Electric up-and-down adjusting headrest mechanism of automobile seat

Abstract

The invention relates to the technical field of automobile mechanical equipment, in particular to an electric up-and-down adjusting headrest mechanism of an automobile seat. The backrest adjusting device is arranged on a pair of backrest guide pipes and comprises a middle shell mechanism assembly, an outer shell assembly and an adjusting driving assembly, the middle shell mechanism assembly comprises a headrest middle shell and headrest guide rods symmetrically and vertically arranged on the two sides of the headrest middle shell, the headrest middle shell is fixedly sleeved with the outer shell assembly, and the adjusting driving assembly comprises a lead screw motor, an electric lead screw and a headrest rod connecting rod. The headrest rod connecting rod is provided with a lead screw bolt hole which allows the upper end of the electric lead screw to penetrate through and is in threaded connection with the electric lead screw. The electric lead screw and the headrest rod connecting rod are in threaded transmission fit, so that the electric lead screw generates linear displacement relative to the headrest rod connecting rod during rotation and drives the lead screw motor, the headrest middle shell and the shell assembly to integrally slide up and down along the headrest guide rod, and electric adjustment of the height of the headrest is achieved.

Description

Technical Field

[0001] This invention relates to the field of automotive mechanical equipment technology, specifically to an electric up-and-down adjustable headrest mechanism for automotive seats. Background Technology

[0002] With the continuous development of the automotive industry and the increasing demands of consumers for driving and riding comfort, car seats, as core components directly affecting the riding experience, are receiving increasing attention for their functionality and intelligence. Headrests, as an important part of the seat, not only ensure passenger head safety but also play a crucial role in riding comfort. Currently, most common electric headrest adjustment mechanisms on the market place the drive components inside the seat back, resulting in complex structures, large space occupation, and affecting the layout of functions such as ventilation and massage. They also suffer from problems such as unstable adjustment, slow response, and difficult maintenance.

[0003] A currently disclosed Chinese patent, CN212022432U, discloses an adjustable headrest for seats. The headrest includes a headrest body, a plug-in device, and a pillowcase device located at one end of the plug-in device. The plug-in device includes headrest rods that plug into two seat posts. Multiple adjustment slots are formed along the height direction at the end of each headrest rod away from the seat. An adjustment device is provided between the headrest rods. The adjustment device includes a fixed plate and a movable plate. A first locking post is fixedly provided at one end of the movable plate, and a second locking post is fixedly provided at the end of the fixed plate near the first locking post. Torsion springs are provided on the first and second locking posts. A locking rod is provided on the movable plate to engage with the adjustment slots. The movable plate can drive the locking rod to disengage from the adjustment slots. A button frame is provided at the end of the fixed plate away from the torsion spring. A button for pressing against the movable plate is elastically provided within the button frame, and the button abuts against the end of the movable plate away from the torsion spring.

[0004] As described in the aforementioned patent, the reliance on precise coordination between multiple mechanical components results in poor overall structural stability, making it prone to jamming or failure after prolonged use. Therefore, there is a need for a more simplified, highly integrated, and stable operating electric height-adjustable headrest mechanism for car seats, fully integrated within the headrest itself. Summary of the Invention

[0005] To address the problems existing in the prior art, an electric height-adjustable headrest mechanism for automobile seats is provided. By forming a threaded transmission engagement between an electric lead screw and a headrest rod connecting rod, the electric lead screw generates a linear displacement relative to the headrest rod connecting rod when it rotates, thereby driving the lead screw motor, the headrest middle shell, and the outer shell assembly to slide up and down along the headrest guide rod, thus realizing the electric adjustment of the headrest height.

[0006] To address the problems of existing technologies, this invention provides an electrically adjustable headrest mechanism for an automobile seat, mounted on a pair of backrest guides. The mechanism includes a middle shell assembly, an outer shell assembly, and an adjustment drive assembly. The middle shell assembly comprises a headrest middle shell and headrest guide rods symmetrically and vertically arranged on both sides. The headrest middle shell slides with the two headrest guide rods. The lower end of each headrest guide rod is fixedly inserted into the upper end of one backrest guide. The outer shell assembly is fixedly sleeved on the headrest middle shell. The adjustment drive assembly includes a lead screw motor, an electric lead screw, and a headrest rod connecting rod. The lead screw motor is located on the inner wall of the outer shell assembly. One end of the electric lead screw is connected to the output shaft of the lead screw motor, and the other end extends vertically upward. The headrest rod connecting rod is horizontally fixed between the two headrest guide rods. A lead screw bolt hole is provided on the headrest rod, through which the upper end of the electric lead screw passes and is threadedly connected. When the lead screw motor drives the electric lead screw to rotate, a threaded sliding fit is formed between the electric lead screw and the headrest rod connecting rod, causing the outer shell assembly to slide synchronously up and down along the headrest guide rods, following the headrest middle shell.

[0007] Preferably, the outer shell assembly includes a front cover and a rear cover of the headrest. The front cover is provided with a front cover mounting buckle on its periphery, and the rear cover is provided with a rear cover buckle groove on its periphery. The front cover mounting buckle is engaged with the rear cover buckle groove.

[0008] Preferably, the headrest middle shell has a middle shell guide sleeve mounting groove on each side, and a headrest rod guide sleeve is provided in each middle shell guide sleeve mounting groove in a snap-fit ​​manner, with the two headrest guide rods inserted into the two headrest rod guide sleeves respectively.

[0009] Preferably, the headrest back cover is provided with back cover positioning posts on both sides, and the headrest middle shell has positioning holes on both sides of the middle shell for the two back cover positioning posts to pass through respectively.

[0010] Preferably, the front cover of the headrest is provided with front cover positioning posts on both sides, which correspond to the rear cover positioning posts, and the front cover positioning posts and the rear cover positioning posts are inserted into each other.

[0011] Preferably, the lower end of the headrest guide rod is provided with a headrest rod positioning groove that is fixedly connected to the backrest guide tube. The headrest guide rod is a hollow structure for connecting the power supply line and the backrest wiring harness. The upper end of the headrest guide rod has a headrest rod center hole through which the power supply line passes.

[0012] Preferably, the headrest back cover is provided with a plurality of back cover center positioning pins, and the headrest middle shell has a middle shell positioning hole for each back cover center positioning pin to pass through, and the back cover center positioning pin is inserted into the middle shell positioning hole.

[0013] Preferably, the headrest back cover is provided with back cover guide rails on both sides, and the headrest middle shell is provided with middle shell slide rail claws for the two back cover guide rails to pass through respectively.

[0014] Preferably, the front cover of the headrest is provided with inner guide rails on both sides, and the inner guide rails of the front cover slide in conjunction with the outer guide rails of the rear cover. The front cover of the headrest and the rear cover of the headrest are fixedly connected by outer shell bolts.

[0015] Preferably, the two ends of the headrest rod connecting rod are respectively provided with connecting rod steel wires that are welded and fixed to the upper end of the corresponding headrest guide rod, and the upper end of the electric screw is welded and fixed with a screw welding nut to prevent it from detaching from the headrest rod connecting rod.

[0016] The advantages of this application compared to the prior art are:

[0017] 1. This invention achieves electric adjustment of the headrest height by forming a threaded transmission engagement between an electric lead screw and a horizontally fixed headrest rod connecting rod. When the electric lead screw rotates, it generates a linear displacement relative to the headrest rod connecting rod, which drives the lead screw motor, the headrest middle shell, and the outer shell assembly to slide up and down along the headrest guide rod.

[0018] With the headrest shell rising or falling through forward and reverse control, the structure is compact and the adjustment is smooth. Guided by the headrest guide rod, the headrest has good stability and smoothness during operation, which improves the overall performance and user experience of the up-and-down adjustment headrest mechanism.

[0019] 2. This invention achieves precise alignment and stable connection between the front cover and the back cover of the headrest through buckles, positioning posts and guide rails, and further enhances the overall structural strength by using outer shell bolts.

[0020] While ensuring structural strength, the motor wiring and backrest wiring harness are routed through the hollow headrest guide rod to ensure safe and stable electrical connections. This effectively improves the overall rigidity and operational smoothness of the up-and-down headrest adjustment mechanism, ensuring a stable and smooth adjustment process.

[0021] 3. This invention uses connecting rods and steel wires to weld and fix both ends of the headrest rod connecting rod to the headrest guide rod, forming a stable structural support and ensuring synchronicity and reliability during the adjustment process.

[0022] Meanwhile, the screw-welded nut at the upper end of the electric screw prevents the electric screw from disengaging during rotation, further improving transmission stability and safety, and ensuring smooth operation and long-term durability of the headrest adjustment. Attached Figure Description

[0023] Figure 1 This is a three-dimensional structural diagram of an electric up-and-down adjustable headrest mechanism for a car seat according to the present invention.

[0024] Figure 2 This is a three-dimensional exploded view of an electrically adjustable headrest mechanism for a car seat according to the present invention. Figure 1 .

[0025] Figure 3 This is a three-dimensional exploded view of an electrically adjustable headrest mechanism for a car seat according to the present invention. Figure 2 .

[0026] Figure 4 This is a schematic diagram of the three-dimensional structure of an electrically adjustable headrest mechanism for a car seat, excluding the headrest foam and cover, according to the present invention. Figure 1 .

[0027] Figure 5 This is a schematic diagram of the three-dimensional structure of an electrically adjustable headrest mechanism for a car seat, excluding the headrest foam and cover, according to the present invention. Figure 2 .

[0028] Figure 6 This is an exploded view of the three-dimensional structure of an electrically adjustable headrest mechanism for a car seat, excluding the headrest foam and cover, according to the present invention. Figure 1 .

[0029] Figure 7 This is an exploded view of the three-dimensional structure of an electrically adjustable headrest mechanism for a car seat, excluding the headrest foam and cover, according to the present invention. Figure 2 .

[0030] Figure 8 This is a three-dimensional structural diagram of the headrest guide rod, headrest middle shell, and adjustment drive assembly of an electric up-and-down adjustable headrest mechanism for a car seat according to the present invention.

[0031] Figure 9 This is an exploded three-dimensional structural diagram of the headrest guide rod, headrest middle shell, and adjustment drive assembly of an electric up-and-down adjustable headrest mechanism for a car seat according to the present invention. Figure 1 .

[0032] Figure 10 This is an exploded three-dimensional structural diagram of the headrest guide rod, headrest middle shell, and adjustment drive assembly of an electric up-and-down adjustable headrest mechanism for a car seat according to the present invention. Figure 2 .

[0033] Figure 11 This is a three-dimensional structural diagram of the front cover of an electric up-and-down adjustable headrest mechanism for a car seat according to the present invention.

[0034] Figure 12 This is a three-dimensional structural diagram of the headrest shell of an electric up-and-down adjustable headrest mechanism for a car seat according to the present invention.

[0035] The diagram is labeled as follows: 1. Middle shell assembly; 11. Headrest middle shell; 111. Middle shell guide sleeve mounting groove; 112. Positioning holes on both sides of the middle shell; 113. Middle shell slide rail claw; 114. Middle shell center positioning hole; 115. Middle shell motor mounting groove; 1151. Middle shell lead screw through hole; 1152. Middle shell bolt fixing hole; 12. Headrest guide rod; 121. Headrest rod positioning groove; 122. Headrest rod center hole; 13. Headrest rod guide sleeve; 131. Middle shell guide sleeve fixing buckle; 132. Middle shell guide sleeve buckle fixing groove; 2. Outer shell assembly; 21. Headrest front cover; 211. Front cover mounting buckle; 212. Front cover positioning post; 2 13. Front cover guide inner rail; 214. Front cover bolt through hole; 22. Headrest rear cover; 221. Rear cover snap groove; 222. Rear cover positioning post; 223. Rear cover guide outer rail; 224. Rear cover center positioning pin; 225. Rear cover bolt fixing hole; 23. Outer shell bolt; 3. Adjustment drive assembly; 31. Screw motor; 311. Motor bolt fixing hole; 312. Motor fixing bolt; 32. Electric screw; 321. Screw bolt hole; 33. Headrest rod connecting rod; 331. Connecting rod steel wire; 332. Connecting rod plastic covering; 34. Screw welding nut; 4. Headrest foam; 5. Cover; 6. Backrest guide tube. Detailed Implementation

[0036] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0037] See Figures 1-7 and Figure 12 As shown, an electrically adjustable headrest mechanism for a car seat is mounted on a pair of backrest guides 6. It includes a middle shell assembly 1, an outer shell assembly 2, and an adjustment drive assembly 3. The middle shell assembly 1 includes a headrest middle shell 11 and headrest guide rods 12 symmetrically and vertically arranged on both sides. The headrest middle shell 11 is slidably engaged with the two headrest guide rods 12. The lower end of each headrest guide rod 12 is fixedly inserted into the upper end of a backrest guide 6. The outer shell assembly 2 is fixedly sleeved on the headrest middle shell 11. The adjustment drive assembly 3 includes a lead screw motor 31, an electric lead screw 32, and a headrest rod connecting rod 33. The lead screw motor 31 is mounted on the inner wall of the outer casing assembly 2. One end of the electric lead screw 32 is connected to the output shaft of the lead screw motor 31 for transmission, and the other end extends vertically upward. The headrest rod connecting rod 33 is horizontally fixed between the two headrest guide rods 12. The headrest rod connecting rod 33 has a lead screw bolt hole 321 through which the upper end of the electric lead screw 32 passes and is threadedly connected. When the lead screw motor 31 drives the electric lead screw 32 to rotate, a threaded sliding fit is formed between the electric lead screw 32 and the headrest rod connecting rod 33, so that the outer casing assembly 2 slides up and down synchronously with the headrest middle shell 11 along the headrest guide rod 12.

[0038] The bottom of the headrest middle shell 11 is provided with a middle shell motor mounting groove 115 for the lead screw motor 31 to be inserted. The middle shell motor mounting groove 115 is provided with a middle shell lead screw through hole 1151 for the lead screw 32 to pass through. The middle shell motor mounting groove 115 has a middle shell bolt fixing hole 1152, and the lead screw motor 31 has a motor bolt fixing hole 311. The middle shell bolt fixing hole 1152 and the motor bolt fixing hole 311 are fixed by a motor fixing bolt 312.

[0039] When the lead screw motor 31 is energized and starts working, the electric lead screw 32 begins to rotate under the drive of the lead screw motor 31. At this time, the electric lead screw 32 forms a threaded engagement with the lead screw bolt hole 321 on the headrest rod connecting rod 33 through its external thread. Since the headrest rod connecting rod 33 is laterally fixed between the two symmetrically arranged headrest guide rods 12, and the lower ends of the headrest guide rods 12 are respectively inserted into the backrest guide tube 6, the headrest rod connecting rod 33 itself cannot move axially along the electric lead screw 32.

[0040] During the rotation of the electric lead screw 32, since one end of it is connected to the output shaft of the lead screw motor 31 and the other end passes through the lead screw bolt hole 321 of the headrest rod connecting rod 33 and is threaded therewith, the rotational motion of the electric lead screw 32 will be converted into linear displacement relative to the headrest rod connecting rod 33.

[0041] When the electric lead screw 32 rotates forward, the threaded force between it and the headrest rod connecting rod 33 causes the electric lead screw 32 to move upward. Since the lead screw motor 31 is fixedly installed on the inner wall of the outer shell assembly 2, and the outer shell assembly 2 is fixedly sleeved on the headrest middle shell 11, and the headrest middle shell 11 is in sliding engagement with the two headrest guide rods 12, the upward movement of the electric lead screw 32 will drive the lead screw motor 31, the headrest middle shell 11, and the entire outer shell assembly 2 to move upward together, thereby realizing the upward adjustment action of the entire headrest mechanism.

[0042] Conversely, when the electric lead screw 32 reverses, the threaded force between it and the headrest rod connecting rod 33 will cause the electric lead screw 32 to move downward, which in turn will drive the lead screw motor 31, the headrest middle shell 11, and the outer shell assembly 2 to move downward, thereby realizing the downward adjustment of the headrest mechanism.

[0043] Throughout the entire driving process, the headrest guide rod 12 serves as a guide and support, ensuring the smoothness and stability of the headrest middle shell 11 and the outer shell assembly 2 during the lifting and lowering process. The lower end of the headrest guide rod 12 is inserted into the backrest guide tube 6, which not only achieves a stable structural installation but also provides a reliable guide path for the up and down sliding of the headrest middle shell 11.

[0044] See Figures 1-7 and Figure 11As shown, the outer shell assembly 2 includes a front cover 21 and a rear cover 22. The front cover 21 is provided with a front cover mounting buckle 211 around its periphery, and the rear cover 22 is provided with a rear cover buckle groove 221 around its periphery. The front cover mounting buckle 211 is connected to the rear cover buckle groove 221.

[0045] The outer shell assembly 2 is fitted with a headrest foam 4, and the headrest foam 4 is fitted with a face cover 5.

[0046] When assembling the headrest front cover 21 and the headrest back cover 22, first align the front cover mounting clips 211 on the periphery of the headrest front cover 21 with the rear cover clip grooves 221 on the periphery of the headrest back cover 22, and apply a certain amount of pressure to make them lock together. As the front cover mounting clips 211 gradually insert into the rear cover clip grooves 221, a stable connection structure is formed between the headrest front cover 21 and the headrest back cover 22, ensuring that the entire outer shell assembly 2 maintains its integrity during adjustment.

[0047] Subsequently, after assembling the outer shell component 2, the headrest foam 4 is fitted over it. The headrest foam 4 has a certain degree of elasticity and deformation capability, allowing it to fit tightly against the surface of the outer shell component 2, while providing the soft support and comfortable feel required when sitting. Next, the cover 5 is further fitted over the outside of the headrest foam 4. The cover 5, through its own elasticity, firmly covers the headrest foam 4, forming a complete outer surface. This not only enhances the overall aesthetics but also protects the internal structure and improves durability.

[0048] See Figures 3-10 and Figure 12 As shown, the headrest middle shell 11 has middle shell guide sleeve mounting grooves 111 on both sides. Each middle shell guide sleeve mounting groove 111 has a headrest rod guide sleeve 13 in a snap-fit ​​manner. The two headrest guide rods 12 are respectively inserted into the two headrest rod guide sleeves 13.

[0049] Each of the headrest rod guide sleeves 13 is provided with a middle shell guide sleeve fixing buckle 131, and each middle shell guide sleeve mounting groove 111 has a middle shell guide sleeve buckle fixing groove 132 for the corresponding middle shell guide sleeve fixing buckle 131 to engage.

[0050] When the middle shell guide sleeve mounting grooves 111 on both sides of the headrest middle shell 11 are assembled with the headrest rod guide sleeve 13, the headrest rod guide sleeve 13 is first aligned with the opening position of the middle shell guide sleeve mounting groove 111, and a certain pressure is applied along the groove direction so that the headrest rod guide sleeve 13 is gradually embedded into the middle shell guide sleeve mounting groove 111.

[0051] As the headrest rod guide sleeve 13 is inserted, the middle shell guide sleeve fixing buckle 131 provided thereon is squeezed and undergoes elastic deformation. When the headrest rod guide sleeve 13 reaches the predetermined installation position, the middle shell guide sleeve fixing buckle 131 returns to its original shape under its own elastic force and forms a snap-fit ​​with the middle shell guide sleeve buckle fixing groove 132, thereby realizing the firm fixation of the headrest rod guide sleeve 13 in the middle shell guide sleeve mounting groove 111.

[0052] After the two headrest rod guide sleeves 13 are snapped and fixed, the two headrest guide rods 12 are vertically inserted into the corresponding headrest rod guide sleeves 13, so that the headrest guide rods 12 and the headrest rod guide sleeves 13 form a sliding fit structure, providing guidance and support for the subsequent overall up and down adjustment of the head.

[0053] See Figures 3-7 As shown, the headrest back cover 22 has back cover positioning posts 222 on both sides, and the headrest middle shell 11 has positioning holes 112 on both sides of the middle shell for the two back cover positioning posts 222 to pass through respectively.

[0054] When the headrest back cover 22 is assembled with the headrest middle shell 11, the back cover positioning pins 222 provided on both sides of the headrest back cover 22 are first aligned with the corresponding middle shell positioning holes 112 on both sides of the middle shell 11, and pressure is applied along the axial direction to gradually insert the back cover positioning pins 222 into the middle shell positioning holes 112 on both sides of the middle shell.

[0055] As the rear cover positioning post 222 is inserted deeper, its outer wall gradually fits against the inner wall of the positioning holes 112 on both sides of the middle shell, forming a tight fit. This achieves precise positioning and stable connection between the headrest rear cover 22 and the headrest middle shell 11 in the lateral direction. This ensures structural alignment and stable connection between the outer shell assembly 2 and the middle shell mechanism assembly 1, providing a reliable foundation for subsequent overall assembly and the realization of electric adjustment functions.

[0056] See Figures 3-7 and Figure 11 As shown, the front cover 21 of the headrest is provided with front cover positioning posts 212 on both sides, which correspond to the rear cover positioning posts 222. The front cover positioning posts 212 and the rear cover positioning posts 222 are inserted into each other.

[0057] When assembling the front cover 21 and the back cover 22 of the headrest, first align the front cover positioning posts 212 on both sides of the front cover 21 with the corresponding back cover positioning posts 222 on the back cover 22, and slowly apply force along the axial direction to make the front cover positioning posts 212 fit into the outside of the back cover positioning posts 222.

[0058] As the front cover positioning post 212 is gradually inserted into the rear cover positioning post 222, a tight insertion fit is formed between the two, thereby achieving precise positioning and stable connection of the headrest front cover 21 and the headrest rear cover 22 in the vertical direction.

[0059] See Figures 3-10 As shown, the lower end of the headrest guide rod 12 is provided with a headrest rod positioning groove 121 that is fixedly connected to the backrest guide tube 6. The headrest guide rod 12 is a hollow structure for connecting the power supply line and the backrest wire harness. The upper end of the headrest guide rod 12 has a headrest rod center hole 122 through which the power supply line passes.

[0060] The installed headrest guide rod 12 is inserted into the backrest guide tube 6 and fixed through the headrest rod positioning groove 121.

[0061] When the headrest guide rod 12 is inserted into the backrest guide tube 6 for installation, first align the headrest guide rod 12 vertically with the upper opening of the backrest guide tube 6, and apply a downward force to gradually insert the headrest guide rod 12 into the tube. As the headrest guide rod 12 moves downward, the headrest rod positioning groove 121 at its lower end contacts the outer edge of the backrest guide tube 6 and forms a snap-fit ​​engagement, thereby achieving axial fixation between the headrest guide rod 12 and the backrest guide tube 6, preventing loosening or displacement during subsequent adjustments.

[0062] Meanwhile, the headrest guide rod 12 has a hollow structure, through which the motor wires pass and exit through the central hole 122 at the upper end of the headrest guide rod 12, completing the electrical connection with the backrest wiring harness. This not only ensures the stable fixation of the headrest guide rod 12, but also ensures the safe layout and stable transmission of the motor wiring in the electric adjustment system, providing the necessary electrical guarantee for the normal operation of the electric adjustment function.

[0063] See Figures 3-7 As shown, the headrest back cover 22 is provided with a plurality of back cover center positioning pins 224, and the headrest middle shell 11 has a middle shell center positioning hole 114 through which each back cover center positioning pin 224 passes, and the back cover center positioning pin 224 is inserted into the middle shell center positioning hole 114.

[0064] When the headrest back cover 22 is assembled with the headrest middle shell 11, the multiple back cover middle positioning pins 224 on the headrest back cover 22 are first aligned with the corresponding middle shell middle positioning holes 114 on the headrest middle shell 11, and pressure is applied axially to gradually insert the back cover middle positioning pins 224 into the middle shell middle positioning holes 114.

[0065] As the center positioning pin 224 of the back cover is inserted, its outer wall fits tightly against the inner wall of the center positioning hole 114 of the middle shell, forming a stable insertion fit, thereby achieving precise positioning and reliable connection between the headrest back cover 22 and the headrest middle shell 11 in the longitudinal direction.

[0066] See Figures 3-7 As shown, the headrest back cover 22 is provided with back cover guide rails 223 on both sides, and the headrest middle shell 11 is provided with middle shell slide rail claws 113 for the two back cover guide rails 223 to pass through respectively.

[0067] When the headrest back cover 22 is assembled with the headrest middle shell 11, first align the back cover guide rails 223 on both sides of the headrest back cover 22 with the corresponding middle shell slide rail claws 113 on the headrest middle shell 11, and apply pressure in the insertion direction to make the back cover guide rails 223 gradually pass through the middle shell slide rail claws 113.

[0068] As the outer guide rail 223 of the back cover enters the inner cavity of the slide rail claw 113 of the middle shell, a sliding guide engagement is formed between the two, ensuring that the headrest back cover 22 can move smoothly along the predetermined trajectory during the assembly process and maintain a stable connection with the headrest middle shell 11 after assembly.

[0069] See Figures 3-7 and Figure 11 As shown, the front cover 21 of the headrest is provided with front cover guide inner rails 213 on both sides. The front cover guide inner rails 213 and the rear cover guide outer rails 223 are slidably engaged. The front cover 21 of the headrest and the rear cover 22 of the headrest are fixedly connected by outer shell bolts 23.

[0070] The front cover 21 and the back cover 22 of the headrest are each provided with a housing bolt 23. The front cover 21 has a front cover bolt through hole 214, and the back cover 22 has a back cover bolt fixing hole 225. The four housing bolts 23 pass through the front cover bolt through hole 214 and are fixed in the back cover bolt fixing hole 225, thereby fixing the front cover 21 and the back cover 22 of the headrest.

[0071] When assembling the front cover 21 and the back cover 22 of the headrest, first align the inner guide rails 213 on both sides of the front cover 21 with the outer guide rails 223 on the back cover 22, and apply pressure in the insertion direction so that the inner guide rails 213 slide smoothly into the inner guide rails 223, forming a sliding guide fit, ensuring that the front cover 21 and the back cover 22 can be accurately aligned and maintain a stable connection during the closing process.

[0072] Subsequently, after completing the guide assembly, the four outer shell bolts 23 are passed through the front cover bolt through hole 214 on the front cover of the headrest 21 in sequence, and further tightened and fixed in the corresponding rear cover bolt fixing hole 225 of the rear cover of the headrest 22, thereby realizing a rigid connection between the front cover of the headrest 21 and the rear cover of the headrest 22.

[0073] See Figures 3-10 As shown, the headrest rod connecting rod 33 has connecting rod wires 331 at both ends that are welded and fixed to the upper end of the corresponding headrest guide rod 12. The upper end of the electric screw rod 32 is welded and fixed with a screw welding nut 34 to prevent it from detaching from the headrest rod connecting rod 33.

[0074] The headrest rod connecting rod 33 is provided with a connecting rod plastic cover 332. The connecting rod plastic cover 332 reduces friction, lowers noise, and improves sliding smoothness. At the same time, it can also effectively prevent wear between metal parts, improve wear resistance and service life.

[0075] When the electric lead screw 32 starts to rotate under the drive of the lead screw motor 31, the electric lead screw 32 forms a threaded transmission with the lead screw bolt hole 321 on the headrest rod connecting rod 33, and moves linearly relative to the headrest rod connecting rod 33. The connecting rod wires 331 at both ends of the headrest rod connecting rod 33 are respectively welded to the upper end of the corresponding headrest guide rod 12 to form a strong structural connection, so that the headrest rod connecting rod 33 can stably support and guide the entire headrest middle shell 11 and outer shell assembly 2 to slide up and down along the headrest guide rod 12.

[0076] During the downward movement, the upper end of the electric lead screw 32 is fixed by welding the lead screw welding nut 34 to prevent the electric lead screw 32 from disengaging during rotation, thus ensuring the stability and reliability of the transmission.

[0077] This invention achieves electric adjustment of the headrest height through the threaded transmission between the electric lead screw 32 and the headrest rod connecting rod 33. It has a compact structure and runs smoothly. The upward or downward movement is achieved through forward and reverse control, which improves the convenience of adjustment operation and user experience.

[0078] The headrest guide rod 12 provides stable guidance for the overall structure, ensuring a smooth and reliable adjustment process. The front headrest cover 21 and the rear headrest cover 22 are precisely assembled through snaps, positioning posts, and guide rails, and reinforced by the outer shell bolts 23, enhancing the overall structural strength and further improving transmission stability, safety, and long-term durability.

[0079] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. An electrically adjustable headrest mechanism for a car seat, disposed on a pair of backrest guide tubes; Its features are, Including the middle shell assembly, the outer shell assembly, and the adjustment drive assembly; The middle shell assembly includes a headrest middle shell and headrest guide rods symmetrically and vertically arranged on both sides thereon. The headrest middle shell is slidably engaged with the two headrest guide rods, and the lower end of each headrest guide rod is fixedly inserted into the upper end of a backrest guide tube. The outer shell assembly is fixedly fitted onto the headrest's inner shell; The adjustment drive assembly includes a lead screw motor and an electric lead screw, as well as a headrest rod connecting rod; The lead screw motor is mounted on the inner wall of the housing assembly; One end of the electric lead screw is connected to the output shaft of the lead screw motor, and the other end extends vertically upward. The headrest rod connecting rod is horizontally fixed between the two headrest guide rods. The headrest rod connecting rod has a screw bolt hole through which the upper end of the electric screw rod passes and is threadedly connected to it. When the lead screw motor drives the electric lead screw to rotate, a threaded sliding fit is formed between the electric lead screw and the headrest rod connecting rod, so that the outer shell assembly slides up and down synchronously along the headrest guide rod along with the middle shell of the headrest.

2. The electric height-adjustable headrest mechanism for a car seat according to claim 1, characterized in that, The outer shell assembly includes a front cover and a back cover of the headrest. The front cover is provided with a front cover mounting buckle on its periphery, and the back cover is provided with a back cover buckle groove on its periphery. The front cover mounting buckle is connected to the back cover buckle groove.

3. The electric height-adjustable headrest mechanism for a car seat according to claim 1, characterized in that, The headrest middle shell has middle shell guide sleeve mounting grooves on both sides. Each middle shell guide sleeve mounting groove has a headrest rod guide sleeve in a snap-fit ​​manner. The two headrest guide rods are inserted into the two headrest rod guide sleeves respectively.

4. The electric height-adjustable headrest mechanism for a car seat according to claim 2, characterized in that, The headrest back cover has positioning posts on both sides, and the headrest middle shell has positioning holes on both sides of the middle shell for the two positioning posts to pass through.

5. The electric height-adjustable headrest mechanism for a car seat according to claim 4, characterized in that, The front cover of the headrest has front cover positioning posts on both sides, which are corresponding to the rear cover positioning posts. The front cover positioning posts and the rear cover positioning posts are inserted into each other.

6. The electric height-adjustable headrest mechanism for a car seat according to claim 1, characterized in that, The lower end of the headrest guide rod is provided with a headrest rod positioning groove that is fixedly connected to the backrest guide tube. The headrest guide rod is a hollow structure for connecting the power supply line and the backrest wire harness. The upper end of the headrest guide rod has a center hole through which the power supply line passes.

7. The electric height-adjustable headrest mechanism for a car seat according to claim 4, characterized in that, The headrest back cover is provided with multiple back cover center positioning pins, and the headrest middle shell has a middle shell positioning hole for each back cover center positioning pin to pass through. The back cover center positioning pin is inserted into the middle shell positioning hole.

8. The electric height-adjustable headrest mechanism for a car seat according to claim 7, characterized in that, The headrest back cover has guide rails on both sides, and the headrest middle shell has sliding rail claws for the two guide rails to pass through.

9. A car seat electrically adjustable headrest mechanism according to claim 8, characterized in that, The front cover of the headrest is provided with inner guide rails on both sides. The inner guide rails of the front cover slide with the outer guide rails of the rear cover. The front cover and the rear cover of the headrest are fixedly connected by outer shell bolts.

10. The electric height-adjustable headrest mechanism for a car seat according to claim 1, characterized in that, Both ends of the headrest rod connecting rod are respectively provided with connecting rod steel wires that are welded and fixed to the upper end of the corresponding headrest guide rod. The upper end of the electric screw is welded and fixed with a screw welding nut to prevent it from detaching from the headrest rod connecting rod.

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