CN203860826U

CN203860826U - Chair backrest

Info

Publication number: CN203860826U
Application number: CN201420144354.9U
Authority: CN
Inventors: 吴耀全
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-03-26
Filing date: 2014-03-26
Publication date: 2014-10-08
Anticipated expiration: 2024-03-26

Abstract

The utility model discloses a chair backrest which comprises a chair back and a chair back frame, wherein a connecting structure between the chair back and the chair back frame comprises a sliding connecting structure capable of sliding up and down; the sliding connecting structure is composed of a sliding block and a sliding chute matched with each other; one of the sliding block and the sliding chute is arranged on the chair back, and the other of the sliding block and the sliding chute is arranged on the chair back frame; a fixed point bending structure is arranged on the chair back frame and comprises a soft section capable of deforming elastically, as well as an upper hard section and a lower hard section connected onto the two ends of the soft section; a transverse crippling groove is formed in the rear side surface of the soft section. According to the utility model, relative sliding can be generated between the chair back and the chair back frame, so that relative sliding is not generated between the back of a user and the chair back when the back of the user leans backwards forcibly; in addition, the chair back frame has a certain bending deflection capacity at a designated position, so that the using comfort level of the chair is improved.

Description

A kind of backrest

Technical field

The utility model relates to a kind of seat component, is specifically related to a kind of backrest.

Background technology

In existing office seating, backrest is formed by connecting by the chair back and chair back rack conventionally, and wherein, the chair back is used for arranging screen cloth or cortical face cloth, is the parts at direct support human body back; Chair back rack, for connecting chair chassis and the chair back, is effectively fixed the chair back.Conventionally between the chair back and chair back rack for being fixedly connected with, in addition, in order to improve comfortableness, between the chair back of part seat and chair back rack, also there is hinged form, make the chair back relatively chair back rack relatively rotate.There is following deficiency in the connected mode between the existing chair back and chair back rack: when user's back relies on backrest, if firmly to layback, the relative chair back down sliding of human body back meeting, relative motion meeting between human body and the chair back simultaneously allows user's clothes be heaved out, and therefore brings discomfort.

In addition, the rigid bar that existing chair back rack is normally made by hard material, the deficiency of its existence is: when user's back relies on backrest, the local location at back (for example, at upper back) sometimes also needs the certain angle of further swinging back, to obtain more comfortable sitting posture, this just requires chair back rack to have certain crooked deformability at assigned address, yet the chair back rack of rigidity does not obviously possess this function.

Utility model content

The purpose of this utility model is to overcome the deficiencies in the prior art, and a kind of backrest is provided, and between the chair back of this backrest and chair back rack, can produce the slip of meeting, and when human body back is firmly swung back, does not produce relative sliding between human body back and the chair back; And chair back rack has certain crooked deformability in the position of appointment, improved the comfortableness that seat is used.

The technical scheme that the utility model solves the problems of the technologies described above is:

A backrest, comprises the chair back and chair back rack, and wherein, described chair back rack is a rod member extending from bottom to top, and the lower end of this chair back rack is connected with Chair underframe; Syndeton between the described chair back and chair back rack is: comprise the sliding connection structure that can slide along the vertical direction, this sliding connection structure consists of the slide block mutually mating and chute, in slide block and chute, one of them is located on the chair back, and another is located on chair back rack;

Described chair back rack is provided with fixed point warp architecture, and this fixed point warp architecture comprises soft section of elastically deformable and be connected in two hard sections up and down at these soft section of two ends, and wherein, the rear side surface of described soft section is provided with the weakening groove of horizontally set; Described soft section and two chair back racks that hard sections link together described in forming.

A preferred version of the present utility model, wherein, described sliding connection structure comprises sliding connection structure, on this, the formation of sliding connection structure is: the top of the described chair back is provided with guide plate, in this guide plate, is provided with gathering sill; Described chair back rack is a rod member extending along the vertical direction, and the upper end of this chair back rack extend in described gathering sill; The inwall of described gathering sill is provided with projection, and the side of described chair back rack is provided with groove, and described projection is matched with in groove, and wherein, projection forms described slide block, and groove forms described chute.

By above-mentioned upper sliding connection structure, make between the chair back and chair back rack can relative sliding, by the both sides at chair back rack, chute is set, connect reliably, slide smooth and easy.

A preferred version of the present utility model, wherein, described upper sliding connection structure place is provided with automatic reset mechanism, this automatic reset mechanism comprises sliding part, sliding tray and spring, wherein, sliding tray is arranged on chair back rack, and described sliding part is matched with in this sliding tray, and this sliding part is connected with the chair back; Described spring is arranged on the below of sliding part.

By above-mentioned automatic reset mechanism is set, after the relative chair frame of the chair back is slided, if external force is cancelled, the position relationship between the chair back and chair back rack can return to reset condition.

A preferred version of the present utility model, wherein, syndeton between the described chair back and chair back rack also comprises back height governor motion, this back height governor motion comprises the locating slot being located on the chair back and is located at the locating dowel on chair back rack, wherein, a plurality of bayonet sockets that described locating slot comprises cannelure and is positioned at cannelure inner side, described a plurality of bayonet sockets are arranged at a side of the vertical center line of cannelure, these bayonet sockets are arranged along the vertical direction, and this bayonet socket is tilted to down and is communicated with cannelure; Described locating dowel extend in described locating slot.

By above-mentioned back height governor motion is set, height that can adjusting back, thus adapt to the needs without user.

A preferred version of the present utility model, wherein, described locating dowel is arranged on beat piece, and this beat piece is arranged on described sliding part, and the upper end of this beat piece is rotationally connected with on sliding part, and lower end arranges described locating dowel; Described beat piece is provided with the locating dowel of impelling on beat piece and snaps onto the spring on described bayonet socket; The top of the described chair back is provided with connecting plate, and described locating slot is arranged on the dorsal part of this connecting plate; Described guide plate is fixedly connected on the dorsal part of connecting plate, and this guide plate is provided with through hole at the position corresponding with described locating slot.

A preferred version of the present utility model, wherein, described sliding connection structure also comprises lower slider syndeton, the formation of this lower slider syndeton is: the bottom of described chair back plate is provided with from the middle linking arm extending of two side direction, the middle part of this linking arm is provided with opening towards the link slot in the place ahead, and this link slot forms described chute; The bottom of described chair back rack is provided with the guide post through described link slot, and two ends and the chair back rack of this guide post are fixed, and this guide post forms described slide block.

By described lower slider syndeton is set, match with upper sliding connection structure, make the slip of the relative chair back rack of the chair back more stable.

A preferred version of the present utility model, wherein, described fixed point warp architecture also comprises firm elasticity switching mechanism, this firm elasticity switching mechanism comprises the brace being arranged on along the vertical direction on soft section, the upper end of this brace is stiff end, this stiff end is fixedly connected in hard section, and lower end is free end, and this free end extends to lower hard section place;

Described lower hard section is provided with the change-over switch that can laterally slide, and this change-over switch is rigid state while sliding into wherein one end, is elastic stage while sliding into the other end; The free end of described brace is provided with hook, and when change-over switch is during in rigid state, this change-over switch extend in described hook, and when change-over switch is during in elastic stage, this change-over switch is positioned at outside described hook.

The operation principle of above-mentioned elasticity switching mechanism is: when soft section backward during flexural deformation, described brace can upwards produce certain displacement, and when described change-over switch is during in rigid state, this change-over switch extend in the hook of brace, thereby moving upward of brace caused to obstruction, brace cannot be moved upward, and therefore the flexural deformation of soft section is also restricted, and now soft section is equivalent to rigid body; And when described change-over switch is during in elastic stage, this change-over switch is positioned at outside the hook of brace, brace can freely move upward, and soft section can be freely crooked.

By above-mentioned firm elasticity switching mechanism is set, whether user can independently select to need chair back rack crooked, to meet the needs of different use occasions.

A preferred version of the present utility model, wherein, described soft section is provided with for holding the mounting groove of described brace; Described lower hard section is provided with for holding the free-ended holding tank of brace, and the side direction of this holding tank is connected with for the gathering sill of change-over switch is installed; The top of described holding tank and gathering sill is provided with cover plate.By said structure, realized the installation of brace and change-over switch, allowed brace be hidden in chair back rack, specious.

A preferred version of the present utility model, wherein, described change-over switch is formed by connecting with the stop part that is positioned at below by the pushing portion that is positioned at top, between described pushing portion and stop part, there is gap, the free end of described brace passes from this gap, and the hook on this brace is adjacent on described stop part.The effect that pushing portion is set is conveniently to control this change-over switch, and the effect that stop part is set is the hook of brace to carry out spacing.

A preferred version of the present utility model, wherein, described weakening groove is a plurality of, these weaken groove and are arranged in order from top to bottom; Described fixed point warp architecture is arranged at the middle and upper part of chair back rack; Syndeton between described soft section and hard section is: in described soft section, be embedded with rigid disk, stretch out outside soft section one end of this rigid disk, and this extension is inserted in hard section and is fixedly connected with it.

In the utility model, the operation principle of the syndeton between the chair back and chair back rack is: because the chair back and chair have been adopted the sliding connection structure of relative sliding along the vertical direction to connect between frame, therefore when human body back is firmly swung back, the downward power of human body can drive the chair back to move downward together, thereby makes relative sliding can not occur between human body back and the chair back.

The operation principle of described fixed point warp architecture is: due to the parts of soft section elastically deformable, therefore, when human body produces the active force of layback to chair back rack, this soft section just can produce certain distortion; And, because the rear side surface at soft section is provided with the weakening groove of horizontally set, make this weakening groove become weak part, more yielding, not only can increase deflection, and it is crooked to have realized fixed point.

The utility model compared with prior art has the following effect of having a mind to:

When 1, user firmly swings back, between human body back and the chair back, can produce relative sliding, clothes can not heaved out, and has improved comfortableness.

When 2, user firmly swings back, because the relative position of the chair back and human body back is constant, therefore, along with the motion of human body, human body back mates mutually with the chair back, is always human body back abundant and optimum support effect is provided.

3, can allow chair back rack there is certain crooked deformability in the position of appointment, improve the comfortableness that seat is used.

Accompanying drawing explanation

Fig. 1 is the perspective view of a specific embodiment of backrest of the present utility model.

Fig. 2 is the side direction view of Fig. 1.

Fig. 3 is the structural representation of the chair back in Fig. 1.

Fig. 4 and Fig. 5 are the explosive view of Fig. 1 on two visual angles.

Fig. 6 and Fig. 7 are the structural representation of the upper hard section of the chair back in Fig. 4, and wherein, Fig. 6 is front view, the A-A cutaway view that Fig. 7 is Fig. 6.

Fig. 8 is the perspective view of guide plate in Fig. 4.

Fig. 9 is sliding part and beat part enlarged drawing partly in Fig. 4.

Figure 10 is the enlarged drawing of locating slot part in Fig. 5.

Figure 11 is the perspective view of chair back rack in Fig. 1.

Figure 12 is the perspective view at another visual angle of Fig. 1.

Figure 13 is the explosive view of Figure 12.

Figure 14 is that Figure 15 is the structural representation of soft section in Fig. 1, and wherein, Figure 14 is front view, and Figure 15 is left view (cutaway view).

Figure 16 is the perspective view of brace in Figure 12.

Figure 17 is the perspective view of change-over switch in Figure 12.

The specific embodiment

Below in conjunction with embodiment and accompanying drawing, the utility model is described in further detail, but embodiment of the present utility model is not limited to this.

Referring to Fig. 1～Fig. 3, backrest of the present utility model consists of the chair back 1 and chair back rack 2, and the described chair back 1 is frame structure, comprises the framework that is positioned at surrounding, screen cloth or face cloth is set, for support human body back in framework; Chair back rack 2 is a rod member extending along the vertical direction, and this chair back rack is provided with fixed point warp architecture.

Below in conjunction with accompanying drawing, syndeton between the chair back 1 in backrest of the present utility model and chair back rack 2 is described in detail:

Referring to Fig. 1～Fig. 6, syndeton between the described chair back 1 and chair back rack 2 is: comprise the sliding connection structure that can slide along the vertical direction, this sliding connection structure consists of the slide block mutually mating and chute, in slide block and chute, one of them in both is located on the chair back 1, and another is located on chair back rack 2.

Referring to Fig. 6～Fig. 8, described sliding connection structure comprises sliding connection structure, and on this, the formation of sliding connection structure is: the top of the described chair back 1 is provided with guide plate 6, in this guide plate 6, is provided with gathering sill 6-2; The upper end of described chair back rack 2 extend in described gathering sill 6-2; On the both sides of the inwall of described gathering sill 6-2, be respectively equipped with a protruding 6-2, on the dual-side of described chair back rack 2, be respectively equipped with a groove 2-4, described protruding 6-2 is matched with in groove 2-4 and forms and be slidably connected, wherein, projection 6-2 forms described slide block, and groove 2-4 forms described chute.

Referring to Fig. 4～Fig. 6, for the chair back 1 and chair back rack 2 can be automatically reset after the slip of meeting, described upper sliding connection structure place is provided with automatic reset mechanism, this automatic reset mechanism comprises sliding part 9, sliding tray 14 and spring (not shown), wherein, sliding tray 14 is arranged on chair back rack 2, and described sliding part 9 is matched with in this sliding tray 14 and can slides along the vertical direction, and this sliding part 9 is connected with the chair back 1; Described spring is arranged on the below of sliding part 9.Particularly, the lower end of described sliding part 9 is provided with two for the slide bar 9-2 of spring is set, the below of this sliding part 9 is provided with the guide 11 being fixed on chair back rack 2, and this guide 11 is provided with two pilot holes that match with above-mentioned slide bar 9-2, and described spring housing is located on slide bar 9-2.

Referring to Fig. 4～Figure 10, syndeton between the described chair back 1 and chair back rack 2 also comprises back height governor motion, this back height governor motion is also arranged on sliding connection structure place, this back height governor motion comprises the locating slot 13 being located on the chair back 1 and is located at the locating dowel 12 on chair back rack 2, wherein, a plurality of bayonet socket 13-2 that described locating slot 13 comprises cannelure 13-1 and is positioned at cannelure 13-1 inner side, described a plurality of bayonet socket is arranged at a side of the vertical center line of cannelure 13-1, these bayonet sockets 13-2 arranges along the vertical direction, this bayonet socket 13-2 is tilted to down and is communicated with cannelure 13-1, described locating dowel 12 extend in described locating slot 13.Particularly, described locating dowel 12 is arranged on beat piece 7, and this beat piece 7 is arranged on described sliding part 9, and sliding part 9 is provided with the mounting groove 9-1 matching with beat piece 7 shapes; The connecting hole 9-3 that the upper end of this beat piece 7 is rotationally connected with sliding part 9 by rotating shaft 7-1 is upper, and lower end arranges described locating dowel 12.The both sides of described beat piece 7 are respectively equipped with a 7-2 of spring fitting portion, on each 7-2 of spring fitting portion, a spring 8 is set, in two springs 8, wherein the rigidity of is greater than another root, and the spring 8 that this rigidity is large impels the locating dowel 12 on beat piece 7 to snap onto described bayonet socket 13-2.

Referring to Fig. 4～Figure 10, the operation principle of above-mentioned back height governor motion is: under original state, locating dowel 12 is positioned on one of them bayonet socket 13-2; In the time need to heightening the height of the chair back 1, upwards pull the chair back 1, locating dowel 12 is left original bayonet socket 13-2 and is entered into cannelure 13-1, when next bayonet socket 13-2 moves upward to the position corresponding with locating dowel 12, under spring 8 effects, locating dowel 12 has sticked into this bayonet socket 13-2, make the chair back 1 risen with two adjacent bayonet socket 13-2 between height corresponding to distance, Using such method, is stuck in different bayonet socket 13-2 by locating dowel 12 upper, realizes the adjusting of height; And from nethermost bayonet socket 13-2, enter after cannelure 13-1 when locating dowel 12, can move to from the top/bottom part of cannelure 13-1 the top of cannelure 13-1, then enter the bayonet socket 13-2 of the top, the height of the chair back 1 pulls back to minimumly from the highest, now can proceed highly to regulate.

Referring to 4 and Fig. 5, the top of the described chair back 1 is provided with connecting plate 3, and described locating slot 13 is arranged on the dorsal part of this connecting plate 3; Described guide plate 6 is fixedly connected on the dorsal part of connecting plate 3, and this guide plate 6 is provided with through hole 6-3 at the position corresponding with described locating slot 13.By described connecting plate 3 is set, be convenient to be connected with guide plate 6 on the one hand, be convenient on the other hand arrange described locating slot 13.

Referring to Fig. 4 and Fig. 5, the top of the described chair back 1 is provided with the bonnet 10 outside the top that covers chair back rack 2, by described bonnet 10 is set, can block sliding connection structure, automatic reset mechanism and back height governor motion, makes appearance more attractive in appearance.

Referring to Fig. 1～Fig. 3, described sliding connection structure also comprises lower slider syndeton, the formation of this lower slider syndeton is: the bottom of the described chair back 1 is provided with from the middle linking arm 4 extending of two side direction, the middle part of this linking arm 4 is provided with opening towards the link slot 5-1 in the place ahead, and this link slot 5-1 forms described chute; The bottom of described chair back rack 2 is provided with the guide post 5 through described link slot 5-1, and the two ends of this guide post 5 and chair back rack 2 are fixing, and this guide post 5 forms described slide block.By described lower slider syndeton is set, match with upper sliding connection structure, make the slip of the chair back 1 relative chair back rack 2 more stable.

Below in conjunction with accompanying drawing, the fixed point warp architecture on chair back rack 2 in backrest of the present utility model is described in detail:

Referring to Figure 11, Figure 14, Figure 15, described fixed point warp architecture comprises soft section of 2-1 of elastically deformable and is connected in two hard sections up and down at these soft section of 2-1 two ends, and wherein, the rear side surface of described soft section of 2-1 is provided with the weakening groove 2-11 of horizontally set.Described soft section of 2-1 and two hard sections link together and form described chair back rack 2.

Referring to Figure 14 and Figure 15, described weakening groove 2-11 is a plurality of, and these weakening grooves 2-11 is arranged in order from top to bottom, makes soft section of 2-1 on above-below direction, have a plurality of bending points.Described fixed point warp architecture is arranged at the middle and upper part of chair back rack 2, and corresponding user's upper back allows this position of human body obtain comfortable resiliency supported.Described chair back rack 2 is combined by above-mentioned upper hard section 2-2, soft section of 2-1 and lower hard section 2-3, wherein, described upper hard section for arrange sliding connection structure groove 2-4 and and automatic reset mechanism in sliding tray 14.

Referring to Figure 13, syndeton between described soft section of 2-1 and hard section is: in the two ends of described soft section of 2-1, be all embedded with rigid disk 18, stretch out outside soft section of 2-1 one end of this rigid disk 18, and this extension is inserted in the connecting hole that is located at hard section, and both are fixedly connected with by screw.When soft section of 2-1 of injection moulding, rigid disk 18 is one-body molded as embedded component and soft section of 2-1, and during assembling, by rigid disk 18 and the fixing connection that can realize soft section of 2-1 and hard section of hard section, assembling is simple, is connected firmly.

Referring to Figure 13, Figure 14, Figure 16 and Figure 17, described fixed point warp architecture also comprises firm elasticity switching mechanism, this firm elasticity switching mechanism comprises and is arranged on along the vertical direction the soft section of brace 15 on 2-1, the upper end of this brace 15 is stiff end, this stiff end is fixedly connected on hard section 2-2, lower end is free end, and this free end extends to lower hard section 2-3 place.

Referring to Figure 13, Figure 14, Figure 16 and Figure 17, described lower hard section 2-3 is provided with the change-over switch 16 that can laterally slide, and this change-over switch 16 is rigid state while sliding into wherein one end, is elastic stage while sliding into the other end; The free end of described brace 15 is provided with hook 15-1, and when change-over switch 16 is during in rigid state, this change-over switch 16 extend in described hook 15-1, and when change-over switch 16 is during in elastic stage, this change-over switch 16 is positioned at outside described hook 15-1.

Referring to Figure 13, Figure 14, Figure 16 and Figure 17, described soft section of 2-1 is provided with for holding the mounting groove 2-12 of described brace 15, and brace 15 is arranged in this mounting groove 2-12, and is fixedly connected with soft section of 2-1 by screw; Described lower hard section 2-3 is provided with for holding the free-ended holding tank 2-31 of brace 15, and the side direction of this holding tank 2-31 is connected with for the gathering sill 2-32 of change-over switch 16 is installed, and change-over switch 16 is done laterally to slide in this gathering sill 2-32; The top of described holding tank 2-31 and gathering sill 2-32 is provided with cover plate 17.

Referring to Figure 13, Figure 14, Figure 16 and Figure 17, described change-over switch 16 is formed by connecting with the stop part 16-2 that is positioned at below by the 16-1 of pushing portion that is positioned at top, wherein, the 16-1 of pushing portion is for controlling change-over switch 16, stop part 16-2 is for stopping spacing to the hook 15-1 of brace 15, between the described pushing 16-1 of portion and stop part 16-2, there is gap, the free end of described brace 15 passes from this gap, and the hook 15-1 on this brace 15 is adjacent on described stop part 16-2.

Referring to Figure 12 and Figure 17, the side of described change-over switch 16 is provided with breach 16-3, and the edge of described cover plate 17 extend in this breach 16-3, thereby it is spacing to utilize the side of cover plate 17 to carry out change-over switch 16, prevents from getting loose.

Referring to Figure 11～Figure 17, the operation principle of above-mentioned elasticity switching mechanism is: when soft section of 2-1 is backward during flexural deformation, described brace 15 can upwards produce certain displacement, and when described change-over switch 16 is during in rigid state, this change-over switch 16 extend in the hook 15-1 of brace 15, thereby moving upward of brace 15 caused to obstruction, and brace 15 cannot be moved upward, therefore the flexural deformation of soft section of 2-1 is also restricted, and now soft section of 2-1 is equivalent to rigid body; And when described change-over switch 16 is during in elastic stage, this change-over switch 16 is positioned at outside the hook 15-1 of brace 15, brace 15 can freely move upward, and soft section of 2-1 can be freely crooked.By above-mentioned firm elasticity switching mechanism is set, user can independently select whether to need chair back rack 2 bendings, to meet the needs of different use occasions.

Above-mentioned is preferably embodiment of the utility model; but embodiment of the present utility model is not subject to the restriction of foregoing; other any do not deviate from change, the modification done under Spirit Essence of the present utility model and principle, substitutes, combination, simplify; all should be equivalent substitute mode, within being included in protection domain of the present utility model.

Claims

1. a backrest, comprises the chair back and chair back rack, and wherein, described chair back rack is a rod member extending from bottom to top, and the lower end of this chair back rack is connected with Chair underframe; It is characterized in that, syndeton between the described chair back and chair back rack is: comprise the sliding connection structure that can slide along the vertical direction, this sliding connection structure consists of the slide block mutually mating and chute, in slide block and chute, one of them is located on the chair back, and another is located on chair back rack;

2. backrest according to claim 1, is characterized in that, described sliding connection structure comprises sliding connection structure, and on this, the formation of sliding connection structure is: the top of the described chair back is provided with guide plate, in this guide plate, is provided with gathering sill; Described chair back rack is a rod member extending along the vertical direction, and the upper end of this chair back rack extend in described gathering sill; The inwall of described gathering sill is provided with projection, and the side of described chair back rack is provided with groove, and described projection is matched with in groove, and wherein, projection forms described slide block, and groove forms described chute.

3. backrest according to claim 2, it is characterized in that, described upper sliding connection structure place is provided with automatic reset mechanism, this automatic reset mechanism comprises sliding part, sliding tray and spring, wherein, sliding tray is arranged on chair back rack, and described sliding part is matched with in this sliding tray, and this sliding part is connected with the chair back; Described spring is arranged on the below of sliding part.

4. backrest according to claim 3, it is characterized in that, syndeton between the described chair back and chair back rack also comprises back height governor motion, this back height governor motion comprises the locating slot being located on the chair back and is located at the locating dowel on chair back rack, wherein, a plurality of bayonet sockets that described locating slot comprises cannelure and is positioned at cannelure inner side, described a plurality of bayonet socket is arranged at a side of the vertical center line of cannelure, these bayonet sockets are arranged along the vertical direction, and this bayonet socket is tilted to down and is communicated with cannelure; Described locating dowel extend in described locating slot.

5. backrest according to claim 4, is characterized in that, described locating dowel is arranged on beat piece, and this beat piece is arranged on described sliding part, and the upper end of this beat piece is rotationally connected with on sliding part, and lower end arranges described locating dowel; Described beat piece is provided with the locating dowel of impelling on beat piece and snaps onto the spring on described bayonet socket; The top of the described chair back is provided with connecting plate, and described locating slot is arranged on the dorsal part of this connecting plate; Described guide plate is fixedly connected on the dorsal part of connecting plate, and this guide plate is provided with through hole at the position corresponding with described locating slot.

6. backrest according to claim 2, it is characterized in that, described sliding connection structure also comprises lower slider syndeton, the formation of this lower slider syndeton is: the bottom of described chair back plate is provided with from the middle linking arm extending of two side direction, the middle part of this linking arm is provided with opening towards the link slot in the place ahead, and this link slot forms described chute; The bottom of described chair back rack is provided with the guide post through described link slot, and two ends and the chair back rack of this guide post are fixed, and this guide post forms described slide block.

7. backrest according to claim 1, it is characterized in that, described fixed point warp architecture also comprises firm elasticity switching mechanism, this firm elasticity switching mechanism comprises the brace being arranged on along the vertical direction on soft section, the upper end of this brace is stiff end, this stiff end is fixedly connected in hard section, and lower end is free end, and this free end extends to lower hard section place;

8. backrest according to claim 7, is characterized in that, described soft section is provided with for holding the mounting groove of described brace; Described lower hard section is provided with for holding the free-ended holding tank of brace, and the side direction of this holding tank is connected with for the gathering sill of change-over switch is installed; The top of described holding tank and gathering sill is provided with cover plate.

9. backrest according to claim 8, it is characterized in that, described change-over switch is formed by connecting with the stop part that is positioned at below by the pushing portion that is positioned at top, between described pushing portion and stop part, there is gap, the free end of described brace passes from this gap, and the hook on this brace is adjacent on described stop part.

10. backrest according to claim 7, is characterized in that, described weakening groove is a plurality of, and these weaken groove and are arranged in order from top to bottom; Described fixed point warp architecture is arranged at the middle and upper part of chair back rack; Syndeton between described soft section and hard section is: in described soft section, be embedded with rigid disk, stretch out outside soft section one end of this rigid disk, and this extension is inserted in hard section and is fixedly connected with it.