DE102023111913A1 - drive device with predetermined breaking element - Google Patents

Abstract

The proposed solution relates to a drive device (1) for adjusting a vehicle seat (2), comprising: a transmission (10) with a transmission holder (100) and a motor unit (11) with a motor housing (110) which is arranged on the transmission holder (100) and is held in an operating position (BP) relative to the transmission holder (100) by means of a predetermined breaking element (111), wherein the motor housing (110) can be moved from the operating position (BP) into an evasive position (AP) relative to the transmission holder (100) by destroying the predetermined breaking element (111).

Description

The proposed solution concerns a drive device for a vehicle seat and a corresponding vehicle seat.

Vehicle seats are typically adjustable to allow different seat users to have a comfortable sitting position and to be able to adapt to different space conditions. For example, a vehicle seat can be mounted in a vehicle so that it can be adjusted lengthwise using a longitudinal adjustment device to allow different sitting positions along the vehicle's longitudinal axis, a vehicle seat can be adjustable using a height adjustment device to adjust a seat height, and in a vehicle seat the inclination of a backrest relative to a seat part can be adjustable, to name just a few examples. Motor drive devices can be provided to make such adjustments. This allows the adjustments to be made in a simple manner, e.g. by pressing buttons, or even completely automatically.

Typically, motor drive devices are mounted as firmly as possible to a component in order to be able to transmit functional forces when making an adjustment. In the case of external forces, e.g. as a result of a crash or misuse, the attachment should typically be sufficiently robust or be able to absorb the forces in another way.

To account for such forces, various approaches have been proposed.

The DE 198 31 442 A1 describes a gear for seat adjustment devices in motor vehicles which, on the one hand, has an optimized efficiency and, on the other hand, ensures sufficient safety against adjustment of the gear by output-side forces even in the case of comparatively high output-side forces.

In the US 2020/0331362 A1 a device for adjusting a length of a seat part of a motor vehicle seat is described, wherein the adjusting device contains a threaded rod, a rotatable nut, and a housing receiving the nut and the threaded rod, wherein the nut has a nut weak point for breaking open the nut.

The task is to improve the safety of a drive device for a vehicle seat.

This object is solved by an article having the features of claim 1.

A drive device for adjusting a vehicle seat is then specified. The drive device comprises a gear and a motor unit. The gear has a gear holder. The motor unit has a motor housing which is arranged on the gear holder and is held in an operating position relative to the gear holder by means of a predetermined breaking element. The motor housing can be moved from the operating position into an evasive position relative to the gear holder by destroying the predetermined breaking element.

This is based on the knowledge that housings of such drive devices have not yet been sufficiently considered. However, if a housing of the drive device breaks, e.g. the motor housing, then an electric motor attached to it or in it can fall off and represent an additional source of danger. By holding the motor housing in the operating position using the predetermined breaking element, a force can be predetermined by appropriate dimensioning of the predetermined breaking element, from which the motor housing is transferred to the evasive position. This allows the motor housing to evade in a crash, for example, while still being held securely on the gearbox holder. This can improve the safety of the drive device. When the motor housing is in the operating position, the drive device can be operated as intended.

For example, the motor housing can be pivoted from the operating position to the evasive position relative to the gearbox holder by destroying the predetermined breaking element. This enables the motor housing to be securely held on the gearbox holder and at the same time enables an evasive movement in the event of an overload.

Optionally, the motor housing can be pivoted from the operating position to the evasive position about a rotation axis of a gear element of the gearbox relative to the gearbox holder. This allows an unhindered evasive movement of the motor housing in a simple manner without further damage.

The gear element can have an internal thread. The axis of rotation is, for example, aligned concentrically to the internal thread.

For example, the gear element is engaged with a spindle. This enables precise and smooth adjustment.

It can be provided that the predetermined breaking element can be sheared off in order to prevent movement, in particular to enable the pivoting movement of the motor housing from the operating position to the evasive position relative to the gearbox holder. In this way, the force at which the predetermined breaking element fails can be predetermined with particular precision.

For example, the predetermined breaking element is designed in the form of a shearing nose. Such a design is particularly easy to manufacture.

In one embodiment, the motor housing forms the predetermined breaking element. This allows for simple manufacture. Alternatively or additionally, a gear housing that is firmly connected to the motor housing (e.g. in one piece) can form the predetermined breaking element. Alternatively, the gear holder can form the predetermined breaking element, for example.

Optionally, a stop is provided that is permanently connected to the motor housing and is designed to hit a counter stop on the gearbox holder in the evasive position. This allows the path from the operating position to the evasive position to be defined.

The motor housing can be made of plastic. The described design with the predetermined breaking element can achieve improved crash safety despite the plastic housing.

The motor unit includes an electric motor, for example. This allows for convenient operation.

The drive device can still be adjustable even after the predetermined breaking element has been destroyed. For example, the drive device is adjustable both when the motor housing is in the operating position and when it is in the avoidance position. For example, the electric motor can drive a gear element of the transmission both when the motor housing is in the operating position and when it is in the avoidance position. This means that functionality can still be guaranteed even after an overload.

According to one aspect, a vehicle seat is provided, comprising the drive device according to any embodiment described herein. With regard to the advantages, reference is made to the above information on the drive device.

For example, the drive device is configured to adjust a seat height of a seat part of the vehicle seat relative to a base of the vehicle seat.

The seat part is supported on the base, for example, via a lever. The drive device can be designed to exert a force on the lever and/or on the seat part in order to effect an adjustment.

Optionally, the motor unit is arranged under a seat mat on the seat part of the vehicle seat, which is designed to support a seat cushion. In the event of a crash, this can be pressed against the motor unit, which can move out of the way when the breaking element is released.

• 1 einen Fahrzeugsitz mit einer Höhenverstelleinrichtung;
• 2 eine schematische Darstellung der Höhenverstelleinrichtung gemäß 1 und einer Antriebsvorrichtung für die Höhenverstelleinrichtung;
• 3 die am Fahrzeugsitz montierte Antriebsvorrichtung gemäß 2;
• 4A und 4B Ansichten der Antriebsvorrichtung gemäß 2 mit einem Motorgehäuse in einer Betriebsposition und in einer relativ zur Betriebsposition verlagerten Ausweichposition;
• 4C eine Explosionsansicht der Antriebsvorrichtung gemäß 2; und
• 5 Getriebeelemente eines Getriebes der Antriebsvorrichtung gemäß 2.

The idea underlying the invention will be explained in more detail below using the embodiments shown in the figures. They show:

• 1 a vehicle seat with a height adjustment device;
• 2 a schematic representation of the height adjustment device according to 1 and a drive device for the height adjustment device;
• 3 the drive device mounted on the vehicle seat according to 2 ;
• 4A and 4B Views of the drive device according to 2 with an engine housing in an operating position and in an alternative position displaced relative to the operating position;
• 4C an exploded view of the drive device according to 2 ; and
• 5 Transmission elements of a transmission of the drive device according to 2 .

1 shows a vehicle seat 2 with a seat part 20 and a backrest 21. The backrest 21 is mounted on the seat part 20 by means of a fitting arrangement 22 so as to be pivotable about a pivot axis S.

The seat part 20 has a seat height relative to a base B along a height axis z. The seat part 20 (together with the backrest 21) is adjustable in seat height by means of a height adjustment device 23, as will be explained in more detail below.

The vehicle seat 2 can be mounted on a vehicle floor FB of a vehicle and according to 1 mounted. The vehicle seat 2 also comprises a longitudinal adjustment device 24. The longitudinal adjustment device 24 allows a longitudinal adjustment of the vehicle seat 2 along a longitudinal axis x. By means of the longitudinal adjustment device 24, the seat part 20 and the backrest 21 can be moved together along the longitudinal axis x relative to the vehicle floor FB. The longitudinal axis x is aligned perpendicular to the height axis z. The longitudinal adjustment device 24 comprises two pairs of a rail that can be fixed to the vehicle floor FB and is fixed in the example shown, which can also be referred to as a floor rail, and a seat rail 240 that is mounted on it so that it can move along the longitudinal axis x. The remaining vehicle seat 2 can be mounted on the seat rail 240 and is mounted in the example shown. The two pairs, of which in the view of the 1 only one is visible, are spaced apart along a lateral axis. The lateral axis is aligned perpendicular to the longitudinal axis x and perpendicular to the height axis z.

In the example shown, the floor rail serves as base B.

2 shows the two seat rails 240 running parallel to each other, as well as two side parts 202 of the seat part 20 supported thereon via the height adjustment device 23. The side parts 202 are connected to each other via a cross tube 201, in this case firmly connected to each other.

The height adjustment device 23 comprises several levers 230, in this case two levers 230 per side part 202.

A motor drive device 1 is used to adjust the vehicle seat 2, namely in the present case for adjusting the seat height. For this purpose, the drive device 1 is arranged here, for example, on one of the levers 230.

The drive device 1 comprises a gear 10 and a motor unit 11. The gear 10 is mounted on one of the levers 230 (in the example shown on a rear lever 230). In the present case, the gear 10 is pivotally connected to the lever 230. It would also be conceivable to pivot the gear 10, for example, on a side part 202 or on the cross tube 201. The gear 10 is engaged with a spindle 12. The spindle 12 is pivotally mounted on the seat rail 240.

The motor unit 11 is operatively connected to the gear 10 via a shaft. The motor unit 11 drives the gear 10 so that the gear 10 moves up or down on the spindle 12 depending on the direction of rotation, whereby the lever 230 is pivoted and the height of the seat part 20 is subsequently adjusted.

The motor unit 11 is arranged adjacent to the cross tube 201. The motor unit 11 is aligned parallel to the cross tube 201.

3 shows the drive device 1 on the vehicle seat 2 with further details. It can be seen that the transmission 10 has a transmission holder 100 and that the motor unit 11 has a motor housing 110. The motor housing 110 is arranged on the transmission holder 100. Specifically, the motor housing 11 is attached to the transmission holder 10.

An electric motor 113 of the motor unit 11 is held on the gear box 10 by means of the motor housing 110. The electric motor 113 drives the gear box 10. The spindle 12 has a bearing point 120, in the present case in the form of an opening for receiving a bearing element 13, here in the form of a bolt. The bearing element 13 is fixed relative to the seat rail 240, in the present case mounted on an adapter attached to the seat rail 240. The spindle 12 is pivotally mounted on the bearing element 13.

3 also shows a part of a seat mat 200 of the seat part 20. The seat mat 200 is designed to support a cushion of the seat part 20. In the present case, the seat mat 200 is designed to be spring-elastic. The seat mat 200 is attached to the cross tube 201 at a rear end.

If large forces act on the vehicle seat, particularly as a result of a crash, the seat mat 200, the upholstery or other parts can press against the motor unit 11, particularly against the electric motor 113. In 3 A force F is illustrated with an arrow, which can act on the motor unit 11. In this example, the force F acts diagonally backwards and downwards.

In order to absorb such a force F, the drive device 1 is designed as shown in the 4A and 4B illustrated. It is provided that the motor housing 110 of the motor unit 11 is held in an operating position BP relative to the gear holder 100 by means of a predetermined breaking element 111, wherein the motor housing 110 can be moved from the operating position BP into an evasive position AP relative to the gear holder 100 by destroying the predetermined breaking element 111.

4A shows the operating position, 4B shows the alternative position AP. 4A further illustrates the force F.

Based on the 4A and 4B It can be seen that the predetermined breaking element 111 can be sheared off in order to release the movement of the motor housing 110 from the operating position BP into the avoidance position AP relative to the gear holder 100. Specifically, the predetermined breaking element 111 is designed in the form of a shearing nose.

As can be seen in particular from 4C As can be seen, the motor housing 110 is fixed, here integrally connected to a gear housing 109. The gear housing 109 supports several gear elements of the gear 10. The shearing nose is part of the gear housing 109 (but could alternatively also be formed as part of the motor housing 110). The motor housing 110 is made of a plastic, for example PU, PA or another polymer (as is the motor housing 109). The gear housing 109 is held by the gear holder 100. The gear housing 109 is arranged in the gear holder 100.

The gear holder 100 is made of metal, in this case from a steel sheet. It has a cage 107, which is closed by a bearing cover 105. In the assembled state, the bearing cover 105 is firmly connected to the cage 107, specifically: welded to it.

The gear holder 100 has (on the bearing cover 105) a bearing point 108 (here in the form of an opening), with which the gear holder 100 is pivotally mounted on a bearing element 14 (here in the form of a bolt) on the lever 230 (alternatively on the seat part 20). The cage 107 and the bearing cover 105 each have an opening for the spindle 12.

In the operating position BP, the motor housing 110 is held, for example, in a form-fitting manner on the gear holder 100. The predetermined breaking element 111 rests on a side edge of a section 106 of the gear holder 100. The section 106 of the gear holder 100 is formed in the present case on the bearing cover 105.

The shearing nose is designed in such a way that it can safely transmit the functional and blocking forces that occur during operation. If the force F exceeds a predetermined amount, the predetermined breaking element 111 is destroyed, namely in this case sheared off, so that the motor housing 110 can be moved relative to the gear holder 100, and can be pivoted. The motor housing 110 (with the gear housing 109) pivots from the operating position BP to the avoidance position AP about a rotation axis D of a gear element of the gear 10 relative to the gear holder 100. An additional deformation path and angle is released without the plastic motor housing 110 (or the gear housing 109) being additionally damaged. This prevents, for example, the electric motor 113 from falling off.

As can be seen by comparing the 4A and 4B As can be seen, the axis of rotation D corresponds to the longitudinal axis of the spindle 12. The electric motor 113 has a motor axis of rotation M, about which a rotor of the electric motor 113 rotates. If the motor housing 110 pivots from the operating position BP into the avoidance position AP, the motor axis of rotation M is pivoted relative to the gear holder 100. The motor axis of rotation M is aligned perpendicular to the axis of rotation D and arranged offset therefrom. The drive device 1 can still be adjusted even after the predetermined breaking element 111 has been destroyed. The vehicle seat 1 can still be adjusted with the drive device 1 even after the predetermined breaking element 111 has been destroyed. When the motor housing 110 moves from the operating position BP into the avoidance position AP, the electric motor 113 pivots about the axis of rotation D (and remains in operative connection with the spindle 12).

As can be seen in particular from 4C As can be seen, the gear housing 109 has several (in this case four) bearing sections L. The gear holder 100 (more specifically: the bearing cover 105) has several sliding surfaces G, which slide along the bearing sections L when the motor housing 110 (with the gear housing 109) pivots relative to the gear holder 100. The bearing sections L are each designed in the form of an axially projecting projection. The predetermined breaking element 111 is arranged on one of the bearing sections L in the example shown.

A stop 112 is also firmly connected to the motor housing 110. The stop 112 is in the form of a projection (in this case on the gear housing 109). The gear holder 100 has a counter stop 104. In the operating position BP, the stop 112 is spaced from the counter stop 104. After the breaking element 111 is destroyed and as a result of the pivoting movement of the motor housing 110 relative to the gear holder 100, the stop 112 strikes the counter stop 104 and thus defines the avoidance position AP. The stop 112 is arranged here at an end of the gear housing 109 facing away from the electric motor 113. In this case, several stops and counter stops are provided.

5 shows the aforementioned gear element 101 of the gear 10, which can be rotated about the axis of rotation D. The gear element 101 is arranged in the gear holder 100. The gear element 101 is in the form of a spindle nut. The gear element 101 has an internal thread 102 and external teeth. The internal thread 102 of the gear element 101 engages the spindle 12. The external teeth engage with a further gear element 103 in the form of a worm. The further gear element 103 is aligned parallel to the motor axis of rotation M. The further gear element 103 can be driven by the electric motor 113 and drives the gear element 101 in the form of the spindle nut, so that it is screwed along the spindle 12. The gear elements 101, 103 are mounted in the gear housing 109 and arranged with the gear housing 109 in the gear holder 100.

list of reference symbols

1

drive device

10

transmission

100

gearbox mount

101

gear element (spindle nut)

102

internal thread

103

gear element (worm)

104

counterattack

105

bearing cap

106

Section

107

cage

108

storage location

109

gearbox housing

11

engine unit

110

engine housing

111

predetermined breaking element

112

stop

113

electric motor

12

spindle

120

storage location

13, 14

bearing element

2

vehicle seat

20

seat part

200

seat mat

201

cross tube

202

side panel

21

backrest

22

fitting arrangement

23

height adjustment device

230

lever

24

longitudinal adjustment device

240

seat rail

AP

alternative position

B

base

BP

operating position

D

axis of rotation

F

Power

FB

vehicle floor

G

sliding surface

L

storage section

M

motor rotation axis

S

swivel axis

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 198 31 442 A1 [0005]
• US 2020/0331362 A1 [0006]

Claims (16)

Drive device (1) for adjusting a vehicle seat (2), with: - a transmission (10) with a transmission holder (100) and - a motor unit (11) with a motor housing (110) which is arranged on the transmission holder (100) and is held in an operating position (BP) relative to the transmission holder (100) by means of a predetermined breaking element (111), wherein the motor housing (110) can be moved from the operating position (BP) into an evasive position (AP) relative to the transmission holder (100) by destroying the predetermined breaking element (111). Drive device (1) according to claim 1 , characterized in that the motor housing (110) can be pivoted from the operating position (BP) into the avoidance position (AP) relative to the gear holder (100) by the destruction of the predetermined breaking element (111). Drive device (1) according to claim 2 , characterized in that the motor housing (110) can be pivoted from the operating position (BP) into the avoidance position (AP) about an axis of rotation (D) of a gear element (101) of the gear (10) relative to the gear holder (100). Drive device (1) according to claim 3 , characterized in that the gear element (101) has an internal thread (102). Drive device (1) according to claim 3 or 4 , characterized in that the gear element (101) is in engagement with a spindle (12). Drive device (1) according to one of the preceding claims, characterized in that the predetermined breaking element (111) can be sheared off in order to release a movement of the motor housing (110) from the operating position (BP) into the avoidance position (AP) relative to the gear holder (100). Drive device (1) according to claim 6 , characterized in that the predetermined breaking element (111) is designed in the form of a shearing nose. Drive device (1) according to one of the preceding claims, characterized in that the motor housing (110) and/or a gear housing (109) firmly connected to the motor housing (110) forms the predetermined breaking element (111). Drive device (1) according to one of the preceding claims, characterized in that a stop (112) is provided which is firmly connected to the motor housing (110) and is designed to strike a counter stop (104) of the gear holder (100) in the evasive position. Drive device (1) according to one of the preceding claims, characterized in that the motor housing (110) is made of a plastic. Drive device (1) according to one of the preceding claims, characterized in that the motor unit (11) comprises an electric motor (113). Drive device (1) according to one of the preceding claims, characterized in that the drive device (1) is adjustable both when the motor housing (110) is arranged in the operating position (BP) and when it is arranged in the avoidance position (AP). Vehicle seat (2), characterized by the drive device (1) according to one of the preceding claims. Vehicle seat (2) after claim 13 , characterized in that the drive device (1) is designed to adjust a seat height of a seat part (20) of the vehicle seat (1) relative to a base (B) of the vehicle seat (1). Vehicle seat (2) after claim 14 , characterized in that the seat part (20) is supported on the base (B) via a lever (230), wherein the drive device (1) is adapted to exert a force on the lever (230) and/or on the seat part (20). Vehicle seat (2) according to one of the Claims 13 until 15 , characterized in that the motor unit (11) is arranged under a seat mat (200) of the vehicle seat (2) designed to support a seat cushion.

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