Angle adjustment system

Abstract

An angle adjustment system (10), comprising: a headrest portion (100), which has a headrest back panel (110), headrest side panels (120), and first brackets (130) connected to the headrest back panel and the headrest side panels; a backrest portion (200), which has a backrest back panel (210), backrest side panels (220), and second brackets (230) connected to the backrest back panel and the backrest side panels; and an adjustment device (300), which has a first adjustment portion (320) and a second adjustment portion (330) able to move relative to each other, wherein the first adjustment portion is connected to a first bracket, the second adjustment portion is connected to a second bracket and, when the first adjustment portion moves relative to the second adjustment portion, the first brackets pivot relative to the second brackets. The system is used for adjusting the pitch angle of a seat headrest, and has high structural strength and involves a small number of parts.

Description

Angle adjustment system Technical Field

[0001] The present application relates to an angle adjustment system, in particular to an angle adjustment system for a seat headrest. Background Art

[0002] In modern seat design, comfort is a factor that requires adjustments to seat components, such as the pitch angle of the headrest, to accommodate individual differences between users and their varying usage states (e.g., resting or working). Therefore, an angle adjustment system is required in the seat.

[0003] To achieve angle adjustment in an effortless manner, the angle adjustment system can be designed with a power-assisting device, such as a motor. These power-assisting devices are relatively large, making their placement within the seat particularly important. This requires both aesthetics (i.e., the motor is typically built into the seat), comfort (i.e., ensuring the user does not experience a foreign object sensation while seated), and maximizing the adjustable angle.

[0004] On the other hand, in addition to the above factors, lightweight, strong and economical are other factors that must be considered in product design, and these factors are usually in conflict with each other.

[0005] For example, adding an angle adjustment system for comfort inevitably increases the overall mass and cost of the product. Therefore, while ensuring that the angle adjustment system can adjust seat components, such as the pitch angle of the headrest, the angle adjustment system is often required to have fewer parts to minimize its mass and cost.

[0006] For example, common wooden chairs often have high strength, but the wood production process requires complex processes such as plywood and wood cutting, which leads to high labor costs and long production cycles.

[0007] Summary of the Invention

[0008] The object of the present application is to provide an angle adjustment system so as to be able to adjust the pitch angle of the headrest of a seat while having relatively high structural strength and a small number of parts.

[0009] The angle adjustment system according to the present application includes: a headrest part, the headrest part having a headrest backboard, a headrest side panel connected to the end of the headrest backboard, and a first bracket connected to the headrest backboard and the headrest side panel; a backrest part, the backrest part having a backrest backboard, a backrest side panel connected to the end of the backrest backboard, and a second bracket connected to the backrest backboard and the backrest side panel; and an adjustment device, the adjustment device having a first adjustment part and a second adjustment part, the first adjustment part being able to move relative to the second adjustment part, wherein the first adjustment part is connected to the first bracket, the second adjustment part is connected to the second bracket, and the first bracket and the second bracket are connected by a pivot shaft, and when the first adjustment part moves relative to the second adjustment part, the first bracket pivots relative to the second bracket.

[0010] Here, the first bracket connects the headrest back panel and headrest side panels, while the second bracket connects the backrest back panel and backrest side panels. Furthermore, the first and second brackets are connected to the first and second adjustment parts of the adjustment device, respectively, serving as follower components. This structure significantly reduces the number of components in the angle adjustment system while maintaining angle adjustment functionality and structural strength, simplifying production and manufacturing.

[0011] Preferably, the headrest back panel, headrest side panels, backrest back panel, and backrest side panels are plastic parts. In particular, the headrest back panel, headrest side panels, backrest back panel, and backrest side panels can be selected from one or more of wood plastic parts, injection molded parts, blow molded parts, and extruded parts. Plastic parts such as wood plastic parts, injection molded parts, blow molded parts, and extruded parts can be formed in a single step using a mold and subsequently automated for installation, significantly reducing labor costs while also meeting lightweight requirements.

[0012] More preferably, the headrest back plate and the backrest back plate can be constructed as wood plastic parts, and the headrest side plates and the backrest side plates can be constructed as injection molded parts. Wood plastic parts have lower costs, while injection molded parts are suitable for bearing loads.

[0013] In a preferred embodiment, the first bracket can be configured to have a first side portion and a second side portion arranged at an angle to each other. The first bracket is connected to the headrest back panel via the first side portion, and the first bracket is connected to the headrest side panel via the second side portion. This configuration of the first bracket is easy to manufacture and effectively connects the headrest back panel and headrest side panel at a fixed angle, ensuring the stability of the overall structure. This is particularly advantageous in structures constructed from wood-plastic parts, injection molded parts, blow molded parts, and / or extruded parts.

[0014] Alternatively or additionally, the second bracket may also be constructed in a similar manner and have a similar technical effect. That is, the second bracket is configured to have a fourth side portion and a fifth side portion arranged at an angle to each other, the second bracket being connected to the backrest backboard via the fourth side portion, and the second bracket being connected to the backrest side panel via the fifth side portion.

[0015] Preferably, the headrest back panel has a generally flat body and a top portion extending perpendicularly thereto. The first bracket has a third side portion arranged at an angle to the first side portion, and the first bracket is connected to the body of the headrest back panel via the third side portion. The first bracket can direct the adjustment force applied by the adjustment device to the top of the headrest back panel via the third side portion, thereby reducing shear forces acting at the connections between the first bracket, the headrest back panel, and the headrest side panels, thereby reducing the likelihood of damage to these connections. This is particularly advantageous for protecting the connections between plastic components.

[0016] In a preferred embodiment, the headrest back panel is provided with first accommodating portions at both ends, and the headrest side panels have protrusions that protrude perpendicularly to the side panel planes of the headrest side panels. The headrest side panels are plugged into the ends of the headrest back panel by inserting the protrusions into the first accommodating portions. This pluggable headrest back panel and headrest side panels provide pre-positioning before connection to the first bracket and also provide additional connection strength. The backrest back panel and backrest side panels can also be configured similarly.

[0017] Preferably, a recessed portion is provided in the protrusion, a nut is provided in the recessed portion, and the first bracket and / or the second bracket are connected to the nut in the recessed portion of the protrusion by means of bolts.

[0018] Alternatively, the projections are configured as cross ribs.

[0019] In a preferred embodiment, the adjustment device further comprises a driver capable of driving the first adjustment portion to move relative to the second adjustment portion. Thus, the driver as a power assist device can help the user to easily adjust the angle of the seat headrest.

[0020] Preferably, a linear actuator can be selected as the adjustment device, wherein the driver is capable of driving the first adjustment part to perform linear movement relative to the second adjustment part, and wherein the first adjustment part is pivotally connected to the first bracket via a first axis, and the second adjustment part is pivotally connected to the second bracket via a second axis.

[0021] Preferably, the first shaft can be fixedly connected to the first bracket and pivotally connected to the first adjusting part through a bearing; the second shaft can be fixedly connected to the second bracket and pivotally connected to the second adjusting part through another bearing.

[0022] Here, fixed connection includes integral formation by, for example, molding, or fixing together by subsequent means such as welding, snap-fit ​​connection, threaded connection, etc.

[0023] Alternatively, the first shaft may be fixedly connected to the first adjusting portion and pivotally connected to the first bracket via a bearing; the second shaft may be fixedly connected to the second adjusting portion and pivotally connected to the second bracket via another bearing.

[0024] Preferably, the headrest side panel is provided with a second accommodating portion that accommodates and supports the first shaft. By providing the second accommodating portion in the headrest side panel and arranging and supporting the first shaft therein, the second accommodating portion of the headrest side panel can be largely utilized to withstand the adjustment force applied by the adjustment device, thereby reducing the force acting on the connection between the first bracket, the headrest back panel, and the headrest side panel, thereby reducing the possibility of damage to the connection. This is particularly beneficial for protecting the connection between plastic parts. In this case, it is also particularly advantageous to select a high-strength injection molded or extruded part as the material for the headrest side panel.

[0025] Alternatively or additionally, the backrest side plate may also be provided with a second accommodation portion, which accommodates and supports the second shaft.

[0026] In a preferred embodiment, a limit mechanism for limiting the angle adjustment range may be provided between the first and second brackets. Specifically, one of the first and second brackets is provided with a guide slot having limit portions at both ends of the guide slot, and the other of the first and second brackets is provided with a sliding member that cooperates with the guide slot. When the first bracket pivots relative to the second bracket, the sliding member slides along the guide slot and stops when it contacts the limit portion.

[0027] In a preferred embodiment, the headrest back panel is connected to the two headrest side panels at both ends through two first brackets, and the backrest back panel is connected to the two backrest side panels at both ends through two second brackets, wherein the adjustment device is arranged on one end, and a tensioning member connected to the first bracket and the second bracket is arranged on the other end.

[0028] The unilateral placement of the adjustment device further reduces the need for components such as extension members. To prevent unilateral collapse or deformation of the headrest due to uneven load-bearing during use, a tensioning member such as a spring can be placed on the end where the adjustment device is not located to provide tension, which is particularly beneficial for ride comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] To better understand the above and other objects, features, advantages, and functions of the present application, reference may be made to the preferred embodiments shown in the accompanying drawings. Like reference numerals in the accompanying drawings refer to like components. Those skilled in the art should understand that the accompanying drawings are intended to schematically illustrate preferred embodiments of the present application and have no limiting effect on the scope of the present application. The components in the drawings are not drawn to scale.

[0030] FIG1 shows a perspective view of the angle adjustment system of the present application;

[0031] FIG2 shows a perspective view of the headrest back plate of the angle adjustment system of the present application;

[0032] FIG3 shows a perspective view of a headrest side panel of the angle adjustment system of the present application;

[0033] FIG4 shows a perspective view of the backrest of the angle adjustment system of the present application;

[0034] FIG5 shows a perspective view of the backrest side panel of the angle adjustment system of the present application; and

[0035] FIG6 shows a perspective view of an angle adjustment device connected to a first bracket and a second bracket of the angle adjustment system of the present application. DETAILED DESCRIPTION

[0036] Now, with reference to the accompanying drawings, the specific embodiments of the present application will be described in detail. What is described here is only the preferred embodiment of the present application. Those skilled in the art may conceive of other ways to implement the present application based on the preferred embodiment, and the other ways also fall within the scope of the present application.

[0037] FIG1 shows a perspective view of an angle adjustment system 10 of the present application, which includes a headrest portion 100, a backrest portion 200, and an adjustment device 300 for adjusting the angle between the headrest portion 100 and the backrest portion 200. The headrest portion 100 includes a headrest back plate 110, a headrest side plate 120, and a first bracket 130 connected to the headrest back plate 110 and the headrest side plate 120; the backrest portion 200 includes a backrest back plate 210, a backrest side plate 220, and a second bracket 230 connected to the backrest back plate 210 and the backrest side plate 220; the adjustment device 300 includes a first adjustment portion 320 and a second adjustment portion 330 that can move relative to each other. By connecting the first adjustment portion 320 and the second adjustment portion 330 to the first bracket 130 and the second bracket 230, respectively, the relative position of the first bracket 130 and the second bracket 230 is controlled, thereby achieving angle adjustment between the headrest portion 100 and the backrest portion 200. This structure is particularly simple and can effectively reduce the number of components of the angle adjustment system 100 .

[0038] 2 to 6 , the detailed structures of the various components of the angle adjustment system 10 and their connection methods are further described below.

[0039] 2 , in this embodiment, the headrest back plate 110 has a substantially flat body 111 and a top portion 114 protruding and extending perpendicularly from the body 111. The body 111 and the top portion 114 have a hollow configuration and a plurality of first receiving portions 112 are formed at both ends.

[0040] 3 , the headrest side plate 120 has a substantially truncated cone-shaped body 121 and a plurality of protrusions 122 protruding perpendicularly from the body 121 , wherein each protrusion 122 is provided with a recess 123 for accommodating a connecting member such as a nut.

[0041] Returning to Figure 1, there are two headrest side panels 120 in this embodiment, as shown in Figure 3, which are respectively installed at both ends of the headrest back panel 110, wherein the multiple protrusions 122 of the headrest side panels 120 are inserted into the multiple first accommodating portions 112 of the headrest back panel 110, so that the headrest side panels 120 are installed to be roughly perpendicular to the main body 111 of the headrest back panel 110, and the top of the headrest side panels 120 is aligned with the top 114 of the headrest back panel 110.

[0042] 6 , the first bracket 130 includes a first side portion 131 , a second side portion 132 and a third side portion 133 , wherein the first side portion 131 is roughly rectangular, the second side portion 132 is connected to the long side of the first side portion 131 at right angles to each other, and the third side portion 133 is connected to the short side of the first side portion 131 at right angles to each other.

[0043] 1 , corresponding bolt holes are provided on the headrest back plate 110, the headrest side plate 120, and the first side portion 131, the second side portion 132, and the third side portion 133 of the first bracket 130, so that the first bracket 130 can be bolted to the main body 111 of the headrest back plate 110 through the first side portion 131, to the top 114 of the headrest back plate 110 through the third side portion 133, and to the headrest side plate 120 through the second side portion 132.

[0044] According to the above-mentioned connection relationship, the angle between the first side portion 131 and the second side portion 132 can be determined according to the angle between the headrest back panel 110 and the headrest side panel 120, and the angle between the first side portion 131 and the third side portion 133 can be determined according to the angle between the main body 111 and the top 114 of the headrest back panel 110.

[0045] 4 , the backrest backboard 210 has a substantially flat body 211 having a hollow configuration and having a plurality of first receiving portions 212 formed at both ends.

[0046] 5 , the backrest side panel 220 has a generally truncated cone-shaped body 221 and a plurality of protrusions 222 and 222 ′ protruding perpendicularly to the body 221 , wherein each protrusion 222 is provided with a recessed portion 223 for accommodating a connector such as a nut, while the protrusion 222 ′ is formed by a cross rib as another example.

[0047] Returning to Figure 1, there are two backrest side panels 220 in this embodiment, as shown in Figure 5, which are respectively installed at both ends of the backrest backboard 210, wherein the multiple protrusions 222 and 222' of the backrest side panels 220 are inserted into the multiple first accommodating portions 212 of the backrest backboard 210, so that the backrest side panels 220 are installed to be roughly perpendicular to the main body 211 of the backrest backboard 210.

[0048] 6 , the second bracket 230 includes a fourth side portion 231 and a fifth side portion 232 , wherein the fourth side portion 231 is substantially rectangular, and the fifth side portion 232 is connected to a long side of the fourth side portion 231 at a right angle to each other.

[0049] Returning to Figure 1, corresponding bolt holes are provided on the backrest backboard 210, the backrest side panel 220 and the fourth side portion 231 and the fifth side portion 232 of the second bracket 230, so that the second bracket 230 can be bolted to the main body 211 of the backrest backboard 210 through the fourth side portion 231 and to the backrest side panel 220 through the fifth side portion 232.

[0050] According to the above connection relationship, the angle formed between the fourth side portion 231 and the fifth side portion 232 may be determined according to the angle formed between the backrest backboard 210 and the backrest side panel 220 .

[0051] Referring to Figure 6 , the adjustment device 300 is configured as a linear actuator, particularly an electric linear actuator, comprising a driver 310 configured as a motor, a second adjustment portion 330 fixedly connected to the driver 310, and a first adjustment portion 320 capable of linear motion relative to the second adjustment portion 330 under the drive of the driver 310. Furthermore, the adjustment device 300 may also be configured as a hydraulic cylinder, a pneumatic cylinder, an electric swing arm, or other devices. Alternatively, the adjustment device 300 may be configured as a manual device, comprising a first adjustment portion and a second adjustment portion, and manually moving the first adjustment portion relative to the second adjustment portion.

[0052] The first adjustment portion 320 is pivotally connected to the second side portion 132 of the first bracket 130 via the first shaft 140, and the second adjustment portion 330 is pivotally connected to the fifth side portion 232 of the second bracket 230 via the second shaft 240. Furthermore, the first bracket 130 and the second bracket 230 are pivotally connected via the pivot shaft 150. Thus, when the adjustment device 300 drives the first adjustment portion 320 to perform linear motion relative to the second adjustment portion 330, the first bracket 130 is able to pivot relative to the second bracket 230, thereby enabling adjustment of the angle between the headrest portion 100 and the backrest portion 200.

[0053] The first shaft 140 can be integrally formed with the first bracket 130 and then pivotally connected to the first adjustment portion 320 via a bearing. The first shaft 140 can be molded together with the first bracket 130. The first shaft 140 can also be molded separately from the first bracket 130 and then secured together, for example, by welding. The first shaft 140 can also be first secured to the first adjustment portion 320 and then pivotally connected to the first bracket 130 via a bearing.

[0054] The second shaft 240 can be integrally formed with the second bracket 230 and then pivotally connected to the second adjustment portion 330 via a bearing. The second shaft 240 can be molded together with the second bracket 230. The second shaft 240 can also be molded separately from the second bracket 230 and then secured together, for example, by welding. The second shaft 240 can also be first secured to the second adjustment portion 330 and then pivotally connected to the second bracket 230 via a bearing.

[0055] Furthermore, the second shaft 240 further extends on a side away from the adjustment device 300 to form a sub-shaft 241. This sub-shaft 241 can be accommodated and supported in the second accommodating portion 224 of the backrest side panel 220. Thus, the force applied by the adjustment device 300 to the second bracket 230 can be introduced into and absorbed by the second accommodating portion 224, thereby reducing the shear force acting on the connection between the second bracket 230 and the backrest backboard 210 and the backrest side panel 220, thereby reducing the possibility of damage to the connection.

[0056] The first shaft 140 can also form a sub-shaft and thus be received and supported by the second receiving portion in the headrest side plate 120. In this embodiment, the force on the first bracket 130 has been introduced into the top 114 of the headrest back plate 110 through the third side portion 133.

[0057] Preferably, the first adjustment portion 320 is connected to the lower portion of the first bracket 130, and the second adjustment portion 330 is connected to the lower portion of the second bracket 230. Because the headrest side panels 120 and the back side panels 220 are truncated cones that gradually increase in size from top to bottom, they create a larger space at the lower portion after assembly with the back panels 110 and 120. Placing the adjustment device 300 lower down facilitates accommodating the adjustment device 300, preventing the user from touching the adjustment device 300 while leaning on the headrest, which could negatively impact comfort.

[0058] To limit the angle adjustment range of the angle adjustment device 10, an arc-shaped guide groove 234 is provided on the second bracket 230, with the pivot axis 150 as its center. Limiting portions 235 and 236 are provided at both ends of the guide groove 234, and a sliding member 134 is provided on the first bracket 130 to cooperate with the guide groove 234. When the first bracket 130 pivots relative to the second bracket 230, the sliding member 134 can slide along the guide groove 234 and stop sliding after contacting either of the limiting portions 235 and 236. Thus, by properly arranging the positions of the limiting portions 235 and 236, the sliding range of the sliding member 134 can be limited, thereby limiting the angle adjustment range of the angle adjustment device 10. Alternatively, the guide groove can be arranged on the first bracket 130, and the sliding member can be arranged on the second bracket 230.

[0059] Advantageously, the adjustment device 300 is only arranged on one side, thereby reducing the number of required connecting members. However, the arrangement of the adjustment device 300 on only one side may cause one side to collapse or deform during use. Therefore, a tensioning member 400 can be arranged on the other side. Here, the tensioning member 400 is configured as a spring, with one end of the spring connected to the first shaft 140 on the first bracket 130 and the other end connected to the second shaft 240 on the second bracket 230. In this way, the tensioning force of the spring can be utilized to avoid the above-mentioned adverse situation.

[0060] Preferably, the headrest back panel 110, headrest side panels 120, backrest back panel 210, and backrest side panels 220 are plastic parts, particularly one or more selected from wood plastic parts, injection molded parts, blow molded parts, and extruded parts. On the one hand, the above-described structure of the headrest back panel 110, headrest side panels 120, backrest back panel 210, and backrest side panels 220 is suitable for production using wood plastic parts, injection molded parts, blow molded parts, or extruded parts. On the other hand, the plastic parts can be formed in a single step using a mold during production and can also be subsequently assembled automatically, thereby significantly reducing labor costs and production cycle time, while also meeting lightweight requirements.

[0061] More preferably, the headrest back plate 110 and the backrest back plate 210 are constructed of wood-plastic parts, while the headrest side plates 120 and the backrest side plates 220 are constructed of injection-molded parts. This is because wood-plastic parts are relatively low in cost, while injection-molded parts have relatively high strength, which is suitable for forming the second accommodating portion 224 to bear the load.

[0062] Reference Signs List 10 Angle adjustment system 100 Headrest portion 110 Headrest back plate 111 Body of headrest back plate 112 First accommodation portion of headrest back plate 114 Top portion of headrest back plate 120 Headrest side plate 121 Body of headrest side plate 122 Protrusion of headrest side plate 123 Recessed portion of headrest side plate 130 First bracket 131 First side portion 132 Second side portion 133 Third side portion 134 Slider 140 First shaft 150 Pivot shaft 200 Backrest portion 210 Backrest back plate 211 Body of backrest back plate 212 First accommodation portion of backrest back plate 220 Backrest side plate 221 Body of backrest side plate 222 Protrusion of backrest side plate 223 Recessed portion 224 of backrest side plate Second accommodation portion 230 Second bracket 231 Fourth side portion 232 Fifth side portion 234 Guide groove 235 Limiting portion 236 Limiting portion 240 Second shaft 300 Adjusting device 310 Driver 320 First adjusting portion 330 Second adjusting portion 400 Tensioning member

Claims

1. An angle adjustment system (10), characterized in that: The angle adjustment system (10) comprises: A headrest portion (100), the headrest portion (100) comprising a headrest back plate (110), a headrest side plate (120) connected to the end of the headrest back plate (110), and a first bracket (130) connected to the headrest back plate (110) and the headrest side plate (120); A backrest portion (200), the backrest portion (200) comprising a backrest backboard (210), a backrest side panel (220) connected to the end of the backrest backboard (210), and a second bracket (230) connected to the backrest backboard (210) and the backrest side panel (220); and An adjusting device (300), the adjusting device (300) having a first adjusting portion (320) and a second adjusting portion (330), the first adjusting portion (320) being movable relative to the second adjusting portion (330), The first adjusting portion (320) is connected to the first bracket (130), the second adjusting portion (330) is connected to the second bracket (230), and the first bracket (130) and the second bracket (230) are connected via a pivot shaft (150). When the first adjusting portion (320) moves relative to the second adjusting portion (330), the first bracket (130) pivots relative to the second bracket (230).

2. The angle adjustment system (10) according to claim 1, characterized in that: The first bracket (130) has a first side portion (131) and a second side portion (132) arranged at an angle to each other, the first bracket (130) is connected to the headrest back plate (110) through the first side portion (131), the first bracket (130) is connected to the headrest side plate (120) through the second side portion (132), and / or the second bracket (230) has a fourth side portion (231) and a fifth side portion (232) arranged at an angle to each other, the second bracket (230) is connected to the backrest back plate (210) through the fourth side portion (231), and the second bracket (230) is connected to the backrest side plate (220) through the fifth side portion (232).

3. The angle adjustment system (10) according to claim 2, characterized in that: The headrest back plate (110) has a substantially flat body (111) and a top portion (114) protruding and extending perpendicularly to the body (111); the first bracket (130) has a third side portion (133) arranged at an angle to the first side portion (131); the first bracket (130) is connected to the body (111) of the headrest back plate (110) via the third side portion (133).

4. The angle adjustment system (10) according to claim 1, characterized in that: The headrest back plate (110) and / or the backrest back plate (210) are provided with first accommodating portions (112, 211) at both ends, and the headrest side plate (120) and / or the backrest side plate (220) have protruding portions (122, 222) protruding perpendicularly to the side plate plane of the headrest side plate (120) and / or the backrest side plate (220), and the headrest side plate (120) and / or the backrest side plate (220) are plugged into the two ends of the headrest back plate (110) and / or the backrest back plate (210) by inserting the protruding portions (122, 222) into the first accommodating portions (112, 211).

5. The angle adjustment system (10) according to claim 4, characterized in that: The protrusion (122, 222) is provided with a recessed portion (123, 223), a nut is provided in the recessed portion (123, 223), and the first bracket (130) and / or the second bracket (230) are connected to the nut in the recessed portion (123, 223) of the protrusion (122, 222) by bolts; or, the protrusion (122, 222) is configured as a cross rib (222').

6. The angle adjustment system (10) according to claim 1, characterized in that: The adjusting device (300) comprises a driver (310) capable of driving the first adjusting part (320) to move relative to the second adjusting part (330).

7. The angle adjustment system (10) according to claim 6, characterized in that: The adjusting device (300) is a linear actuator, and the driver (310) is capable of driving the first adjusting part (320) to perform linear movement relative to the second adjusting part (330), and wherein the first adjusting part (320) is pivotally connected to the first bracket (130) via a first shaft (140), and the second adjusting part (330) is pivotally connected to the second bracket (230) via a second shaft (240).

8. The angle adjustment system (10) according to claim 7, characterized in that: The first shaft (140) is fixedly connected to the first bracket (130) and is pivotally connected to the first adjustment part (320) via a bearing; the second shaft (240) is fixedly connected to the second bracket (230) and is pivotally connected to the second adjustment part (330) via another bearing.

9. The angle adjustment system (10) according to claim 7, characterized in that: The first shaft (140) is fixedly connected to the first adjusting part (320) and is pivotally connected to the first bracket (130) via a bearing; the second shaft (240) is fixedly connected to the second adjusting part (330) and is pivotally connected to the second bracket (230) via another bearing.

10. The angle adjustment system (10) according to claim 7, characterized in that: The headrest side plate (120) and / or the backrest side plate (220) are provided with a second accommodating portion (224), and the second accommodating portion (224) accommodates and supports the first shaft (140) and / or the second shaft (240).

11. The angle adjustment system (10) according to claim 1, characterized in that: One of the first bracket (130) and the second bracket (230) is provided with a guide groove (234), and limiting portions (235, 236) are provided at both ends of the guide groove (234); the other of the first bracket (130) and the second bracket (230) is provided with a sliding member (134) that cooperates with the guide groove (234), wherein when the first bracket (130) pivots relative to the second bracket (230), the sliding member (134) slides along the guide groove (234) and stops sliding after contacting the limiting portions (235, 236).

12. The angle adjustment system (10) according to claim 1, characterized in that: The headrest back plate (110) is connected to the two headrest side plates (120) at both ends through the two first brackets (130), and the backrest back plate (210) is connected to the two backrest side plates (220) at both ends through the two second brackets (230), wherein the adjustment device (300) is arranged at one end, and a tensioning member (400) connected to the first bracket (130) and the second bracket (230) is arranged at the other end.

13. The angle adjustment system (10) according to claim 1, characterized in that: The headrest back plate (110), the headrest side plates (120), the backrest back plate (210), and the backrest side plates (220) are plastic parts.

14. The angle adjustment system (10) according to claim 13, characterized in that: The headrest back plate (110), the headrest side plate (120), the backrest back plate (210), and the backrest side plate (220) are selected from one or more of wood-plastic parts, injection-molded parts, blow-molded parts, and extruded parts.

15. The angle adjustment system (10) according to claim 14, characterized in that: The headrest back plate (110) and the backrest back plate (210) are wood plastic parts, and the headrest side plates (120) and the backrest side plates (220) are injection molded parts.

Images