A zero-gravity seat back frame

Abstract

The present invention discloses a zero-gravity seat back frame, including two back side panels arranged opposite to each other on the left and right sides, the two back side panels are arranged vertically, an upper back cross tube is connected between the upper ends of the two back side panels, a lower back cross plate is connected between the lower ends of the two back side panels, one of the back side panels is provided with a side panel reinforcement, a guide constraint mechanism for guiding the sliding of a safety belt is provided at the rear side of the back side panel, and a support frame for reversing the direction of the safety belt is provided at the upper end of the back side panel. Compared with the prior art, the present invention has the following beneficial effects: a safety belt guide constraint structure and a reversing structure are installed on one side panel of the backrest, so that it bears a larger safety belt tension, and by reinforcing the back side panel on this side, the overall strength of the backrest is improved, and the safety of the safety belt system is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile seat frame structures, and in particular relates to a zero-gravity seat back frame. Background Art

[0002] The functions of car seats are becoming more and more diverse, so their structural design is also becoming more complex. In order to improve the comfort of riding, multiple connections between the various parts of the seat frame are designed as adjustable connections to facilitate the adjustment of the seat posture, thereby providing sufficient and appropriate support for various parts of the body, reducing joint tension, and putting the body in a highly relaxed state. Based on this, the concept of the so-called "zero-gravity" seat is proposed. Under the concept of "zero gravity", the adjustment range of each part of the seat is large, but there is a contradictory relationship between adjustability and stability and safety. In order to meet the safety requirements of the seat, the design and testing of the seat frame must be carried out carefully during the research and development stage, which also brings some difficulties in the design of the seat's auxiliary structure. For example, due to the large adjustment range, the seat belt retractor of the "zero-gravity" seat must be installed on the seat body, not on the body like a traditional seat. This poses a challenge to the strength of the seat frame, and on the other hand, it also poses a challenge to whether the guidance and sliding state of the seat belt meet the safety requirements. Therefore, the design of the seat back frame must be reasonably improved. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a zero-gravity seat back frame. The technical solution is as follows:

[0004] A zero-gravity seat back frame includes two back side panels arranged opposite to each other on the left and right sides, the two back side panels are arranged vertically, an upper back cross tube is connected between the upper ends of the two back side panels, and a lower back cross plate is connected between the lower ends of the two back side panels. The key lies in that a side panel reinforcement is arranged on one of the back side panels, a guide and restraint mechanism for guiding the sliding of a safety belt is arranged on the rear side of the back side panel, and a support frame for reversing the direction of the safety belt is arranged on the upper end of the back side panel.

[0005] As a preferred technical solution, the above-mentioned guide restraint mechanism has a sliding cavity for the seat belt to slide, the sliding cavity is a continuous cavity or at least two separated cavities located on the same curve, the sliding cavity defines a seat belt sliding path for the seat belt to slide, and an elastic disturbance member is arranged on the seat belt sliding path;

[0006] The support frame includes a support body, a reversing slot is fixedly arranged on the upper part of the support body, the reversing slot is arranged along the front-to-back direction, and the rear end of the reversing slot corresponds to the seat belt sliding path;

[0007] A positioning connection portion is fixedly arranged below the bracket body. The bracket body is a box-shaped structure surrounded by plates and having an internal cavity, so as to allow the bracket body to collapse downward when the load loaded on the reversing slot exceeds its compressive strength.

[0008] As a preferred technical solution, the guide restraint mechanism comprises a guide bar arranged at the rear side of the backrest frame, one side of the guide bar faces the backrest frame, and a limit plate is arranged on the other side of the guide bar, and a flat cavity is formed between the limit plate and the guide bar, and the cavity forms the sliding cavity;

[0009] The local segments of the guide strip are deformed alternately on both sides thereof to form a corrugated plate, the corrugated plate forms the elastic disturbance member, and the lines on the corrugated plate are perpendicular to the extension direction of the sliding path of the safety belt;

[0010] The guide strip has at least one bent portion.

[0011] As a preferred technical solution, at least two limit plate groups are arranged on the guide bar, each of the limit plate groups includes two limit plates, the two limit plates are arranged opposite to each other and are respectively located on both sides of the guide bar;

[0012] The limiting plate is in a strip shape, and extends along the direction of the guide bar. The cross section of the limiting plate is L-shaped, and one long side of the limiting plate is connected to the edge of the rear side of the guide bar, and the other long side of the limiting plate is located at the rear side of the guide bar and parallel to it;

[0013] The corrugated plates and the bent parts are distributed between the limiting plate groups.

[0014] As a preferred technical solution, the backrest side plate comprises a rear convex section located at the upper part and a front convex section located at the lower part, and the rear convex section and the front convex section are smoothly transitionally connected;

[0015] At least three guide bar seats are fixed to the rear side of the backrest side plate where the guide bar is located, all the guide bar seats are distributed along the backrest side plate, the same guide bar is installed on all the guide bar seats, and the limit plate group is distributed between the guide bar seats;

[0016] A guide bar seat is provided at the recessed part on the rear side of the front convex section, and a curved limiting steel wire is fixedly provided on the guide bar seat. The limiting steel wire passes around the guide bar backwards, and the two ends of the limiting steel wire are respectively fixedly connected to the guide bar seat, and the middle section of the limiting steel wire is parallel to the guide bar.

[0017] As a preferred technical solution, ribs are formed on the bracket body, the ribs extend parallel to the bottom surface of the reversing through groove, and the ribs are formed by partially protruding inward or outward of the plate material surrounding the bracket body.

[0018] As a preferred technical solution, the bracket body includes a first support plate and a second support plate arranged vertically, the two are arranged opposite to each other, the first support plate and the second support plate support the same reversing groove above, the first support plate and the second support plate are respectively located below the two side groove walls of the reversing groove, and the first support plate and the second support plate are respectively formed with the ribs;

[0019] A transverse connecting plate is also provided between the first support plate and the second support plate. The transverse connecting plate is located in the vertical plane. Both side edges of the transverse connecting plate are respectively connected to the same side edges of the first support plate and the second support plate. The transverse connecting plate is integrally formed with the first support plate and the second support plate to form the bracket body.

[0020] As a preferred technical solution, the second support plate extends downward beyond the lower edge of the transverse connecting plate, and at least two ribs are formed on the second support plate;

[0021] The positioning connection part is an arc-shaped plate, and there are two arc-shaped plates, namely a first arc-shaped plate and a second arc-shaped plate;

[0022] The first arc-shaped plate is integrally formed below the first supporting plate, and the inner arc surface of the first arc-shaped plate faces downward;

[0023] The second arc-shaped plate is integrally formed below the second supporting plate, and the inner arc surface of the second arc-shaped plate faces the first supporting plate;

[0024] The inner arc surface of the first arc plate falls on and is welded to the upper transverse tube of the backrest, and the inner arc surface of the second arc plate abuts against and is welded to the side tube.

[0025] As a preferred technical solution, the backrest side panel includes a side panel sheet metal, which includes a side panel body extending vertically, and the two side surfaces of the side panel body are respectively facing the left and right sides of the seat, the front edge of the side panel body is connected to the side panel front flange, and the rear edge of the side panel body is connected to the side panel rear flange, and the side panel rear flange and the side panel front flange are located on the inner side of the side panel body;

[0026] The two ends of the upper horizontal tube of the backrest extend downward to form side tubes respectively, and the side tubes are close to the front side of the rear flange of the corresponding side plate and the inner side of the side plate body and connected thereto;

[0027] The side plate reinforcement comprises a first reinforcement sheet metal and a second reinforcement sheet metal;

[0028] The side tube where the guide and restraint mechanism is located extends along the rear flange of the side plate to its lower end, and the first reinforcing sheet metal is connected between the side tube and the front flange of the side plate, and the three form a hollow box-shaped structure;

[0029] The second reinforcing sheet metal is arranged on the outer side of the side plate body, the second reinforcing sheet metal is close to the outer side surface of the side plate body and the rear side surface of the rear flange of the side plate, and the second reinforcing sheet metal is welded to the side plate body.

[0030] As a preferred technical solution, the first reinforced sheet metal comprises a first reinforcing plate, the first reinforcing plate is arranged parallel to the side plate body, the rear edge of the first reinforcing plate is provided with a first rear flange, the first rear flange is close to the side tube and welded thereto;

[0031] The front edge of the first reinforcing plate is provided with a first front flange facing the side plate body, the first front flange is adapted to the shape of the front flange of the side plate, and the first front flange is close to the front flange of the side plate and is welded thereto.

[0032] As a preferred technical solution, the above-mentioned second reinforced sheet metal includes a second reinforcing plate, which is abutted against the rear flange of the side plate, and the edge of the second reinforcing plate close to the side plate body is connected with a second flange facing forward, which is abutted against the side plate body and welded thereto, and the lower part of the second flange is consistent in shape with the lower part of the side plate body.

[0033] Compared with the prior art, the present invention has the following beneficial effects: a safety belt guide constraint structure and a reversing structure are installed on one side panel of the backrest, so that it can bear a larger safety belt tension. By strengthening the side panel of the backrest on this side, the overall strength of the backrest is improved, thereby ensuring the safety of the safety belt system. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic structural diagram of the present invention from a first viewing angle, in which the guide constraint mechanism is not shown;

[0035] Figure 2 It is a structural schematic diagram of the second viewing angle of the present invention;

[0036] Figure 3 A schematic structural diagram of a backrest side panel with a side panel reinforcement from a first perspective;

[0037] Figure 4 for Figure 3 A schematic diagram of the structure from the second perspective;

[0038] Figure 5 A structural diagram of the first perspective of the guiding constraint mechanism;

[0039] Figure 6 for Figure 5 Schematic diagram of the second perspective;

[0040] Figure 7 for Figure 5 Schematic diagram of the third perspective;

[0041] Figure 8 is a structural schematic diagram of the support frame;

[0042] Fig. 9 It is a structural schematic diagram of the support frame being installed on the seat back frame;

[0043] Fig.10 for Fig. 9 Schematic diagram from another perspective. DETAILED DESCRIPTION

[0044] The present invention will be further described below in conjunction with the embodiments and drawings. For ease of description, the directions of "up", "down", "left", "right", "front" and "rear" are directions corresponding to when the seat is installed in a car.

[0045] like Figure 1 and 2 As shown, a zero-gravity seat back frame includes two back side panels arranged opposite to each other on the left and right, the two back side panels are arranged vertically, an upper back cross tube 110 is connected between the upper ends of the two back side panels, and a lower back cross plate is connected between the lower ends of the two back side panels, one of the back side panels is provided with a side panel reinforcement, a guide restraint mechanism 170 for guiding the sliding of a seat belt is provided on the rear side of the back side panel, and a support frame 160 for reversing the seat belt is provided on the upper end of the back side panel.

[0046] Specifically, Figure 3 and 4 As shown, the backrest side panel includes a side panel sheet metal 130, which includes a side panel body 131 extending vertically, and the two side surfaces of the side panel body 131 face the left and right sides of the seat respectively, and the front edge of the side panel body 131 is connected to a side panel front flange 133, and the rear edge of the side panel body 131 is connected to a side panel rear flange 132, and the side panel rear flange 132 and the side panel front flange 133 are located on the inner side of the side panel body 131. The front edge of the side panel body 131 gradually extends forward from the upper end to the middle of the side panel body 131, so that the side panel body 131 gradually widens from the upper end to the middle, thereby meeting the purpose of installing various seat accessory structural parts, connecting with the recliner, and increasing the strength of the seat frame side panel.

[0047] The two ends of the backrest upper transverse tube 110 extend downward to form side tubes 120, which are attached to and connected with the front side of the corresponding side panel rear flange 132 and the inner side of the side panel body 131. The upper part of the side panel rear flange 132, the upper part of the side panel front flange 133 and the upper part of the side panel body 131 surround and attach to the side tube 120.

[0048] like Figure 2 and 4 As shown, one of the side tubes 120 extends downward along the side panel rear flange 132 to the middle thereof, and the other side tube 120 extends downward along the side panel rear flange 132 to the lower end thereof, and a side panel reinforcement is arranged on the backrest side panel on this side. The side panel reinforcement comprises a first reinforcement sheet metal 140 and a second reinforcement sheet metal 150.

[0049] The first reinforcing sheet metal 140 is connected between the corresponding side tube 120 and the side plate front flange 133, and the three form a hollow box-shaped structure. The first reinforcing sheet metal 140 includes a first reinforcing plate 141, which is arranged parallel to the side plate body 131. The rear edge of the first reinforcing plate 141 is provided with a first rear flange 142, which is close to the side tube 120 and welded thereto. The front edge of the first reinforcing plate 141 is provided with a first front flange 143 facing the side plate body 131, which is adapted to the shape of the side plate front flange 133, and is close to the side plate front flange 133 and welded thereto.

[0050] The second reinforcing sheet metal 150 is arranged on the outside of the side plate body 131, and the second reinforcing sheet metal 150 is close to the outer side surface of the side plate body 131 and the rear side surface of the side plate rear flange 132, and the second reinforcing sheet metal 150 is welded to the side plate body 131. The second reinforcing sheet metal 150 includes a second reinforcing plate 151, and the second reinforcing plate 151 is close to the side plate rear flange 132. The second reinforcing plate 151 is connected to a second flange 152 facing forward at the edge close to the side plate body 131, and the second flange 152 is close to the side plate body 131 and welded thereto, and the lower part of the second flange 152 is consistent in shape with the lower part of the side plate body 131. The second reinforcing plate 151 is formed with a strip-shaped reinforcing rib protruding backwards to improve its strength.

[0051] The reason for reinforcing the single-side backrest side panel of the seat back frame is that the seat belt retractor is installed on the seat frame and extends forward along the side backrest side panel. When the seat belt is locked to ensure the safety of the occupants in an emergency, the side backrest side panel is subjected to greater force, so its strength must be increased to meet the seat safety requirements. The side backrest side panel on the other side is subjected to relatively less force, so it is not reinforced. The left and right side panel sheet metal 130 structures of the seat back frame are mirror-symmetrical to facilitate production, so only the first reinforcement sheet metal 140 and the second reinforcement sheet metal 150 are added to strengthen one side of the backrest side panel. During assembly, the side tube 120 and the two side panel sheet metals 130 are assembled first, and then the first reinforcement sheet metal 140 and the second reinforcement sheet metal 150 are welded to the side of the backrest side panel that needs to be reinforced.

[0052] like Figures 5 to 7 As shown, a guide and restraint mechanism 170 is provided at the rear side of the side plate of the backrest with the side plate reinforcement. The guide and restraint mechanism 170 has a sliding cavity 176 for the seat belt to slide. The sliding cavity 176 is a continuous cavity or at least two separated cavities located on the same curve. The sliding cavity 176 defines a seat belt sliding path for the seat belt to slide. An elastic disturbance member 172 is provided on the seat belt sliding path. The elastic disturbance member 172 generates elastic vibration when being touched by the sliding seat belt, thereby playing a toggling role on the seat belt and reducing the resistance of the seat belt when it is retracted.

[0053] The guide restraint mechanism 170 includes a guide bar 171 , one side of which faces the corresponding side plate of the backrest, and a limiting plate 173 is arranged on the other side of the guide bar 171 .

[0054] At least two limit plate groups are arranged on the guide bar 171, and each limit plate group includes two limit plates 173, which are arranged opposite to each other and are respectively located on both sides of the guide bar 171. The limit plates 173 are in a strip shape, extending along the direction of the guide bar 171, and the cross section of the limit plate 173 is L-shaped, one long side of the limit plate 173 is connected to the edge of the rear side of the guide bar 171, and the other long side of the limit plate 173 is located at the rear side of the guide bar 171 and is parallel to it. A flat cavity is enclosed between the limit plate 173 and the guide bar 171, and the cavity forms the sliding cavity 176.

[0055] The guide strip 171 has at least one curved portion to adapt to the curve of the back side panel. Figure 7 The backrest side plate includes a rear convex section located at the upper part and a front convex section located at the lower part, and the rear convex section and the front convex section are smoothly transitionally connected. The curved portion is located between the limit plate groups.

[0056] One form of the elastic disturbance member 172 is a corrugated plate, which is formed by the partial segments of the guide strip 171 being deformed alternately toward both sides thereof, and the lines on the corrugated plate are perpendicular to the extending direction of the seat belt sliding path. The corrugated plate is located between the limit plate groups.

[0057] At least three guide bar seats 174 are fixed to the rear side of the backrest side panel where the guide bar 171 is located, all the guide bar seats 174 are distributed along the backrest side panel, the same guide bar 171 is installed on all the guide bar seats 174, and the limiting plate group is distributed between the guide bar seats 174.

[0058] like Figure 5 and 6 A guide bar seat 174 is provided at the recessed part at the rear side of the front convex section, and a curved limit wire 175 is fixedly provided on the guide bar seat 174. The limit wire 175 goes around the guide bar 171 backwards, and the two ends of the limit wire 175 are respectively fixedly connected to the guide bar seat 174, and the middle section of the limit wire 175 is parallel to the guide bar 171. Since the direction of the seat belt changes greatly at the limit wire 175, in order to make the seat belt slide along the rear side of the backrest side plate, a limit wire 175 that can withstand a large tension is provided to constrain it.

[0059] When in use, a safety belt (not shown in the figure) is inserted into the sliding cavity 176, and the safety belt slides along the sliding path of the safety belt, and the side of the safety belt facing the inner arc surface of the curve of the sliding path of the safety belt is pressed against the corrugated plate. Since the safety belt is inserted into the sliding cavity 176 along the guide strip 171, the safety belt bends along the direction of the guide strip 171, especially at the position of the limiting steel wire 175, the rear side of the safety belt is pressed against the limiting steel wire 175. However, at the corrugated plate, the front side of the safety belt is pressed against the corrugated plate. Since the safety belt passes through multiple curved parts, it rubs against the inner wall of the sliding cavity 176 and the guide strip 171 during the sliding process, so the safety belt may get stuck when it is retracted. When the corrugated plate is touched by the safety belt and vibrates to both sides, the safety belt is always in a state of small amplitude vibration when it is retracted and slides, which can effectively prevent jamming.

[0060] like Figures 8 to 10 The support frame 160 includes a support body, a reversing slot 164 is fixedly disposed on the top of the support body, the reversing slot 164 is disposed along the front-rear direction, and the rear end of the reversing slot 164 corresponds to the seat belt sliding path. A positioning connection portion is fixedly disposed at the bottom of the support body, and the support body is a box-shaped structure with an internal cavity surrounded by a plate material, so as to allow the support body to collapse downward when the load loaded on the reversing slot 164 exceeds its compressive strength.

[0061] Specifically, the bracket body includes a first support plate 161 and a second support plate 162 which are arranged vertically, and the two are arranged opposite to each other. The first support plate 161 and the second support plate 162 support the same reversing slot 164 above, and the first support plate 161 and the second support plate 162 are respectively located below the slot walls on both sides of the reversing slot 164, and ribs 163 are respectively formed on the first support plate 161 and the second support plate 162. The ribs 163 extend parallel to the bottom surface of the reversing slot 164, and the ribs 163 are formed by partially protruding inward or outward from the plate surrounding the bracket body.

[0062] After the ribs 163 are processed, the local area of ​​the plate where the ribs 163 are located has a greater ability to resist the force acting in the direction of the ribs 163, and the ability to resist the compressive stress perpendicular to the ribs 163 is relatively little increased. When the tension applied by the safety belt to the bottom surface of the reversing groove 164 exceeds its compressive strength, the bracket body collapses downward as a whole, and the height is reduced. However, the bracket body is not prone to deformation in other directions. After the bracket body collapses downward as a whole, the safety belt is closer to the seat back, restraining the occupant's torso near the seat back, reducing the range of the occupant's torso moving forward, and further improving safety.

[0063] A transverse connecting plate 165 is also provided between the first support plate 161 and the second support plate 162. The transverse connecting plate 165 is located in the vertical plane. Both side edges of the transverse connecting plate 165 are respectively connected to the same side edges of the first support plate 161 and the second support plate 162. The transverse connecting plate 165 is integrally formed with the first support plate 161 and the second support plate 162 to form the bracket body.

[0064] The second support plate 162 extends downward beyond the lower edge of the transverse connecting plate 165 , and at least two ribs 163 are formed on the second support plate 162 .

[0065] The positioning connection part is an arc-shaped plate, and there are two arc-shaped plates, namely a first arc-shaped plate 166 and a second arc-shaped plate 167. The first arc-shaped plate 166 is integrally formed below the first support plate 161, and the inner arc surface of the first arc-shaped plate 166 faces downward. The second arc-shaped plate 167 is integrally formed below the second support plate 162, and the inner arc surface of the second arc-shaped plate 167 faces the first support plate 161. During assembly, the inner arc surface of the first arc-shaped plate 166 falls on the upper cross tube 110 of the backrest and is welded thereto, and the inner arc surface of the second arc-shaped plate 167 is abutted against the corresponding side tube 120 and is welded thereto, thereby fixing the support frame 160 on the backrest frame. The reversing through groove 164 is separated from the upper cross tube 110 of the backrest, thereby reserving space for the collapse of the bracket.

[0066] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Under the guidance of the present invention, ordinary technicians in this field can make various similar expressions without violating the purpose and claims of the present invention, and such changes all fall within the scope of protection of the present invention.

Claims

1. A zero-gravity chair backrest frame, comprising two backrest side panels arranged opposite to each other on the left and right, the two backrest side panels being arranged vertically, an upper backrest cross pipe (110) being connected between the upper ends of the two backrest side panels, and a lower backrest cross plate being connected between the lower ends of the two backrest side panels, characterized in that: One of the backrest side panels is provided with a side panel reinforcement, a guide restraint mechanism (170) for guiding the seat belt to slide is provided at the rear side of the backrest side panel, and a support frame (160) for reversing the seat belt is provided at the upper end of the backrest side panel; The guide restraint mechanism (170) has a sliding cavity (176) for the seat belt to slide, the sliding cavity (176) is a continuous cavity or at least two separated cavities located on the same curve, the sliding cavity (176) defines a seat belt sliding path for the seat belt to slide, and an elastic disturbance member (172) is arranged on the seat belt sliding path; The support frame (160) comprises a support body, a reversing slot (164) is fixedly arranged above the support body, the reversing slot (164) is arranged along the front-rear direction, and the rear end of the reversing slot (164) corresponds to the seat belt sliding path; A positioning connection portion is fixedly arranged below the bracket body, and the bracket body is a box-shaped structure surrounded by a plate material and having an internal cavity, so as to allow the bracket body to collapse downward when the load applied to the reversing slot (164) exceeds its compressive strength; The guide restraint mechanism (170) comprises a guide strip (171) arranged at the rear side of the backrest frame, one side of the guide strip (171) faces the backrest frame, and a limit plate (173) is arranged on the other side of the guide strip (171), a flat cavity is formed between the limit plate (173) and the guide strip (171), and the cavity forms the sliding cavity (176); The local segments of the guide strip (171) are deformed alternately on both sides thereof to form a corrugated plate, the corrugated plate forms the elastic disturbance member (172), and the lines on the corrugated plate are perpendicular to the extension direction of the safety belt sliding path; The guide strip (171) has at least one bent portion; A rib (163) is formed on the bracket body, the rib (163) extending parallel to the bottom surface of the reversing through slot (164), and the rib (163) is formed by partially protruding inwards or outwards of a plate material surrounding the bracket body.

2. The zero-gravity seat back frame according to claim 1, characterized in that: At least two limit plate groups are arranged on the guide bar (171), each limit plate group comprises two limit plates (173), and the two limit plates (173) are arranged opposite to each other and are respectively located on two sides of the guide bar (171); The limiting plate (173) is strip-shaped, the limiting plate (173) extends along the direction of the guide strip (171), the cross-section of the limiting plate (173) is L-shaped, one long side of the limiting plate (173) is connected to the rear side edge of the guide strip (171), and the other long side of the limiting plate (173) is located at the rear side of the guide strip (171) and is parallel to the guide strip (171); The corrugated plates and the bent parts are distributed between the limiting plate groups.

3. The zero-gravity chair back frame according to claim 2, characterized in that: The backrest side plate comprises a rear convex section located at the upper part and a front convex section located at the lower part, and the rear convex section and the front convex section are smoothly transitionally connected; At least three guide bar seats (174) are fixed to the rear side of the backrest side plate where the guide bar (171) is located, all the guide bar seats (174) are distributed along the backrest side plate, the same guide bar (171) is installed on all the guide bar seats (174), and the limit plate group is distributed between the guide bar seats (174); A guide bar seat (174) is provided at the recessed portion at the rear side of the front convex section, and a curved limiting steel wire (175) is fixedly provided on the guide bar seat (174). The limiting steel wire (175) bypasses the guide bar (171) backwards, and both ends of the limiting steel wire (175) are respectively fixedly connected to the guide bar seat (174), and the middle section of the limiting steel wire (175) is parallel to the guide bar (171).

4. The zero-gravity seat back frame according to claim 3, characterized in that: The bracket body comprises a first support plate (161) and a second support plate (162) which are arranged vertically, and the two support plates are arranged opposite to each other. The first support plate (161) and the second support plate (162) support the same reversing slot (164) above. The first support plate (161) and the second support plate (162) are respectively located below the two side slot walls of the reversing slot (164). The first support plate (161) and the second support plate (162) are respectively formed with the ribs (163); A transverse connecting plate (165) is further provided between the first supporting plate (161) and the second supporting plate (162); the transverse connecting plate (165) is located in the vertical plane; two side edges of the transverse connecting plate (165) are respectively connected to the same side edges of the first supporting plate (161) and the second supporting plate (162); the transverse connecting plate (165) is integrally formed with the first supporting plate (161) and the second supporting plate (162), thereby forming the bracket body.

5. The zero-gravity chair back frame according to claim 1, characterized in that: The backrest side panel comprises a side panel sheet metal (130), the side panel sheet metal (130) comprises a side panel body (131) extending vertically, the two side surfaces of the side panel body (131) respectively face the left and right sides of the seat, the front edge of the side panel body (131) is connected to a side panel front flange (133), the rear edge of the side panel body (131) is connected to a side panel rear flange (132), and the side panel rear flange (132) and the side panel front flange (133) are located on the inner side of the side panel body (131); Both ends of the backrest upper transverse tube (110) extend downwards to form side tubes (120), and the side tubes (120) are attached to the front side of the corresponding side plate rear flange (132) and the inner side of the side plate body (131), and are connected thereto; The side plate reinforcement comprises a first reinforcement sheet metal (140) and a second reinforcement sheet metal (150); The side tube (120) where the guide and restraint mechanism (170) is located extends along the rear flange (132) of the side plate to its lower end, and the first reinforcing sheet metal (140) is connected between the side tube (120) and the front flange (133) of the side plate, and the three form a hollow box-shaped structure; The second reinforcing sheet metal (150) is arranged on the outside of the side plate body (131), the second reinforcing sheet metal (150) is in contact with the outer side surface of the side plate body (131) and the rear side surface of the side plate rear flange (132), and the second reinforcing sheet metal (150) is welded to the side plate body (131).

6. The zero-gravity chair back frame according to claim 5, characterized in that: The first reinforcing sheet metal (140) comprises a first reinforcing plate (141), the first reinforcing plate (141) being arranged parallel to the side plate body (131), the rear edge of the first reinforcing plate (141) being provided with a first rear flange (142), the first rear flange (142) being abutted against the side tube (120) and welded thereto; The front edge of the first reinforcing plate (141) is provided with a first front flange (143) facing the side plate body (131); the first front flange (143) is adapted in shape to the side plate front flange (133); the first front flange (143) is abutted against the side plate front flange (133) and is welded thereto.

7. The zero-gravity chair back frame according to claim 5, characterized in that: The second reinforcing sheet metal (150) comprises a second reinforcing plate (151), the second reinforcing plate (151) being attached to the rear flange (132) of the side plate, the edge of the second reinforcing plate (151) close to the side plate body (131) being connected to a second flange (152) facing forward, the second flange (152) being attached to the side plate body (131) and welded thereto, the lower portion of the second flange (152) being consistent in shape with the lower portion of the side plate body (131).

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