JP2017000205A - Pipe frame structure of stacking chair, stacking chair, and manufacturing method of pipe frame structure of stacking chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To build a frame structure of a stacking chair without welding.SOLUTION: At least right/left vertical rods 3b, 3b of a back rest reception part receiving and supporting a back rest, right/left seat reception parts 3a, 3a receiving and supporting a seat, right/left leg parts each including a front leg 3d, a rear leg 3e, and a leg bottom side 3f connecting a lower edge of the front leg 3d and a lower edge of the rear leg 3e, and a rear horizontal rod 3g connecting the right/left leg parts are continuously formed without including a welding part as a continuous and integrated object comprising one bent pipe member having a thin diameter.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pipe frame structure of a stacking chair, a stacking chair, and a manufacturing method of the pipe frame structure of the stacking chair. More specifically, the present invention relates to a pipe frame structure of a stacking chair constituted by small-diameter pipes used as a pipe frame of a chair stackable in the vertical direction, a stacking chair including the pipe frame structure, and the The present invention relates to a method for manufacturing a pipe frame structure.

  Conventionally, there is a chair (also called a stacking chair) that can be stacked by bending a thin pipe to form a leg frame. As such a chair, for example, the main body frame is composed of left and right leg frames, a horizontal frame connecting the left and right leg frames, and a backrest frame that supports the backrest, and the frames are fixed to each other by welding. There is a chair having a frame structure (Patent Document 1).

  Since this type of chair (in other words, this type) is used in, for example, a large hall, a large amount of demand is generated at one time. Therefore, it is desired that the chair can be produced in a large amount in a short time. In addition, since a chair having a frame made up of small-diameter pipes has a simple structure, it is generally traded at a low price. For this reason, it is desired to suppress production costs.

JP 2002-142907 A

  However, for example, a chair with a frame structure as in Patent Document 1 has the following problems in its manufacture.

1) It cannot be manufactured in a short time and efficiently.
The manufacturing process of a small-diameter pipe chair usually requires five processes: bending process → welding process → surface treatment process → leg frame assembly process → seat and back assembly process. That is, since a welding process and a leg frame assembling process are performed, it is difficult to efficiently manufacture a chair in a short time and with little effort.

2) There is an easily breakable part.
In welding in the manufacture of chairs such as welding between frames, CO2 welding and TIG welding are usually used, and the welding joint surface is firmly connected, but when a chair durability test is performed In many cases, the side of the welding surface breaks. This can be said to be because durability is lowered by the periphery of the welded portion being cured by welding.

3) Yield is poor due to poor welding.
In the welding process, welding defects may occur. In particular, in TIG welding and the like, the optimum welding conditions change depending on conditions such as temperature and humidity, so that the occurrence of poor welding may increase and the yield deteriorates.

  Therefore, the present invention relates to a pipe frame structure and a stacking chair of a stacking chair that can be assembled without welding, and a pipe frame of a stacking chair that can assemble a frame structure of a stacking chair without welding. An object is to provide a method of manufacturing a structure.

  To achieve this object, the pipe frame structure of the stacking chair of the present invention is a chair pipe frame that can be stacked in the vertical direction. The left and right vertical saddle parts of the backrest receiving part that supports and supports, the left and right seat receiving parts that receive and support the seat, the front leg part and the rear leg part, and the bottom part of the leg that connects the lower end of the front leg part and the lower end of the rear leg part The left and right leg portions having the left and right leg portions and the rear lateral flange portion connecting the left and right leg portions are formed continuously and without having a welded portion.

  In addition, the manufacturing method of the pipe frame structure of the stacking chair according to the present invention includes a chair pipe frame that can be stacked in the vertical direction. The left and right vertical saddles that support the seat, the left and right seat receivers that support the seat, the front legs and the rear legs, and the left and right legs that have the bottoms of the legs that connect the lower ends of the front legs and the lower ends of the rear legs. The leg portion and the rear lateral flange portion connecting the left and right leg portions are formed continuously and without having a welded portion.

  Therefore, according to the pipe frame structure of these stacking chairs and the manufacturing method of the pipe frame structure of the stacking chair, the frame structure of the chair is formed only by bending one small-diameter pipe member. A chair is manufactured by only three processes: a bending process, a surface treatment process, and a seat and back assembly process. For this reason, according to the pipe frame structure of the stacking chair and the manufacturing method of the pipe frame structure of the stacking chair, the chair is manufactured without going through the welding process and the assembly process of the leg frame.

  According to the pipe frame structure of the stacking chair and the manufacturing method of the pipe frame structure of the stacking chair, the chair frame structure is formed by bending a single small-diameter pipe member without having a welded portion. Since it is formed, problems such as a decrease in durability due to hardening around the welded portion and a decrease in yield due to the occurrence of poor welding are avoided.

  According to the pipe frame structure of the stacking chair and the manufacturing method of the pipe frame structure of the stacking chair, the chair frame structure is formed by bending a single small-diameter pipe member. This eliminates the need for parts for joining the various parts that make up the frame structure, so the number of parts can be reduced, and as a result, the frame structure of the chair can be manufactured efficiently by simplifying the assembly work. In addition, the cost of the frame structure is reduced.

  The pipe frame structure of the stacking chair according to the present invention is a chair pipe frame that can be stacked in the vertical direction. It is formed as a rear leg part and a leg bottom side part connecting the lower end of the front leg part and the lower end of the rear leg part, and without a welded part, and the pair of left and right pipe frames are connected by a connecting member. I try to do it.

  Also, the manufacturing method of the pipe frame structure of the stacking chair according to the present invention includes a chair pipe frame that can be stacked in the vertical direction, a pair of left and right pipe frames bent by one small-diameter pipe member, and a series of at least front legs. And the rear leg part and the bottom part of the leg part connecting the lower end of the front leg part and the lower end of the rear leg part are formed continuously and without a welded part. I try to connect them.

  Therefore, according to the pipe frame structure of the stacking chair and the manufacturing method of the pipe frame structure of the stacking chair, the frame structure of the chair is formed without the welded portion by being formed by bending the small-diameter pipe member. As a result, the chair is manufactured by only three processes: a bending process, a surface treatment process, a seat and a back assembly process. Therefore, according to the pipe frame structure of these stacking chairs and the manufacturing method of the pipe frame structure of the stacking chair, the chair is manufactured without passing through the welding process and the assembly process of the leg frame, and the periphery of the welded portion is cured. The problem of the deterioration of the yield and the deterioration of the yield by generation | occurrence | production of the welding defect by this is avoided.

  According to the pipe frame structure of these stacking chairs and the manufacturing method of the pipe frame structure of the stacking chair, the pair of left and right pipe frames constituting the chair frame structure is formed by bending the small diameter pipe member. Therefore, for example, parts for joining various parts for constituting the frame structure of the chair are not required, so the number of parts can be reduced, and as a result, the assembly work can be simplified and efficiently performed. A frame structure is manufactured, and the cost of the frame structure is reduced.

  The pipe frame structure of the stacking chair of the present invention may be configured such that at least a part of at least one of the seat and the backrest functions as a connecting member, and the manufacturing method of the pipe frame structure of the stacking chair of the present invention. In this case, at least one of at least one of the seat and the backrest may function as a connecting member. In these cases, at least one of the member connecting the pair of left and right pipe frames and the seat or the backrest may be used. Since the parts are shared, the number of parts can be reduced and the manufacturing process of the chair can be simplified.

  The stacking chair of the present invention has the pipe frame structure of the above stacking chair. Therefore, according to the stacking chair of the present invention, the effects exhibited by the above-described pipe frame structure of the stacking chair are exhibited with respect to the frame structure of the chair.

  According to the pipe frame structure of a stacking chair and the manufacturing method of the pipe frame structure of the stacking chair of the present invention, the chair can be manufactured without going through the welding process and the assembly process of the leg frame. It is possible to reduce the labor for manufacturing work and reduce the cost.

  According to the pipe frame structure of the stacking chair and the manufacturing method of the pipe frame structure of the stacking chair according to the present invention, there is a problem in that the durability is deteriorated due to hardening around the welded portion and the yield is deteriorated due to the occurrence of poor welding. Since it can be avoided, it is possible to improve the durability of the chair and extend the safety, and at the same time to maintain the yield at a good level and reduce waste and reduce the cost. Is possible.

  According to the pipe frame structure of the stacking chair and the method of manufacturing the pipe frame structure of the stacking chair according to the present invention, the assembly work can be simplified and the chair frame structure can be efficiently manufactured. Therefore, it is possible to provide a highly versatile stacking chair frame structure in that a large number of chairs can be manufactured in a short time.

  In the pipe frame structure of the stacking chair of the present invention, the pair of left and right pipe frames are formed by bending one thin pipe member, and at least a part of at least one of the seat and the backrest is a pair of left and right. When it is made to function as a connecting member for connecting the pipe frame, the number of parts can be reduced and the manufacturing process of the chair can be simplified, so that the labor for the manufacturing work can be further reduced and the cost can be further reduced. It becomes possible to make it cheaper.

  In the manufacturing method of the pipe frame structure of the stacking chair according to the present invention, the pair of left and right pipe frames are formed by bending one small-diameter pipe member, and at least a part of at least one of the seat and the backrest is left and right. When it is made to function as a connecting member for connecting a pair of pipe frames, the number of parts can be reduced and the manufacturing process of the chair can be simplified. It becomes possible to make it cheaper.

  In addition, according to the stacking chair of the present invention, the effects exhibited by the pipe frame structure of the stacking chair described above can be exhibited with respect to the frame structure of the chair.

It is a front overhead perspective view which shows an example of embodiment of the pipe frame structure of the stacking chair of this invention. It is a front view of the pipe frame structure of the stacking chair shown in FIG. It is a side view of the pipe frame structure of the stacking chair shown in FIG. It is a top view of the pipe frame structure of the stacking chair shown in FIG. It is a front overhead perspective view which shows other embodiment of the pipe frame structure of the stacking chair of this invention. FIG. 6 is a front overhead perspective view showing a pipe frame of the stacking chair shown in FIG. 5. It is the figure which expressed the seat and backrest of the stacking chair shown in FIG. 5 in a transparent state. It is a front bird's-eye perspective view which shows other embodiment of the pipe frame structure of the stacking chair of this invention. It is an exploded view of the stacking chair shown in FIG. It is the figure which expressed the seat frame and backrest of the stacking chair shown in FIG. 8 in a transparent state. It is a front bird's-eye view perspective view which shows other embodiment of the pipe frame structure of the stacking chair of this invention. It is a front bird's-eye perspective view which shows the pipe frame of the stacking chair shown in FIG. It is the figure which expressed the seat and backrest of the stacking chair shown in FIG. 11 in the transparent state. It is a front bird's-eye view perspective view which shows other embodiment of the pipe frame structure of the stacking chair of this invention. It is a front bird's-eye perspective view which shows the pipe frame of the stacking chair shown in FIG. It is the figure which expressed the seat and backrest of the stacking chair shown in FIG. 14 in the transparent state. It is a front bird's-eye view perspective view which shows other embodiment of the pipe frame structure of the stacking chair of this invention. It is a front bird's-eye perspective view which shows the pipe frame of the stacking chair shown in FIG. It is the figure which expressed the seat and backrest of the stacking chair shown in FIG. 17 in the transparent state.

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

  FIG. 1 to FIG. 19 show an example of an embodiment of a pipe frame structure of a stacking chair and a stacking chair of the present invention and a manufacturing method of the pipe frame structure of the stacking chair. In the description of the present invention, vertical, front-rear, and left-right are defined based on a seated person sitting on a chair.

  A chair having a frame structure constituted by small-diameter pipes has a seat 1 (not shown in FIGS. 1 to 4 and 8 to 10) and a backrest 2 (however, in FIGS. 1 to 4). (Not shown) and a pipe frame 3 that supports the seat 1 and the backrest 2 and are configured to be stackable up and down.

  In the present invention, the stacking pitch as the stacking chair (that is, the interval between the chairs adjacent to each other when stacked in the vertical direction) is not limited to a specific value. For example, the storage efficiency ( That is, the value is appropriately set to an appropriate value in consideration of the number of storage legs per unit volume). Specifically, for example, the stacking pitch is preferably about 25 to 30 mm.

  Further, in the present invention, the number of stacking legs as a stacking chair is not limited to a specific value. For example, considering the transport efficiency when installing or removing the chair, the number of stacking legs is appropriately set to an appropriate value. Is set. Specifically, for example, it may be set to about 10 legs for carrying by hand, and about 20 to 40 legs for carrying by carriage. In addition, when the overall dimensions and stacking are made so that there is no hindrance when carrying about 10 legs by hand, and there is no hindrance when carrying around 20 to 40 legs by carriage. The magnitude of the deviation of the center of gravity is adjusted.

  Here, in the present invention, a skeleton of a chair body that is formed by using a small-diameter pipe member and supports a seat, a backrest, or an armrest or a note stand in some cases to support them. This is called a pipe frame structure. And the pipe frame structure of this invention may be comprised as what integrated the seat and the backrest.

  The outer diameter / inner diameter of the small-diameter pipe member in the present invention is not limited to a specific value, for example, for forming each part such as strength or seat and backrest required for the purpose of use. The value is appropriately set to an appropriate value after taking into account the ease of bending. Specifically, for example, the outer diameter of the small-diameter pipe member is preferably about 12 to 14 mm, and more preferably about 13 mm.

  In addition to the hollow pipe, a solid solid rod can be used as the small-diameter pipe member in the present invention. That is, the small diameter pipe member in the description of the present invention includes a hollow pipe and a solid solid bar. In the case where a solid solid rod is used as the thin pipe member in the present invention and the desired strength can be ensured, the outer diameter of the thin pipe member is more preferably about 12 mm.

  In addition, the thickness of the small-diameter pipe member in the present invention (that is, in the case of a hollow pipe) is not limited to a specific value. For example, the strength or the seat or backrest required in consideration of the application, etc. In consideration of easiness of bending for forming each part, etc., the value is appropriately set to an appropriate value. Specifically, for example, the thickness of the small-diameter pipe member is preferably in the range of about 1.0 to 2.2 mm, and more preferably in the range of about 1.2 to 2.0 mm.

  In addition, the material of the small-diameter pipe member in the present invention is not limited to a specific material, and for example, the strength and durability required in consideration of the use and the like, or each part such as a seat and a backrest is formed. In consideration of easiness of bending for the purpose, an appropriate one is appropriately selected. Specifically, for example, steel or stainless steel can be selected as the material of the small-diameter pipe member.

  1 to 4 show an example of a pipe frame structure of a stacking chair. The pipe frame 3 is not welded (in other words, does not have a welded portion), but is formed by bending a single small-diameter pipe member to form each part as a single unit. By matching the start point and the end point of the backrest, the backrest receiving portion that supports and supports the backrest (specifically, the left and right vertical saddle portions 3b and 3b, the lateral reed portion 3c) and the left and right support that supports the seat Seat receiving portions 3a, 3a, left and right leg portions (specifically, left and right front leg portions 3d, 3d, left and right rear leg portions 3e, 3e, left and right leg bottom sides 3f, 3f), and these left and right legs The back reed part 3g which connects a part is formed continuously.

  In the following description, the vertical saddle portion of the backrest receiving portion is referred to as the backrest vertical portion 3b, and the upper horizontal portion connecting the right and left backrest vertical portions 3b is backrest. It is called a recumbent part 3c.

  The pipe frame 3 shown in FIGS. 1 to 4 has, for example, the center of the backrest 3c as a starting point and an end point of bending, and the right side 3cr of the backrest 3c → the backrest 3b ( Right) → seat receiving part 3a (right) → front leg part 3d (right) → leg base part 3f (right) → rear leg part 3e (right) → rear heel part 3g → rear leg part 3e (left) → leg base 3f (left) → front leg 3d (left) → seat receiving portion 3a (left) → backrest vertical saddle portion 3b (left) → backrest side horizontal portion 3c in the order of left side 3cl. The

  Then, the right side 3cr and the left side 3cl of the backrest recumbent portion 3c that are in a butted state are arranged, for example, inside the right side 3cr and the left side 3cl, with a single rod-like core member disposed across the right side 3cr and the left side 3cl. 3cr and 3cl on the left side are joined by being fastened to the core by a fastener or joint such as a screw, or by being joined by an inlay joint (also referred to as an “indian joint”) ( However, the pipe frame structure of the chair is formed.

  Note that the right side 3cr and the left side 3cl of the backrest horizontal portion 3c that are in the butted state do not necessarily have to be in direct contact with or integrated with each other, for example, formed as a part of the backrest or attached to the backrest. The distance between the right side 3cr and the left side 3cl may be constrained so as not to be widened by being fixed by a frame that has been removed.

  Further, the starting point and the ending point of the bending process (that is, the part to be joined in the butt state after the bending process) are not limited to the backrest side part 3c, but other parts of the pipe frame 3 It may be. Specifically, for example, the center of the rear recumbent part 3g may be set as a start point and an end point of bending.

  In addition, the pipe frame 3 shown in FIGS. 1 to 4 is provided with a member for connecting the rear leg portion 3e, the rear lateral flange portion 3g, and the seat receiving portion 3a (in other words, fixing the mutual positional relationship). You may be allowed to. Specifically, for example, the bent portion and the rear end portion are mutually connected while being interposed between the bent portion where the rear leg portion 3e and the rear lateral flange portion 3g are continuous and the rear end portion of the seat receiving portion 3a. A separate part for supporting and supporting may be provided, or a part that enters between the bent part and the rear end part and supports the bent part and the rear end part as a part of the seat. It may be formed. In this case, the separate part or the part formed as a part of the seat and the pipe frame 3 are formed with a C-shaped receiving part having a clip function in the part or the part, and a pipe is formed in the receiving part. A part of the frame 3 may be fixed to each other by fitting, or may be fixed to each other by a fastener / joint such as a screw.

  When the pipe frame structure is formed by the pipe frame 3 shown in FIGS. 1 to 4, the method of attaching the seat and the backrest is not limited to a specific method or mechanism, and for example, the use is considered. An appropriate method and mechanism are appropriately selected in consideration of the seat and backrest shape and material selected in this way.

  Specifically, for example, the seat is placed so as to be bridged between the left and right seat receiving portions 3a, 3a of the pipe frame 3, and is fastened by fasteners / joints such as screws (in this case, the seat and the seat receiving portion). A separate fixing part such as a receiving / gripping mode intervening between the base plate 3a and the like, or a C-shaped receiving part having a clip function formed on the lower surface of the seat. The seat receiving portion 3a is attached to the pipe frame 3 by a fastening method or a joining method such as fitting.

  Further, the backrest is provided with a back plate so as to cover at least a part of a space surrounded by the left and right backrest vertical flange portions 3b, 3b and the backrest horizontal flange portion 3c of the pipe frame 3, such as screws. Depending on the fastener / joint (in this case, a separate fixing component such as a receiving / holding mode interposed between the seat and the backrest 3b or the backrest 3c may be used. Or a fastening method / contact such as fitting the backrest vertical flange portions 3b, 3b and the backrest horizontal portion 3c to a C-shaped receiving portion formed on the rear surface of the back plate and having a clip function. It is attached to the pipe frame 3 by law.

  The material of the seat and backrest is not limited to a specific type, and an appropriate one is appropriately selected in consideration of, for example, the required strength and preferred weight in consideration of the application. Is done. Specifically, for example, various plastics can be used as an example.

  As shown in FIGS. 5 to 7, the pipe frame 3 may not include the backrest lying portion 3 c.

  In this case, the left and right backrest vertical flange portions 3b, 3b are used as the start and end points of the bending process, so that they are not welded (in other words, do not have a welded portion). The small-diameter pipe member is bent to form each part as a continuous unit. In the example shown in FIGS. 5 to 7, the backrest vertical flange 3 b is formed shorter than the examples shown in FIGS. 1 to 4.

  The pipe frame 3 shown in FIGS. 5 to 7 includes, for example, a backrest 3b (right) → a seat receiving portion 3a (right) → a front leg 3d (right) → a leg base 3f (right) → a rear leg 3e (right) → rear heel part 3g → rear leg part 3e (left) → leg base 3f (left) → front leg part 3d (left) → seat receiving part 3a (left) → backrest vertical part 3b (left) ) In the order of production).

  In the example shown in FIGS. 5 to 7, pipe receiving holes 2a and 2a that are open at the lower end surface of the backrest 2 and are generally parallel to each other at the lower left and right edges of the lower end portion of the backrest 2 are shown. It is formed.

  The left and right backrest vertical flange portions 3b and 3b are inserted into and fitted into the left and right pipe receiving holes 2a and 2a of the backrest 2, respectively. The backrest 2 and the backrest 3b are fixed to each other by, for example, a fastener or a joint such as a screw screwed in the front-rear direction from the rear surface of the backrest 2 or an adhesive or the like as necessary. Used to adhere to each other.

  Thereby, the right and left backrest vertical portions 3b and 3b are connected to each other via the backrest 2 to form a pipe frame structure of the chair in which the backrest 2 is integrated.

  In addition, the pipe frame 3 shown in FIGS. 5 to 7 is provided with a member for connecting the rear leg portion 3e, the rear lateral flange portion 3g, and the seat receiving portion 3a (in other words, fixing the mutual positional relationship). You may be allowed to. Specifically, for example, the bent portion and the rear end portion are mutually connected while being interposed between the bent portion where the rear leg portion 3e and the rear lateral flange portion 3g are continuous and the rear end portion of the seat receiving portion 3a. A separate part for receiving and supporting may be provided, or a part that enters between the bent part and the rear end part and supports the bent part and the rear end part is a part of the seat 1. It may be formed as. In this case, the separate part or the part formed as a part of the seat 1 and the pipe frame 3 are formed with a C-shaped receiving part having a clip function in the part or the part. A part of the pipe frame 3 may be fixed to each other by fitting, or may be fixed to each other by a fastener / joint such as a screw.

  When the pipe frame structure is formed by the pipe frame 3 shown in FIG. 5 to FIG. 7, the mounting method of the seat 1 is not limited to a specific method or mechanism, and is selected in consideration of, for example, an application. An appropriate method and mechanism are appropriately selected in consideration of the form, material, and the like of the seat 1 formed.

  Specifically, for example, the seat 1 is placed so as to be bridged between the left and right seat receiving portions 3a, 3a of the pipe frame 3, and is fastened by fasteners / joints such as screws (in this case, the seat 1 and the seat 1). A separate fixing part such as a receiving / gripping mode interposed between the receiving part 3a and the like may be used), or a C-shaped clip having a clip function formed on the lower surface of the seat 1 It is attached to the pipe frame 3 by a fastening method or a joining method such as fitting the seat receiving portion 3a to the receiving portion.

  The concept of the material of the seat 1 and the backrest 2 is the same as the example shown in FIGS.

  Here, when manufacturing the pipe frame 3 shown in FIG. 1 to FIG. 4 or FIG. 5 to FIG. 7, in order to bend a pipe that is long enough to form a single pipe frame structure for one chair. Large work space and large equipment are required.

  Therefore, in order to enable manufacture with a narrower working space and small equipment, a pair of left and right pipe frames formed in a plane-symmetric form are connected to each other by a connecting member, and the pipe frame structure of the chair May be formed. In particular, at least a part of the seat or the seat frame and the backrest functions as a connecting member, so that the pair of left and right pipe frames are connected to each other to integrate the seat or the seat frame and the backrest (in other words, A pipe frame structure of the chair may be formed.

  According to the pair of left and right pipe frames, since the pipe frame structure for one chair is formed by two pipes, the pipe for one chair as in the pipe frame 3 shown in FIGS. Compared with the case where the frame structure is formed of a single pipe, the working space can be narrowed and the equipment can be miniaturized, which facilitates mass production.

  8 to 10, a pair of left and right pipe frames 3A and 3B formed in a plane-symmetric form are connected to each other by a seat frame 4 and a backrest 2, that is, the seat frame 4 and the backrest 2 are ( 8 to 10, the seat frame 4) functions as a connecting member for connecting the pair of left and right pipe frames 3 </ b> A and 3 </ b> B, and the pipe of the stacking chair in which the seat frame 4 and the backrest 2 are integrated. It is an example of a frame structure.

  The pipe frames 3A and 3B shown in FIG. 8 to FIG. 10 are not welded (in other words, have no welded portion), and a single small-diameter pipe member is bent to form a series of front legs 3d. The leg base 3f, the rear leg 3e, and the backrest 3b are continuously and symmetrically formed as a pair of left and right surfaces. The pipe frames 3A and 3B shown in FIGS. 8 to 10 do not include the backrest part 3c and the rear side part 3g, and do not include the seat receiving part 3a. Therefore, in the example shown in FIGS. 8 to 10, the weight of the entire chair can be reduced.

  In the examples shown in FIGS. 8 to 10, the rear leg 3e and the backrest vertical portion 3b are not bent and both are straight, and the backrest vertical portion 3b is It is formed shorter than the example shown in FIGS.

  In the example shown in FIGS. 8 to 10, a seat frame 4 is also provided. The material of the seat frame 4 is not limited to a specific type, and an appropriate material is appropriately selected in consideration of, for example, required strength and preferable weight in consideration of the application. The Specifically, for example, fiber reinforced plastic can be used as an example.

  Specifically, the seat frame 4 in the example shown in FIGS. 8 to 10 has four planes at the upper ends of the front leg portions 3d and 3d and the upper ends of the rear leg portions 3e and 3e of the left and right pipe frames 3A and 3B, respectively. It is formed in a frame having four belt-like frame sides (specifically, a front frame side 4a, left and right side frame sides 4b and 4b, and a rear frame side 4c).

  The seat frame 4 is formed such that each of the connecting portions of the front frame side 4a and the left and right side frame sides 4b and 4b bends and the front frame side 4a hangs downward. Front leg insertion holes 4d and 4d, which are substantially in the vertical direction of the lower surface opening and parallel to each other, are formed at the left and right ends, and the left and right edges of the rear frame side 4c (in other words, the left and right side frame sides 4b and 4b Through-holes 4e and 4e that are substantially in the vertical direction and parallel to each other are formed at the rear end position).

  The upper end portions of the front leg portions 3d and 3d of the left and right pipe frames 3A and 3B are inserted into and fitted into the left and right front leg insertion holes 4d and 4d of the seat frame 4, respectively, and the backrest vertical flange portions 3b and 3b are fitted. Passes through the left and right through holes 4e, 4e of the seat frame 4. The seat frame 4 and the front leg 3d may be fixed to each other by a fastener or a joint such as a screw that is screwed in the front-rear direction from the rear surface of the front frame side 4a in the hanging state of the seat frame 4 as necessary. Adhesives or the like are used to adhere to each other.

  Here, the support of the front part of the seat frame 4 by the front leg parts 3d, 3d is provided in the front leg insertion holes 4d, 4d formed in the seat frame 4 as in the examples shown in FIGS. It is not restricted to the aspect which the upper end part of 3d is inserted and it fits. Specifically, for example, continuously bent from the upper ends of the front leg portions 3d, 3d toward the opposing pipe frames 3A, 3B (in other words, toward the central position in the left-right direction for the chair), horizontally bent The front portion of the seat frame 4 may be received and supported by the front leg portions 3d and 3d by forming a portion to be bent and contacting the lower portion of the seat 1 with the bent portion.

  The seat frame 4 is fixed to the boundary position (height) between the rear leg 3e and the backrest 3b with the backrest 3b, 3b passing through the through holes 4e, 4e. The fixing of the position of the rear portion of the seat frame 4 with respect to the rear legs 3e of the pipe frames 3A and 3B is not limited to a specific method or mechanism, and for example, the configuration of the seat frame 4 selected in consideration of the application, An appropriate method and mechanism are appropriately selected in consideration of the material and strength required for fixing the position.

  Specifically, for example, as an example only, the rear leg 3e and the backrest 3b are compressed in the axial direction so that the boundary between the rear leg 3e and the backrest 3b May be deformed to form a round lantern-shaped part, and the part may be used as a step so that the seat frame 4 is hooked and fixed in position, or a hooking member such as a washer is further attached to the part. After the fitting, the rear portion of the seat frame 4 may be supported and fixed in position.

  In the example shown in FIGS. 8 to 10, pipe receiving holes 2 a and 2 a that open at the lower end surface of the backrest 2 and are generally parallel to each other at the lower end surface of the backrest 2 are formed at the left and right edges of the lower end portion of the backrest 2. It is formed.

  The left and right pipe frames 3A and 3B projecting from the upper surface of the seat frame 4 through the left and right through holes 4e and 4e of the seat frame 4 are the left and right pipes of the backrest 2, respectively. They are inserted into the receiving holes 2a and 2a, respectively. The backrest 2 and the backrest 3b are fixed to each other by, for example, a fastener or a joint such as a screw screwed in the front-rear direction from the rear surface of the backrest 2 or an adhesive or the like as necessary. Used to adhere to each other.

  As described above, the left and right pipe frames 3A and 3B are connected to each other via the seat frame 4 and the backrest 2 to form a pipe frame structure of a chair in which the seat frame 4 and the backrest 2 are integrated. In this case, the pair of left and right pipe frames 3A and 3B and the attachment of the seat frame 4 and the backrest 2 are simultaneously performed, and the leg frame assembling process and the seat and back of the conventional chair manufacturing process are performed. The assembly process is performed together.

  When the pipe frame structure is formed by the pair of left and right pipe frames 3A and 3B and the seat frame 4 and the backrest 2 shown in FIGS. 8 to 10, a method of attaching the seat to the seat frame 4 is as follows. It is not limited to the mechanism, and an appropriate method or mechanism is appropriately selected in consideration of, for example, the form and material of the seat selected in consideration of the application.

  Specifically, for example, as an example only, a seat plate made of plastic or the like is placed so as to be bridged over the four frame sides 4a, 4b, 4b, and 4c of the seat frame 4, and a fastener such as a screw It is attached to the seat frame 4 by a connector. Further, a stretch fabric such as a mesh fabric or a canvas fabric is stretched over the upper surface of the seat frame 4 and is formed on the seat frame 4 and an elongated plate-like locking member made of resin or the like attached to the edge of the stretch fabric. And is attached to the seat frame 4 by a combination with a groove into which the locking member is fitted.

  Further, instead of using the seat frame 4 in combination with the seat plate, the upholstery, etc., in other words, the seat may be configured without the seat frame 4 interposed. Specifically, for example, the inner portion of the seat frame 4 is closed, the front leg insertion holes (4d, 4d) at the left and right ends of the front end, and the through holes (4e, 4e) at the left and right edges of the rear end. For example, a plate-like seat 1 as shown in FIGS. 5 to 7 may be used.

  The concept of the material of the seat and the backrest 2 is the same as the example shown in FIGS.

  11 to 13, a pair of left and right pipe frames 3A and 3B formed in a plane-symmetrical form are connected to each other by a backrest 2, that is, the backrest 2 (example shown in FIGS. 11 to 13). Then, at least the backrest 2 is an example of a pipe frame structure of a stacking chair in which the backrest 2 functions as a connecting member that connects the pair of left and right pipe frames 3A and 3B.

  The pipe frames 3A and 3B shown in FIGS. 11 to 13 are not welded (in other words, do not have a welded portion), and a single thin-diameter pipe member is bent so as to be a series of seats. 3a, the front leg part 3d, the leg base part 3f, the rear leg part 3e, and the backrest vertical saddle part 3b are formed continuously and symmetrically as a pair of left and right. The pipe frames 3A and 3B shown in FIGS. 11 to 13 do not include the backrest part 3c and the rear side part 3g. Therefore, in the example shown in FIGS. 11 to 13, the weight of the chair as a whole can be reduced.

  In the examples shown in FIG. 11 to FIG. 13, the bending is not performed between the rear leg portion 3e and the backrest vertical portion 3b, and both are straight, and the backrest vertical portion 3b is It is formed shorter than the example shown in FIGS.

  In the example shown in FIGS. 11 to 13, a portion (referred to as “fixing insertion portion 3 h”) that is bent upward in the direction along the backrest vertical flange portion 3 b from the rear end of the seat receiving portion 3 a is formed. The The fixing insertion portion 3h is also formed continuously with the seat receiving portion 3a as a single unit by bending a small diameter pipe member simultaneously with the formation of the above-described portions.

  Further, in the example shown in FIGS. 11 to 13, pipe receiving holes 2a and 2a that are open at the lower end surface of the backrest 2 and are substantially parallel to each other at the lower end surface of the backrest 2 are provided at the left and right edges of the lower end portion of the backrest 2. And formed at the lower end surface of the backrest 2 so as to be adjacent to the inside of each of the left and right pipe receiving holes 2a, 2a (that is, the side closer to the center position in the left-right direction of the backrest 2) and the pipe Pipe insertion holes 2b and 2b are formed in a direction along the receiving hole 2a (that is, approximately in the vertical direction and parallel to each other).

  Then, the backrest vertical flange portions 3b, 3b of the left and right pipe frames 3A, 3B are inserted and fitted into the left and right pipe receiving holes 2a, 2a of the backrest 2, respectively, and the fixing insertion portions 3h, 3h are provided. The right and left pipe insertion holes 2b, 2b of the backrest 2 are respectively inserted and fitted. The backrest 2 and the backrest 3b and the fixing insertion portion 3h are fixed to each other by fasteners / joints such as screws screwed in the front-rear direction from the rear surface of the backrest 2 as necessary. Or glued to each other using an adhesive or the like.

  As a result, the left and right pipe frames 3A and 3B are connected to each other via the backrest 2 to form a pipe frame structure of a chair in which the backrest 2 is integrated. In this case, the pair of left and right pipe frames 3A and 3B are connected and the backrest 2 is attached at the same time, and the assembly process of the leg frame and the assembly process of the back in the conventional chair manufacturing process are performed together. Done.

  The way of attaching the seat 1 in the examples shown in FIGS. 11 to 13 is the same as that in the examples shown in FIGS. Depending on how the seat 1 is attached to the left and right pipe frames 3A, 3B, the seat 1 also functions as a connecting member that connects the pair of left and right pipe frames 3A, 3B.

  The concept of the material of the seat 1 and the backrest 2 in the example shown in FIGS. 11 to 13 is the same as that in the example shown in FIGS.

  14 to 16, a pair of left and right pipe frames 3A and 3B formed in a plane-symmetric form are connected to each other by a backrest 2, that is, the backrest 2 (example shown in FIGS. 14 to 16). Then, at least the backrest 2) functions as a connecting member for connecting the pair of left and right pipe frames 3A and 3B, and is another example of a pipe frame structure of a stacking chair in which the backrest 2 is integrated. Note that the examples shown in FIGS. 14 to 16 do not include the backrest 3c and the backside 3g, so that the weight of the entire chair can be reduced.

  The example shown in FIGS. 14 to 16 is different from the example shown in FIGS. 11 to 13 in that the fixing insertion part 3h (in FIGS. 14 to 16) is continuous with the rear end of the seat receiving part 3a of the pipe frames 3A and 3B. The mode of the symbol 3h ′ and the mode of the left and right pipe insertion holes 2b and 2b (also denoted by symbols 2b ′ and 2b ′) of the backrest 2 are different. In addition, the aspect of the backrest vertical flange part 3b of the pipe frames 3A and 3B and the aspect of the left and right pipe receiving holes 2a and 2a of the backrest 2 are the same as the examples shown in FIGS.

  Specifically, in the example shown in FIGS. 14 to 16, the fixing insertion portion 3 h ′ continuous with the rear end of the seat receiving portion 3 a is directed toward the opposing pipe frames 3 </ b> A and 3 </ b> B (in other words, It is formed in the horizontal direction (towards the central position in the left-right direction for the chair).

  A pair of left and right connecting portions 2c and 2c extending diagonally forward and downward from each of the positions near the left and right ends of the lower end of the backrest 2 are formed. Pipe insertion holes 2b 'and 2b' are formed.

  The backrest vertical flange portions 3b, 3b of the left and right pipe frames 3A, 3B are inserted and fitted into the left and right pipe receiving holes 2a, 2a of the backrest 2, respectively, and the fixing insertion portions 3h ', 3h 'Is inserted into and fitted into the pipe insertion holes 2b' and 2b 'of the left and right connecting portions 2c and 2c of the backrest 2, respectively. The backrest 2 and the backrest vertical portion 3b and the fixing insertion portion 3h 'are, for example, screws that are screwed in the front-rear direction or the vertical direction from the rear surface of the backrest 2, as necessary. They are fixed to each other by a fastener or a joint, or are bonded to each other using an adhesive or the like.

  Thereby, the left and right pipe frames 3A and 3B are connected to each other via the backrest 2, and a pipe frame structure of a stacking chair in which the backrest 2 is integrated is formed. In this case, the pair of left and right pipe frames 3A and 3B are connected and the backrest 2 is attached at the same time, and the assembly process of the leg frame and the assembly process of the back in the conventional chair manufacturing process are performed together. Done.

  The way of attaching the seat 1 in the examples shown in FIGS. 14 to 16 is the same as that in the examples shown in FIGS. Depending on how the seat 1 is attached to the left and right pipe frames 3A, 3B, the seat 1 also functions as a connecting member that connects the pair of left and right pipe frames 3A, 3B.

  Further, the concept of the material of the seat 1 and the backrest 2 in the examples shown in FIGS. 14 to 16 is the same as the examples shown in FIGS.

  17 to 19, a pair of left and right pipe frames 3A and 3B formed in a plane-symmetric form are connected to each other by a seat 1 and a backrest 2, that is, the seat 1 and the backrest 2 (see FIG. 17). In the example shown in FIG. 19, at least the seat 1 and the backrest 2 function as a connecting member for connecting the pair of left and right pipe frames 3A and 3B, and the pipe of the stacking chair in which the seat 1 and the backrest 2 are integrated. It is an example of a frame structure.

  The pipe frames 3A and 3B shown in FIGS. 17 to 19 are not welded (in other words, without a welded part), and a single thin pipe member is bent to form a series of seat receiving parts. 3a, the front leg part 3d, the leg base part 3f, the rear leg part 3e, and the backrest vertical saddle part 3b are formed continuously and symmetrically as a pair of left and right. The pipe frames 3A and 3B illustrated in FIGS. 17 to 19 do not include the backrest 3c and the backside 3g. Therefore, in the example shown in FIGS. 17 to 19, the weight of the entire chair can be reduced.

  In the example shown in FIGS. 17 to 19, the bending is not performed between the rear leg portion 3 e and the backrest vertical portion 3 b, and both are straight.

  In the example shown in FIGS. 17 to 19, the backrest vertical flange 3 b is slightly bent so as to have a “<” shape protruding forward in a side view. Bending of the backrest vertical flange 3b is performed simultaneously with the formation of each of the above-described parts, that is, a single small-diameter pipe member is bent and integrated as a series. The backrest vertical flange 3b of the example shown in FIGS. 17 to 19 is formed slightly shorter than the example shown in FIGS. 1 to 4 after being subjected to bending.

  In the example shown in FIGS. 17 to 19, the through holes 1 a and 1 a are formed in the left and right edges of the rear end portion of the seat 1, and the connecting band member 5 is provided on the lower surface side of the seat 1.

  Specifically, the seat 1 is formed with through-holes 1a and 1a that are generally in the vertical direction and parallel to each other at the left and right edges of the rear end.

  The connecting band member 5 functions as a connecting member that connects the pair of left and right pipe frames 3A and 3B.

  The connecting band member 5 is formed in a band shape, is bridged in the left-right direction between the seat receiving portions 3a, 3a of the left and right pipe frames 3A, 3B, and is fixedly attached to the lower surface side of the seat 1.

  The material of the connecting band member 5 is not limited to a specific type, and an appropriate one is appropriately selected in consideration of, for example, required strength and preferable weight in consideration of the application. Is done. Specifically, for example, metal or fiber reinforced plastic can be used as an example.

  At both ends in the longitudinal direction of the connecting band member 5, concave grooves 5 a and 5 a having a semicircular cross section and a direction perpendicular to the longitudinal direction are formed for gripping and supporting the seat receiving portion 3 a. .

  Then, the seat 1 is placed so as to be bridged between the seat receiving portions 3a, 3a of the left and right pipe frames 3A, 3B. At this time, the backrest vertical flange portions 3b, 3b penetrates the left and right through holes 1a, 1a of the seat 1.

  The seat 1 is fixed to a boundary position (height) between the rear leg 3e and the backrest 3b with the backrest 3b, 3b passing through the through holes 1a, 1a. Also good. The fixing of the position of the rear portion of the seat 1 with respect to the rear legs 3e of the pipe frames 3A and 3B is not limited to a specific method or mechanism. For example, the shape and material of the seat 1 selected in consideration of the application and the like, An appropriate method or mechanism is appropriately selected in consideration of the strength required for fixing the position.

  Specifically, for example, as an example only, the rear leg portion 3e and the backrest vertical protuberance portion 3b are compressed in the axial direction at the boundary portion of the rear leg portion 3e and the backrest vertical protuberance portion 3b. The boundary part with 3b may be deformed to form a round lantern-shaped part, and the part may be used as a step so that the seat 1 is hooked and fixed in position. After the hook member is fitted, the rear portion of the seat 1 may be received and supported and fixed in position.

  The connecting band member 5 is attached to the lower surface side of the seat 1 with the seat 1 placed between the seat receiving portions 3a, 3a of the left and right pipe frames 3A, 3B. Note that the connecting band member 5 is fixed and attached to the seat 1 by a fastener / joint such as a screw that is screwed up and down from the lower surface of the connecting band member 5, for example.

  Thereby, the left and right seat receiving portions 3a, 3a are gripped by the concave grooves 5a, 5a at both ends in the longitudinal direction of the connection band member 5 so that the mutual positional relationship can be fixed.

  In the example shown in FIGS. 17 to 19, there is only one connecting band member 5, but the number of connecting band members 5 is not limited to one, and a plurality of connecting band members 5 are used. May be.

  In addition, in the example shown in FIGS. 17 to 19, a band-shaped member (that is, the connection band member 5) is used as a connection member for connecting the pair of left and right pipe frames 3A and 3B. The shape is not limited to a belt shape, and an appropriate shape can be appropriately selected in consideration of design and the like. Specifically, for example, a connecting member having an “X” shape in plan view may be used, and a connecting member that covers the entire lower surface or substantially the entire surface of the seat as a seat back cover may be used. Also good.

  In addition, the seat 1 is left and right only by holding the seat receiving portions 3a and 3a between the seat 1 and the connecting band member 5 and through the through-holes 1a and 1a of the seat 1 through the vertical saddle portions 3b and 3b. The seat 1 may be attached to the pipe frames 3A and 3B, and if necessary, the seat 1 may be further fixed by a fastener / joint such as a screw (in this case, the seat 1). 1 and a separate fixing component such as a receiving / holding mode interposed between the seat receiving portion 3a and the like may be used.

  In the example shown in FIGS. 17 to 19, pipe receiving holes 2a and 2a that are open at the lower end surface of the backrest 2 and are generally parallel to each other at the lower left and right edges of the lower end portion of the backrest 2 are shown. It is formed.

  The left and right pipe frames 3A and 3B projecting from the upper surface of the seat 1 through the left and right through holes 1a and 1a of the seat 1 are the back and right pipe receiving holes of the backrest 2 respectively. 2a and 2a are inserted and fitted respectively. The backrest 2 and the backrest 3b are fixed to each other by, for example, a fastener or a joint such as a screw screwed in the front-rear direction from the rear surface of the backrest 2 or an adhesive or the like as necessary. Used to adhere to each other.

  As described above, the left and right pipe frames 3A and 3B are connected to each other via the seat 1, the connecting band member 5 and the backrest 2, and the pipe frame structure of the stacking chair in which the seat 1 and the backrest 2 are integrated is formed. The In this case, the pair of left and right pipe frames 3A and 3B are connected and the seat 1 and the backrest 2 are attached at the same time, and the leg frame assembling step and the seat and back assembling in the conventional chair manufacturing process are performed. The process is performed together.

  Here, in the example shown in FIGS. 17 to 19, in addition to the connection band member 5 being provided as a connection member for connecting the pair of left and right pipe frames 3A, 3B, the seat 1 and the backrest 2 can function as the connection members. However, when the connecting band member 5 is provided, the seat 1 and the backrest 2 may not be configured to function as a connecting member. Specifically, for example, the seat 1 may not have the through holes 1a and 1a, and thus the backrest vertical flange portions 3b and 3b may be configured not to penetrate the seat 1.

  The concept of the material of the seat 1 and the backrest 2 in the examples shown in FIGS. 17 to 19 is the same as the examples shown in FIGS.

  According to the pipe frame structure of the stacking chair and the manufacturing method of the pipe frame structure of the stacking chair configured as described above, the small-diameter pipe member is bent without being welded (in other words, without having a welded portion). Thus, the chair frame structure is formed, so that the chair is manufactured by only three steps: bending step → surface treatment step → seat and back assembly step. Therefore, according to the pipe frame structure of these stacking chairs and the manufacturing method of the pipe frame structure of the stacking chair, the chair can be manufactured without going through the welding process and the assembly process of the leg frame. It is possible to reduce the labor required for manufacturing work by reducing the amount of material used, and to reduce the cost. Also, there is a problem in that the durability around the welded part is hardened and the yield is deteriorated due to the occurrence of poor welding. Therefore, it is possible to improve the durability of the chair and thereby improve safety, and at the same time, maintain the yield at a good level to reduce waste and reduce the cost. It becomes possible.

  According to the pipe frame structure of the stacking chair configured as described above and the manufacturing method of the pipe frame structure of the stacking chair, the chair frame structure is further formed by bending the small-diameter pipe member. For example, since the parts for joining various parts for constituting the chair frame structure are not required, the number of parts can be reduced, and as a result, the assembly frame structure can be simplified and efficiently. It is possible to provide a highly versatile chair frame structure in that the work is simple and a large number of chairs can be manufactured in a short time.

  Although the above-described embodiment is an example of a preferred embodiment for carrying out the present invention, the embodiment of the present invention is not limited to the above-described embodiment, and the present invention is not deviated from the gist of the present invention. Various modifications can be made.

  Further, the specific mode of the stacking chair to which the present invention can be applied is not limited to the mode shown in FIGS. 1 to 19, and the present invention can be applied to various types of stacking chairs. For example, the seating and backrest aspects of the stacking chair to which the present invention can be applied are not limited to the examples shown in FIGS. Specifically, the seat may be configured by a single plate-like member as in the example shown in FIG. 5, for example, or the frame-like seat frame as in the example shown in FIG. May be configured to be combined with a seat plate, a tension fabric, or the like, or may be configured with a combination of a plate-shaped seat plate and a cushion material disposed on the upper surface of the seat plate. You may make it. Further, the backrest may be constituted by a plate-like member alone as in the example shown in FIG. 5, for example, or a frame-like backrest frame and a backboard or a tension fabric are combined. Alternatively, a plate-like back plate and a cushion material disposed on the front surface of the back plate may be combined. Furthermore, the seat and the backrest are configured as a single unit, specifically, the seat plate and the back plate are configured as a single unit, or the seat frame and the backrest frame are configured as a single unit. You may make it do.

  In addition, when the seat and the backrest are configured as a single body as described above, the backrest vertical flange portions 3b and 3b are inserted into the pipe receiving holes 2a and 2a formed in the backrest 2. Instead of fitting, it is continuous from the upper ends of the rear leg portions 3e, 3e toward the opposing pipe frames 3A, 3B (in other words, toward the center position in the left-right direction for the chair). A bent portion is formed in the direction, and the bent portion abuts on the rear end portion of the lower surface of the seat (in other words, the lower end surface of the backrest), so that the rear portion of the seat and the backrest are brought into contact with the rear leg portions 3e and 3e. It may be supported.

  Further, in the examples shown in FIGS. 11 to 19, the seat 1 and the backrest 2 are formed with through holes 1a, 1a, pipe receiving holes 2a, 2a, or pipe insertion holes 2b, 2b or 2b ′, 2b ′. The seat 1 and the backrest 2 themselves function as a connecting member that connects the pair of left and right pipe frames 3A and 3B. However, there are separate parts that form part of the seat and the backrest and function as a connecting member. It is also possible that the remaining parts constituting the seat and the backrest are attached to the parts. In the example shown in FIGS. 8 to 10, the seat frame 4 is a part that constitutes a part of the seat and functions as a connecting member. Corresponds to an example in which

1 seat 2 backrest 3 pipe frame 3a seat receiving part 3b backrest vertical saddle 3c backrest lateral lateral part 3cr right side 3cl left side 3d front leg part 3e rear leg part 3f leg bottom part 3g rear lateral part

Claims (7)

  As a pipe frame of a chair that can be stacked in the vertical direction, a single small-diameter pipe member is bent and integrated into a series, at least the left and right vertical saddle parts of the backrest receiving part that supports the backrest, and the seat Left and right seat receivers, front and rear legs, left and right legs having leg bases connecting the lower ends of the front legs and the lower ends of the rear legs, and the rear side connecting the left and right legs A pipe frame structure for a stacking chair, wherein the collar portion is formed continuously and without having a welded portion.   As a pipe frame of a chair that can be stacked in the vertical direction, a pair of left and right pipe frames are each bent by a thin pipe member, and at least a front leg portion and a rear leg portion, and a lower end of the front leg portion and a rear leg are integrally formed. A pipe frame structure for a stacking chair, wherein the pipe frame structure is formed with a leg bottom side connecting the lower end of the part continuously and without a welded portion, and a pair of left and right pipe frames are connected by a connecting member. .   The pipe frame structure of a stacking chair according to claim 2, wherein at least a part of at least one of a seat and a backrest functions as the connecting member.   A stacking chair comprising the pipe frame structure of the stacking chair according to any one of claims 1 to 3.   The pipe frame of the chair that can be stacked in the vertical direction is folded into a single unit by bending one small-diameter pipe member, and at least the left and right vertical saddle portions of the backrest receiving portion that supports the backrest, and the left and right that supports the seat Seat receiving part, front leg part, rear leg part, left and right leg parts having leg bases connecting the lower end of the front leg part and the lower end of the rear leg part, and a rear lateral joint connecting the left and right leg parts Forming a pipe frame structure of a stacking chair, wherein the part is formed continuously and without having a weld.   A pipe frame of a chair that can be stacked in the vertical direction, and a pair of left and right pipe frames, each of which is a single small-diameter pipe member, are joined together to form at least a front leg portion and a rear leg portion, and a lower end of the front leg portion and a rear leg portion. A pipe frame structure for a stacking chair, characterized in that it is formed with a leg bottom side connecting to the lower end of the base plate, without a welded portion, and a pair of left and right pipe frames are connected by a connecting member. Method.   7. The method for manufacturing a pipe frame structure for a stacking chair according to claim 6, wherein at least a part of at least one of a seat and a backrest functions as the connecting member.