Headrest rotation adjusting device

Abstract

The utility model discloses a headrest rotation adjusting device which comprises a headrest body, the headrest body comprises a supporting part and a connecting part which are spliced front and back, the rear end of the supporting part is sunken, a containing cavity is formed in a gap between the supporting part and the connecting part, a connecting shaft is transversely arranged in the containing cavity, and two avoiding grooves which are symmetrical left and right are formed in the connecting part in a hollowed-out mode; and the front end of the support is provided with two rotary supporting rings which are in bilateral symmetry, and the rotary supporting rings on the two sides penetrate through the avoiding grooves and are hinged to the connecting shaft. The gear adjusting mechanism comprises gear adjusting pieces connected to the two ends of the connecting shaft, the gear adjusting pieces are attached to the rotating supporting ring, an elastic clamping head is arranged on the end face, close to one side of the rotating supporting ring, of each gear adjusting piece, and a plurality of annularly-distributed positioning grooves are correspondingly formed in the end face, close to one side of each gear adjusting piece, of the rotating supporting ring. According to the headrest rotation adjusting device, the headrest body is obvious in gear adjusting feeling, good in supporting performance, easy and convenient to adjust and operate and simple in appearance.

Description

Technical Field

[0001] The utility model generally relates to the technical field of seats, and in particular to a headrest rotation adjustment device. Background Art

[0002] The headrest is an important component of the seat and is used to support the user's head. With the continuous improvement of the quality of life, current users pay more and more attention to the support and comfort of the headrest. However, the headrest of a traditional seat is often fixed to the seat back, and the position and angle of the headrest relative to the seat are fixed. When users of different body shapes and sitting postures sit on the seat to rest, the inclination angle between their heads and the headrest support surface is different. If the headrest angle cannot be adjusted as needed, the headrest cannot provide stable and comfortable support for the user's head.

[0003] In seats currently on the market with rotatable headrests, the headrest and the backrest are often connected by a rotating shaft, and a damping washer is provided between the headrest and the backrest, so that the rotation of the headrest relative to the backrest is restricted, and a certain damping feel is provided during adjustment. However, this solution cannot achieve reliable fixation between the headrest and the backrest, and the headrest is prone to rotation during use, which affects the support of the headrest; or a locking mechanism is provided to achieve relative fixation of the headrest and the backrest at any angle, but this solution requires repeated operation of the locking mechanism during the adjustment process, and the locking mechanism is located relatively far back, which is often not convenient for users sitting on the seat to reach, and the user needs to leave the seat to adjust it, and the operation is relatively troublesome; in addition, the rotation adjustment mechanism of most existing headrests is exposed to the outside, which is abrupt and affects the appearance. Summary of the invention

[0004] In view of the above defects or deficiencies in the prior art, it is desirable to provide a headrest rotation adjustment device, by providing an elastic clamp on the gear adjustment member, and correspondingly providing a number of positioning grooves on the rotation support ring, so that the headrest body has multiple adjustment gears during the rotation relative to the support, and the adjustment freedom is high and the gear sense is obvious. In addition, in the fixed state, the elastic clamp is engaged with the positioning groove, which can limit the rotation of the headrest body relative to the support; in the adjustment state, the elasticity of the elastic clamp not only makes the adjustment have a good damping feel, but also can further provide damping to limit the rotation of the headrest body, so that the headrest body can stay stably at any rotation angle, so that the headrest body has a relatively stable support performance. And the adjustment operation can be performed by directly applying a force to the headrest body, so that the adjustment operation is very simple. In addition, the connecting shaft and the gear adjustment mechanism are hidden in the accommodating cavity inside the headrest body, without abruptness, and the appearance is more concise and beautiful.

[0005] The effect of the utility model is achieved in this way:

[0006] The present application provides a headrest rotation adjustment device, comprising:

[0007] The headrest body is a split structure, including a support part and a connecting part spliced ​​front and back, the support part is configured to support the user's head, the rear end of the support part is recessed, and the space between the support part and the connecting part forms a receiving cavity, a connecting shaft is transversely arranged in the receiving cavity, and two symmetrical avoidance grooves are hollowed out on the connecting part, the avoidance grooves are connected to the receiving cavity and face the connecting shaft;

[0008] The support is configured to connect to the seat back, and the front end of the support is provided with two left-right symmetrical rotating support rings. The rotating support rings on both sides pass through the avoidance groove and are hinged to the connecting shaft, so that the connecting shaft rotates circumferentially relative to the rotating support ring, thereby driving the headrest body to rotate up and down relative to the support.

[0009] The gear adjustment mechanism includes a gear adjustment member connected to both ends of the connecting shaft, the gear adjustment member fits the rotating support ring, an elastic clamp is provided on the end face of the gear adjustment member close to the rotating support ring, and a plurality of ring-shaped positioning grooves are correspondingly provided on the end face of the rotating support ring close to the gear adjustment member. When the connecting shaft rotates circumferentially relative to the rotating support ring, the elastic clamp switches in the plurality of positioning grooves with the help of elasticity and engages with the positioning grooves, thereby realizing gear adjustment.

[0010] Furthermore, the gear adjustment member is symmetrically provided with at least one pair of elastic clamps. The gear adjustment member is symmetrically engaged with the rotating support ring through at least one pair of elastic clamps, which not only makes the connection strength between the rotating ring and the connecting shaft higher in the fixed state, but also makes the left and right sides of the connecting shaft limited by at least two elastic clamps in the adjusted state, so that the rotation process of the headrest body is more stable, less likely to shake, and the adjustment operation is smoother.

[0011] Furthermore, a mounting groove is provided in a recessed position at one end of the gear adjustment member near the connecting shaft, and the gear adjustment member is clamped to the end of the connecting shaft through the mounting groove, which not only increases the connection strength between the two, but also makes the positioning operation of the gear adjustment member during installation easier.

[0012] Furthermore, a connecting hole is hollowed out on the gear adjustment member, and the connecting hole and the mounting groove are connected front to back, and the gear adjustment member is connected to the connecting shaft through the connecting hole and the connecting shaft screw, which further improves the connection strength between the two and makes the installation and removal of the gear adjustment member more convenient.

[0013] Furthermore, the front end of the rotating support ring is provided with an opening, and the connecting shaft can be inserted into the support ring through the opening, so that the installation and disassembly operation of the rotating support ring is relatively simple.

[0014] Furthermore, the side wall of the connecting shaft near the gear adjusting member extends outward to form a limiting portion, and the limiting portion is configured to clamp the rotating support ring between the limiting portion and the gear adjusting member, so that the rotating support ring is not easy to swing left and right relative to the connecting shaft after installation, thereby further improving the connection stability between the two.

[0015] Furthermore, the avoidance groove is a straight groove extending vertically up and down, so that the headrest body can slide up and down relative to the rotating support ring through the avoidance groove. The headrest body can not only rotate to adjust the angle, but also slide up and down to adjust the vertical height, thereby improving the adjustment freedom of the headrest body and ensuring that the headrest body can adapt to the heads of users of different body shapes.

[0016] Furthermore, the front end of the connecting part protrudes to form a sliding support part, and a sliding groove is provided on the sliding support part, and the connecting shaft passes through the sliding groove and can slide up and down in the sliding groove. In the process of sliding adjustment of the headrest body, the connecting shaft is limited by the sliding groove and is not easy to shake, so that the sliding adjustment operation of the headrest body is more stable and smooth.

[0017] Furthermore, a gear adjustment mechanism is provided between the connecting portion and the connecting shaft, and the gear adjustment mechanism includes an elastic washer provided on the connecting shaft and a plurality of gear slots provided on the connecting portion, and the plurality of gear slots are arranged in the vertical direction and connected to each other to form a complete wave-shaped slot; when the headrest body slides up and down relative to the connecting shaft, the elastic washer switches in the plurality of gear slots by means of elastic deformation and engages with the gear slots to achieve gear adjustment. Under the engagement and engagement of the elastic washer and the plurality of gear slots, the headrest body has a plurality of adjustment gears, with a high degree of adjustment freedom and an obvious gear sense. Moreover, the elastic deformation capacity of the elastic washer not only makes the adjustment have a good damping feel, but also can further provide damping to limit the sliding of the headrest body, so that the headrest body can stably stay at any vertical height, so that the headrest body has a relatively stable supporting performance. Moreover, the adjustment operation can be performed by directly applying a force to the headrest body, and the adjustment can be performed with only one hand when sitting on the seat, so that the adjustment operation is very simple.

[0018] Furthermore, the connecting shaft is provided with a plurality of elastic washers along the width direction, and the connecting portion is provided with a plurality of wavy grooves formed by a combination of a plurality of gear grooves. By providing a plurality of gear adjustment mechanisms between the connecting shaft and the connecting portion, the headrest body is restricted by the plurality of elastic washers and gear grooves when sliding, so that the sliding process is smoother, less prone to left and right shaking, and the adjustment operation is more stable.

[0019] The headrest rotation adjustment device provided by the present application is provided with an elastic clamp on the gear adjustment member, and a plurality of positioning grooves are correspondingly provided on the rotation support ring, so that during the rotation of the headrest body relative to the support, under the cooperation of the elastic clamp and the positioning groove, the headrest body has multiple adjustment gears, the adjustment freedom is high and the gear sense is obvious. In addition, in the fixed state, the elastic clamp is engaged with the positioning groove, which can limit the rotation of the headrest body relative to the support; in the adjustment state, the elasticity of the elastic clamp not only makes the adjustment have a good damping feel, but also can further provide damping to limit the rotation of the headrest body, so that the headrest body can stay stably at any rotation angle, so that the headrest body has a relatively stable support performance. And the adjustment operation can be performed by directly applying a force to the headrest body, and it can be adjusted with only one hand when sitting on the seat, so that the adjustment operation is very simple. In addition, the connecting shaft and the gear adjustment mechanism are hidden in the accommodating cavity inside the headrest body, and only the rotation support ring is the visible part between the headrest body and the support, without abrupt feeling, and the appearance is more concise and beautiful. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0021] Figure 1 A schematic diagram of the three-dimensional structure of the headrest body and the seat back provided in an embodiment of the present application;

[0022] Figure 2 A schematic diagram of the back structure of the headrest body provided in an embodiment of the present application;

[0023] Figure 3 A schematic diagram of the internal structure of a headrest body provided in an embodiment of the present application;

[0024] Figure 4 A schematic diagram of the cross-sectional structure of the headrest body provided in the embodiment of the present application when it is rotated to the front end;

[0025] Figure 5 A schematic diagram of the cross-sectional structure of the headrest body provided in the embodiment of the present application when it is rotated to the rear end;

[0026] Figure 6 A schematic diagram of the cross-sectional structure of the headrest body provided in an embodiment of the present application when it slides to the top;

[0027] Figure 7 A schematic diagram of the connection structure between the support and the connecting shaft provided in an embodiment of the present application;

[0028] Figure 8 A schematic diagram of the connection structure between the connecting shaft and the connecting part provided in an embodiment of the present application.

[0029] The figures are marked as follows: 1-headrest body, 110-support part, 111-accommodating cavity, 120-connecting part, 121-avoidance groove, 122-gear groove, 130-connecting shaft, 131-limiting part, 132-elastic washer, 140-gear adjustment part, 141-positioning protrusion, 142-installing groove, 143-connecting hole, 150-sliding support part, 151-sliding groove, 2-support, 210-rotating support ring, 211-positioning groove, 3-seat back. DETAILED DESCRIPTION

[0030] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant utility model, rather than to limit the utility model. It is also necessary to explain that, for ease of description, only the parts related to the utility model are shown in the accompanying drawings.

[0031] The embodiment of the present application provides a headrest rotation adjustment device, comprising:

[0032] The headrest body 1 is a split structure, including a support portion 110 and a connecting portion 120 spliced ​​together at the front and rear ends. The support portion 110 is configured to support the user's head. The rear end of the support portion 110 is recessed. The space between the support portion 110 and the connecting portion 120 forms a receiving cavity 111. A connecting shaft 130 is transversely arranged in the receiving cavity 111. Two symmetrical avoidance grooves 121 are hollowed out on the connecting portion 120. The avoidance grooves 121 are connected to the receiving cavity 111 and face the connecting shaft 130.

[0033] The support 2 is configured to connect to the seat back 3. The front end of the support 2 is provided with two left-right symmetrical rotating support rings 210. The rotating support rings 210 on both sides pass through the avoidance groove 121 and are hinged to the connecting shaft 130, so that the connecting shaft 130 rotates circumferentially relative to the rotating support ring 210, thereby driving the headrest body 1 to rotate up and down relative to the support 2.

[0034] The gear adjustment mechanism includes a gear adjustment member 140 connected to both ends of the connecting shaft 130, the gear adjustment member 140 is fitted into the rotating support ring 210, and an elastic clamp 141 is provided on the end face of the gear adjustment member 140 close to the rotating support ring 210, and a plurality of annularly distributed positioning grooves 211 are correspondingly opened on the end face of the rotating support ring 210 close to the gear adjustment member 140. When the connecting shaft 130 rotates circumferentially relative to the rotating support ring 210, the elastic clamp 141 switches in the plurality of positioning grooves 211 with the help of elasticity and engages with the positioning grooves 211, thereby realizing gear adjustment.

[0035] In this embodiment, by providing an elastic clamp 141 on the gear adjustment member 140 and correspondingly providing a plurality of positioning grooves 211 on the rotating support ring 210, the headrest body 1 has multiple adjustment gears under the cooperation of the elastic clamp 141 and the positioning groove 211 during the rotation of the headrest body 1 relative to the support 2, with a high degree of adjustment freedom and an obvious gear sense. In addition, in the fixed state, the elastic clamp 141 and the positioning groove 211 are engaged and matched to limit the rotation of the headrest body 1 relative to the support 2; in the adjustment state, the elasticity of the elastic clamp 141 not only provides a good damping feel during adjustment, but also further provides damping to limit the rotation of the headrest body 1, so that the headrest body 1 can stably stay at any rotation angle, thereby making the headrest body 1 have a relatively stable support performance. Moreover, the adjustment operation can be performed by directly applying a force to the headrest body 1, and it can be adjusted with only one hand when sitting on the seat, making the adjustment operation very simple. Moreover, the connecting shaft 130 and the gear adjustment mechanism are hidden in the accommodating cavity 111 inside the headrest body 1, and only the rotating support ring 210 is visible between the headrest body 1 and the support 2, which has no abrupt feeling and is more simple and beautiful in appearance.

[0036] In some embodiments of the present application, the gear adjustment member 140 is symmetrically provided with at least one pair of elastic clamps 141. The gear adjustment member 140 is engaged with the rotating support ring 210 through at least one pair of elastic clamps 141 symmetrically arranged above and below, which not only makes the connection strength between the rotating ring 210 and the connecting shaft 130 higher in the fixed state; but also makes the left and right sides of the connecting shaft 130 limited by at least two elastic clamps 141 in the adjustment state, so that the rotation process of the headrest body 1 is more stable, less likely to shake, and the adjustment operation is smoother.

[0037] Among them, preferably, the gear adjustment member 140 is symmetrically provided with a pair of elastic clamps 141, which not only makes the damping between the gear adjustment member 140 and the connecting shaft 130 moderate, but also reduces the manufacturing cost.

[0038] In some embodiments of the present application, a mounting groove 142 is recessed at one end of the gear adjustment member 140 close to the connecting shaft 130 , and the gear adjustment member 140 is clamped to the end of the connecting shaft 130 through the mounting groove 142 .

[0039] In this embodiment, the snap-fitting between the gear adjustment member 140 and the connecting shaft 130 not only makes the connection strength between the two higher, but also makes the positioning operation of the gear adjustment member 140 during installation easier.

[0040] Among them, preferably, the end of the connecting shaft 130 is a flat shaft structure, and the installation groove 142 is also a corresponding shape, so that after the gear adjustment member 140 is inserted into the connecting shaft 130, it cannot rotate circumferentially relative to the connecting shaft 130, further improving the positioning effect.

[0041] In some embodiments of the present application, a connecting hole 143 is hollowed out on the gear adjustment member 140, and the connecting hole 143 and the mounting groove 142 are connected front to back. After the gear adjustment member 140 is clamped on the connecting shaft 130, it is screwed to the connecting shaft 130 through the connecting hole 143.

[0042] In this embodiment, the gear adjustment member 140 and the connecting shaft 130 are connected by screws, which further improves the connection strength between the two and makes the installation and disassembly operations of the gear adjustment member 140 more convenient.

[0043] In some embodiments of the present application, the front end of the rotating support ring 210 is open, and the connecting shaft 130 can be inserted into the support ring 210 through the opening, so that the installation and removal operations of the rotating support ring 210 are relatively simple.

[0044] Among them, preferably, the end of the connecting shaft 130 is a flat shaft structure, the opening width of the rotating support ring 210 is not less than the width of the end of the connecting shaft 130, and the opening width of the rotating support ring 210 is less than the length of the end of the connecting shaft 130; so that when the rotating support ring 210 is installed, the opening can be aligned with the narrower side of the end of the connecting shaft 130 and inserted, which is easy to operate; and after the rotating support ring 210 is inserted, it is limited by the length of the end of the connecting shaft 130, and the connecting shaft 130 is not easy to fall out of the opening of the rotating support ring 210, so that the connection between the two is more stable.

[0045] In some embodiments of the present application, the side wall of the connecting shaft 130 close to the gear adjustment member 140 extends outward to form a limiting portion 131 , and the limiting portion 131 is configured to clamp the rotating support ring 210 between the limiting portion 131 and the gear adjustment member 140 .

[0046] In this embodiment, the rotating support ring 210 is clamped between the limiting portion 131 and the gear adjustment member 140 so that the rotating support ring 210 is not easily shaken left and right relative to the connecting shaft 130 after installation, thereby further improving the connection stability between the two.

[0047] In some embodiments of the present application, the avoidance groove 121 is a straight groove extending up and down in the vertical direction, so that the headrest body 1 can slide up and down relative to the rotating support ring 210 through the avoidance groove 121 .

[0048] In this embodiment, for users of different body shapes, the distance between their heads and the seat is also different when they sit upright. Therefore, if the headrest body 1 can only be rotated to adjust the angle, the user's head may be too high or too low from the headrest body 1, which cannot meet the use needs of users of different body shapes. By setting the avoidance groove 121 as a straight groove extending in the vertical direction, the headrest body 1 can not only be rotated to adjust the angle, but also slide up and down to adjust the vertical height, thereby improving the adjustment freedom of the headrest body 1 and ensuring that the headrest body 1 can adapt to the heads of users of different body shapes.

[0049] In some embodiments of the present application, the front end of the connecting portion 120 protrudes to form a sliding support portion 150 , and a sliding groove 151 extending left and right is opened on the sliding support portion 150 . The connecting shaft 130 passes through the sliding groove 151 and can slide up and down in the sliding groove 151 .

[0050] In this embodiment, by setting the connecting shaft 130 in the sliding groove 151 and sliding up and down in the sliding groove 151, during the sliding adjustment process of the headrest body 1, the connecting shaft 130 is limited by the sliding groove 151 and is not prone to shaking, thereby making the sliding adjustment operation of the headrest body 1 more stable and smooth.

[0051] In some embodiments of the present application, a gear adjustment mechanism is also provided between the connecting portion 120 and the connecting shaft 130, and the gear adjustment mechanism includes an elastic washer 132 provided on the connecting shaft 130 and a plurality of gear grooves 122 opened on the connecting portion 120, and the plurality of gear grooves 122 are arranged in a vertical direction and interconnected to form a complete wavy groove; when the headrest body 1 slides up and down relative to the connecting shaft 130, the elastic washer 132 switches in the plurality of gear grooves 122 by means of elastic deformation and engages with the gear grooves 122, thereby realizing gear adjustment.

[0052] In this embodiment, under the snap-fitting action of the elastic washer 132 and the plurality of gear slots 122, the headrest body 1 has multiple adjustment gears, with a high degree of adjustment freedom and an obvious gear sense. Moreover, in the fixed state, the elastic washer 132 and the gear slot 122 snap-fit, which can limit the sliding of the headrest body 1 relative to the support 2; in the adjustment state, the elastic deformation capacity of the elastic washer 132 not only makes the adjustment have a good damping feel, but also can further provide damping to limit the sliding of the headrest body 1, so that the headrest body 1 can stay stably at any vertical height, so that the headrest body 1 has a relatively stable support performance. Moreover, the adjustment operation can be performed by directly applying a force to the headrest body 1, and it can be adjusted with only one hand when sitting on the seat, making the adjustment operation very simple.

[0053] Preferably, the elastic gasket 132 is made of silicone material, which not only has good elastic deformation ability, but also has a large friction coefficient, which can provide a good damping feeling. Of course, in other embodiments of the present application, the elastic gasket 132 can also be made of rubber, resin, etc.

[0054] In some embodiments of the present application, a plurality of elastic washers 132 are disposed along the width direction of the connecting shaft 130 , and a plurality of wavy grooves formed by a combination of a plurality of gear grooves 122 are correspondingly formed on the connecting portion 120 .

[0055] In this embodiment, by setting multiple sets of gear adjustment mechanisms between the connecting shaft 130 and the connecting part 120, the headrest body 1 is restricted by multiple sets of elastic washers 132 and the gear grooves 122 when sliding, the sliding process is smoother, less likely to shake left and right, and the adjustment operation is more stable.

[0056] It should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like used above to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means more than three.

[0057] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the utility model involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the concept of the utility model. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) by each other to form a technical solution.

Claims

1. A headrest rotation adjustment device, characterized in that: include: A headrest body (1), the headrest body (1) being a split structure, comprising a support portion (110) and a connection portion (120) which are spliced ​​front and back, the support portion (110) being configured to support a user's head, the rear end of the support portion (110) being recessed, the space between the support portion (110) and the connection portion (120) forming a receiving cavity (111), a connecting shaft (130) being transversely arranged in the receiving cavity (111), and two symmetrical avoidance grooves (121) being hollowed out on the connection portion (120), the avoidance grooves (121) being connected to the receiving cavity (111) and facing the connecting shaft (130); A support (2), the support (2) being configured to be connected to a chair back (3), the front end of the support (2) being provided with two left-right symmetrical rotating support rings (210), the rotating support rings (210) on both sides passing through the avoidance groove (121) and being hinged to the connecting shaft (130), so that the connecting shaft (130) is circumferentially rotated relative to the rotating support ring (210), thereby driving the headrest body (1) to rotate up and down relative to the support (2); A gear adjustment mechanism, the gear adjustment mechanism comprising a gear adjustment member (140) connected to both ends of the connecting shaft (130), the gear adjustment member (140) being in contact with the rotating support ring (210), an elastic clamp (141) being provided on the end surface of the gear adjustment member (140) close to the rotating support ring (210), a plurality of positioning grooves (211) distributed in an annular shape being correspondingly provided on the end surface of the rotating support ring (210) close to the gear adjustment member (140), when the connecting shaft (130) rotates circumferentially relative to the rotating support ring (210), the elastic clamp (141) switches in the plurality of positioning grooves (211) by means of elasticity and is engaged with the positioning grooves (211), thereby achieving gear adjustment.

2. The headrest rotation adjustment device according to claim 1, characterized in that: The gear adjustment member (140) is symmetrically provided with at least one pair of elastic clamping heads (141) in upper and lower positions.

3. The headrest rotation adjustment device according to claim 1, characterized in that: An end of the gear adjustment member (140) close to the connecting shaft (130) is recessed and provided with a mounting groove (142), and the gear adjustment member (140) is clamped to the end of the connecting shaft (130) through the mounting groove (142).

4. The headrest rotation adjustment device according to claim 3, characterized in that: The gear adjustment member (140) is also hollowed out to form a connection hole (143), the connection hole (143) and the mounting groove (142) are connected front to back, and the gear adjustment member (140) is screwed to the connection shaft (130) through the connection hole (143).

5. The headrest rotation adjustment device according to claim 1, characterized in that: The front end of the rotating support ring (210) is provided with an opening, and the connecting shaft (130) can be inserted into the support ring (210) through the opening.

6. The headrest rotation adjustment device according to claim 1, characterized in that: The connecting shaft (130) extends outwardly from a side wall close to the gear adjustment member (140) to form a limiting portion (131), and the limiting portion (131) is configured to clamp the rotating support ring (210) between the limiting portion (131) and the gear adjustment member (140).

7. The headrest rotation adjustment device according to claim 1, characterized in that: The avoidance groove (121) is a straight groove extending up and down in the vertical direction, so that the headrest body (1) can slide up and down relative to the rotating support ring (210) through the avoidance groove (121).

8. The headrest rotation adjustment device according to claim 7, characterized in that: The front end of the connecting portion (120) protrudes to form a sliding support portion (150), and the sliding support portion (150) is provided with a sliding groove (151) that passes through the sliding groove (151) to the left and right, and the connecting shaft (130) passes through the sliding groove (151) and can slide up and down in the sliding groove (151).

9. The headrest rotation adjustment device according to claim 7, characterized in that: A gear adjustment mechanism is also provided between the connecting portion (120) and the connecting shaft (130), the gear adjustment mechanism comprising an elastic washer (132) provided on the connecting shaft (130) and a plurality of gear slots (122) provided on the connecting portion (120), the plurality of gear slots (122) being arranged in a vertical direction and interconnected to form a complete wave-shaped slot; when the headrest body (1) slides up and down relative to the connecting shaft (130), the elastic washer (132) switches within the plurality of gear slots (122) by means of elastic deformation and engages with the gear slots (122), thereby achieving gear adjustment.

10. The headrest rotation adjustment device according to claim 9, characterized in that: The connecting shaft (130) is provided with a plurality of elastic washers (132) along the width direction, and the connecting portion (120) is correspondingly provided with a plurality of wavy grooves formed by combining the plurality of gear slots (122).

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