JP2013209003A - Back frame structure of vehicle seat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain dimensional accuracy of the entire back frame without strictly managing length dimensions of a side frame and an upper frame.SOLUTION: A back frame comprises an upper frame 31 forming an upper side of a frame shape and a side frame 33 forming each of left and right lateral sides. A portion where the upper frame 31 and the side frame 33 gather is provided with a bracket 70 for attaching a belt guide of a seat belt unit. Both of the side frame 33 and the upper frame 31 are joined to the bracket by welding and connected to each other. The bracket 70 comprises a flange 73a extending toward the front upper frame 31. A recess 73b corresponding to a sectional circular shape of the upper frame 31 is formed at an end of each flange 73a. The upper frame 31 is joined to the bracket 70 by welding in a fitted state into both of the recesses 73b.

Description

  The present invention relates to a back frame structure of a vehicle seat.

  A general structure of a back frame serving as a skeleton of a seat back in a seat provided in a vehicle is described in Patent Document 1 below. Usually, such a back frame is configured in a frame shape with an upper frame forming an upper side and side frames forming left and right sides. In the back frame structure described in the same document, the upper frame and the side frame are separated from each other, and both are directly joined and connected to each other at the end. Further, the seat in the document is equipped with a three-point seat belt unit including a lap belt and a shoulder belt. The shoulder belt is inserted through a belt guide (shoulder anchor in the same document) fixed in the vicinity of the joint between the upper frame and the side frame, and is slidably held.

JP 2011-178194 A

  However, since the belt guide is joined to the end portion of the upper frame and not directly joined to the side frame in the above-described structure, the belt guide is not involved in joining the upper frame and the side frame. Therefore, if there are variations in the length dimensions of the side frame and the upper frame, the relative position of the upper frame with respect to the side frame also varies when they are joined to each other at the ends. Further, the relative position of the belt guide with respect to the side frame also varies. If there is such a variation, when assembling a pad material of a predetermined dimension to the completed back frame (by direct molding etc.) There was a problem that the position of the guide was displaced.

  The present invention has been made in view of such problems, and the problem to be solved by the present invention is that the entire back frame can be obtained without strictly managing the length dimensions of the side frame and the upper frame. It is possible to maintain dimensional accuracy.

In order to solve the above problems, the back frame structure of a vehicle seat according to the present invention takes the following means.
A back frame structure of a vehicle seat according to a first aspect of the present invention is a back frame structure of a vehicle seat provided with a frame-shaped back frame serving as a skeleton of the seat back, and each of the back frames has a frame shape. It has an upper frame and a side frame that are divided into upper and side sides, and a part for attaching a belt guide or the like for guiding the movement of the seat belt is attached to the meeting point between the upper frame and the side frame. A bracket is provided, and the side frame and the upper frame are both connected to each other by being joined to the bracket.
According to this configuration, since the side frame and the upper frame are both connected to each other by being joined to the bracket, even if the length dimension varies, the joining position to both brackets can be adjusted. Variation is absorbed. Therefore, the dimensional accuracy of the entire back frame can be maintained without strictly managing the length dimensions of the side frame and the upper frame.

A back frame structure for a vehicle seat according to a second invention of the present invention is the back frame structure for a vehicle seat according to the first invention, wherein the upper frame is a pipe-shaped member having a circular cross section, The bracket has a plate-like flange extending toward the upper frame, and the bracket is joined to the upper frame at the flange, and the joint portion of the bracket is the upper part. It is formed in the concave shape corresponding to the cross-sectional circular shape of a flame | frame.
According to this structure, since the junction part of a bracket is formed in the concave shape corresponding to the cross-sectional circular shape of an upper frame, both contact area is taken large. Therefore, the bracket can be more firmly joined to the upper frame.

A vehicle seat back frame structure according to a third aspect of the present invention is the vehicle seat back frame structure according to the first or second aspect of the present invention, and is arranged to be joined to the bracket in the upper frame. The positional relationship is characterized in that an end portion of the upper frame is disposed so as to protrude ahead of a joint portion with the bracket.
According to this configuration, since the end portion of the upper frame protrudes before the joint portion with the bracket, the variation in the length dimension of the upper frame is absorbed. Therefore, the dimensional accuracy of the entire back frame can be maintained without strictly managing the length dimension of the upper frame.

According to the first invention, it is possible to maintain the dimensional accuracy of the entire back frame without strictly managing the length dimensions of the side frame and the upper frame.
According to the second invention, the bracket can be more firmly joined to the upper frame.
According to the third aspect of the present invention, the dimensional accuracy of the entire back frame can be maintained without strictly managing the length dimension of the upper frame.

It is a perspective view which shows a sheet | seat. It is a perspective view which shows a back frame. It is a perspective view which shows the bracket of a belt guide. It is a front view which shows the state which joined the upper frame and the side frame to the bracket. It is a side view which shows the state which joined the upper frame and the side frame to the bracket.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The seat 10 is installed in a vehicle and used by an occupant. As shown in FIG. 1, the seat 10 includes a seat cushion 11 on which an occupant sits and a seat back 13 that serves as a backrest of the seated occupant. Yes. Note that the seat 10 according to the present embodiment is a seat for three people. In the following description, the front, rear, left, and right directions are directions determined based on the traveling direction of the vehicle and the posture of the seated person, and the width direction means the left-right direction. The seat back 13 is connected to the rear part of the seat cushion 11. On the seat back 13, a headrest 15 for supporting the head of each seated person is provided.

  The seat of the present embodiment is equipped with a three-point seat belt unit that restrains the seated person's body on the backrest surface of the seat back. Although the seat belt unit is provided for each seated person, the following description will be limited to the seat belt unit for the left and right outside seated persons. The belt 21 of the seat belt unit is pulled out from a retractor (not shown) provided at the rear of the seat 10, and an end is fixed to an anchor (not shown) provided at the lower part of the seat 10. A tongue plate 23 is slidably attached to the belt 21. The belt 21 is divided into a retractor side shoulder belt 21S and an anchor side lap belt 21L with the tongue plate 23 as a boundary. The shoulder belt 21 </ b> S is slidably inserted into a belt guide 27 provided on a shoulder portion on the outer side in the width direction of the seat back 13. The belt guide 27 is a resin part and a design part that requires design properties.

  As shown in FIG. 2, the seat back 13 includes a back frame 30 serving as a skeleton, and a urethane foam pad material 40 (virtually illustrated in FIG. 2) that forms a backrest surface on the back frame 30. Is shown). The back frame 30 is formed in a frame shape as shown in FIG. The back frame 30 includes an upper frame 31 that forms the upper side of the frame shape, a side frame 33 that forms the left and right sides, and a lower frame 35 that forms the lower side, all of which are made of metal pipe material. Is the material. The side frame 33 and the lower frame 35 are integrally formed from a single pipe material. However, the side frame 33 and the lower frame 35 are separately formed from the upper frame 31. A bracket 70 for attaching the belt guide 27 is disposed at a location where the upper frame 31 and the side frame 33 meet. Both the side frame 33 and the upper frame 31 are joined to the bracket by welding, and are thereby connected to each other. A center frame 37 is stretched between the upper frame 31 and the lower frame 35 at two positions in the center in the width direction and joined to each other by welding. Wires 39 that hold the form of the pad material 40 to be put on are laid across the back frame 30 vertically and horizontally and are joined to each other by welding.

  The back frame 30 is directly fastened and fixed to the vehicle body. The upper frame 31 is provided with two upper fastening portions 51 at intervals in the width direction. The lower frame 35 is provided with three lower fastening portions 53 at intervals in the width direction. Each of the upper fastening portion 51 and the lower fastening portion 53 is formed of a metal wire bent into a U shape, and both end portions are joined to the frame by welding. In addition, a headrest stay 61 that supports the headrest 15 for the outside seated person and a support bracket 63 for attaching the headrest 15 for the center seated person are joined to the upper frame 31 by welding.

  As shown in FIG. 3, the bracket 70 is formed by generally bending a metal plate material. As for the bracket 70, one part (belt guide attaching part 71) is extended ahead, and the other part (frame joining part 73) is extended below, with the bent part as a boundary. The belt guide mounting portion 71 is disposed in a positional relationship such that the upper surface thereof is flush with the surface of the pad material 40 as shown in FIG. 2, and the belt guide 27 is exposed to the outside of the pad material 40. It is attached to the upper surface of the attachment part 71. The belt guide mounting portion 71 is provided with three holes through which screws for fixing the belt guide 27 are inserted.

  As shown in FIGS. 4 and 5, the upper frame 31 is disposed in a positional relationship across the front of the frame joint portion 73 in the width direction. A flange portion 73 a extending toward the front upper frame 31 is provided at each of the left and right positions of the frame joint portion 73. A concave portion 73b corresponding to the circular cross section of the upper frame 31 is formed at the end of each flange portion 73a. The upper frame 31 is joined to the bracket 70 by welding in a state where the upper frame 31 is fitted in both the concave portions 73b. FIG. 4 shows these two joint points W1. The end portion 31 a of the upper frame 31 protrudes outward in the seat back width direction from the joint portion W <b> 1 outside the bracket 70.

  As shown in FIGS. 4 and 5, the side frame 33 is disposed in a positional relationship in which the upper end portion is superimposed on the front side of the frame joint portion 73. The flange portion 73a on the outer side in the width direction (left side in FIG. 4) is formed in parallel with the direction in which the side frame 33 extends, and the side frame 33 is disposed close to the inner side. A welding hole 73 d used for welding to the side frame 33 is formed at a position near the outside of the lower portion of the frame joint portion 73. The welding hole 73d has an elongated shape parallel to the direction in which the side frame 33 extends. The upper end portion of the side frame 33 is joined to the inner edge of the weld hole 73d by welding. In the same figure, this joint location W3 is shown.

  A pad coupling hole 73 e is formed through the center of the frame joint 73. The pad material 40 made of urethane foam goes around from both sides of the frame joint 73 into the pad coupling hole 73e when foamed. For this reason, the pad material 40 can firmly hold the frame joint portion 73, and the pad material 40 is difficult to peel off from the surface of the frame joint portion 73. Two positioning holes 73c used for positioning when joining the frames are formed through the lower portion of the frame joining portion 73.

  The assembly process of the seat back will be described. Hereinafter, the side frame 33 and the lower frame 35 formed integrally with the side frame 33 are simply referred to as the side frame 33. First, the three members of the upper frame 31, the side frame 33, and the bracket 70 are placed on a jig for relative positioning. The jig has a plate shape with a width capable of placing three members, and a plurality of pins are erected, and the three members are fitted into the pins. The upper frame 31 and the side frame 33 are positioned in a predetermined position with respect to the jig by being set in a state sandwiched by pins from both sides. The bracket 70 is positioned at a predetermined position with respect to the jig by being set in a state in which the positioning hole 73c is inserted into the pin. Thereby, relative positioning of three members is made. That is, the relative positional accuracy of the three members can be managed by the jig. The three members that have been positioned relative to each other are then joined together by welding to form the frame structure of the back frame 30. The back frame 30 that has been joined is then set in a pad material mold. Then, a foamed urethane raw material is poured into the mold, and the pad material 40 is assembled around the back frame 30 while being foam-molded. The pad material 40 that has been molded is covered with a cover, and the belt guide 27 is fixed to the bracket 70 with screws. The seat back 13 is assembled through the above steps.

The embodiment configured as described above has the following operational effects.
First, the side frame 33 and the upper frame 31 are connected to each other by being joined to the bracket. For this reason, even if there is a variation in any of the length dimensions, the variation is absorbed by adjusting the joining position of both brackets. Therefore, the dimensional accuracy of the entire back frame 30 can be maintained without strictly managing the length dimensions of the side frame 33 and the upper frame 31.
Specifically, the upper frame 31 is joined to the bracket 70 on its side surface, and the end portion protrudes ahead of the joint location with the bracket 70. Therefore, as shown by the horizontal arrow in FIG. 4, the upper frame 31 can be shifted inward and outward during joining, so that variations in length dimensions are absorbed. Further, the side surface of the side frame 33 is disposed along the inside of the flange portion 73a, and is joined to the bracket 70 at the side surface. Therefore, as shown by the vertical arrow in FIG. 4, the upper frame 31 can be shifted in the vertical direction along the flange portion 73a at the time of joining, so that variations in length are similarly absorbed.
Therefore, for example, based on the lower coupling portion 53 (see FIG. 2) coupled to the vehicle body, the relative position (height direction) of the bracket 70 with respect to the side frame 33, and further the relative of the upper frame 31 via the bracket 70. These three members can be joined together while adjusting the position (height direction and width direction). Thereby, the positional accuracy of the upper coupling part 51 and the belt guide 27 with respect to the lower coupling part 53 can be ensured.
Moreover, since the junction part of a bracket is formed in the concave shape corresponding to the cross-sectional circular shape of the upper frame 31, the contact area of both is taken large. Therefore, the bracket can be more firmly joined to the upper frame 31.

In addition, the back frame structure of the vehicle seat according to the present invention is not limited to the above-described embodiment, and can be implemented in various other forms.
First, the bracket used for joining the frames is not limited to the bracket 70 for attaching the belt guide 27 of the shoulder belt 21S as described above. For example, in a seat in which the seat back can be moved forward, a bracket to which a release operation member such as a button, a knob, a hook, or the like that releases the fixed state of the seat back and switches it to the forward retractable state can be targeted. Further, in a similar seat, a bracket for attaching a back lock device for fixing the side portion of the seat back to the side panel of the vehicle body can be used.
In addition, the belt guide attaching portion 71 of the bracket 70 is provided at an upper position with respect to the frame joining portion 73. However, when attaching the above-described back lock device, the device attaching portion has a width with respect to the frame joining portion 73. It can be provided at a position outside the direction (left side in FIG. 4). Further, in order to attach both the release operation member and the back lock device, attachment portions can be provided at both the upper and outer positions with respect to the frame joint portion 73.
Further, the upper frame 31 and the side frame 33 do not have to be different from each other in the direction of the end joined to the bracket as shown in FIG. 4, and the end of the side frame is bent by bending the end of the upper frame. Arbitrary positional relationships such as butting can be achieved.
Further, the seat is not limited to a seat for three people, and the present invention can be applied to a seat for one or two people.

10 seat 11 seat cushion 13 seat back 15 headrest 21 belt 21S shoulder belt 21L lap belt 23 tongue plate 25 buckle 27 belt guide 30 back frame 31 upper frame 31a end 33 side frame 35 lower frame 37 center frame 39 wire 40 pad material 51 Upper fastening part 53 Lower fastening part 70 Bracket 71 Belt guide attachment part 71a Screw hole 73 Frame joint part 73a Flange part 73b Recessed part 73c Positioning hole 73d Welding hole 73e Pad joint hole W1 Upper frame joint part W3 Side frame joint part

Claims (3)

A back frame structure of a vehicle seat including a frame-shaped back frame that serves as a skeleton of the seat back,
Each of the back frames includes an upper frame and a side frame that are configured to be divided into an upper side and a side side of the frame shape,
A bracket for attaching parts such as a belt guide for guiding the movement of the seat belt is disposed at a meeting place between the upper frame and the side frame,
A back frame structure for a vehicle seat, wherein the side frame and the upper frame are connected to each other by being joined to the bracket. The vehicle seat back frame structure according to claim 1,
The upper frame is a pipe-shaped member having a circular cross section,
The bracket has a plate-like flange extending toward the upper frame,
The vehicle is characterized in that the bracket is joined to the upper frame at the flange, and the joint of the bracket is formed in a concave shape corresponding to the circular cross section of the upper frame. Seat back frame structure. The back frame structure of the vehicle seat according to claim 1 or 2,
An arrangement position relationship of the upper frame to be joined to the bracket is such that an end portion of the upper frame protrudes ahead of a joining position with the bracket. Construction.

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