JP2004261466A - Backrest structure of chair - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a backrest of a chair with a structure simplified by eliminating a separate reaction device. <P>SOLUTION: A back panel 2 is attached to an elastic structure body 1 having two arm parts 1a and 1b attached to support members of the chair so as to be freely rocked, whose rocking axes C1 and C2 are different, and a connection part 1c for connecting the arm parts 1a and 1b. The back panel 2 is tilted by rocking the elastic structure body 1 while elastically deforming the elastic structure body, and the elastic force of the elastic structure body 1 is used as a reaction force for uprighting the tilted back panel 2. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a chair back structure.
[0002]
[Prior art]
The backrest of the chair is attached to a supporting member such as a seat or a support so as to be tiltable, that is, to be movable backward. As a conventional chair backrest structure, for example, there is one disclosed in Japanese Patent Application Laid-Open No. 2000-139604 as a prior art. In this backrest structure, as shown in FIG. 11, a front seat frame 101 fixed to a support 104, a rear seat frame 102 swingable with respect to the support 104, and an intervening space between the two frames 101 and 102. The rear seat frame 102 includes a reaction force device 108 for applying a reaction force to return the rear seat frame 102 to an upright position, and a back plate 105 attached to a back support rod 106 fixed to the rear seat frame 102.
[0003]
When a person sitting on the seat 103 leans on the back plate 105, the rear seat frame 102 swings, and the back plate 105 tilts. At this time, the coil spring 107 of the reaction force device 108 is compressed and contracted, so that the elastic force becomes a reaction force for erecting the rear seat frame 102, that is, the back plate 105.
[0004]
[Patent Document 1]
JP 2000-139604 A
[Problems to be solved by the invention]
However, in the chair back structure described above, a reaction force device 108 is required separately from structural members such as the seat frames 101 and 102 and the back support rod 106. For this reason, the number of parts has increased and the structure has become complicated, leading to an increase in manufacturing costs. In addition, in order to obtain the required reaction force, the spring 107 of the reaction force device 108 must be increased to some extent. For this reason, the reaction force device 108 becomes large, which is a constraint when designing a chair and the The degree of freedom was getting worse. On the other hand, it is possible to obtain the required reaction force even if a small spring 107 is employed as the reaction force device 108, but in that case, the structure of the reaction force device 108 becomes complicated, so that the reaction force The device 108 could not be miniaturized much, but rather increased the manufacturing cost.
[0006]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a chair back structure that can eliminate a separate reaction force device and simplify the structure.
[0007]
[Means for Solving the Problems]
In order to achieve this object, a chair backrest structure according to claim 1 comprises two arm portions which are swingably attached to a support member of the chair and which have different swinging center axes, and these two arm portions. A back plate is attached to an elastic structure having a connecting portion to be connected, and the back plate is tilted by swinging as a whole while elastically deforming the elastic structure, and the elastic force of the elastic structure is tilted. The reaction force is to raise the plate.
[0008]
Since the swing center axes of the two arm portions of the elastic structure are different, the elastic structure needs to be elastically deformed in order to swing as a whole. Therefore, in a state where the chair is not used, the elastic structure is urged toward the reference position (a position where it does not swing) by its own elastic force, and stands up the back plate.
[0009]
On the other hand, when the seated person leans on the back plate and leans backward, that is, when the back plate is tilted, the elastic structure swings while being elastically deformed. Since the elastic structure tries to return to its original shape by its own elastic force, this elastic force is a reaction force for returning the elastic structure to the reference position, and is a reaction force for erecting the back plate.
[0010]
In the backrest structure of a chair according to a second aspect, the connecting portion is arranged along the rear peripheral edge of the seat, and a back plate is attached to the connecting portion. Therefore, since the back plate can be directly supported by the elastic structure, it is not necessary to integrally form the mounting stay with the back plate, and the shape of the back plate can be simplified. Further, the back plate can be supported in a wide range by the connecting portion.
[0011]
The chair backrest structure according to claim 3 is provided with a stopper for limiting the swing angle of the arm portion. Therefore, the tilting range of the back plate can be limited. That is, it is possible to prevent the back plate from falling down too much or standing vigorously to strongly hit the back of the seat or the seated person.
[0012]
Further, in the chair backrest structure according to the fourth aspect, a stopper for limiting a swing angle is provided in each of the two arm portions. Therefore, the load applied to each stopper can be dispersed. Further, since the stopper is provided on the arm, the swing of the arm can be directly restricted.
[0013]
In the chair backrest structure according to the fifth aspect, a stopper for limiting the swing angle is provided in each of the two arms, and the timing at which each stopper limits the swing of the arm is shifted. .
[0014]
Therefore, when the back plate is greatly tilted and the elastic structure is largely swung, the stoppers of the two arm portions operate to stop the swing. At this time, if the stoppers of the two arm portions operate simultaneously, the impact is generated at once, so that a so-called bottom feeling is given to the occupant. However, according to the present invention, the stoppers of the two arm portions operate in sequence one by one at a shifted timing, so that it is possible to disperse the generation of impact, and it is not necessary to suddenly stop the movement of the elastic structure. It does not give the seated person a feeling of bottom.
[0015]
Further, in the chair back structure according to the sixth aspect, a plurality of elastic structures are arranged symmetrically. For example, in the case of a single elastic structure, there is a possibility that the tilt locus of the back plate is twisted due to the elastic deformation of the elastic structure. The movement of the board can be canceled.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the configuration of the present invention will be described in detail based on the best mode shown in the drawings.
[0017]
1 to 3 show an embodiment of a chair back structure to which the present invention is applied. The backrest structure of this chair connects two arms 1a and 1b which are swingably attached to a support member 3 of the chair and have different swing center axes C1 and C2, and these two arms 1a and 1b. The back plate 2 is attached to the elastic structure 1 having the connecting portion 1c to be connected, and the back plate 2 is tilted by swinging the entire elastic structure 1 while elastically deforming the elastic structure 1, and the elastic force of the elastic structure 1 Is a reaction force for erecting the tilted back plate 2.
[0018]
The support member 3 is a member for attaching a backrest, and is, for example, a seat 4, a support 5, or the like. In the present embodiment, the seat 4 is the support member 3. A bracket 6 is attached to the bottom surface of the seat 4. Sleeves 7, 8 are fixed to the front and rear of the bracket 6, and the front and rear sleeves 7, 8 are arranged in parallel. In the present embodiment, since the front and rear sleeves 7 and 8 are arranged in parallel, the swing center axes C1 and C2 of the two arms 1a and 1b are parallel.
[0019]
The elastic structure 1 is a structure that supports the back plate 2 and has both rigidity as a structure and elasticity that generates a reaction force that causes the rocked back plate 2 to stand. The elastic structure 1 is, for example, a stainless steel pipe having a circular cross section. However, the pipe is not limited to a pipe having a circular cross section, and may be a pipe having a rectangular cross section or a pipe having another shape. The elastic structure 1 is not limited to a stainless steel pipe, but may be another metal pipe, or may be another material such as a resin or carbon pipe. Further, the elastic structure 1 is not limited to a pipe, but may be another member such as a solid rod.
[0020]
The elastic structure 1 forms two arm portions 1a and 1b and a connecting portion 1c by bending a pipe. The arm length of one arm 1a is short, and the arm length of the other arm 1b is long. The tip portions of the two arms 1a, 1b are bent inward in the width direction of the chair, and are inserted into the front and rear sleeves 7, 8 so as to be relatively rotatable. That is, the tip of the shorter arm portion 1a is inserted into the rear sleeve 8 so as to be relatively rotatable, and the tip of the longer arm portion 1b is inserted into the front sleeve 7 so as to be relatively rotatable.
[0021]
With such a configuration, the swing center axes C1 and C2 of the two arms 1a and 1b can be shifted, and the elastic structure 1 is always elastically deformed when swinging as a whole. That is, one arm 1a swings around the swing center axis C1, and the other arm 1b swings around the swing center axis C2, so that the elastic structure 1 swings as a whole while being elastically deformed. I do. Therefore, when the elastic structure 1 swings, an elastic force is generated to return the shape, and the elastic force is used to return the elastic structure 1 to its original position (reference position) before swinging. be able to. That is, a reaction force for returning the rocked elastic structure 1 to the reference position can be generated.
[0022]
The magnitude of the reaction force can be appropriately set by changing the material, shape and size of the elastic structure 1 and the distance and positional relationship between the two swing center axes C1 and C2. When a cross-sectional shape other than a circle is used as the elastic structure 1, a rotating member is interposed between the arms 1 a and 1 b and the bracket 6.
[0023]
The connecting portion 1c is provided with a rising portion 9 that rises from the rear of the seat 4. In the present embodiment, the entire connecting portion 1c is the start-up portion 9. However, it is not necessary that the entire connecting portion 1c be the rising portion 9, and a part of the connecting portion 1c may be the rising portion 9. Further, the rising portion 9 may be attached to the connecting portion 1c as a separate member. The back plate 2 is attached to the rising section 9.
[0024]
FIG. 4 shows the elastic structure 1 in a natural state. In a natural state where no load is applied, the heights of the tips of the arms 1a and 1b are shifted. On the other hand, the heights of the sleeves 7, 8 before and after attaching the arm portions 1a, 1b are the same. For this reason, at the time of assembly, the elastic structure 1 is slightly elastically deformed in order to equalize the heights of the tips of the arms 1a and 1b. That is, a preload (initial reaction force) is applied to the assembled elastic structure 1 in a direction in which the elastic structure 1 stands, and this force (elastic force) causes the elastic structure 1 to function as a stopper provided on the bottom surface of the seat 4. It hits 10 per degree. In other words, when the chair is not used, the elastic structure 1 is urged toward the reference position by its own elastic force, and the back plate 2 stands up.
[0025]
When the seated person leans on the back plate 2 and tilts the back plate 2, the elastic structure 1 swings. Since the rocking motion of the elastic structure 1 generates a reaction force for returning the elastic structure 1 to the reference position, the back plate 2 can be erected by the reaction force.
[0026]
As described above, since the reaction force against the tilting of the back plate 2 can be generated by the elastic structure 1 which is the structure supporting the back plate 2, a separate reaction force device conventionally required becomes unnecessary. Therefore, the number of parts of the chair can be greatly reduced, and the structure for tilting the back plate 2 can be simplified, so that the manufacturing cost can be reduced.
[0027]
In addition, since the assembly to the chair is completed by attaching the elastic structure 1 to the bracket 6 and attaching the back plate 2 to the elastic structure 1, the backrest can be easily assembled, and the manufacturing cost can be further reduced.
[0028]
In addition, since a separate reaction device, which is conventionally required, is not required, the space under the seat 4 can be spared, so that space can be saved, and the degree of freedom in chair design can be improved. Can be.
[0029]
Further, since the back plate 2 is attached to the elastic structure 1 and tilted, the tilt angle of the back plate 2 can be increased. That is, the tilt stroke can be increased.
[0030]
Further, since the elastic structure 1 is formed of a pipe having a circular cross section, the arms 1a and 1b can be swung with respect to the sleeves 7 and 8 as they are, and the arms 1a and 1b are swung. There is no need for a bearing mechanism for making this possible, and the manufacturing cost can be further reduced.
[0031]
Further, by attaching the back plate 2 to the elastic structure 1, a stay for attaching the back plate, which is conventionally required, can be eliminated. Therefore, the number of parts can be reduced, and the shape of the mold for manufacturing the back plate can be simplified, so that the manufacturing cost can be further reduced. Further, the degree of freedom in the design of the chair can be further improved.
[0032]
Further, since the stopper 10 is provided on the bottom surface of the seat 4 as a stopper, by applying the elastic structure 1 to the stopper 10, the backboard 2 stands up vigorously and strongly hits the back of the seated person, The elastic structure 1 can be prevented from strongly hitting the seat 4.
[0033]
The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the spirit of the present invention. For example, in the above description, the elastic structure 1 is formed by one pipe. However, the elastic structure 1 does not necessarily need to be formed by one pipe. For example, the arm parts 1a and 1b and the connecting part are formed. 1c may be formed as a separate member, and these may be fixed and integrated.
[0034]
In the above description, the rising portion 9 is integrally formed by bending the elastic structure 1. However, the rising portion 9 is formed as a separate member and is integrated with the connecting portion 1c by being fixed thereto. May be.
[0035]
Further, in the above description, the rising portion 9 is provided in the connecting portion 1c, and the back plate 2 is attached to the rising portion 9, but the present invention is not necessarily limited to this configuration. For example, the connecting portion 1c may be arranged along the rear peripheral edge 4a of the seat 4, and the back plate 2 may be attached to the connecting portion 1c. An embodiment in this case is shown in FIGS. The connecting portion 1c of the elastic structure 1 is curved to have substantially the same shape as the rear peripheral edge 4a of the seat 4, and is disposed diagonally behind the seat 4.
[0036]
By doing so, the back plate 2 can be supported using the entire length of the connecting portion 1c. That is, the back plate 2 can be supported in a wide range, and the mounting rigidity of the back plate 2 can be increased. Further, the back plate 2 having a shape that wraps the back and waist of the seated person from behind can be used by tilting. Furthermore, since it is not necessary to integrally form mounting stays on the back plate 2, the shape of the back plate 2 can be simplified, and the shape and structure of the mold for manufacturing the back plate can be simplified. can do. Therefore, the manufacturing cost can be further reduced. It should be noted that the backrest structure shown in FIGS. 5 to 8 has the same effect as the backrest structure shown in FIGS.
[0037]
In the above description, the swing center axes C1 and C2 of the two arm portions 1a and 1b are shifted back and forth, but may be shifted up and down, or may be shifted up and down and up and down. May be.
[0038]
In the above description, the swing center axes C1 and C2 of the two arm portions 1a and 1b are set to be parallel.
[0039]
In the above description, a preload (initial reaction force) is applied to the elastic structure 1 to be assembled. However, the preload does not always have to be applied. Even if the preload is not applied, since the swing center axes C1 and C2 of the two arms 1a and 1b are different, when the elastic structure 1 as a whole swings, it is elastically deformed and tends to return to its original state. Is generated, and the elastic structure 1 can be urged in the direction of hitting 10 per degree by the elastic force, and the back plate 2 can be kept upright.
[0040]
Further, a stopper for limiting the swing angle of at least one of the two arms 1a and 1b may be provided. By providing such a stopper, the tilting range of the back plate 2 can be limited, and the back plate 2 may fall too much, or the back plate 2 may be erected vigorously and strongly hit the back of the seated person, It is possible to prevent the structure 1 from hitting the seat 4 strongly.
[0041]
As such a stopper, a stopper for limiting the swing angle may be provided in each of the two arms 1a and 1b. By providing a stopper on each of the two arms 1a and 1b, the load on each stopper can be dispersed and reduced. Further, by providing the stoppers on the arm portions 1a and 1b, the swing of the arm portions 1a and 1b can be directly limited, and the structure of the stopper can be simplified. In addition, by providing the arm portions 1a and 1b with stoppers, the stoppers become less noticeable, and the degree of freedom in chair design can be further improved.
[0042]
FIG. 9 shows an example of a stopper provided on each of the two arms 1a and 1b. In the example of FIG. 9, stoppers 11 and 12 for limiting the swing angle are provided on each of the two arms 1a and 1b, and the timing at which the stoppers 11 and 12 limit the swing of the arms 1a and 1b is determined. I'm staggering.
[0043]
The stoppers 11, 12 are composed of elongated holes 7a, 8a provided in the sleeves 7, 8, and a protruding piece 13 projecting from the peripheral surface of the arm portions 1a, 1b and penetrating through the elongated holes 7a, 8a. Since the projecting piece 13 moves in the slots 7a, 8a with the swing of the arms 1a, 1b, the arms 1a, 1b swing until the projecting piece 13 hits (activates) the ends of the slots 7a, 8a. can do. That is, the swing angle of the arm portions 1a and 1b (the rotation angle of the arm portions 1a and 1b with respect to the sleeves 7 and 8) is limited by the length of the long holes 7a and 8a. Although the two arm portions 1a and 1b have different arm lengths, they also swing at different angles. However, when the elastic structure 1 swings, the protruding piece 13 of one stopper 11 is close to the end of the long hole 7a. By slightly shifting the timing of hitting (operating) and the timing of hitting (operating) of the protruding piece 13 of the other stopper 12 at the end of the long hole 8a, the occurrence of the hit impact is dispersed. In addition, since the movement of the elastic structure 1 can be prevented from being suddenly stopped, it is possible to prevent the occupant from giving a feeling of bottoming. The two stoppers 11, 12 may be operated simultaneously. Also, when returning the elastic structure 1 to the reference position, the two stoppers 11 and 12 may be operated one by one in order, or when returning the elastic structure 1 to the reference position, two stoppers may be used. 11 and 12 may be operated simultaneously. When the stoppers 11 and 12 are provided, 10 per degree can be made unnecessary.
[0044]
In the above description, the sleeves 7 and 8 are provided with the elongated holes 7a and 8a, and the arms 1a and 1b are provided with the protruding pieces 13. However, the sleeves 7 and 8 are provided with the protruding pieces 13 and the arm sections 1a and An elongated hole may be provided in 1b.
[0045]
Further, a plurality of elastic structures 1 may be provided. FIG. 10 shows an example in which the elastic structures 1 are provided symmetrically one by one. In the backrest structure shown in FIG. 1 or the backrest structure shown in FIG. 5, the swing trajectory of the back plate 2 may be twisted due to the elastic deformation of the elastic structure 1. However, the elastic structures 1 are arranged symmetrically. Thus, the back plate 2 can be swung straight. In addition, by providing a plurality of elastic structures 1, the generated reaction force can be increased. It should be noted that the backrest structure shown in FIG. 10 also has the same effect as the backrest structure shown in FIGS.
[0046]
【The invention's effect】
As described above, in the chair backrest structure according to the first aspect, two arm portions which are swingably attached to the support member of the chair and have different swing center axes, and connect these two arm portions. A back plate is attached to an elastic structure having a connecting portion, and the back plate is tilted by swinging the entire elastic structure while elastically deforming the elastic structure, and the elastic force of the elastic structure is tilted. , The need for a separate reaction device is eliminated. For this reason, the number of components of the chair can be significantly reduced, and the structure for tilting the back plate can be simplified, so that the manufacturing cost can be reduced. Also, since the number of parts can be reduced, the assembling work can be facilitated. Furthermore, since a separate reaction force device is not required, the space below the seat can be provided with parts, and the degree of freedom in designing the chair can be improved.
[0047]
In the backrest structure of the chair according to the second aspect, the connecting portion is arranged along the rear peripheral edge of the seat and the back plate is attached to the connecting portion, so that the back plate is directly supported by the elastic structure. can do. Therefore, the shape of the back plate can be simplified, so that the shape and structure of the mold for manufacturing the back plate can be simplified, and the manufacturing cost can be further reduced. Further, since the back plate can be supported in a wide range, the mounting rigidity of the back plate can be increased.
[0048]
Further, in the backrest structure of the chair according to the third aspect, since the stopper for limiting the swing angle of the arm portion is provided, the tilt angle of the back plate can be limited. For this reason, it is possible to prevent the back plate from falling down too much or standing vigorously to strongly hit the seat or the back of the seated person.
[0049]
In the chair backrest structure according to the fourth aspect, since the stoppers for limiting the swing angle are provided in each of the two arm portions, the load applied to each stopper can be dispersed and reduced. In addition, since the stopper is provided on the arm portion, the swing of the arm portion can be directly restricted, so that the structure of the stopper can be simplified, and the stopper can be made inconspicuous, so that the degree of freedom of the chair design can be improved. Can be further improved.
[0050]
Furthermore, in the backrest structure of the chair according to the fifth aspect, since the stopper for limiting the swing angle is provided in each of the two arms, the timing for limiting the swing of the arm is shifted by each stopper. When the back plate is tilted significantly, it is possible to prevent the occupant from feeling bottomed. For this reason, it is possible to prevent the occupant from feeling uncomfortable and to improve the comfort of the chair.
[0051]
In the backrest structure of the chair according to claim 6, since a plurality of elastic structures are arranged symmetrically, even if each of the elastic structures swings so as to be twisted, as a whole, The movement can be canceled and the back plate can be tilted straight.
[Brief description of the drawings]
FIG. 1 is a bottom view showing a first embodiment of a backrest structure of a chair to which the present invention is applied, which is assembled to a chair.
FIG. 2 is a side view showing the first embodiment of the backrest structure of the chair to which the present invention is applied, in a state where the chair is assembled to the chair.
FIG. 3 is a rear view showing the first embodiment of the backrest structure of the chair to which the present invention is applied, which is assembled to the chair.
FIG. 4 is a side view showing a free shape of the elastic structure of FIG. 1;
FIG. 5 is a bottom view showing a second embodiment of the backrest structure of the chair to which the present invention is applied, which is assembled to the chair.
FIG. 6 is a side view showing a second embodiment of the backrest structure of the chair to which the present invention is applied, which is in a state of being assembled to the chair.
FIG. 7 is a rear view showing the second embodiment of the backrest structure of the chair to which the present invention is applied, which is assembled to the chair.
FIG. 8 is a side view showing a free shape of the elastic structure shown in FIG. 5;
9A and 9B are cross-sectional views illustrating a state in which the elastic structure is not oscillated, and FIG. 9B is a cross-sectional view illustrating a state in which the elastic structure is oscillated. FIG.
FIG. 10 is a bottom view showing the third embodiment of the backrest structure of the chair to which the present invention is applied, which is assembled to the chair.
FIG. 11 is a side view of a conventional chair backrest structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Elastic structure 1a, 1b Arm part 1c Connecting part 2 Back plate 3 Supporting member 4 Seat 4a Peripheral edge of rear side of seat 10 degrees (stopper)
11, 12 Stopper C1, C2 Oscillating center axis

Claims (6)

A back plate is attached to an elastic structure having two arm portions that are swingably attached to a support member of the chair and have different swing center axes, and a connecting portion that connects the two arm portions. The chair is characterized in that the back plate is tilted by swinging the entire structure while elastically deforming the structure, and a reaction force is generated to raise the back plate in which the elastic force of the elastic structure is tilted. Backrest structure. The chair backrest structure according to claim 1, wherein the connecting portion is arranged along a rear peripheral edge of the seat, and the back plate is attached to the connecting portion. 3. The chair back structure according to claim 1, further comprising a stopper for limiting a swing angle of the arm portion. 3. The chair back structure according to claim 1, wherein a stopper for limiting a swing angle is provided on each of the two arms. 3. The chair according to claim 1, wherein a stopper for limiting a swing angle is provided in each of the two arm portions, and a timing at which each stopper limits the swing of the arm portion is shifted. Backrest structure. The backrest structure for a chair according to any one of claims 1 to 5, wherein a plurality of the elastic structures are symmetrically arranged.

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