JP2013121383A - Pipe frame of chair and folding chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe frame of a chair, which allows a bent portion to be sharply curved while satisfying both securement of the thickness of the bent portion and reduction in weight of a pipe, and further which can reduce restrictions on a structure adoptable as a chair folding mechanism.SOLUTION: The pipe frame 4 of a chair having a bent portion 2 formed by bending a pipe 1 includes a thickness increased portion 3 for compensating reduction in thickness in the bending, which is integrally formed at least on an outside portion 2a of the bending of the bent portion 2.

Description

  The present invention relates to a pipe frame of a chair having a bent portion obtained by bending a pipe, and a foldable chair using the pipe frame.

  As a pipe frame of a foldable pipe chair, there is one that uses an oval pipe or a flat oval pipe (hereinafter, both are collectively referred to as an oval pipe) (for example, Patent Document 1 that uses a flat oval pipe). In such a pipe chair, for example, as shown in FIG. 12, a pipe frame 101 such as a leg is formed by bending the middle of the oval pipe in the short axis direction of the cross-sectional shape, but the bent portion 102 of the oval pipe is bent. Since the thickness of the part extending outside the outer surface decreases, it is possible to prevent the occurrence of processing defects such as cracks and wrinkles even when the thickness is reduced, and to ensure the strength as a frame, In general, a thick-walled oval tube is used in consideration of thickness reduction (thinning) due to elongation. In addition, by making the curve of the bent portion moderate to some extent, it may be possible to suppress the outside extension of the bend and prevent the meat from becoming too thin.

  In addition, as a pipe frame of another type of folding pipe chair, ribs 112 (FIG. 13) are provided in the oval tube 111 to solve the lack of strength due to a decrease in the thickness of the bent portion, and processing defects such as cracks and wrinkles The thing which prevents this is proposed (patent document 2).

Japanese Patent Laid-Open No. 2000-41973 JP 2010-154915 A

  However, in the pipe frame 101 of FIG. 12, when the thickness of the entire oval pipe is increased, the weight becomes heavy. On the other hand, when the curve of the bent portion is made gentle, the straight portion is shortened by the amount of the curve, and the length of the portion in contact with the floor is shortened, which may deteriorate the stability against the tilt of the chair. . Further, in the pipe frame in which the rib 112 is provided in FIG. 13, another rib having a simple shape cannot be inserted into the oval pipe 111 due to the obstruction of the rib 112 in the oval pipe 111. Therefore, it is difficult to make the pipe frame extendable and contractable, and the mechanism that can be adopted as a mechanism for folding the chair is greatly restricted.

  The present invention can achieve both the securing of the thickness of the bent portion and the reduction in the weight of the pipe frame, the tight curve of the bent portion, and a mechanism that can be employed as a mechanism for folding the chair. An object of the present invention is to provide a pipe frame of a chair that can reduce the restriction of the chair.

  In order to achieve such an object, according to the first aspect of the present invention, in a pipe frame of a chair having a bent portion obtained by bending a pipe, at least a portion outside the bent portion of the bent portion is compensated for a thickness reduction during bending. The thickened portion is integrally formed.

  Generally, when a pipe is bent, a portion outside the bent portion of the bent portion is stretched to reduce the thickness of the meat. In the present invention, the thickened portion is provided in advance in the portion where the thickness is reduced by being stretched at the time of bending, and the thickness of the meat is partially increased, so that the thickness is reduced by bending. Thus, a desired thickness can be ensured. That is, the thickness of the portion where the thickened portion of the pipe as a material is provided is a desired thickness in a state where the thickness is reduced by bending.

  Moreover, the pipe frame of the chair according to claim 2 uses an oval pipe as a pipe.

  In the pipe frame of the chair according to claim 3, the thickened portion is provided over the entire length of the pipe.

  Further, in the pipe frame of the chair according to the fourth aspect, the thickened portion is provided in both the outer portion and the inner portion of the bent portion.

  Moreover, the folding chair of Claim 5 uses the pipe frame as described in any one of Claim 1 to 4 for the flame | frame.

  In the pipe frame of the chair according to the first aspect, in general, the thickness of the portion outside the bent portion of the bent portion of the pipe that is likely to be insufficient in thickness can be secured to a desired thickness. Therefore, processing defects such as cracks and wrinkles can be prevented at the time of bending processing, and strength as a frame can be secured. Further, since the thickened portion is provided at least at a portion where the thickness is reduced, the weight can be reduced as compared with the case where the thickness of the entire pipe is increased. In addition, it is not necessary to moderate the curve of the bent portion and suppress the outside elongation, and the curve of the bent portion can be tightened. Therefore, it becomes possible to lengthen the linear part adjacent to a bending part, and it can lengthen the part which touches a floor, and can improve the stability with respect to the inclination of a chair. Furthermore, since there is no member that obstructs the space in the pipe, it is possible to insert another simple member into the pipe, and the pipe frame can be easily expanded and contracted, and the chair is folded. The restriction of the mechanism that can be adopted as the mechanism is reduced.

  Here, an oval pipe may be used as the pipe as in the pipe frame of the chair according to claim 2.

  Further, in the pipe frame of the chair according to claim 3, since the thickened portion is provided over the entire length of the pipe, the pipe to be used can be manufactured by a simple extrusion process, and the pipe is easily manufactured. Cost can be reduced. In addition, when the thickened part is partially provided, it is necessary to align the pipe so that the position where the thickened part is provided is bent at the time of bending of the pipe. Providing the thickened portion eliminates the need for such alignment. Therefore, the bending work of the pipe becomes easy and the productivity of the pipe frame can be improved. Furthermore, since the thickening portion is also provided in the portion where the rotating shaft is incorporated when assembling as a chair, the strength of the portion incorporating the rotating shaft can be increased.

  Furthermore, in the pipe frame of the chair according to claim 4, since the thickening portions are provided in both the outer portion and the inner portion of the bent portion, the pipe can be used without worrying about the inner and outer directions of the bend. Can be bent. Therefore, the bending work of the pipe becomes easy and the productivity of the pipe frame can be improved. Furthermore, since the thickening portion is also provided in the portion into which the rotating shaft that penetrates when assembling as a chair, the strength of the portion into which the rotating shaft is incorporated can be increased.

  Here, since the folding chair uses a pipe frame having a bent portion, it is suitable for use of the pipe frame according to any one of claims 1 to 4. That is, as in the fifth aspect of the invention, the folding chair can be provided by using the pipe frame according to any one of the first to fourth aspects of the frame.

It is a cross-sectional view of the pipe used, showing an example of the embodiment of the pipe frame of the chair of the present invention. It is a perspective view of the use condition of the chair to which the pipe frame of the present invention is applied. It is a side view of the use condition of the chair to which the pipe frame of the present invention is applied. It is a side view of the folding state of the chair to which the pipe frame of the present invention is applied. The expansion-contraction mechanism of the pipe frame of this invention is shown, (A) is the longitudinal cross-sectional view of the contracted state, (B) is the longitudinal cross-sectional view of the expanded state. It is sectional drawing which follows the VI-VI line of FIG. It is a transverse cross section showing the 1st modification of a pipe to be used. It is a transverse cross section showing the 2nd modification of a pipe to be used. It is a transverse cross section showing the 3rd modification of a pipe to be used. It is a transverse cross section showing the 4th modification of a pipe to be used. It is a transverse cross section showing the 5th modification of a pipe to be used. It is a perspective view of a chair provided with a pipe frame using a conventional flat oval pipe. It is a cross-sectional view of a flat oval pipe used and showing a pipe frame of a conventional chair.

  Hereinafter, the configuration of the present invention will be described in detail based on the form shown in the drawings.

  FIGS. 1-6 shows an example of embodiment of the pipe frame of the chair of this invention. The pipe frame of the chair has a bent portion 2 formed by bending the pipe 1 and has a thickened portion 3 having a thickness that compensates for a thickness reduction at the time of bending at least a portion 2 a outside the bent portion 2. Are integrally formed.

  The pipe frame 4 of this embodiment is a pipe frame 4 of a folding pipe chair. However, the pipe frame 4 of the applicable chair is not limited to the pipe frame of the folding pipe chair, and any pipe frame 4 formed by bending the pipe 1 can be used. .

  The pipe chair is configured to support the seat 5 with a front leg frame 6 and a rear leg frame 7, and the pipe frame 4 of the present invention is used as the front leg frame 6 and the rear leg frame 7. The front leg frame 6 forms a front connecting part 6b that bends one pipe 1 and connects the left and right front leg parts 6a and the lower ends of the left and right front leg parts 6a. The bent portion 2 is bent at a substantially right angle between the lower ends of the left and right front leg portions 6a and the front connecting portion 6b. A backrest 8 is attached to the upper ends of the left and right front legs 6a. A substantially central position of the left and right front legs 6a is pivotally connected to the seat 5 using a rotating shaft 15. Further, the rear leg frame 7 forms a rear connecting portion 7b that bends one pipe 1 and connects the left and right rear leg portions 7a and the lower ends of the left and right rear leg portions 7a. The bent portion 2 is bent at a substantially right angle between the lower ends of the left and right rear leg portions 7a and the rear connecting portion 7b. The upper ends of the left and right rear leg portions 7a are connected to the front leg portion 6a of the front leg frame 6 via the telescopic mechanism 9, and the position slightly below the upper end is connected to the seat 5 via the bracket 10 so as to be swingable. .

  In this embodiment, an oval pipe is used as the pipe 1 that forms the pipe frame 4, that is, the front leg frame 6 and the rear leg frame 7. A cross section of the pipe 1 (oval pipe) is shown in FIG. Although FIG. 1 shows a cross section of the bent portion 2 of the pipe 1, the shape is shown before bending in consideration of the ease of understanding the present invention. The bent portion 2 of the pipe 1 is bent in the minor axis direction (arrow S in FIG. 1) of an elliptical cross section. Now, in FIG. 1, if the oval tube is bent upward in the short axis direction described as the vertical direction, the portion described below becomes the outer portion 2a of the bending, and the upper side The part described in (2) becomes the part 2b inside the bend. The portion 2a outside the bend is stretched during the bending process to reduce its thickness (thickening). A thickened portion 3 having a thickness that compensates for the thinned portion is integrally formed in a portion 2a outside the bend. The thickened portion 3 is provided on the inner peripheral surface of the pipe 1, and the contour of the outer shape of the cross section is the same as that of a normal oval tube.

  Here, the thickness of the thickened portion 3, that is, the thickness that compensates for the thickness reduction, does not necessarily need to be a thickness corresponding to the thickness reduction during bending, and is thinner than the thickness corresponding to the thickness reduction. It may be thick or thick. That is, the thickness of the thickened portion 3 is set such that the portion 2a outside the bend can prevent the occurrence of processing defects such as cracks and wrinkles during the bending process and can ensure the strength as a frame. Anything can be used.

  In the present embodiment, the thickened portion 3 is provided in both the outer portion 2a and the inner portion 2b of the bend. By providing both, if it is a short axis direction, it can be bent in any of the upper and lower directions in FIG. 1, so that the pipe 1 can be bent without worrying about the inner and outer directions of the bending. That is, the pipe 1 which is an oval pipe can be easily identified in the short axis direction from its shape, and if it is in the short axis direction, it may be bent in either the upper or lower direction in FIG. It is no longer necessary to identify, and the bending work of the pipe 1 becomes easy. Therefore, the productivity of the pipe frame 4 can be improved.

  However, it is not always necessary to provide the thickened portion 3 in both the outer portion 2a and the inner portion 2b of the bend, and it is sufficient if it is provided at least in the outer portion 2a of the bend. That is, the thickened portion 3 may be provided only on one side in the short axis direction, and the pipe 1 may be bent so that the portion where the thickened portion 3 is provided is on the outside. FIG. 7 shows an example in which the thickened portion 3 is provided only in the portion 2a outside the bend. In this case, the weight of the pipe 1 can be further reduced.

  In the present embodiment, the thickened portion 3 is provided over the entire length of the pipe 1. That is, the thickened portion 3 is also provided in a portion other than the bent portion 2. By providing the thickened portion 3 over the entire length of the pipe 1, it is not necessary to align the position where the thickened portion 3 is provided. Therefore, the bending work of the pipe 1 becomes easy and the productivity of the pipe frame 4 can be improved. Further, when the chair is assembled, the thickened portion 3 is also provided in the portion connected to the seat 5 through the rotary shaft 15 and the portion through which the screw for attaching the bracket 10 is passed, so that the strength of these portions can be increased. . Such a pipe 1 can be easily manufactured by extrusion. Furthermore, not only the outer portion 2a but also the inner portion 2b can be provided with the thickened portion 3 to increase the strength of the portion to which the rotary shaft 15 or the like penetrating the pipe 1 is attached.

  However, it is not always necessary to provide the thickened portion 3 over the entire length of the pipe 1, and it is sufficient if it is provided at least at the bent portion 2. That is, the thickened portion 3 may be partially provided and the portion provided with the thickened portion 3 may be bent. In this case, the weight of the pipe 1 can be further reduced.

  In this embodiment, a pipe made of an aluminum alloy is used as the pipe 1. However, the pipe is not limited to an aluminum alloy pipe, and other metal pipes or pipes made of materials other than metal may be used. The pipe 1 is manufactured by extrusion processing, for example. The thickened portion 3 is formed integrally with the pipe 1 by extruding the pipe 1. However, the pipe 1 and the thickened portion 3 may be manufactured by a processing method other than the extrusion processing.

  The expansion / contraction mechanism 9 includes a sleeve 11 fitted to the upper end of the rear leg portion 7a, and a slider 12 that is slidably inserted into the sleeve 11 and has a connecting portion 12a at the upper end protruding from the sleeve 11. Yes. By sliding the slider 12 with respect to the sleeve 11, the slider 12 can be stretched or compressed in the axial direction of the rear leg 7a (FIGS. 5A and 5B), and the length of the entire rear leg Can be changed.

  The outer peripheral surface of the sleeve 11 has a shape that fits snugly with the inner peripheral surface of the rear leg 7a (pipe 1). Further, the inner peripheral surface of the sleeve 11 has a shape for guiding the shaft portion 12b of the slider 12 in the axial direction of the rear leg portion 7a. The sleeve 11 is provided with a flange 11a that is hooked on the upper end surface of the rear leg 7a. The sleeve 11 is made of resin, for example.

  The slider 12 is, for example, a metal core member 14 sandwiched between a resin cover member 13, and slides with respect to the rigidity and the sleeve 11 as a part of the pipe frame 4 and the shaft of the rear leg 7 a. The function to expand and contract in the direction is secured. The outer peripheral surface of the shaft portion 12 b of the slider 12 has a shape that matches the inner peripheral surface of the sleeve 11. The connecting portion 12a of the slider 12 is swingably connected to the front leg portion 6a.

  Since the rib 112 as shown in FIG. 13 is not provided in the pipe 1 serving as the rear leg portion 7 a, it is possible to insert the simple expansion / contraction mechanism 9 into the pipe 1. Therefore, it is possible to employ the telescopic mechanism 9 as a mechanism for folding the chair. That is, as a mechanism for folding the chair, it is possible to adopt a structure in which a simple-shaped part is inserted into the pipe 1, and the restrictions on the mechanism that can be employed are reduced accordingly.

  In addition, the curve of the bent portion 2 can be tightened. Therefore, it becomes possible to lengthen the straight part (front side connection part 6b, rear side connection part 7b) adjacent to a bending part, and it can lengthen the part which touches a floor, and can improve the stability with respect to the inclination of a chair.

  2 and 3, the chair can be folded by lifting the front portion of the seat 5 and superimposing the seat 5, the front leg frame 6 and the rear leg frame 7 on the same plane (see FIG. 2). 4). By lifting the front part of the seat 5, the left and right telescopic mechanisms 9 are extended at the same time, so that the interconnecting portions of the seat 5, the front leg frame 6, and the rear leg frame 7 can be swung, and the chair can be folded.

  In the pipe frame 4 of the present invention, since the thickened portion 3 is provided in the pipe 1 as a material in consideration of the thickness reduction at the time of bending, the bending of the pipe 1 which is generally insufficient in thickness is generally performed. The thickness of the part 2a outside the bending of the portion 2 can be ensured to a desired thickness. Therefore, processing defects such as cracks and wrinkles can be prevented during bending of the pipe 1, and the strength as a frame can be ensured. Further, since the thickening portion 3 is partially provided at a predetermined site, the weight of the pipe 1 can be reduced as compared with the case where the thickness of the pipe 1 is increased as a whole. Can be.

  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 scope of the present invention.

  For example, in the above description, an oval pipe is used as the pipe 1, but the pipe 1 is not limited to an oval pipe. For example, a flat oval pipe (FIG. 8) may be used, or a pipe having a rectangular cross section (FIG. 9), a pipe having a square cross section (FIG. 10), and a pipe having a circular cross section (FIG. 8). 11) etc. can also be used. Also in these cases, by providing the thickened portion 3 at least at the outer portion 2a of the bent portion 2, it is possible to secure the thickness of the portion where the thickness is reduced during bending.

DESCRIPTION OF SYMBOLS 1 Pipe 2 Bending part 2a Outside part of bending 2b Inside part of bending 3 Thickening part 4 Pipe frame

Claims (5)

  In a pipe frame of a chair having a bent portion obtained by bending a pipe, a thickened portion having a thickness that compensates for a reduced thickness at the time of bending is integrally formed at least at a portion outside the bent portion of the bent portion. The pipe frame of the chair.   The chair pipe frame according to claim 1, wherein the pipe is an oval pipe.   The pipe frame of the chair according to claim 1 or 2, wherein the thickening portion is provided over the entire length of the pipe.   4. The pipe frame of the chair according to claim 1, wherein the thickening portion is provided in both an outer portion and an inner portion of the bent portion.   A folding chair characterized in that the pipe frame according to any one of claims 1 to 4 is used as a frame.

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