 is located at a position corresponding to the joint W3 between the first recliner and the first side frame 3. As a result, even if stress is generated in the back frame that induces torsional deformation that twists the first side frame 3, the lower beam 6 and the first side frame 3 are joined at the first joint W1, so the lower beam 6 receives the torsional torque M generated in the first side frame 3 as a tensile force. Therefore, deformation that twists the first side frame 3 significantly can be suppressed.

Description

Technical Field

[0001] The present disclosure relates to a back frame used for a seat back of a vehicle seat.

Background Art

[0002] For example, the back frame described in Patent Document 1 is configured to include a round pipe bent into a portal shape, and a pipe or the like that extends in the seat width direction and connects portions extending in the vertical direction of the round pipe.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure discloses an example of a back frame capable of suppressing deformation when an external force acts to twist a portion extending in the vertical direction (hereinafter referred to as a side frame) of the back frame. Note that the “deformation such as twisting of the side frame” refers to, for example, a torsional deformation centered on a virtual axis that passes through the center of the cross section of the side frame and extends along the extending direction of the side frame.

Means for Solving the Problems

[0005] The back frame used for the seat back of a vehicle seat preferably includes at least one of the following constituent elements. In other words, the constituent elements are a first side frame (3) positioned at one end in the seat width direction and extending vertically, a second side frame (4) positioned at the other end in the seat width direction and extending vertically, a first connecting member (5) extending in the seat width direction and connecting the upper end of the first side frame (3) and the upper end of the second side frame (4), a recliner (7A) for changing and maintaining the angles of the first side frame (3) and the second side frame (4), the recliner (7A) being joined and fixed to at least the lower end of the first side frame (3), and a second connecting member (6) extending in the seat width direction and connecting the lower end of the first side frame (3) and the lower end of the second side frame (4).

[0006] Furthermore, the second connecting member (6) is joined to the first side frame (3) at its front and rear sides, and it is desirable that the front joining point (W1) between the second connecting member (6) and the first side frame (3) is located at the same position as the joining point (W3) between the recliner (7A) and the first side frame (3).

[0007] As a result, in the back frame, when an external force acts on the first side frame (3) in such a way that it twists the first side frame (3), the second connecting member (6) and the first side frame (3) are joined together, and therefore the second connecting member (6) receives the torsional torque generated in the first side frame (3) as tensile and compressive forces.

[0008] Furthermore, since torsional deformation is a type of shear deformation, and generally, tensile and compressive deformations can suppress deformation more effectively than shear deformation, deformations that cause a large twist in the first side frame (3) can be suppressed compared to a configuration that relies solely on shear stress to counteract the torsional deformation.

[0009] The back frame may also have the following configuration: In other words, when the recliner (7A) is designated as the first recliner (7A), a second recliner (7B) is provided on the lower end of the second side frame (4), and the front joint (W1) of the joint between the second connecting member (6) and the second side frame (4) is located at a position corresponding to the joint between the second recliner (7B) and the second side frame (4). Furthermore, it is desirable that the front longitudinal middle portion of the second connecting member (6) is located further rearward than one end and the other end in that longitudinal direction. This helps to prevent the second connecting member (6) from interfering with the seated person.

[0010] Furthermore, it is desirable that the cross-sectional shape of the longitudinal middle portion be a roughly C-shape with the upper side open. And, if a rod (8) is provided that extends in the seat width direction and connects the first recliner (7A) and the second recliner (7B), it is desirable that the cross-sectional shape of the longitudinal middle portion of the second connecting member (6) be a roughly C-shape that surrounds the rod (8).

[0011] Incidentally, the symbols in each of the parentheses above are just examples showing the correspondence with the specific configurations etc. described in the embodiments described later, and this disclosure is not limited to the specific configurations etc. indicated by the symbols in the parentheses above. [Brief explanation of the drawing]

[0012] [Figure 1] This is a diagram showing the back frame according to the first embodiment. [Figure 2] This is a diagram showing the upper part of the back frame according to the first embodiment. [Figure 3] This is a diagram showing the back frame according to the first embodiment. [Figure 4] This is a diagram showing the lower beam portion according to the first embodiment. [Figure 5] This diagram shows the connection structure between the lower beam and the first side frame. [Figure 6] This diagram shows the connection structure between the lower beam and the first side frame. [Figure 7] This diagram shows the connection structure between the lower beam and the first side frame. [Figure 8] It is a diagram showing the joining structure between the lower beam part and the first side frame.

Mode for Carrying Out the Invention

[0013] The following "Embodiments of the Invention" show an example of embodiments belonging to the technical scope of the present disclosure. That is, the invention-specific matters described in the claims are not limited to the specific configurations, structures, etc. shown in the following embodiments.

[0014] This embodiment is an example in which the back frame according to the present disclosure is applied to a seat (hereinafter referred to as a vehicle seat) mounted on a vehicle such as a car. The arrows, slashes, etc. indicating the directions attached to each figure are described to facilitate understanding of the relationship between the figures and the shapes of members or parts.

[0015] Therefore, the back frame is not limited to the directions attached to each figure. The directions shown in each figure are the directions in the state where the vehicle seat according to this embodiment is assembled to the vehicle. The figure with slashes does not always show a cross-sectional view.

[0016] At least the members or parts described with reference numerals are provided with at least one, unless otherwise specified such as "one". That is, when there is no such specification as "one", the member may be provided with two or more. The back frame shown in the present disclosure includes at least one of the components such as the members or parts described with reference numerals and the structural parts shown in the drawings.

[0017] (First Embodiment) <1. Outline of the Back Frame> As shown in FIG. 1, the back frame 1 according to this embodiment is an example of a frame used for the seat back of a rear seat of a vehicle. Specifically, the back frame 1 is a frame used for the right seat of the rear seat where three people can ride.

[0018] Note that the seat back is a part for supporting the back of the seated person. The back frame 1 is a member constituting the skeleton of the seat back. Incidentally, a frame 2 for the middle seat is connected to the back frame 1.

[0019] <2. Details of the back frame> <2.1 Composition of the back frame> The back frame 1 includes at least a first side frame 3, a second side frame 4, an upper beam portion 5, a lower beam portion 6, a first recliner 7A, a second recliner 7B, a rod 8, and a back panel (not shown).

[0020] The first side frame 3 is a strength member disposed on one end side in the seat width direction (the left end side in this embodiment) and extending in the vertical direction. The second side frame 4 is a strength member disposed on the other end side in the seat width direction (the right end side in this embodiment) and extending in the vertical direction.

[0021] The upper beam portion 5 is an example of a first connecting member that extends in the seat width direction and connects the upper end sides of the first side frame 3 and the second side frame 4. The upper beam portion 5 is configured to have a substantially U-shaped or substantially C-shaped cross-sectional shape (see FIG. 2) with the rear side open. Incidentally, the cross-sectional shape is an integral part formed by pressing a single steel plate.

[0022] As shown in FIG. 3, the lower beam portion 6 is a lower panel that is an example of a second connecting member that extends in the seat width direction and connects the lower end sides of the first side frame 3 and the second side frame 4. A rectangular frame-shaped frame body is formed by the first side frame 3, the second side frame 4, the upper beam portion 5, and the lower beam portion 6.

[0023] The back panel (not shown) is a plate-shaped member disposed on the back side of the frame body and covering the entire back of the frame body. Incidentally, a retractor 9 for winding the seat belt 10 is fixedly disposed below the upper beam portion 5 of the back panel as shown in FIG. 1.

[0024] Furthermore, a belt receiving portion 5A is provided in the upper beam portion 5. The belt receiving portion 5A is a through-hole through which the seat belt 10 is inserted. When tension T is generated in the seat belt 10, the belt receiving portion 5A receives that tension T.

[0025] The first recliner 7A and the second recliner 7B are devices for changing and maintaining the angle of the back frame 1. Specifically, one side of the first recliner 7A is welded to the lower end of the first side frame 3, and the other side is fixed to the vehicle via a bracket 11A.

[0026] The second recliner 7B is joined and fixed to the lower end of the second side frame 4 by welding on one side, and fixed to the vehicle via a bracket 11B on the other side. Incidentally, the "one side" mentioned above is the "right side" in this embodiment, and the "other side" mentioned above is the "left side" in this embodiment.

[0027] Rod 8 extends in the seat width direction and connects the first recliner 7A and the second recliner 7B. The driving force generated by the electric motors 8A and 8B is transmitted to the first recliner 7A and the second recliner 7B via rod 8.

[0028] <2.2 Detailed Structure of the Lower Beam Section> As shown in Figure 4, the lower beam section 6 includes a front panel section 61, a rear panel section 62, and a bottom panel section 63. The front panel section 61, the rear panel section 62, and the bottom panel section 63 are integrally formed from a single steel plate through press working.

[0029] Furthermore, at least the longitudinal middle portion of the lower beam 6 is configured with a roughly C-shaped cross-section that opens upwards, as shown in Figure 5. Specifically, this longitudinal middle portion has a roughly C-shaped cross-section that opens upwards, surrounding the rod 8.

[0030] The longitudinal middle section of the lower beam 6 refers to a predetermined range that includes the longitudinal center (midpoint) of the lower beam 6. Incidentally, in this embodiment, the cross-sectional shape is approximately C-shaped in the range from the vicinity of electric motor 8A to the vicinity of electric motor 8B.

[0031] As shown in Figure 1, the longitudinal middle portion of the front panel 61 is recessed towards the rear, as it is located further rearward than one end and the other end in the longitudinal direction. This recessed shape is intended to avoid interference with the seated person's buttocks.

[0032] As shown in Figure 4, the rear panel section 62 is provided with a beam section 62A that extends in the sheet width direction. As shown in Figure 5, the beam section 62A is composed of protrusions that project in the front-rear direction of the sheet and extend in the sheet width direction. Therefore, the beam section 62A functions as a reinforcing part that improves the bending rigidity of the rear panel section 62.

[0033] Furthermore, one longitudinal end of the lower beam 6 is joined to the lower end of the first side frame 3 by arc welding. The other longitudinal end of the lower beam 6 is joined to the lower end of the second side frame 4 by arc welding.

[0034] <2.3 Joint structure between the lower beam and the side frame> The following description concerns the connection structure between the lower beam 6 and the first side frame 3. Since the connection structure between the lower beam 6 and the first side frame 3 is the same as that between the lower beam 6 and the second side frame 4, the description of the connection structure between the lower beam 6 and the second side frame 4 is omitted.

[0035] As shown in Figure 6, the lower beam section 6 is provided with a first joint W1, a second joint W2, and the like. The first joint W1 is the part that is joined to the front side of the first side frame 3. The second joint W2 is the part that is joined to the rear side of the first side frame 3.

[0036] The first joint W1 is located at a position corresponding to the joint W3 between the first recliner 7A and the first side frame 3, as shown in Figure 7. Note that "the first joint W1 is located at a position corresponding to the joint W3" refers to, for example, the following configuration.

[0037] In other words, this configuration refers to a state in which the first joint W1 is included in a sector-shaped range obtained by expanding the radius of the sector that indicates the joint range. The joint range refers to a sector-shaped range centered on the center of the first recliner 7A (in this embodiment, the center of the rod 8), with the length of the arc of the sector being the longitudinal dimension of the arc-shaped joint W3.

[0038] <3. Features of the back frame according to this embodiment> When tension T is generated in the seat belt 10, the back frame 1 receives this tension T at the belt receiving portion 5A, and as shown in Figure 8, stress is generated in the first side frame 3 that induces torsional deformation that twists the first side frame 3.

[0039] In contrast, in the back frame 1 according to this embodiment, the first joint W1 on the front side of the joint between the lower beam 6 and the first side frame 3 is located at a position corresponding to the joint W3 between the first recliner 7A and the first side frame 3.

[0040] As a result, even if stress occurs in the back frame 1 that induces torsional deformation such as twisting of the first side frame 3, the lower beam 6 and the first side frame 3 are joined at the first joint W1 and the second joint W2, so the lower beam 6 receives the torsional torque M generated in the first side frame 3 as tensile force F1 and compressive force F2.

[0041] Furthermore, since torsional deformation is a type of shear deformation, and generally, tensile and compressive deformations can suppress deformation more effectively than shear deformation, this configuration can suppress deformations that cause the first side frame 3 to twist significantly, compared to a configuration where the torsional deformation is counteracted solely by the shear stress generated in the first side frame 3.

[0042] Furthermore, the front longitudinal middle portion of the lower beam 6 is located further rearward than the one and other ends in the longitudinal direction. This helps to prevent the lower beam 6 from interfering with the seated person. For this reason, the first joint W1 in this embodiment is provided at the tip of the arm portion 64 that extends from the front panel portion 61 to one and the other end in the longitudinal direction.

[0043] (Other embodiments) In the above-described embodiment, the first joint W1, the second joint W2, and the joint W3 were joined by arc welding. However, this disclosure is not limited thereto. That is, the disclosure may also include a configuration in which the joints are joined by, for example, an adhesive.

[0044] In the embodiments described above, two recliners and two electric motors were provided. However, the disclosure is not limited thereto. That is, the disclosure may include, for example, a configuration in which there is one recliner and one electric motor, a configuration having two recliners and one electric motor, or a configuration without an electric motor.

[0045] In the embodiments described above, the back frame 1 had a metal back panel. However, the disclosure is not limited thereto. That is, the disclosure may also include, for example, a back frame without a back panel, or a back frame having a resin back panel.

[0046] In the embodiments described above, the retractor 9 was fixed to a metal back panel. However, the disclosure is not limited thereto. That is, the disclosure may also include, for example, a configuration without a retractor 9, or a configuration in which the retractor 9 is fixed to a side frame or upper beam.

[0047] In the embodiments described above, the vehicle seat according to this disclosure was applied to a vehicle. However, the application of the invention disclosed herein is not limited to this. That is, the disclosure can be applied, for example, to seats used in vehicles such as railway cars, ships and aircraft, as well as to stationary seats used in theaters, homes, etc.

[0048] Furthermore, this disclosure is not limited to the embodiments described above, but is sufficient to be consistent with the intent of the disclosures described in the embodiments described above. Therefore, it may be a configuration in which at least two of the embodiments described above are combined, or a configuration in which any of the illustrated components or components described with reference numerals in the embodiments described above are omitted. [Explanation of Symbols]

[0049] 1… Back frame 3… First side frame 4… Second side frame 5… Upper beam part 6… Lower beam part 7A… First recliner 7B… Second recliner 8… Rod W1... 1st joint W2… Second joint W3… Joint location

Claims

1. In a back frame used for the seat back of a vehicle seat, A first side frame is positioned at one end in the width direction of the seat and extends in the vertical direction, A second side frame is positioned on the other end in the width direction of the seat and extends in the vertical direction, A first connecting member extending in the width direction of the sheet and connecting the upper end of the first side frame and the upper end of the second side frame, A recliner for changing and maintaining the angles of the first side frame and the second side frame, comprising a recliner joined and fixed to at least the lower end side of the first side frame, It includes a second connecting member that extends in the width direction of the sheet and connects the lower end of the first side frame and the lower end of the second side frame, The second connecting member is joined to the first side frame at the front and rear sides of the first side frame. Furthermore, the front joint between the second connecting member and the first side frame is a back frame located at a position corresponding to the joint between the recliner and the first side frame.

2. When the aforementioned recliner is designated as the first recliner, a second recliner is provided on the lower end side of the second side frame, which is joined and fixed to the lower end side. The front joint between the second connecting member and the second side frame is located at a position corresponding to the joint between the second recliner and the second side frame. Furthermore, the back frame according to claim 1, wherein the front longitudinal intermediate portion of the second connecting member is located further rearward than one end and the other end in the longitudinal direction.

3. The back frame according to claim 2, wherein the cross-sectional shape of the longitudinal middle portion of the second connecting member is substantially C-shaped with an open upper side.

4. It includes a rod that extends in the width direction of the seat and connects the first recliner and the second recliner, The back frame according to claim 3, wherein the cross-sectional shape of the longitudinal intermediate portion is substantially C-shaped so as to surround the rod.

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