EP-4375138-B1 - SEAT HEADREST AND VEHICLE SEAT

EP4375138B1EP 4375138 B1EP4375138 B1EP 4375138B1EP-4375138-B1

Inventors

SHEN, Yineng
ZHANG, Xinze
Zhang, Xiaocui
Zhang, Aiping
GAN, Kunjia

Dates

Publication Date: 20260506
Application Date: 20220308

Claims (14)

A seat headrest device, preferably for a zero-gravity vehicle seat, comprising a fixed base (30), which is configured to be mounted to a seat backrest, a headrest (20) and a headrest electric motor (40), wherein the seat headrest device further comprises a composite motion mechanism comprising a screw-nut mechanism (70) and a pinion-rack mechanism (10), wherein the screw-nut mechanism comprises a lead screw (71), which is drivable by the headrest electric motor to rotate, and a nut (72), which is movable along the lead screw, and wherein the pinion-rack mechanism comprises a pinion (12) coupled with the nut and a movable rack coupled with the headrest (13) as well as a fixed rack (11), wherein the fixed rack and the movable rack are opposite to each other with respect to the pinion and engage with the pinion respectively, characterized in that , the headrest electric motor can drive the headrest to move up and down relative to the fixed base through the composite motion mechanism, wherein the pinion and the nut are coupled by a slider (60), wherein the nut is fixedly mounted to the slider, and the pinion is rotatably mounted to the slider.
The seat headrest device as recited in claim 1, characterized in that , the seat headrest device further comprises a headrest support rod, which is configured to mount the fixed base to the seat backrest.
The seat headrest device as recited in claim 1 or 2, characterized in that , the pinion is rotatably mounted to the slider through a countersunk screw (12a) and a bushing (12b) sleeved on the countersunk screw, wherein the countersunk screw is fixed to the slider.
The seat headrest device as recited in any one of claims 1 to 3, characterized in that , the headrest is fixed to the movable rack.
The seat headrest device as recited in any one of claims 1 to 4, characterized in that , the headrest has a chamber, and the seat headrest device comprises an internal base (50), wherein the internal base is arranged in the chamber of the headrest and penetrates through the headrest and is fixed to the fixed base.
The seat headrest device as recited in claim 5, characterized in that , the headrest electric motor, the screw-nut mechanism and the pinion-rack mechanism are arranged in the chamber of the headrest, wherein the headrest electric motor is fixedly mounted to the internal base; and/or the headrest is movably supported on the internal base by the pinion-rack mechanism.
The seat headrest device as recited in claim 5 or 6, characterized in that , the slider is arranged in the chamber of the headrest, the slider is drivable by the headrest electric motor to move up and down relative to the internal base through the screw-nut mechanism, wherein the lead screw of the screw-nut mechanism is connected with an output shaft of the headrest electric motor, wherein the fixed rack is fixed to the internal base, and the movable rack is fixed to the headrest.
The seat headrest device as recited in claim 7, characterized in that , the slider has a nut receptacle (61) that receives the nut, and the internal base has a guide groove (51) for the nut receptacle, wherein the nut receptacle is guidable in the guide groove for the nut receptacle; and/or the slider and the internal base are coupled in a slidable manner through a first sliding rail structure (A), and the headrest and the slider are coupled in a slidable manner through a second sliding rail structure (B).
The seat headrest device as recited in any one of claims 1 to 8, characterized in that , the headrest comprises a headrest front cover and a headrest rear cover.
The seat headrest device as recited in claim 9, characterized in that , the headrest front cover and the headrest rear cover are connected through a fastener.
The seat headrest device as recited in any one of claims 1 to 10, characterized in that , the seat headrest device comprises one set of screw-nut mechanism and two sets of pinion-rack mechanisms arranged side by side, wherein the one set of screw-nut mechanism is arranged between the two sets of pinion-rack mechanisms.
The seat headrest device as recited in any one of claims 7 to 11, characterized in that , the seat headrest device comprises two sets of pinion-rack mechanisms arranged side by side, the respective fixed racks of the two sets of pinion-rack mechanisms and the slider form a U-shaped part, and the respective pinions of the two sets of pinion-rack mechanisms are arranged between the two fixed racks and engage with the associated fixed racks.
The seat headrest device as recited in claim 11 or 12, characterized in that , the headrest comprises a headrest front cover and a headrest rear cover, wherein the headrest front cover is provided with the respective movable racks of the two sets of pinion-rack mechanisms.
A vehicle seat comprising the seat headrest device as recited in any one of claims 1 to 13.

Description

Technical Field The present invention relates to the technical field of vehicles, and in particular, to a seat headrest and a vehicle seat, wherein the seat headrest may be in particular configured for a zero-gravity vehicle seat. Background of Invention With the development of the automobile industry and the change of the automobile market, for improvement of the user experience, more, higher and more comfort requirements are provided for automobile seats. In combination with the trend of zero-gravity seats, not only a large-stroke adjustment of a headrest but also a delicate shape and appearance of a seat are expected. The Chinese utility model CN 208344015U discloses an electric headrest, comprising: a hollow headrest body; a support rod, which is configured as a U-shaped pipe, wherein a bottom of the U-shape of the support rod is arranged in the headrest body, and two ends of the support rod extend outwards from the bottom of the headrest body; and a driving assembly, which is fixedly mounted inside the headrest body and drives the headrest body to move up and down along the support rod. Here, an electric motor drives a lead screw to rotate, and hence the lead screw moves up and down relative to a screw sleeve, wherein the electric motor is fixedly connected with the headrest body, and the headrest body and the electric motor can move up and down along the support rod, so that a height of the headrest meets the requirements of different users, the overall structure is simple, and the use is convenient. The Chinese utility model CN212047040U discloses a drive module for electrically lifting a headrest for an automobile, wherein a headrest lifting device is arranged in a seat backrest framework, wherein a top part of the headrest lifting device is connected with the seat backrest framework by means of two snap-fit devices, a bottom part of the headrest lifting device is connected with a bottom of a headrest rod, wherein the bottom part and the top part of the headrest lifting device are movable relative to each other to realize a lifting movement of the headrest rod, wherein the snap-fit devices are two-parts respectively, with an upper and a lower part, wherein a lower surface of the upper part has an engagement protrusion and an upper surface of the lower part has a groove, wherein the engagement protrusion can engage into the groove in a corresponding position, wherein an upper end of the snap-fit device has a positioning groove, through which the upper part of the snap-fit device is positioned on the seat backrest framework. The headrest drive module enables a separate drive module detachable from the seat structure, wherein a user can freely select the function configuration of the electric lifting headrest on the same seat backrest platform according to individual requirements. Here, the electric motor is stationary, while the headrest can move up and down together with a guide rod and plastic parts. The Chinese invention application CN108688540A discloses an electric headrest device, wherein an electric motor is configured to electrically adjust a position in an up-down direction and a position in a front-back direction of a headrest arranged at an upper end of a seat backrest of a vehicle. Here, the electric motor is stationary and is configured to drive a headrest to move in the up-down direction and in the front-back direction. The Chinese invention application CN102795133A discloses an automobile seat headrest adjustment mechanism that can realize horizontal electric adjustment forward and backward and both wings front and rear angles can be manually adjusted. The inventors of the present application found in the research and development of products, in the prior art, a headrest is driven by a screw-nut mechanism, wherein a stroke of the headrest is identical to a movement stroke of an output member of the screw-nut mechanism, which may have the following problems: 1. The headrest has an insufficient stroke. Especially when a zero-gravity function of a zero-gravity vehicle seat is realized, the up-down movement stroke of the headrest can't meet the requirements on the comfort of different users well.2. The occupied space is large. The height-adjusting mechanism is arranged inside a seat backrest and needs to occupy a large space in the seat backrest.3. The appearance isn't perfect. When the headrest has a large stroke, some parts are exposed, and hence the overall appearance of the seat is influenced. Summary of Invention An object of the invention is to provide a seat headrest device and a vehicle seat comprising the same, in particular a zero-gravity vehicle seat, wherein a stroke of the headrest can be enhanced. Another object of the invention is to provide a seat headrest device which occupies a small space in a seat backrest and has a good appearance. For this purpose, the present invention defines a seat headrest device according to claim 1. Optional features are defined according to clai