DE102019211773B4 - Headrest for a vehicle seat and vehicle seat - Google Patents

Abstract

Headrest (1) for a vehicle seat (2), comprising a base (10) and an adjustment part (12) which can be moved relative to the base (10) by means of at least one scissor mechanism (11A, 11B), wherein an axis of rotation (D1 -D5) the scissor mechanism (11A, 11B) is provided with a locking device (14) that locks the scissor mechanism (11A, 11B) in one direction of movement, characterized in that the locking device (14) has two locking devices that are arranged next to one another in the axial direction and, when the scissor mechanism ( 11A, 11B) comprises locking elements (140, 141) which can be rotated relative to one another.

Description

The invention relates to a headrest for a vehicle seat according to claim 1 and a vehicle seat.

Headrests of vehicle seats can be designed to be adjustable in the X-direction of the vehicle coordinate system (i.e. essentially in the direction of travel when driving straight ahead) in order to enable a comfort setting or an adjustment triggered as a result of a detected vehicle crash.

A two-part headrest with a base and an adjustment part that can be adjusted for this purpose can be provided for this purpose. Adjustment kinematics are implemented, for example, by pivoting the adjustment part on the base, with the adjustment part rotating during adjustment and thus not always being equally well suited to supporting the back of the seat occupant’s head in different adjustment positions.

The EP 1 661 753 A2 describes a headrest with scissor mechanisms in which a drive motor is provided to displace a power transmission rod. The power transmission rod is coupled to a connecting axle, which is connected to each arm of the scissor mechanisms. As a result, the scissor mechanisms are extended or retracted in order to adjust an adjustment part relative to a base. Due to the type of coupling of the drive motor to the scissor mechanism, however, an adjustment movement is comparatively slow. In addition, it requires a great deal of effort to lock the known device in a crash-proof manner.

In the U.S. 2007/0 246 989 A1 describes an adjustable headrest with an adjustment mechanism in which an elongate toothed rack interacts with a locking element.

The U.S. 2015/0 239 378 A1 and the U.S. 5,020,855A each describe a headrest with a scissor mechanism and toothed segments for locking.

The EP 1 431 109 A1 describes a pyrotechnically activatable headrest.

The object of the present invention is to provide an improved headrest.

This problem is solved by a headrest with the features of claim 1.

Accordingly, a headrest for a vehicle seat is provided, comprising a base and an adjustment part that can be moved relative to the base by means of at least one scissor mechanism. It is provided that on an axis of rotation (which extends in an axial direction) of the at least one scissors mechanism, a one-sided locking mechanism is provided, which locks the at least one scissors kinematics in one direction of movement and the two (interacting) in (relative to the axis of rotation) comprises locking elements arranged next to one another in the axial direction. The locking elements can be rotated relative to one another when the scissor kinematics move.

This makes it possible to adjust the adjustment part in one direction relative to the base, while an adjustment in the other direction (without unlocking the lock) cannot be adjusted. For example, it is possible to adjust the adjustment part forward, ie in the direction of the back of the head of a user sitting on a vehicle seat with the headrest. An adjustment in the opposite direction, on the other hand, is prevented by the one-sided locking mechanism. In this way it can be achieved, for example, that the head of the seat occupant can always be safely supported in the event of a crash.

The lock can also be referred to as a locking device and is designed to release a rotation of two components of the headrest relative to one another in one direction and to block it in the other direction. The lock is designed, for example, as a one-sided locking (particularly releasable) coupling.

The locking mechanism optionally has at least one toothing, in particular two toothings that can be brought into engagement or are stationary. For example, each of the two locking elements has a toothing, it being possible for the toothings to face one another. As a result, a one-sided blocking locking is possible in a simple, robust and secure manner. The toothings are designed and arranged, for example, in such a way that they can slip through one another in one direction, in particular the direction of rotation, and lock to one another in the opposite direction. For this purpose, the toothings include, for example, teeth with flanks of different steepness. Depending on the direction of rotation, the teeth have different effects, in this case due to the differently steep flanks. One of the flanks is designed as a ramp, for example, and the other flank is designed as a stop, for example. For example, the teeth of the toothing lie flat against one another. The teeth each have, for example, two flat surfaces (as flanks). For example, one of the two surfaces extends in a plane in which the axis of rotation of the scissor mechanism runs. The other of the two surfaces is, for example, oriented at an angle to it.

The serrations may be (and are) intermeshable. Optionally, the serrations are biased into engagement with each other, e.g., resiliently, e.g., with a spring. In this way it can be ensured that the teeth always lock in one direction, so that the locking is securely locked in this direction.

At least one of the teeth of the locking mechanism can extend around the axis of rotation, at least in sections or completely, ie closed. This enables a particularly secure locking and simple training.

The lock can be detachable. Optionally, an operable unlocking device is provided to release the lock. Alternatively, the headrest does not have such a release, for example in an embodiment with an actuator. By actuating the unlocking device, the teeth of the locking mechanism can be disengaged. Actuation of the unlocking device thus enables the adjustment part to be reset, e.g. into a basic position. In the basic position, the adjustment part is arranged, for example, close to the base, in particular as close as possible.

Optionally, the unlocking device includes a pivotable lever. This enables simple actuation, e.g. manual actuation.

The locking is designed, for example, as a Hirth tooth system, in particular as an asymmetrical Hirth tooth system. The Hirth toothing is an axially effective, face-side toothing. The Hirth toothing allows a safe and at the same time easy to unlock locking and requires only little space.

The scissor mechanism comprises two scissor arms which cross one another and can be rotated relative to one another at this point about an axis of rotation. The lock can be arranged on this axis of rotation. For example, the teeth of the lock extend around this axis of rotation. For example, the interengaging or non-interlocking serrations of the latch are both formed on the scissor arms of the scissor mechanism. Alternatively, the lock can also be arranged on a different axis of rotation of the scissor mechanism, e.g. on an axis of rotation at one end of one of the scissor arms.

At least one of the scissor arms can be displaceable in the axial direction relative to the base and/or the adjustment part. For example, the scissor arm is mounted on the base and/or on the adjustment part so that it can be displaced in a direction parallel to the axis of rotation, e.g. for unlocking the lock.

The scissors mechanism has five axes of rotation. Two of the axes of rotation can each be formed by a rotating and sliding joint. This enables an adjustment in the X-direction without changing the height or inclination of the adjustment part.

Optionally, the headrest includes an actuator. The actuator can be activatable in order to adjust the adjustment part relative to the base. Alternatively or additionally, the actuator can be activated in order to release the locking. Activation of the actuator then causes the adjustment part to move relative to the base, specifically in particular in the direction that is enabled (and not blocked) by the locking mechanism.

In one embodiment, the actuator is designed as a pyrotechnic actuator. This enables a particularly instantaneous adjustment of the headrest into a position optimized for a vehicle crash, in order to support the seat occupant's head as well as possible.

The headrest can comprise two scissor mechanisms which are arranged next to one another, for example in such a way that the axes of rotation of the two scissor mechanisms are coaxial with one another. This allows a particularly stable construction. Each of the two scissor mechanisms can each have a one-sided locking mechanism. Optionally, the two scissor mechanisms are arranged as mirror images of each other.

Furthermore, it can be provided that the actuator is arranged between the two scissor mechanisms, which is possible in a particularly space-saving manner.

In one aspect, there is provided a vehicle seat that includes a head restraint according to any configuration described herein.

• 1 einen Fahrzeugsitz mit einer Kopfstütze;
• 2 die Kopfstütze des Fahrzeugsitzes gemäß 1 in einer Ausgestaltung mit einem pyrotechnischen Aktuator;
• 3 die Kopfstütze des Fahrzeugsitzes gemäß 1 in einer manuell verstellbaren Ausgestaltung ohne Aktuator; und
• 4 bis 9 mehrere Ansichten der Kopfstütze gemäß 2.

The idea on which the invention is based is to be explained in more detail below with reference to the exemplary embodiments illustrated in the figures. It shows in schematic representations:

• 1 a vehicle seat with a headrest;
• 2 the headrest of the vehicle seat according to 1 in one embodiment with a pyrotechnic actuator;
• 3 the headrest of the vehicle seat according to 1 in a manually adjustable configuration without an actuator; and
• 4 until 9 several views of the headrest according to 2 .

1 shows a vehicle seat 2 with a seat part 20 and a backrest 21. A headrest 1 is arranged on the backrest 21. FIG. In the present case, the headrest 1 is mounted on the backrest 21 in a height-adjustable manner, with fixed mounting thereon also being possible. A headrest rod 22 connects the headrest 1 to the backrest 21.

The vehicle seat 2 can be mounted on a vehicle floor FB of a vehicle and according to FIG 1 assembled. Furthermore, a longitudinal adjustment device is provided, via which the seat part 20 can be connected to the vehicle floor FB and according to 2 connected is. In the example shown, the backrest 21 can also be inclined relative to the seat part 20 about a pivot axis.

2 shows the headrest 1 in a side view. The headrest 1 includes a base 10. The base 10 is attached to the headrest post 22. As shown in FIG. The headrest 1 also includes an adjustment part 12. The adjustment part 12 forms a surface 120 which can support the head of a seat occupant. A cushion and/or a cover can be stretched over the surface 120 .

The adjusting part 12 can be adjusted relative to the base 10, in the present case in a direction which (possibly depending on the inclination of the backrest 21) corresponds to the X-direction or essentially to the X-direction of the vehicle coordinate system.

To move the adjustment part 12 relative to the base 10, the headrest 1 comprises at least one scissor mechanism, in this case two scissor mechanisms 11A, 11B (see Fig 4 ). In 2 the adjusting part 12 is shown removed from the scissor mechanisms 11A, 11B in order to reveal a view of it. The headrest 1 thus has scissor kinematics.

Each of the scissor mechanisms 11A, 11B comprises two scissor arms 110, 111. The scissor arms 110, 111 are arranged crossing one another. The scissor arms 110, 111 are rotatable relative to one another about an axis of rotation D1, e.g. This axis of rotation D1 is arranged at the crossing point of the two scissor arms 110, 111.

Each of the scissor arms 110, 111 is (in the assembled state) pivotally mounted on the base 10 and pivotally mounted on the adjustment part 12. Two of the four bearing points of each of the scissor mechanisms 11A, 11B are each formed by a rotating and sliding joint 15 . In the present case, the scissor arms 110, 111 each have two ends, with a holding part, in the present case in the form of a bolt 112, being arranged at each of the ends. Each bolt 112 is received in a receptacle 101, 102, 121, 122 respectively. Of these, two receptacles 102, 122 are elongated in order to form the rotary and sliding joints 15 together with the bolts 112. Overall, each scissor mechanism 11A, 11B thus has five axes of rotation D1-D5, one at each of the two ends of the scissor arms 110, 111 and one at the crossing point of the scissor arms 110, 111.

In the example shown, it is provided that each of the scissor arms 110, 111 is pivoted at one of its ends via a swivel joint about an axis of rotation D3, D5 (on the base 10 or on the adjustment part 12), while it is pivoted at its other end via one of the Rotary and sliding joints 15 is rotatably mounted about an axis of rotation D2, D4 and is displaceable along the respective receptacle 102, 122. As a result, the adjustment part 12 can be adjusted along a straight line, in particular in the X direction, relative to the base 10 .

In accordance with the design 1 the headrest 1 also includes an actuator 16. The actuator 16 includes a cylinder 161 in which a piston 162 is mounted to be displaceable from a retracted position into an extended position. In 2 1, the actuator 16 is shown in the extended position for clarity. The cylinder 161 is supported on the base 10, in particular fixed thereto. The piston 162 is (in the assembled state) supported on the adjustment part 12, in particular fastened. The actuator 16 is arranged in such a way that the piston 162 can be extended out of the cylinder 161 in a direction which is aligned parallel to the adjustment direction of the adjustment part 12 relative to the base 10 predetermined by the scissor mechanisms 11A, 11B. As a result, the actuator 16 can act directly on the adjustment part 12, which enables a simple, less error-prone and at the same time particularly fast adjustment. As a result, the adjustment part 12 can already be brought into an optimal position for catching the seat occupant's head, even before the head has come into contact with the headrest 1, for example in the event of a rear-end collision.

In the example shown, the actuator 16 is designed as a pyrotechnic actuator. The actuator 16 includes a propellant charge that can be ignited by an igniter of the actuator 16, so that the piston 162 can be extended in an explosive manner by the combustion gases that are produced. As a result, the adjustment part 12 can be adjusted explosively in the event of a trigger.

To activate the igniter, the actuator 16 has a connection 160 for ignition and/or signal cable on. The connection 160 is, for example, connected to a crash sensor and/or operatively connected thereto.

In accordance with the design 3 includes the headrest 1 no actuator 16. Otherwise, the headrest 1 corresponds to 3 according to the headrest 1 2 . The adjustment part 12 of the headrest 1 according to 3 is manually adjustable relative to the base 10, which according to the headrest 1 2 optionally also possible.

The 4 until 9 show further details of the headrest 1 according to FIG 2 , the adjustment part 12 not being shown for the sake of simplicity.

In particular, it can be seen that a one-sided locking mechanism 14 is provided on each axis of rotation D1 of the scissor mechanisms 11A, 11B, which includes two locking elements 140, 141 arranged next to one another in the axial direction (ie along the axis of rotation D1). The lock 14 is designed in such a way that it blocks movement of the scissor mechanism in one of two possible directions of movement of the scissor mechanism and releases it in the other of the two possible directions of movement. The two possible directions of movement are opposite to each other. Each of the locking elements 140, 141 is formed by a central section of one of the scissor arms 110, 111, on which a toothing 142, 143 is formed in each case in the present case. The teeth 142, 143 are designed in such a way that they can be brought into engagement with one another in a locking manner. For this purpose, the teeth 142, 143 of the locks 14 face each other. In the example shown, the teeth 142, 143 are provided on the scissor arms 110, 111.

For this purpose, the teeth of the toothings 142, 143 are designed asymmetrically, so that they can engage and slip softly in one direction of rotation, while they engage hard in the other direction. 5 shows an enlarged section of the 4 facing one of the latches 14.

As can be seen, the headrest 1 comprises two scissor mechanisms 11A, 11B, whose axes of rotation D1-D5 are aligned coaxially with one another. The scissor mechanisms 11A, 11B are thus arranged next to one another. The two inner scissor arms 110 of the two scissor mechanisms 11A, 11B are arranged parallel to one another and the two outer scissor arms 111 of the two scissor mechanisms 11A, 11B are arranged parallel to one another.

For example based on 4 It can be seen that the two scissor arms 111 arranged on the outside are pulled towards one another in a spring-elastic manner by means of a spring 144 . The spring 144 pulls on the two outer scissor arms 111. The spring preload acts in the Y direction of the vehicle coordinate system. The inner scissor arms 110 are axially immovable relative to the base 10 and/or fixed relative to each other. In the present case, the two inner scissor arms 110 are formed in one piece with one another via connecting struts.

As a result of the spring force of the spring 144, the teeth 142, 143 are each biased into locking engagement with one another.

If the adjustment part 12 is displaced away from the base 10, then the teeth 142, 143 slip through. The rising flanks of the teeth slide along each other. In the opposite direction, the adjustment part 12 cannot be adjusted relative to the base 10 without unlocking the locks 14, since tooth flanks abut one another in this direction and are aligned perpendicular to the force acting on the respective flank.

In the 4 until 9 1, the actuator 16 is shown in the non-activated condition in which the piston 162 is located in the retracted position.

5 12 shows the formation of one of the teeth 142. The teeth 142 extend around the axis of rotation D1 (at the crossing point of the scissor arms 110, 111). The toothing 142 is ring-shaped. The lock 14 is designed as a Hirth tooth system, specifically as a Hirth tooth system with asymmetrical teeth.

The teeth 142, 143 are each formed on the scissor arms 110, 111, in particular in one piece with them.

7 and 8th show an unlocking device 13 of the headrest 1. The unlocking device 13 comprises a lever 130. The lever 130 is arranged between the scissor mechanisms 11A, 11B. The lever 130 has a widened end, which is pivotally mounted in a bearing 100, which in the present case forms an at least partially spherical receptacle. The spring 144 extends through a through opening (in the enlarged end) of the lever 130 therethrough

If the lever 130 is pivoted relative to the base 10 (cf. 7 and 8th ), then sections of the widened end of the lever 130 press on both sides against a respective (cylindrical) stamp 131. The stamps 131 extend each through the inner scissor arms 110 and parallel to the axis of rotation D1. The punches 131 are each part of, or are arranged to act on, one of the outer scissor arms 111 . As a result, pivoting of the lever 130 causes the two toothings 142, 143 of each lock 14 to be disengaged from one another (as a result of an axial displacement of the outer scissor arms 111 away from one another). As a result, the latches 14 are released and the adjustment part 12 can be moved towards the base 10, eg to a home position in which the adjustment part 12 is closest to the base 10.

The scissor arms 110, 111, the base 10 and/or the adjustment part 12 are presently injection molded parts and/or made of a plastic.

The use of the scissor mechanisms 11A, 11B, the Hirth toothing and, optionally, the pyrotechnical actuator 16 makes a particularly flat headrest 1 possible particularly easy and quick to reset, e.g. after a crash.

Reference List

1

headrest

10

Base

100

storage

101, 102

Recording

11A, 11B

scissor mechanics

110, 111

scissor arm

112

bolt

12

adjustment part

120

Surface

121, 122

Recording

13

unlocking device

130

lever

131

Rubber stamp

14

locking

140, 141

locking element

142, 143

gearing

144

Feather

15

rotary sliding joint

16

actuator

160

Connection

161

cylinder

162

Pistons

2

vehicle seat

20

seat part

21

backrest

22

headrest rod

D1-D5

axis of rotation

FB

vehicle floor

X

Direction

Claims (15)

Headrest (1) for a vehicle seat (2), comprising a base (10) and an adjustment part (12) which can be moved relative to the base (10) by means of at least one scissor mechanism (11A, 11B), wherein an axis of rotation (D1 -D5) the scissors mechanism (11A, 11B) is provided with a lock (14) locking the scissors mechanism (11A, 11B) in one direction of movement, characterized in that the lock (14) comprises two axially arranged side-by-side locks and when the scissors mechanism ( 11A, 11B) comprises locking elements (140, 141) which can be rotated relative to one another. Headrest (1) after claim 1 , characterized in that each of the two locking elements (140, 141) has a toothing (142, 143), wherein the toothing (142, 143) are in engagement with each other or can be brought. Headrest (1) after claim 2 , characterized in that the teeth (142, 143) are biased into engagement with each other. Headrest (1) after claim 2 or 3 , characterized in that at least one of the teeth (142, 143) of the lock (14) extends around the axis of rotation (D1-D5). Headrest (1) according to one of claims 2 until 4 , characterized by an unlocking device (13), by the actuation of which the teeth (142, 143) of the lock (14) can be disengaged. Headrest (1) after claim 5 , characterized in that the unlocking device (13) comprises a pivotable lever (130). Headrest (1) according to one of the preceding claims, characterized in that the locking mechanism (140, 141) is designed as a Hirth tooth system. Headrest (1) according to one of the preceding claims, characterized in that the scissor mechanism (11A, 11B) comprises two scissor arms (110, 111) which cross one another at a crossing point and can be rotated relative to one another at the crossing point about the axis of rotation (D1), wherein at the axis of rotation (D1) the lock (14) is arranged. Headrest (1) after claim 8 , characterized in that at least one of the scissor arms (111) is displaceable in the axial direction relative to the base (10) and/or to the adjustment part (12). Headrest (1) according to one of the preceding claims, characterized in that the scissor mechanism (11A, 11B) has five axes of rotation (D1-D5), two of which are each formed by a rotary and sliding joint (15). Headrest (1) according to one of the preceding claims, characterized by an actuator (16) which can be activated in such a way that the lock (14) is released and/or the adjustment part (12) is adjusted relative to the base (10). Headrest (1) after claim 11 , characterized in that the actuator (16) is designed as a pyrotechnic actuator. Headrest (1) according to one of the preceding claims, characterized by two scissor mechanisms (11A, 11B) arranged next to one another, each of the scissor mechanisms (11A, 11B) having a lock (14) locking the respective scissor kinematics in one direction of movement. Headrest (1) after claim 11 or 12 and Claim 13 , characterized in that the actuator (16) is arranged between the two scissor mechanisms (11A, 11B). Vehicle seat (2), characterized by a headrest (1) according to one of the preceding claims.

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