JPH0638698U - Chair - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a seat chair in which the curved portion does not bend even when leaning against the backrest plate and the seated state is stable and gives a feeling of relief. [Structure] The backrest plate 2 is curved and rises from the bottom plate 1 and is curved backward with a smooth curved surface, and the cross section of the backrest plate 2 is a convex convex rearward at the center from the upper end to the lower curved portion 3. Protruding in a shape.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a seat chair in which the strength of the backrest is particularly improved.

[0002]

[Prior art]

 Seats are often used not only for relaxing at home but also for banquets. That is, when you sit down and sit down, you can support your body from the back, so you don't feel tired even if you sit for a long time, and you don't have to sit down with your back curled up. Its utility value is high. FIG. 5 shows a specific example of a conventional chair. This chair is made by bending a wooden board and consists of a bottom plate (a) and a back plate (b) .The back plate (b) stands almost vertically, and the cross section of the back curve is a smooth curve. It has a familiar shape. However, this curved surface is only the upper half of the back plate (b).

The seat chair shown in FIG. 6 is another conventional example. In this chair, the shape of the back plate (b) is slightly different, and the back plate (b) does not stand upright vertically and is curved to the back, so that the back plate (b) is easy to lean on when sitting. Similarly, the upper half of the cross section has a convex curved surface with the central part protruding backward. When the backrest plate (b) of a chair is supported in this shape to support the back, the force (P) that presses the backrest plate (b) acts as a bending moment (M), and the boundary with the bottom plate (b) The bending moment (M) becomes maximum at the curved portion (C).

The bending portion (c) of the chair made of wood is not strong enough to withstand the bending moment (M), and as a result, the bending portion (c) bends. There is a case. Of course, the same applies to the seat chair shown in FIG. 5, and the maximum bending moment (M) acts on the curved portion (c), but the shape of the backrest plate (b) stands upright. The pressing force (P) is small because it is difficult to lean.

[0005]

[Problems to be solved by the present invention]

 As described above, the conventional chair has the above problems. The problems to be solved by the present invention are these problems, and provide a seat chair that is easy to sit and has high strength and does not bend even when leaning against a backrest plate.

[0006]

[Means for Solving the Problems]

 The seat chair of the present invention is constructed so that the backrest plate thereof does not bend even when a large pressing force is applied, and in particular, the strength of the curved portion which is the boundary portion between the bottom plate and the backrest plate is increased. . The curved portion of the conventional seat chair shown in FIGS. 5 and 6 is formed by bending a plate material in one direction, and the second moment of area of this portion is not large due to the plate thickness.

In the present invention, in order to increase the second moment of area of this portion, it is formed into a three-dimensional shape, and the center of the curved portion is formed to project backward. If the bending rigidity of the curved portion is increased, the bending moment causes the bottom plate to be bent and deformed. Therefore, a rib is formed on the bottom plate. Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

[0008]

【Example】

 FIG. 1 shows an embodiment of a seat chair according to the present invention, which has the same basic shape as a conventional seat chair, is composed of a bottom plate 1 and a backrest plate 2, and is injection-molded using resin as a material. Be done. Unlike conventional bending of plate materials, injection-molded seat chairs are not restricted in their shape in processing. Therefore, while the bottom plate 1 is a flat plate, the backrest plate 2 is curved backwards, and the center portion is curved backward with a bulging shape so as to conform to the shape of the back when leaning.

FIG. 2 shows a cross section of a seat chair according to the present invention, where a is a YY cross section and b is a XX cross section. As shown in a, the backrest plate 2 has a smooth curved surface and falls backward, and the curved portion 3 has a shape in which the central portion thereof protrudes backward. The dotted line in the figure shows the longitudinal section of the backrest plate (b) of the conventional seat chair shown in FIG. The cross section in the XX direction is a smooth curved surface as shown by b, and although there is some change in this curved shape, it is formed from the upper end of the backrest plate 2 to the lower curved portion 3. In the case of the conventional backrest plate (b) shown in FIG. 6, only the upper half is curved and the lower half forms a flat surface, and when sitting, the hips hit the backrest plate (b). .

FIG. 3 shows a cross section taken along the line XX in the bending portion 3, and a dotted line in the drawing is a bending portion cross section in a conventional seat chair. The pressing force acting on the backrest plate 2 generates the maximum bending moment in the bending portion 3, but since the cross section of the bending portion 3 has such a curved sectional shape, the second moment of area becomes very large. The strength is 2 to 3 times that of the conventional cross-sectional shape shown by the dotted line.

FIG. 4 shows the bottom surface 4 of the bottom plate 1 of the seat chair, but reinforcing ribs 5, 5, ... Are formed on the bottom surface 4 to reinforce the strength of the bottom plate 1. That is, since the bending rigidity is increased by increasing the second moment of area of the bending of the bending portion 3, the bending portion 3 is not largely deformed by the pressing force acting on the backrest plate 2, and the influence thereof is exerted on the bottom plate 1. Will be covered. Therefore, since reinforcement of the curved portion 3 is not sufficient, the reinforcing ribs 5, 5, ... Are formed on the bottom plate 1 as shown in FIG.

By the way, the three-dimensional curved surface of the curved portion 3 and the reinforcing ribs 5, 5, ... On the bottom surface 4 of the bottom plate 1 can be manufactured by injection molding without any problem. With a seat chair made of a plate material, the three-dimensional curved surface of the curved portion 3 and the reinforcing rib 5 of the bottom plate cannot be formed. As described above, in the seat chair of the present invention, the cross-sectional shape of the backrest plate is smoothly curved from the upper end to the lower curved portion, and the central portion is projected rearward. You can get the effect.

[0013]

[Effect of device]

 In the seat chair according to the present invention, the curved portion, which is the boundary between the back plate and the bottom plate, is curved and formed in a three-dimensional shape, so the second moment of area at this portion is high, and therefore the back plate. It can withstand the moment due to the pressing force that acts on the backrest plate and does not bend. Further, since the backrest plate is formed by a curved surface projecting backward from the upper end to the curved portion below, the shape of the backrest plate becomes easy to sit.

That is, if the conventional shape shown by the dotted line in FIG. 2 makes the buttocks hit the curved portion and feels cramped, the curved portion of the present invention does not come into contact with the buttocks because it protrudes backwardly. . Moreover, since the cross section is curved from the upper end of the backrest plate to the curved portion, the state of leaning back is stable and gives a feeling of relief.

[Brief description of drawings]

FIG. 1 is an embodiment showing a seat chair according to the present invention.

2 is a sectional view taken along the line YY of FIG. 1, and FIG. 2B is a sectional view taken along the line XX of FIG.

FIG. 3 is a cross-sectional view taken along the curved portion of FIG.

FIG. 4 shows a bottom surface of a bottom plate.

FIG. 5 is a conventional chair.

FIG. 6 is a conventional chair.

[Explanation of symbols]

 1 bottom plate 2 backrest plate 3 curved portion 4 bottom surface 5 reinforcing rib

Claims (2)

[Scope of utility model registration request] 1. A seat chair having a bottom plate and a backrest plate with a curved portion between the two plates, the material of which is injection-molded as a resin, and the longitudinal section of the backrest plate is rearward at the upper end. The seat chair is characterized in that the curved portion is also smoothly bent to the rear and the curved portion is also projected rearward, and the cross-sectional shape is formed by a smooth curved surface projecting from the upper end to the lower curved portion in the central portion to the rear. 2. The reinforcing rib is formed on the bottom plate.
Seats listed.