JPH04348711A - Seat back frame - Google Patents

Abstract

PURPOSE:To make the main frame light in weight. CONSTITUTION:A cross member 2 is fixed to a main frame 1 by fitting of a keyhole shape by a cross sectional shape having a projecting part 5 of the cross member 2 and a fitting hole 6 of the main frame 1, and also, a fitting arm 4 is fixed so as to hold in the main frame 1 by a flange part 4a, and when a load is applied to the seat back, its load is received by not only the main frame 1 but also the cross member 2 and the fitting frame 4, and the load to be received by the main frame 1 is reduced.

Description

[Detailed description of the invention]

0001

[Purpose of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat back frame for use in a vehicle seat.

0003

2. Description of the Related Art Hitherto, as this type of seat back frame, the one shown in Japanese Utility Model Application Laid-Open No. 135736/1983 has been known. This has a main frame that is approximately inverted U-shaped, a cross member that connects both ends of the main frame, and mounting arms that are fixed to both ends of the main frame and to which a reclining mechanism is connected. The main frame and cross member are connected by welding with the end of the cross member directly against the main frame, and the mounting arm has a plate shape and is fixed directly to the main frame with bolts etc. was.

0004

[Problem to be Solved by the Invention] When a load is applied to the seat back, the seat back should absorb the load as much as possible so that it is not input to the reclining mechanism, and also prevent deformation etc. from occurring due to the load. desirable. However, with the above-mentioned seat back frame, both ends of the main frame are connected only by welding with the cross member against the main frame, and the mounting arm is plate-shaped and is fixed to the main frame with bolts. Therefore, when a load is applied to the seat back, the rigidity at the connection between the main frame and the cross member and the connection between the main frame and the mounting arm is weak, and as a result, the main frame alone takes all of the load. It happens. Therefore, the main frame is required to have high rigidity, and the weight of the main frame increases significantly.

Therefore, the technical object of the present invention is to reduce the weight of the main frame.

[0006]

[Structure of the invention]

[0007]

[Means for Solving the Problems] The first technical means taken in the present invention to solve the above-mentioned technical problem is to make the cross-menha have a substantially keyhole-shaped cross section with a protrusion, and to attach the cross-menu to both ends of the main frame. The second technical means is to form a substantially keyhole-shaped fitting hole that matches the cross-sectional shape of the cross member into which the member is fitted. It has a substantially U-shaped cross section with a flange portion formed by being bent back, and a recessed portion that straddles the bent portion is formed in a part of the flange portion.

[0008]

[Operation] The above technical means operates as follows. When a load is applied to the seat back, the load is applied not only to the main frame, but also to the key-shaped fitting between the cross member and the main frame fitting hole, which improves rigidity, and the flange of the mounting arm to hold the main frame. Due to the increased rigidity, loads can also be carried by the cross member and mounting arms. This reduces the load that the main frame should receive, making the main frame less rigid. As a result, the weight of the main frame can be reduced.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, the main frame 1, which has a rectangular cross section, has a substantially inverted U shape. Both lower ends of the main frame 1 are connected by a cross member 2. Further, both sides of the main frame 1 are connected by a substantially V-shaped reinforcement 3 connected to a cross member 2. Furthermore, a reclining mechanism (not shown) is provided at both ends of the lower part of the cross member 1.
The mounting arms 4 to which the two are connected are fixed respectively.

As shown in FIGS. 1 to 3, the cross member 2 has a circular cross-section, and a bifurcated protrusion 5 that stands up on its outer periphery is formed along its longitudinal direction. As a result, the cross member 2 as a whole has a substantially keyhole shape. Keyhole-shaped fitting holes 6 that match the keyhole shape of the cross member 2 are formed below both lower ends of the main frame 1, respectively. Both ends of the cross member 2 are fitted into the fitting portions 6 with their keyhole shapes matching, and are firmly fixed to the main frame 1 by welding while being prevented from rotating by the projections 5. In this way, the cross member 3 is firmly fixed to the main frame 1 through keyhole-shaped fitting, so that high rigidity can be obtained at the connecting portion. As a result, both lower ends of the main frame are connected via the cross member 2.

As shown in FIGS. 1 and 2, the reinforcement 3 having a substantially V-shape is made of a linear material,
It is fitted and fixed to the protrusion 5 in a bifurcated manner at the bent portion 3a, and fixed at both ends above both sides of the main frame 2 by welding. This allows mainframe 1
Both side parts of are connected via the reinforcement 3.

As shown in FIGS. 1, 2, 4 and 5, the mounting arm 4 has a U-shaped cross section with flanges 4a formed on both sides, and the main frame 1 is attached to the main body 4b. Through holes 9 and 10 through which bolts 7 and 8 for fixing the reclining mechanism are inserted, and through holes 12 each having a nut member 11 on the back side into which a bolt (not shown) for fixing the reclining mechanism is screwed. It is formed. Further, above the fitting holes 6 at the bottom of both sides of the main frame 1, nut members 13 into which bolts 7 are screwed are fixed by welding, and bolts 8 are fixed at both ends of the cross member 2. A nut hole 14 for screwing is formed. The mounting arm 4 has these bolts 7 and 8, a nut member 13, and a nut hole 14.
By screwing with the main frame 1, the main body part 4b faces the side part of the main frame 1, and the flange part 4a embraces the side part of the main frame 1, so that it is firmly fixed to the lower part of both sides of the main frame 1. Ru. In this way, the mounting arm 4 is firmly fixed to the lower side of the main frame 1 with the flange portion 4a hugging the side of the main frame 1.
High rigidity can be obtained at the connecting portion. Furthermore,
The mounting arm 4 is formed with a recessed portion 4c extending from the flange portion 4a to the main body portion 4a via the bent portion, and the mounting arm 4c can be plastically deformed in this recessed portion 4c.

A guide member 15 for supporting the headrest is fixed to the upper part of the main frame by welding.

Next, the operation of the present invention will be explained.

In FIG. 1, when a load is applied to the seat back, the load is applied to the main frame 1 and the cross member 2.
The main frame 1, the cross member 2, and the mounting arm 4 can share the load by increasing the rigidity at the connecting portion between the main frame 1 and the mounting arm 4. As a result, the load to be received by the main frame 1 is reduced, and the main frame 1 can be made of a material with low rigidity such as a light alloy. As a result, it is possible to reduce the weight of the main frame 1, thereby reducing the weight of the seat as a whole and the weight of the vehicle itself in which the seat is mounted, thereby contributing to improved fuel efficiency. In addition, since both lower ends of the main frame 1 are connected via a cross member firmly fixed to the main frame 1, the rigidity against twisting that occurs below the main frame 1 when a load is applied to the seat back is improved. be able to. Furthermore, since the reinforcement 3 is fitted onto the protrusion 5 of the cross member 2 and then welded and fixed, the rigidity of the connection part is improved, and the cross member 2 is also made of a material with low rigidity such as a light alloy. cross member 2
It becomes easy to position the reinforcement 3 relative to the main body, and the ease of assembly can be improved. Moreover, since the mounting arm 4 is formed with a recessed portion 4c that allows the mounting arm 4 to be plastically deformed, the load received by the mounting arm 4 is absorbed by plastic deformation in the recessed portion 4c of the mounting arm 4. This allows the load to be transferred to the reclining mechanism to be reduced. Thereby, it is possible to prevent the reclining mechanism from being destroyed and to achieve a reduction in thickness.

[0017]

Effects of the Invention The present invention provides a seat back frame having a main frame having a substantially inverted U shape and a cross member connecting both ends of the main frame, which is a first technical means, wherein the cross member is A seat bag having a substantially keyhole-shaped cross section with a protrusion, and having substantially keyhole-shaped fitting holes formed at both ends of the main frame to match the cross-sectional shape of the cross member into which the cross member is fitted. In a seat back frame having a main frame having a substantially inverted U shape, which is a frame and a second technical means, and mounting arms fixed to both ends of the main frame and connected to a reclining mechanism, The mounting arm has a substantially U-shaped cross section with flanges formed by being bent to embrace the main frame on both sides, and a portion of the flange has a recess that straddles the bent portion. Since the seat back frame is formed with a section, it has the following effects.

[0018] When a load is applied to the seat bag by the first technical means or the second technical means, the load is
Not only the main frame, but also the cross member and the mounting arm have improved rigidity due to the key-like fitting between the cross member and the main frame fitting hole, and the improved rigidity due to the flange of the mounting arm holding the main frame. It can bear loads even when it is on. This reduces the load that the main frame should receive, and allows the main frame to have low rigidity. As a result, it is possible to reduce the weight of the main frame, thereby reducing the weight of the seat as a whole and the weight of the vehicle itself in which the seat is mounted, contributing to improved fuel efficiency.

The first technical means makes it possible to improve the rigidity against torsion occurring below the main frame 1 when a load is applied to the seat back. With the second technical means, the load received by the mounting arm can be absorbed by plastic deformation in the recessed part of the mounting arm, and the load transmission to the reclining mechanism can be reduced. Thereby, it is possible to prevent the reclining mechanism from being destroyed and to achieve a reduction in thickness.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a seat back frame according to the present invention.

FIG. 2 is an exploded perspective view of FIG. 1;

FIG. 3 is a sectional view taken along line CC in FIG. 1;

FIG. 4 is a sectional view taken along line AA in FIG. 1;

FIG. 5 is a sectional view taken along line BB in FIG. 1;

[Explanation of symbols]

1 Mainframe 2 Cross member 5 Protrusion 6 Fitting hole 4 Mounting arm 4a Flange part 4c Hollow part

Claims (2)

[Claims] 1. A seat back frame having a main frame having a substantially inverted U shape and a cross member connecting both ends of the main frame, wherein the cross member has a substantially keyhole-shaped cross section with a protrusion, The seat back frame has a substantially keyhole-shaped fitting hole formed at both ends of the main frame to match the cross-sectional shape of the cross member into which the cross member is fitted. 2. A seat back frame having a main frame having a substantially inverted U shape, and mounting arms fixed to both ends of the main frame and connected to a reclining mechanism, wherein the mounting arms have the main frame on both sides thereof. A seatback frame having a substantially U-shaped cross section with a flange portion formed by being bent to embrace the frame, and a recessed portion extending over the bent portion is formed in a part of the flange portion.