JPH071843U - Seat back frame - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a seat back frame that can be lightweight while maintaining strength. [Structure] A seat back frame 1 including left and right side frames 2 made of a plate material and a lower frame 5 and an upper frame 4 which are bridged between the side frames 2.
In addition, the side frame 2 is made of an ultra-high tensile steel plate, and the buckling prevention flange 3 is provided inside the side frame 2 by bending the side frame 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a seat back frame applied to a seat of an automobile or the like, and more specifically to a seat back frame that is lightweight.

[0002]

[Prior art]

 Conventionally, in automobiles, weight reduction has been achieved from various aspects in order to improve performance, fuel efficiency, etc., but seat back frames in seats have also been made lighter without exception.

That is, a conventional seat back frame is provided with left and right side frames made of a plate material, and a lower frame and an upper frame made of a pipe material bridged between the both side frames. Is made of high-strength steel, and is designed to be as thin and light as possible considering strength.

[0004]

[Problems to be solved by the device]

 However, there is a great demand for weight reduction of automobiles, and further weight reduction of seat back frames is desired, which is a problem.

The present invention has been made in view of the above circumstances, and provides a seat back frame which is guaranteed in strength and can be further reduced in weight by devising such as material replacement and structural change. The purpose is to do.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention is a seat back frame including left and right side frames made of a plate material and a lower frame and an upper frame that are bridged between the both side frames. In addition to the above configuration, the buckling prevention flange is provided by bending the side frame inside the side frame.

[0007]

[Action]

 With the above configuration, the material of the side frame is changed from the conventional high-tensile steel plate to the ultra-high-strength steel plate, so the material strength is 1.5 to 2 times that of the conventional one, and the thickness and member dimensions are increased. Can be made smaller and lighter in weight. Also, in order to prevent the buckling strength of the member from being reduced by the thinning of the side frame, a buckling prevention flange is provided by bending the side frame inside the side frame. Can be suppressed, and there is no problem even if the weight is reduced, and the strength can be guaranteed.

[0008]

【Example】

 An embodiment according to the present invention will be described below with reference to the drawings. The most commonly used test for evaluating the strength of the seat back frame 10 (which is the conventional one shown in FIG. 4) is a rear moment that applies a rear load to the center of the upper frame 10a of the seat back frame 10. It is a test. Figure 5 shows the distribution of moments generated in the frame during this rear moment test. From this, it can be seen that high moments are concentrated on the side frame 10b.

Therefore, in order to effectively reduce the weight, it is desirable to use an ultra-high-strength steel plate for this side frame. Even in the seat back frame 1 (shown in FIG. 1) of this embodiment, the side frame 2 is also used. Ultra high-strength steel plate was applied to the side frame 10b to reduce the plate thickness and thickness, and the external dimensions to reduce the weight.

Although My (moment, around y-axis) of the side part is much higher than Tx (torsion torque, around x-axis; see FIG. 6), Zy (section modulus, around y-axis) is the member height. Since it is increased by the square of the height, it is possible to relatively easily secure sufficient Zy against My by a slight change in member height. On the other hand, although Tx is very small compared to My, the side frame has an open cross-section structure of a plate and has a significantly smaller Zp (section coefficient, x-axis rotation) than a closed cross-section structure such as a pipe. Since Zp is extremely lowered due to the reduction in thickness (Zp is proportional to the square of the plate thickness), τxy (shear stress due to torsion) is significantly increased as a result. The effect of σy (bending stress due to bending moment My) is also added to this, and a part of the side frame may buckle at the pole part under a low load.

Therefore, in the design of the side frame made of the thin plate member like this time, it is necessary to make a shape modification to suppress the buckling phenomenon. Therefore, in the side frame 2 according to the present embodiment, the side frame 2 is bent inside the side frame 2 to additionally set the buckling prevention flange 3 with a slight weight, thereby suppressing a decrease in buckling strength due to thinning. . FIG. 2 is a characteristic diagram of a rear moment test when the buckling prevention flange 3 is provided, and FIG. 3 is a characteristic diagram of a rear moment test without the buckling prevention flange. It can be seen from FIGS. 2 and 3 that the buckling prevention flange is effectively operating. In FIG. 1, 4 is an upper frame and 5 is a lower frame.

In the present embodiment as described above, the side frame 2 is made of a thin ultra-high-strength steel plate, and the reduction in buckling strength caused by the thinning is called setting of the buckling prevention flange 3. By covering with a design ingenuity, we were able to effectively reduce the weight while maintaining the same strength as the conventional seat back frame.

[0013]

As described above, according to the present invention, it is possible to achieve a strong guarantee and an effective weight reduction by devising a material replacement and a structural change, and it is a very useful seat back. It can be a frame.

[Brief description of drawings]

FIG. 1 is a perspective view of the left half of an embodiment according to the present invention.

FIG. 2 is a diagram showing characteristics of a rear moment test with a buckling prevention flange according to the present invention.

FIG. 3 is a diagram showing characteristics of a rear moment test without a buckling prevention flange.

FIG. 4 is a perspective view of the left half of the prior art.

FIG. 5 is a distribution diagram of bending moments generated during a rear moment test.

FIG. 6 is a distribution diagram of torsional torque generated during a rear moment test.

[Explanation of symbols]

 1 Seat back frame 2 Side frame 3 Buckling prevention flange 4 Upper frame 5 Lower frame

Claims (1)

[Scope of utility model registration request] 1. A seat back frame comprising left and right side frames made of plate material and a lower frame and an upper frame bridged between the side frames, wherein the side frames are made of ultra-high tensile steel plates and A seat back frame, characterized in that the side frame is bent inside the frame to provide a buckling prevention flange.