CN212698238U

CN212698238U - Folding chair

Info

Publication number: CN212698238U
Application number: CN202021060175.9U
Authority: CN
Inventors: 张建
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-06-10
Filing date: 2020-06-10
Publication date: 2021-03-16
Anticipated expiration: 2030-06-10

Abstract

The utility model discloses a folding chair relates to seat technical field, including bracing piece, seat pole, flexible seat face, connection structure, the bracing piece is equipped with at least threely, and the both ends of seat pole are rotated with the upper end of two adjacent bracing pieces respectively and are connected, and the seat pole can be buckled, and flexible seat face is connected on the seat pole, and connection structure is used for connecting two adjacent bracing pieces, and it can deform, and folding chair's state includes fold condition and expansion state, and when folding chair becomes fold condition by expansion state, connection structure deformation drives the bracing piece and is close to each other, and the seat pole is buckled. So set up, the folding seat chair of having solved among the prior art can not satisfy the problem that accomodate small and the seat is firm after folding simultaneously.

Description

Folding chair

Technical Field

The utility model relates to a seat technical field, more specifically say, relate to a folding chair.

Background

The seat is a common living article in our life, and when outdoor activities such as outing, fishing and the like are carried out, the seat capable of being folded can be transported as required in order to meet the requirements of people on small size, easiness in carrying and convenience in storage.

The foldable seats in the prior art are generally divided into two types, one type is a seat which can be folded along one direction, and the seat is plate-shaped after being folded, such as a folding stool, and the seat is stable when being seated, but has limited folding capability, still occupies a part of space when being folded, and is not easy to carry about; the other type of seat can be folded in two directions perpendicular to each other and can be stored in a small size, but the seat of the seat is usually composed of four supporting points of a main body frame and canvas, so that the seat is poor in stability when a user sits on the seat, the canvas is unevenly stressed, and the canvas is easily torn at the connecting part of the seat and the main body frame.

Therefore, how to solve the problem that the folding seat in the prior art cannot satisfy the small storage volume and the stable seat after folding at the same time becomes an important technical problem to be solved by those skilled in the art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a folding chair, it has solved the problem that can not satisfy the storage after folding small and the seat is firm simultaneously than folding seat among the prior art. The utility model provides a plurality of technical effects that preferred technical scheme among a great deal of technical scheme can produce see the explanation below in detail.

In order to achieve the above purpose, the utility model provides a following technical scheme:

the utility model provides a pair of folding chair, include:

at least three support rods are arranged;

two ends of the seat rod are respectively and rotatably connected with the upper ends of the two adjacent support rods, and the seat rod can be bent;

the flexible seat surface is connected to the seat rod;

the connecting structure is used for connecting two adjacent supporting rods and can deform;

the state of folding chair includes fold condition and expansion state, works as the folding chair by the expansion state becomes during fold condition, connection structure deformation drives the bracing piece is close to each other, the seat pole is buckled.

Preferably, the seat rod comprises a first section, a second section and a third section, wherein the first end of the first section and the second end of the third section are respectively and rotatably connected with the upper ends of two adjacent support rods, the first end of the second section is rotatably connected with the second end of the first section, and the second end of the second section is rotatably connected with the first end of the third section.

Preferably, the first section and the third section are both square rods, the second section is a square groove, the open side of the second section faces downwards, and the second end of the first section and the first end of the third section respectively extend into the two ends of the second section and are hinged to the second section.

Preferably, the connecting structure comprises a first straight rod and a second straight rod, the first straight rod and the second straight rod are rotatably connected in a crossed manner to form an X-shaped structure, the lower end of the first straight rod and the lower end of the second straight rod are respectively hinged to the lower ends of the two adjacent supporting rods, and the upper end of the first straight rod and the upper end of the second straight rod are respectively connected with the two adjacent supporting rods in a relatively rotating manner.

Preferably, the circumference of bracing piece is equipped with the sleeve, the sleeve can be followed the bracing piece reciprocates, just it has the connecting piece to articulate on the bracing piece, the connecting piece with the articulated department of bracing piece is located telescopic below, the bracing piece is equipped with four, is first bracing piece, second bracing piece, third bracing piece and fourth bracing piece respectively, first bracing piece with between the second bracing piece connection structure is first connection structure, the third bracing piece with between the fourth bracing piece connection structure is second connection structure, the second bracing piece with between the fourth bracing piece connection structure is third connection structure, the third bracing piece with between the first bracing piece connection structure is fourth connection structure, the upper end of first connecting structure first straight-bar and second straight-bar respectively with first bracing piece and second bracing piece circumference the cover The barrel is hinged, the upper ends of the first straight rod and the second straight rod of the second connecting structure are hinged to the sleeves in the circumferential direction of the third supporting rod and the fourth supporting rod respectively, the upper ends of the first straight rod and the second straight rod of the third connecting structure are rotatably connected with the second supporting rod and the fourth supporting rod through the connecting piece respectively, and the upper ends of the first straight rod and the second straight rod of the fourth connecting structure are rotatably connected with the third supporting rod and the first supporting rod through the connecting piece respectively.

Preferably, a reinforcing rod is connected between the upper end of the second straight rod of the third connecting structure and the upper end of the second straight rod of the fourth connecting structure, and the reinforcing rod can be bent.

Preferably, be equipped with on the third bracing piece rather than rotate the first back of the chair pole of being connected, be equipped with on the fourth bracing piece rather than rotate the second back of the chair pole of being connected, the third bracing piece with between the first back of the chair pole and the fourth bracing piece with all be equipped with the locking structure between the second back of the chair pole, in order to fix first back of the chair pole with the position of second back of the chair pole, first back of the chair pole with be equipped with the flexible back of the chair between the second back of the chair pole.

Preferably, the locking structure includes bolt and nut, the third bracing piece with the junction of first back of the chair pole all is equipped with the through-hole, the fourth bracing piece with the junction of second back of the chair pole all is equipped with the through-hole, the bolt runs through the through-hole, just nut threaded connection is in the pole portion of bolt, the third bracing piece with all be equipped with anti-skidding texture on the face of contact of first back of the chair pole, the fourth bracing piece with all be equipped with on the face of contact of second back of the chair pole anti-skidding texture.

Preferably, a third seat back rod is arranged between the upper end of the first seat back rod and the upper end of the second seat back rod, and the third seat back rod can be bent.

Preferably, still including increasing the pole, it is equipped with the spring pearl on the pole to increase, the spring pearl pressurized can retract increase in the pole, the bracing piece has hollow structure, and is equipped with a plurality of locating holes on its lateral wall, and is a plurality of the locating hole is followed the direction of height align to grid of bracing piece, it follows to increase the pole the lower extreme of bracing piece stretches into in the bracing piece, simultaneously the spring pearl card is gone into in the locating hole.

The utility model provides a technical proposal, the number of the support rods is at least three, a stable stress structure is formed by matching with a connecting structure arranged between two adjacent support rods, a seat rod which is connected with the support rods in a rotating way is arranged on the support rods, thereby the support rods, the connecting structure and the seat rod form a main body structure of the folding chair, a flexible seat surface which can be folded by folds is connected on the seat rod, the state of the folding chair comprises a folding state and an unfolding state, when the folding chair is in the unfolding state, the arrangement of the seat rod ensures that a larger stress area is formed between the flexible seat surface and the main body structure of the folding chair, a user can stably and comfortably sit on the folding chair, the flexible seat surface is not easy to tear, when the folding chair needs to be stored, the connecting structure is deformed to drive the plurality of support rods to be close to each other, the seat rod is bent, the folds of, because all be equipped with connection structure between two adjacent bracing pieces, the major structure of event folding chair can not fold from the single direction to volume when making fold condition is less, is convenient for accomodate. So set up, the folding seat chair of having solved among the prior art can not satisfy the problem that accomodate small and the seat is firm after folding simultaneously.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic structural view of a folding chair according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a locking structure in an embodiment of the present invention;

FIG. 3 is a schematic view of a seat post according to an embodiment of the present invention;

fig. 4 is a schematic structural view of a third back bar in the embodiment of the present invention;

fig. 5 is a schematic structural view of a heightening rod in the embodiment of the present invention;

fig. 6 is a partial sectional view of a heightening rod according to an embodiment of the present invention.

In fig. 1-6:

1. a seat post; 2. a flexible seat surface; 3. a first straight rod; 4. a second straight rod; 5. a sleeve; 6. a connecting member; 7. a first support bar; 8. a second support bar; 9. a third support bar; 10. a fourth support bar; 11. a reinforcing rod; 12. a first seatback bar; 13. a second seatback bar; 14. a locking structure; 15. a flexible chair back; 16. a third seatback bar; 17. a heightening rod; 18. a spring bead; 19. positioning holes; 20. a spring; 21. a circular tube; 101. a first stage; 102. a second stage; 103. a third stage; 141. a bolt; 142. a nut; 143. anti-skid texture; 144. a knob.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. It is to be understood that the embodiments described are only some embodiments of the invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

An object of this embodiment is to provide a folding chair, which can solve the problem that the folding chair in the prior art cannot satisfy the small storage volume and the stable seat after folding at the same time.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The embodiments described below do not limit the scope of the invention described in the claims. Further, the entire contents of the configurations shown in the following embodiments are not limited to those necessary as a solution of the invention described in the claims.

Referring to fig. 1 to 6, the folding chair provided in this embodiment includes at least three support rods, a seat rod 1, a flexible seat surface 2 and a connecting structure, wherein the support rods are arranged vertically, the seat rod 1 is horizontally arranged, and two ends of the seat rod 1 are respectively connected to upper ends of two adjacent support rods in a rotating manner, the seat rod 1 can be bent in a vertical direction, that is, the seat rod 1 can be bent upward or downward, the flexible seat surface 2 is sewn to the seat rod 1 to provide a sitting position for a user, the connecting structure is used for connecting two adjacent support rods, and the connecting structure can be deformed by stress, the states of the folding chair include a folded state and an unfolded state, when the folding chair is in the unfolded state, the user can sit on the seat, when the folding chair is in the folded state, the user can store the seat, when the folding chair is changed from the unfolded state to the folded state, the deformation of the connecting structure drives the supporting rods to approach each other, and the seat rod 1 is bent.

The arrangement is that at least three support rods are arranged, a stable stress structure is formed by matching with a connecting structure arranged between two adjacent support rods, a seat rod 1 connected with the support rods in a rotating manner is arranged on the support rods, so that the support rods, the connecting structure and the seat rod 1 form a main body structure of the folding chair, a foldable flexible seat surface 2 is connected onto the seat rod 1, the state of the folding chair comprises a folding state and an unfolding state, when the folding chair is in the unfolding state, the flexible seat surface 2 and the main body structure of the folding chair have larger stress area due to the arrangement of the seat rod 1, a user can stably and comfortably sit on the seat, the flexible seat surface 2 is not easy to tear, when the folding chair needs to be stored, the connecting structure deforms to drive the plurality of support rods to be close to each other, the seat rod 1 is bent, the flexible seat surface 2 is folded along with the seat rod, and the folding chair is, because all be equipped with connection structure between two adjacent bracing pieces, the major structure of event folding chair can not fold from the single direction to volume when making fold condition is less, be convenient for accomodate, the folding seat chair of having solved among the prior art can not satisfy the problem of accomodating small and the seat is firm after folding simultaneously.

As a specific embodiment, referring to fig. 3, the seat rod 1 may be configured to include a first section 101, a second section 102 and a third section 103, wherein the first section 101 and the third section 103 have the same length, the second section 102 is shorter than the first section 101, a first end of the first section 101 and a second end of the third section 103 are respectively hinged to upper ends of two adjacent support rods, a first end of the second section 102 is hinged to a second end of the first section 101, a second end of the second section 102 is hinged to a first end of the third section 103, and rotation axes of the first section 101, the second section 102 and the third section 103 are all horizontally arranged, so that the seat rod 1 is configured to be a multi-section structure, and a bending function can be achieved when the support rods at two sides of the seat rod are close to each other.

Further, first section 101 and third section 103 all can select to set up to the square bar, second section 102 optional sets up to be square groove, and the opening side of second section 102 sets up down, the second end of first section 101 and the first end of third section 103 stretch into the both ends of second section 102 respectively and rather than articulated, so, seat pole 1 can upwards buckle when the folding chair is in fold condition, when the folding chair is in the expansion state, because the opening side of second section 102 is down, the back cover side is up, can bear pressure better and indeformable after the user takes a seat, improve the steadiness of folding chair.

More specifically, the connecting structure may be configured to include a first straight rod 3 and a second straight rod 4, the first straight rod 3 and the second straight rod 4 may be rotatably cross-connected to form an "X" shaped structure, and specifically, the middle portions of the first straight rod 3 and the second straight rod 4 may be hinged, the lower end of the first straight rod 3 and the lower end of the second straight rod 4 are hinged to the lower ends of the two adjacent support rods, and the upper end of the first straight rod 3 and the upper end of the second straight rod 4 are respectively rotatably connected to the two adjacent support rods.

Furthermore, the circumference of the supporting rod can be selectively provided with a sleeve 5, the sleeve 5 can move up and down along the supporting rod, the supporting rod is hinged with a connecting piece 6, the hinged position of the connecting piece 6 and the supporting rod is positioned in the middle of the supporting rod and below the sleeve 5, namely, the connecting piece 6 can prevent the sleeve 5 from continuously moving downwards, the connecting piece 6 can be specifically arranged as an aluminum lath, the supporting rods are provided with four parts, namely, a first supporting rod 7, a second supporting rod 8, a third supporting rod 9 and a fourth supporting rod 10, the connecting structure between the first supporting rod 7 and the second supporting rod 8 is a first connecting structure, the connecting structure between the third supporting rod 9 and the fourth supporting rod 10 is a second connecting structure, the connecting structure between the second supporting rod 8 and the fourth supporting rod 10 is a third connecting structure, and the connecting structure between the third supporting rod 9 and the first supporting rod 7 is a fourth connecting structure, the upper ends of a first straight rod 3 and a second straight rod 4 of a first connecting structure are respectively hinged with a sleeve 5 around a first supporting rod 7 and a second supporting rod 8, the upper ends of the first straight rod 3 and the second straight rod 4 of a second connecting structure are respectively hinged with a sleeve 5 around a third supporting rod 9 and a fourth supporting rod 10, the upper ends of the first straight rod 3 and the second straight rod 4 of the third connecting structure are respectively hinged with a connecting piece 6 on the second supporting rod 8 and the fourth supporting rod 10, the upper ends of the first straight rod 3 and the second straight rod 4 of the fourth connecting structure are respectively hinged with a connecting piece 6 on the third supporting rod 9 and the first supporting rod 7, when the folding chair is in an unfolded state, the sleeve 5 slides to the position of the connecting piece 6, the first straight rod 3 and the second straight rod 4 connected with the sleeve stop rotating to realize locking, and meanwhile, the first straight rod 3 and the second straight rod 4 correspondingly connected with the connecting piece 6 rotate to the first ends of the first straight rod and the second straight rod 4 to reach the maximum opening, when the folding chair needs to be in a folding state, the sleeve 5 slides upwards, the upper ends of the first straight rod 3 and the second straight rod 4 are close to each other, and the lower ends of the first straight rod and the second straight rod are close to each other.

In addition, two connecting pieces 6 are preferably arranged between the third supporting rod 9 and the first straight rod 3 of the fourth connecting structure, and two connecting pieces 6 are preferably arranged between the fourth supporting rod 10 and the second straight rod 4 of the third connecting structure, so that the pressure bearing capacity of the connecting structure is enhanced.

In order to ensure that the flexible seat surface 2 can bear load well and simplify the structure of the folding chair, two seat rods 1 can be optionally arranged between the first support rod 7 and the second support rod 8 and between the third support rod 9 and the fourth support rod 10.

As a preferred embodiment, a reinforcing rod 11 may be optionally disposed between the upper end of the second straight rod 4 of the third connecting structure and the upper end of the second straight rod 4 of the fourth connecting structure, two ends of the reinforcing rod 11 are respectively hinged to the upper end of the second straight rod 4 of the third connecting structure and the upper end of the second straight rod 4 of the fourth connecting structure, and the reinforcing rod 11 can be bent, so as to further improve the stability of the folding chair in the unfolded state, and improve the use feeling, and the reinforcing rod 11 may be specifically disposed to have the same structure as the seat rod 1.

Further, a first backrest rod 12, a second backrest rod 13 and a flexible seat back 15 can be optionally arranged, wherein the first backrest rod 12 is arranged on the third support rod 9 and is rotatably connected with the third support rod, the second backrest rod 13 is arranged on the fourth support rod 10 and is rotatably connected with the fourth support rod, the flexible seat back 15 is arranged between the first backrest rod 12 and the second backrest rod 13 to provide a leaning position for a user, a locking structure 14 for fixing the position of the first backrest rod 12 is arranged between the third support rod 9 and the first backrest rod 12, and a locking structure 14 for fixing the position of the second backrest rod 13 is arranged between the fourth support rod 10 and the second backrest rod 13.

In order to facilitate the adjustment and fixing of the positions of the first back bar 12 and the second back bar 13, and to simplify the operation steps, referring to fig. 2, the locking structure 14 may be specifically configured to include a bolt 141 and a nut 142, and a knob 144 fixedly connected to the nut 142 is disposed around the nut 142, and a through hole is disposed at a connection portion of the third support bar 9 and the first back bar 12, and a through hole is disposed at a connection portion of the fourth support bar 10 and the second back bar 13, and the bolt 141 penetrates through the through holes, that is, the bolt 141 connecting the third support bar 9 and the first back bar 12 penetrates through the through holes of the two, the bolt 141 connecting the fourth support bar 10 and the second back bar 13 penetrates through the through holes of the two, and the nut 142 is respectively screwed to a rod portion of the bolt 141 matching with the nut 142, and the connection between the bolt 141 and the nut 142 is used to achieve the rotational connection and fix the positions of the first back bar 12 and the second back bar 13, so as to ensure the reliability when the bolt 141 and the nut 142, the contact surface of the third support bar 9 and the first back bar 12 is provided with anti-skid grains 143, the contact surface of the fourth support bar 10 and the second back bar 13 is provided with anti-skid grains 143, more specifically, the anti-skid grains 143 can be arranged in the circumferential direction of the through hole, the anti-skid grains 143 can be arranged in a plurality of saw-toothed convex structures which are uniformly distributed, the plane is provided with protrusions, the original plane is relatively concave, the two mutually contacted surfaces provided with the convex structures can achieve the effect of increasing friction force by mutually matching the protrusions and the concave structures, so that the anti-skid locking effect is achieved, the first back bar 12 and the second back bar 13 are fixed in the vertical direction according to the use requirement, when the folding chair is required to be in a folding state, the rotary knob 144 drives the nut 142 to rotate to enable the nut 142 to be far away from the head of the bolt 141, the third support bar 9 and the first back bar 12, and the fourth support bar 10 and the second back bar 13 are loosened, the first back bar 12 and the second back bar 13 can be smoothly rotated to the positions convenient for storage.

In order to further enhance the comfort and reliability of the backrest of the folding chair, a third backrest rod 16 is disposed between the upper end of the first backrest rod 12 and the upper end of the second backrest rod 13, two ends of the third backrest rod 16 are respectively hinged to the first backrest rod 12 and the second backrest rod 13, the third backrest rod 16 can be bent, the third backrest rod 16 can be specifically configured to have the same structure as the seat rod 1, and in addition, a round tube 21 surrounding a square bar of the third backrest rod 16 can be optionally disposed, please refer to fig. 4, so as to enhance the comfort of the user when leaning on.

In order to enhance the height adjustment of the folding chair, a heightening rod 17 may be further provided, referring to fig. 5-6, a spring ball 18 is provided on the heightening rod 17, the spring ball 18 is embedded in the heightening rod 17 and the edge thereof protrudes with respect to the outer side wall of the heightening rod 17, a spring 20 is connected between the spring ball 18 and the heightening rod 17, the spring ball 18 is compressed to be retractable into the heightening rod 17, the supporting rod has a hollow structure, and the side wall is provided with a plurality of positioning holes 19, the positioning holes 19 are uniformly arranged along the height direction of the supporting rod, when the height of the folding chair needs to be increased, the heightening rod 17 extends into the supporting rod from the lower end of the supporting rod, the spring ball 18 is clamped into the positioning hole 19, the spring balls 18 are clamped into different positioning holes 19 according to different height requirements, and when the heightening is not needed, the heightening rod 17 can be taken out optionally, so that the weight of the folding chair is reduced.

The bracing piece can set up to the steel round bar, and first straight-bar 3 and second straight-bar 4 can set up to steel round bar or steel square bar, and first back of the chair pole 12, second back of the chair pole 13 and increase pole 17 all can set up to the steel round bar, and flexible seat face 2 and flexible back of the chair 15 all can set up to the canvas material.

It is understood that the same or similar parts in the above embodiments may be mutually referred to, and the same or similar parts in other embodiments may be referred to for the content which is not described in detail in some embodiments. The utility model provides a plurality of schemes contain the basic scheme of itself, mutual independence to restrict each other, but it also can combine each other under the condition of not conflicting, reaches a plurality of effects and realizes jointly.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A folding chair, comprising:

at least three support rods are arranged;

the two ends of the seat rod (1) are respectively and rotatably connected with the upper ends of the two adjacent support rods, and the seat rod (1) can be bent;

the flexible seat surface (2) is connected to the seat rod (1);

the state of folding chair includes fold condition and expansion state, works as folding chair by the expansion state becomes during fold condition, connection structure deformation drives the bracing piece is close to each other, seat pole (1) are buckled.

2. A folding chair as claimed in claim 1, characterised in that said seat bar (1) comprises a first section (101), a second section (102) and a third section (103), the first end of said first section (101) and the second end of said third section (103) being rotatably connected to the upper ends of two adjacent support bars, respectively, the first end of said second section (102) being rotatably connected to the second end of said first section (101), and the second end of said second section (102) being rotatably connected to the first end of said third section (103).

3. The folding chair as claimed in claim 2, wherein the first section (101) and the third section (103) are both square bars, the second section (102) is a square groove, the open side of the second section (102) faces downward, and the second end of the first section (101) and the first end of the third section (103) respectively extend into two ends of the second section (102) and are hinged to the second section (102).

4. The folding chair as claimed in claim 1, wherein the connecting structure comprises a first straight bar (3) and a second straight bar (4), the first straight bar (3) and the second straight bar (4) are rotatably connected in a cross manner to form an "X" shaped structure, the lower ends of the first straight bar (3) and the second straight bar (4) are respectively hinged to the lower ends of two adjacent support bars, and the upper ends of the first straight bar (3) and the second straight bar (4) are respectively connected with two adjacent support bars in a relative rotation manner.

5. A folding chair as claimed in claim 4, wherein the supporting bar is provided with a sleeve (5) along its circumference, the sleeve (5) can move up and down along the supporting bar, and the supporting bar is hinged with a connecting member (6), the hinge joint of the connecting member (6) and the supporting bar is located below the sleeve (5), the number of the supporting bar is four, namely a first supporting bar (7), a second supporting bar (8), a third supporting bar (9) and a fourth supporting bar (10), the connecting structure between the first supporting bar (7) and the second supporting bar (8) is a first connecting structure, the connecting structure between the third supporting bar (9) and the fourth supporting bar (10) is a second connecting structure, and the connecting structure between the second supporting bar (8) and the fourth supporting bar (10) is a third connecting structure, the connecting structure between the third supporting rod (9) and the first supporting rod (7) is a fourth connecting structure, the upper ends of the first straight rod (3) and the second straight rod (4) of the first connecting structure are respectively hinged to the first supporting rod (7) and the sleeve (5) in the circumferential direction of the second supporting rod (8), the upper ends of the first straight rod (3) and the second straight rod (4) of the second connecting structure are respectively hinged to the third supporting rod (9) and the sleeve (5) in the circumferential direction of the fourth supporting rod (10), the upper ends of the first straight rod (3) and the second straight rod (4) of the third connecting structure are respectively rotatably connected to the second supporting rod (8) and the fourth supporting rod (10) through the connecting piece (6), and the upper ends of the first straight rod (3) and the second straight rod (4) of the fourth connecting structure are respectively rotatably connected to the third supporting rod (8) and the fourth supporting rod (10) The supporting rod (9) and the first supporting rod (7) are rotatably connected through the connecting piece (6).

6. A folding chair as claimed in claim 5, characterised in that between the upper end of said second straight bar (4) of said third connecting structure and the upper end of said second straight bar (4) of said fourth connecting structure there is connected a reinforcing bar (11), said reinforcing bar (11) being able to be bent.

7. The folding chair as claimed in claim 5, wherein a first back bar (12) is rotatably connected to the third support bar (9), a second back bar (13) is rotatably connected to the fourth support bar (10), locking structures (14) are respectively disposed between the third support bar (9) and the first back bar (12) and between the fourth support bar (10) and the second back bar (13) to fix the positions of the first back bar (12) and the second back bar (13), and a flexible back (15) is disposed between the first back bar (12) and the second back bar (13).

8. The folding chair as claimed in claim 7, wherein the locking structure (14) comprises a bolt (141) and a nut (142), a through hole is formed at the joint of the third support bar (9) and the first back bar (12), a through hole is formed at the joint of the fourth support bar (10) and the second back bar (13), the bolt (141) penetrates through the through hole, the nut (142) is in threaded connection with the rod portion of the bolt (141), anti-slip textures (143) are formed on the contact surfaces of the third support bar (9) and the first back bar (12), and the anti-slip textures (143) are formed on the contact surfaces of the fourth support bar (10) and the second back bar (13).

9. A folding chair as claimed in claim 7, characterized in that a third seat back bar (16) is provided between the upper end of the first seat back bar (12) and the upper end of the second seat back bar (13), said third seat back bar (16) being bendable.

10. The folding chair as claimed in claim 1, further comprising a heightening rod (17), wherein a spring bead (18) is provided on the heightening rod (17), the spring bead (18) can be retracted into the heightening rod (17) under pressure, the supporting rod has a hollow structure, and a plurality of positioning holes (19) are provided on a side wall thereof, the plurality of positioning holes (19) are uniformly arranged along a height direction of the supporting rod, the heightening rod (17) extends into the supporting rod from a lower end of the supporting rod, and the spring bead (18) is snapped into the positioning holes (19).