Electric headrest adjustment mechanism

Abstract

The present invention relates to an electric headrest adjustment mechanism, which includes a drive assembly fixedly connected to a backrest, a bracket assembly fixedly connected to a headrest, and a screw having a longitudinal axis, the screw being connected between the drive assembly and the bracket assembly so as to drive the bracket assembly to move along the longitudinal axis through the drive assembly, the bracket assembly including a crossbeam fixedly connected to the headrest, the bracket assembly also including a first nut installed in the crossbeam through a damping structure, the screw and the first nut cooperate to achieve linear movement of the first nut along the longitudinal axis. According to the electric headrest adjustment mechanism described in the present invention, the screw is floatingly installed with the aid of the damping structure, which can not only reduce shock and absorb energy, but also avoid the situation in which the screw is stuck in the prior art. Moreover, according to the electric headrest adjustment mechanism described in the present invention, the number of parts is small and the structure is simple.

Description

Technical Field

[0001] The invention relates to a car seat, and more particularly to an electric headrest adjustment mechanism. Background Art

[0002] It is known that automobile seats are equipped with electrically adjustable headrests. Usually, a motor for driving a screw rod to rotate is fixed to the seat back, and a nut fixedly connected to the headrest is sleeved on the screw rod to achieve the up and down adjustment of the headrest by driving the nut on the screw rod to move up and down by the motor. Practice shows that the existing corresponding adjustment mechanism is prone to the phenomenon of screw rod jamming. Summary of the invention

[0003] In order to solve the problem of screw rod jamming in the adjustment mechanism in the prior art, the present invention provides an electric headrest adjustment mechanism.

[0004] The electric headrest adjustment mechanism of the present invention includes a drive assembly fixedly connected to the backrest, a bracket assembly fixedly connected to the headrest, and a screw having a longitudinal axis, the screw being connected between the drive assembly and the bracket assembly so as to drive the bracket assembly to move along the longitudinal axis through the drive assembly, the bracket assembly including a crossbeam fixedly connected to the headrest, the bracket assembly also including a first nut installed in the crossbeam through a damping structure, the screw and the first nut cooperate to realize the linear movement of the first nut along the longitudinal axis. It should be understood that the electric headrest adjustment mechanism of the present invention can absorb the installation error of the system through the floating connection between the damping structure and the crossbeam, and can realize the vibration isolation and noise reduction functions through the damping structure.

[0005] Preferably, the crossbeam has a frame-shaped space for accommodating the first nut and the damping structure, and the damping structure includes two damping elements respectively arranged at opposite ends of the first nut, each damping element is a semi-enclosed structure, and the inner side of the damping element is conformally matched with the first nut. It should be understood that each damping element contains and fixes the first nut, which can prevent the damping structure from escaping from the first nut and ensure that the first nut and the damping structure float together. In a preferred embodiment, a sink groove is formed on the end face of each damping element facing the first nut, and the opposite ends of the first nut are sunk into the sink groove for installation. It should be understood that the frame-shaped space can be a semi-enclosed space area such as an elliptical, circular, rectangular, semi-U-shaped, etc.

[0006] Preferably, the end of the screw rod extends out from the cross beam and is fixedly connected with a second nut for limiting the low position of the headrest. In a preferred embodiment, the second nut is fixed to the screw rod by a fixed connection method such as pressure riveting.

[0007] Preferably, the drive assembly includes a housing, a motor, a worm and a gear, wherein the housing is a hollow structure fixedly connected to the backrest, the motor, the worm and the gear are all accommodated in the housing, the motor has a motor body and a rotatable drive shaft extending laterally from the motor body along a transverse axis perpendicular to the longitudinal axis, the worm is fixedly connected to the drive shaft, the gear is meshed with the worm to form a meshing pair, and the screw extends into the housing and is fixedly connected to the gear.

[0008] Preferably, the housing is composed of a box body and a box cover that are fixedly connected, and the motor body is installed therebetween by form fitting. It should be understood that placing the motor in the enclosed space of the box body and the box cover can improve the noise performance of the electric headrest adjustment mechanism of the present invention.

[0009] Preferably, the inner walls of the box body and the box cover respectively have thin rib plates that are slightly interference fit with the outer dimensions of the motor body.

[0010] Preferably, one of the box body and the box cover has a guide groove and a buckle hole, and the other of the box body and the box cover has a protruding buckle to be buckled into the buckle hole along the guide groove.

[0011] Preferably, one of the box body and the box cover having the guide groove and the buckle hole is formed into a double wall, and the buckle on the other of the box body and the box cover extends into the double wall for buckling.

[0012] Preferably, the housing and / or the housing cover has a U-shaped collar rib for supporting a collar at an end of the motor body, and a contoured support rib for supporting the motor shaft.

[0013] Preferably, the inner wall of the box is provided with a slot, the flat gasket is perpendicular to the motor shaft and is fixed in the slot on both sides to be mounted in the slot, and the free end of the motor shaft contacts the flat gasket to support the motor shaft from the side. It should be understood that the side support structure can reduce the vibration and noise when the motor is running, and can reduce the abnormal sound when the motor is reversing.

[0014] According to the electric headrest adjustment mechanism of the present invention, the screw rod is floatingly installed by means of the damping structure, which can not only absorb shock and energy, but also avoid the screw rod stuck in the prior art. In addition, the electric headrest adjustment mechanism of the present invention has a small number of parts and a simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a structural schematic diagram of a car seat including an electric headrest adjustment mechanism according to a preferred embodiment of the present invention, which shows a process in which a headrest moves from a high position to a middle position and then to a low position by means of the electric headrest adjustment mechanism;

[0016] Figure 2 yes Figure 1 Schematic diagram of the overall structure of the electric headrest adjustment mechanism;

[0017] Figure 3 yes Figure 2 Exploded diagram of

[0018] Figure 4A yes Figure 3 A schematic diagram of the structure of a motor;

[0019] Figure 4B yes Figure 3 The schematic diagram of the structure of the motor and the box;

[0020] Figure 4C yes Figure 3 A schematic diagram of the structure of the motor and the box cover;

[0021] Figure 5A Shows Figure 2 Shell;

[0022] Figure 5B Shows a housing of an electric headrest adjustment mechanism according to another preferred embodiment of the present invention;

[0023] Figure 5C Shows a housing of an electric headrest adjustment mechanism according to yet another preferred embodiment of the present invention;

[0024] Figure 6 yes Figure 2 A top view of a housing with a motor installed;

[0025] Figure 7 yes Figure 2 A partial enlarged view of a housing with a motor installed;

[0026] Figure 8 yes Figure 2 Schematic diagram of the box cover with the motor installed. DETAILED DESCRIPTION

[0027] The preferred embodiments of the present invention are given below in conjunction with the accompanying drawings and described in detail.

[0028] like Figure 1 As shown, an electric headrest adjustment mechanism according to a preferred embodiment of the present invention is installed on the car seat, and the headrest is moved from a high position to a middle position and then to a low position in sequence by means of the electric headrest adjustment mechanism. The electric headrest adjustment mechanism includes a drive assembly 1, a bracket assembly 2 and a screw 3, wherein the drive assembly 1 is fixedly connected to the backrest frame, the bracket assembly 2 is fixedly connected to the headrest guide rod, and the screw 3 with a longitudinal axis V is connected between the drive assembly 1 and the bracket assembly 2 to drive the bracket assembly 2 to move along the longitudinal axis V through the drive assembly 1, thereby driving the adjustment of the headrest.

[0029] like Figure 2-Figure 3As shown, the drive assembly 1 includes a housing 11, a motor 12, a worm 13 and a gear 14, wherein the housing 11 is fixedly connected (for example, installed by bolts) to the backrest frame (see Figure 1 ), the motor 12, the worm 13 and the gear 14 are all accommodated in the housing 11. The motor 12 has a motor body 121 and a rotatable drive shaft 122 extending laterally from the center position of the motor body 121 along the transverse axis H perpendicular to the longitudinal axis V. The worm 13 is fixedly connected to the drive shaft 122 so as to be rotatable around the transverse axis H synchronously. The gear 14 meshes with the worm 13 to form a meshing pair so as to drive the gear 14 to rotate around the longitudinal axis V through the motor 12. The proximal end of the screw rod 3 extends into the housing 11 and is fixedly connected to the gear 14, thereby finally realizing the rotation of the screw rod 3 around the longitudinal axis V. In this embodiment, the proximal end of the screw rod 3 is molded in the gear to achieve synchronous movement. It should be understood that the proximal end of the screw rod 3 can also be fixedly connected to the gear 14 through a spline / partial length tooth, and can also be pressed into the gear 14 by interference fit. In addition, in order to reduce the friction coefficient and improve system efficiency, the drive shaft 122 rotating around the horizontal axis H is supported by a first annular flat gasket in the housing 11, and the gear 14 rotating around the longitudinal axis V is supported by a second annular flat gasket in the housing 11.

[0030] In the prior art, the motor is fixed to the housing by self-tapping screws to achieve a semi-enclosed fixation. This assembly relationship not only makes the manufacturing process of the housing complicated, but also is usually only applicable to motors with larger sizes due to the space requirements for mounting screws. Figure 2-Figure 3 As shown, the housing 11 of the present invention is composed of a box body 111 and a box cover 112 that are fixedly connected, and the motor body 121 is installed therebetween by shape matching, which not only avoids the use of self-tapping screws, optimizes the manufacturing process, has a simple structure and a beautiful appearance, but also can be used to assemble a motor with a smaller size, so that the overall package of the electric headrest adjustment mechanism has a smaller size, meeting the diverse requirements of the skeleton connection. Specifically, the inner walls of the box body 111 and the box cover 112 can each have a thin rib plate, which has a slight interference fit with the outer dimensions of the motor body 121 to prevent the motor body 121 from rotating and moving. Figure 4A-4C As shown, the motor body 121 has a groove 1211, the box body 111 has a convex rib 1111, and the box cover 112 has a convex rib 1121. The motor is positioned axially by the clearance between the convex ribs 1111, 1121 and the groove 1211 to prevent the motor body 121 from axially moving during operation. In addition, the box body 111 also has a convex rib 1112, and the motor is positioned circumferentially by the clearance between the convex rib 1112 of the box and the circumferential shape of the motor body 121 to prevent the motor body 121 from circumferentially moving during operation. In addition, two sets of windows are respectively opened on the box body 111 and the box cover 112 to increase the heat dissipation performance of the motor during operation.

[0031] In this embodiment, the box body 111 and the box cover 112 have a group of mounting holes, which are used to fix the electric headrest adjustment mechanism of the present invention on the backrest frame (the mounting holes of the box body 111 and the box cover 112 can be combined and adjusted according to the installation method, and can be connected by self-tapping screws or bolts, which is convenient for installation and adjustment); the box body 111 and the box cover 112 also have a group of positioning shaft holes for positioning between the box body 111 and the box cover 112; the box body 111 and the box cover 112 also have six groups of buckle structures for connecting the box body 111 and the box cover 112. Figure 3 and Figure 5A As shown, the side wall of the box body 111 is provided with a guide groove 111a and a buckle hole 111b, and the box cover 112 has a protruding buckle 112a to be snapped into the buckle hole 111b along the guide groove 111a. In this embodiment, the inner side of the guide groove 111a is thinned by removing material, and the outer side of the buckle 112a is thinned by removing material. This special cross-sectional structure not only makes the mold structure of the shell 11 simpler and easier to manufacture, but also facilitates demolding during manufacturing, while ensuring that the buckle 112a has sufficient flexibility and does not cause stress concentration at the root of the buckle. It should be understood that the box body and the box cover can also have different buckle forms, for example, the side wall of the box cover is provided with a guide groove and a buckle hole, and the box body has a protruding buckle to be snapped into the buckle hole along the guide groove; the box body and the box cover can also be connected in other ways, such as Figure 5B As shown, the box body 111' and the box cover 112' are connected by screws. Figure 5C As shown, the box body 111 ″ and the box cover 112 ″ are bonded together by glue.

[0032] like Figure 6 As shown, the side wall of the box body 111 is formed as a double wall 111c in the buckle area, so that the buckle 112a (see Figure 3 ) extends into the double wall 111c in the box body 111. In this way, once the buckle 112a breaks or is damaged, its fragments are contained in the double wall 111c to prevent it from entering the meshing pair of the worm-gear and producing abnormal noise. In addition, the double wall 111c can also take into account the function of an oil storage wall. In other words, this double wall 111c structure is a protective structure, which is used to ensure that even if the buckle 112a breaks accidentally during assembly or operation, it will not enter the gear meshing area, causing the electric headrest adjustment mechanism of the present invention to produce sharp abnormal noise or even cause serious installation accidents. The structure plays a functional isolation role by physically isolating the fixing features of the box body 111 and the box cover 112 and the transmission function of the gear box, ensuring the foolproof operation of the electric headrest adjustment mechanism of the present invention.

[0033] like Figure 7As shown, the middle part of the box body 111 has a U-shaped collar rib 111d, which is used to support the collar 121a at the end of the motor body 121. Specifically, the end of the box body 111 has a contoured support rib 111e, which is used to support the motor shaft 122 and cooperates with the box cover 112 to prevent radial movement. The inner wall of the box body 111 is provided with a slot 111f, and the flat gasket 15 is installed in the slot 111f perpendicular to the motor shaft 122. The free end of the motor shaft 122 contacts the center of the gasket 15 to support the motor shaft 122 from the side, eliminating noise while eliminating the axial gap, and improving the sound quality.

[0034] like Figure 8 As shown, the middle of the box cover 112 has a U-shaped collar rib 112b for supporting the collar 121a at the end of the motor body 121. The end of the box cover 112 has a contoured support rib 112c for supporting the motor shaft 122 and cooperating with the box body 111 to prevent radial movement. Figure 3 The box cover 112 also has a pre-positioning hole structure 112d. Correspondingly, the backrest frame has a pre-positioning structure. Before fixing the shell 11 to the backrest frame, the pre-positioning structure on the backrest frame is inserted into the pre-positioning hole structure 112d of the box cover 112 to achieve the pre-positioning of the shell 11. It should be understood that the box body 111 also has a pre-positioning hole feature, which can be installed in reverse.

[0035] Back to Figure 2 and Figure 3 The bracket assembly 2 includes a crossbeam 21, a first nut 22 and a damping structure 23, wherein both ends of the crossbeam 21 are fixedly connected to the headrest guide rod (for example, through an opening hole 21a), and the first nut 22 is installed in the crossbeam 21 through the damping structure 23. In this embodiment, the crossbeam 21 has a frame-shaped space 21b for accommodating the first nut 22 and the damping structure 23, and the damping structure 23 includes two damping elements (for example, rubber pads) respectively arranged at the opposite ends of the first nut 22, and a sinking groove 23a is formed on the end surface of each damping element facing the first nut 22, so that the opposite ends of the first nut 22 sink into the sinking groove 23a. The distal end of the screw rod 3 passes through the crossbeam 21 and the damping structure 23 and is threadedly engaged with the first nut 22, and then extends out from the crossbeam 21. The farthest end of the extension is fixedly connected to the second nut 31, so that the low position of the headrest is limited by means of the second nut 31, as shown in FIG. Figure 1 In this embodiment, the outer ring of the second nut 31 is fixed to the distal end of the screw rod 3 by deforming the inner hole by riveting. In this way, with the help of the damping structure 23, the screw rod 3 is installed in a floating manner, which can not only reduce shock and absorb energy, but also avoid the situation of the screw rod being stuck in the prior art.

[0036] The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. The above embodiment of the present invention can also be modified in various ways. That is, all simple, equivalent changes and modifications made according to the claims and the description of the present invention fall within the scope of protection of the claims of the present invention. The contents not described in detail in the present invention are all conventional technical contents.

Claims

1. An electric headrest adjustment mechanism, comprising a drive assembly fixedly connected to a backrest, a bracket assembly fixedly connected to a headrest, and a screw having a longitudinal axis, the screw being connected between the drive assembly and the bracket assembly so as to drive the bracket assembly to move along the longitudinal axis through the drive assembly, the bracket assembly comprising a crossbeam fixedly connected to the headrest, It is characterized in that The drive assembly includes a housing, a motor, a worm and a gear, wherein the housing is a hollow structure fixedly connected to the backrest, the motor, the worm and the gear are all accommodated in the housing, the motor has a motor body and a rotatable driving shaft extending laterally from the motor body along a transverse axis perpendicular to the longitudinal axis, the worm is fixedly connected to the driving shaft, the gear and the worm are meshed to form a meshing pair, the proximal end of the screw rod extends into the housing and is fixedly connected to the gear, the housing is composed of a fixedly connected box body and a box cover, the motor body is installed therebetween by shape matching, the motor body has a groove, the box body and the box cover respectively have a first rib, the first rib is clearance-matched with the groove to prevent the motor body from axially moving during operation, the box body also has a second rib, the second rib is clearance-matched with the circumferential shape of the motor body to prevent the motor body from circumferentially moving during operation, the box body and / or the box cover have a U-shaped collar rib plate for supporting the collar at the end of the motor body, and a contoured support rib for supporting the motor shaft. The plate, the contoured support rib plate cooperates with the box cover and / or the box body to prevent radial movement, the inner wall of the box body is provided with a slot, the flat gasket is perpendicular to the motor shaft and is installed in the slot through both sides, the free end of the motor shaft contacts the center of the flat gasket to support the motor shaft from the side, eliminating the axial clearance and the noise at the same time, the bracket assembly also includes a first nut installed in the crossbeam through the damping structure, the screw rod and the first nut cooperate to realize the linear movement of the first nut along the longitudinal axis, the crossbeam has a frame-shaped space for accommodating the first nut and the damping structure, the damping structure includes two damping elements respectively arranged at the opposite ends of the first nut, each damping element is a semi-closed structure and a recessed groove is formed on its end face facing the first nut, the opposite ends of the first nut are sunk into the recessed groove for contoured cooperation to realize the floating installation of the screw rod, the distal end of the screw rod passes through the crossbeam and the damping structure and cooperates with the first nut thread and then extends out of the crossbeam, and the farthest end of the extension is fixedly connected with the second nut.

2. The electric headrest adjustment mechanism according to claim 1, It is characterized in that One of the box body and the box cover is provided with a guide groove and a buckle hole, and the other of the box body and the box cover is provided with a protruding buckle to be buckled in the buckle hole along the guide groove.

3. The electric headrest adjustment mechanism according to claim 2, It is characterized in that One of the box body and the box cover having the guide groove and the buckle hole is formed into a double-layer wall, and the buckle on the other of the box body and the box cover extends into the double-layer wall for buckling.

Images