Patent Publication Number: US-2022227260-A1

Title: Longitudinal adjuster and vehicle seat

Description:
The invention relates to a longitudinal adjuster, in particular for a vehicle seat, the longitudinal adjuster having at least one pair of rails formed from a first rail and a second rail which is displaceable in the longitudinal direction relative to the first rail, wherein the rails alternately engage around each other forming an inner channel, wherein a spindle nut connected to the second rail and a spindle operatively connected to the spindle nut are arranged in the inner channel, wherein a gear which is drivable by means of a motor and interacts with the spindle is arranged at one end of the first rail. The invention furthermore relates to a vehicle seat. 
     PRIOR ART 
     A drive device of the type in question for a motor vehicle seat in a sliding device is known from DE 10 2005 023 095 A1. The drive device for use with a motor vehicle seat sliding device comprises mating fixed and movable rail parts that can be moved between a front position and a rear position. The drive device comprises an elongated spindle, a spindle nut, a gear and a mounting device. The spindle defines a spindle axis and has a spindle thread extending in the longitudinal direction. The spindle nut can be securely fastened to a first rail part and has an internal thread that can engage in the spindle thread. The gear can be mounted on a different rail part and selectively rotates the spindle around the spindle axis. The spindle of the drive device is provided with a spindle wheel which, in the mounted state of the drive device, extends outward through spindle wheel openings in the movable rail part. 
     A seat sliding device which has a system with a floating threaded spindle and a static nut is known from DE 10 2006 000 193 A1. The nut is fastened to the lower rail while the threaded spindle rotates through it, such that the upper structure can move forward and backward. When this system is used, the nut is fastened to the lower rail. 
     DE 10 2008 024 141 A1 discloses a spindle bearing arrangement for a seat longitudinal adjustment mechanism, said spindle bearing arrangement having a housing which is fastenable by a fastening arrangement to a component on the vehicle side or to a component on the seat side, wherein a spindle opening for the passage of a spindle along a spindle opening axis passes through the housing, and wherein an internal thread in the housing in the region of its spindle opening is designed for engaging in a spindle passed through in this way, in order to adjust the housing and the spindle relative to one another along the spindle opening axis. The spindle bearing arrangement provides that the internal thread is formed in a spindle nut and the spindle nut is mounted in the housing so as to be adjustable relative to the spindle opening axis. 
     A similar bearing arrangement is known from DE 696 20 623 T2 and DE 10 2004 036 735 B4. 
     An alternative drive device for a motor vehicle seat is known from DE 10 2014 201 582 A1, said drive device having a spindle held non-rotatably in a first rail fixed to the vehicle in conjunction with a driven spindle gear held in a second rail fixed to the seat. Such drive devices do not have a static spindle nut. 
     Problem 
     The invention is based on the problem of improving a longitudinal adjuster of the type mentioned at the beginning, in particular of providing a longitudinal adjuster with a static spindle nut, which enables elimination of play and tolerance compensation in the region of the spindle nut, and to provide a corresponding vehicle seat. 
     Solution 
     According to the invention, this problem is solved by a longitudinal adjuster, in particular for a vehicle seat, the longitudinal adjuster having at least one pair of rails formed from a first rail and a second rail which is displaceable in the longitudinal direction relative to the first rail, wherein the rails alternately engage around each other forming an inner channel, wherein a spindle nut connected to the second rail and a spindle operatively connected to the spindle nut are arranged in the inner channel, wherein a gear which is drivable by means of a motor and interacts with the spindle is arranged at one end of the first rail, wherein the spindle nut is fixed to the second rail in such a way that the spindle nut has a degree of freedom of at least one, wherein the spindle nut is connected, in particular fixedly connected, to the second rail by means of a fixing means, wherein a projection is provided in the region of the fixing means on a basic body of the spindle nut or on the second rail, which projection defines a distance between the basic body and the second rail, wherein the spindle nut is connectable to the second rail in the event of a crash by means of at least one crash bolt, in particular two crash bolts. 
     Since the spindle nut is fixed to the second rail in such a way that the spindle nut has a degree of freedom of at least one, manufacturing-related tolerances and play between the individual components, in particular during assembly, can be compensated for. 
     The fact that the “fixing means is fixedly connected to the second rail” is generally to be understood as meaning that the fixing means secures the spindle nut at least in a normal state of use of the longitudinal adjuster in a manner free from play relative to the second rail, but without influencing the degree of freedom. 
     Advantageous refinements which can be used individually or in combination with one another are the subject matter of the dependent claims. 
     The first rail is preferably a seat rail which is connectable to a vehicle seat. The second rail is preferably a floor rail which is connectable to a vehicle structure. A possible internal structure and the manner of operation and function of the spindle gear is known, for example, from DE 10 2013 207 665 A1, the disclosure in respect of which is hereby expressly included. 
     The spindle can be mounted at a front end section of the spindle in the spindle gear and at a rear end section of the spindle in a rotary bearing of the first rail. 
     The crash bolts can be screws. The crash bolts can be threaded bolts. The crash bolts can each be passed through a first opening, in particular for the crash bolts, in the second rail. Furthermore, a radial gap can be provided around each crash bolt, between the bolt and the second rail, in particular between the bolt and the first openings in the second rail. 
     The spindle nut can have a basic body. The spindle nut can have a continuous threaded bore with an internal thread, in particular parallel to the longitudinal direction. The internal thread of the spindle nut can be operatively connected to an external thread of the spindle. 
     The basic body of the spindle nut can have a shoulder in the region of each of the crash bolts, which shoulder defines a distance between a head of the respective crash bolt and the basic body. Here, a gap can be provided around the shoulder, between the shoulder and the second rail, in particular between the shoulder and the first openings in the second rail. 
     Likewise, the crash bolts can each have a shoulder which adjoins a head of the respective crash bolt and defines a distance between the head and the spindle nut, in particular the basic body of the spindle nut. 
     The spindle nut can be fixedly connected to the second rail by means of a centrally arranged fixing means, as viewed in the longitudinal direction. The second rail can have a second opening for this purpose. An inner diameter of the second opening is preferably adapted to an outer diameter of the fixing means. The fixing means can be a screw. The fixing means can be a bolt, in particular a threaded bolt. 
     A projection, in particular parallel to a spindle axis and preferably centrally arranged, can be provided on the basic body of the spindle nut in the region of the fixing means, which projection defines a distance between the basic body and the second rail, in particular an upper side of the second rail oriented in the direction of the inner channel. In the region of the spindle nut, the second rail can have a projection which defines a distance between the spindle nut and the second rail, in particular an upper side of the second rail oriented in the direction of the inner channel. The projection of the second rail can be produced by means of an embossing. A bearing element can be arranged between the basic body of the spindle nut and the second rail. The bearing element can be a plain washer. The bearing element can be a metal sheet. The bearing element can have a projection, in particular a projection arranged centrally parallel to the spindle axis. The bearing element can define a distance between the basic body and the second rail. 
     The degree of freedom can correspond to a pivoting of the spindle nut about a substantially horizontal axis. The degree of freedom can correspond to a pivoting of the spindle nut about an axis running substantially horizontally and parallel to a transverse direction. In this way, due to high loads in crash situations, it can advantageously be made possible for the spindle nut to be tiltable or pivotable, in particular about a contact region between the projection and the second rail. The second rail can preferably be made of metal, in particular spring steel. The second rail can have resilient properties of a spring sheet in some regions. 
     The degree of freedom can correspond to a rotation of the spindle nut about a substantially vertical axis, in particular an axis of the fixing means. The degree of freedom can correspond to a movement of the spindle nut in a vertical direction. The degree of freedom can correspond to a pivoting of the spindle nut about a substantially horizontal axis, in particular along an imaginary connecting line between the two crash bolts. A “degree of freedom” in the context of the present invention is generally understood to mean a number of mutually independent movement possibilities. 
     An elastic means can be arranged between the basic body of the spindle nut and the second rail. A metal spring, in particular a metallic leaf spring, can be arranged between the basic body of the spindle nut and the second rail. A buffer, in particular a flat buffer, made of a plastic, in particular a rubber, can be arranged between the basic body of the spindle nut and the second rail. A buffer, in particular an annular buffer, made of a plastic, in particular a rubber, can be arranged between the head of each of the crash bolts and the second rail. 
     The buffer can be made of a plastic, in particular a rubber. The buffer can be made of metal. The buffer can be made of metal on the one hand and plastic or rubber on the other hand. One side of the buffer can be made of metal and another side of the buffer can be made of plastic and/or rubber. 
     A diameter of the spindle can be increased compared to spindles known from the prior art. The spindle nut is preferably designed in one piece. The spindle nut can advantageously enable a reduction in play or a compensation for manufacturing tolerances. 
     The problem is also solved according to the invention by a vehicle seat with a longitudinal adjuster described above. 
    
    
     
       FIGURES AND EMBODIMENTS OF THE INVENTION 
       Before refinements of the invention are described in more detail below with reference to figures, it should first be noted that the invention is not limited to the components described. Furthermore, the terminology used does not constitute a restriction, but is merely of an exemplary nature. Insofar as the singular is used in the description and the claims below, the plural is also included, unless the context explicitly excludes this. 
       The invention is explained in more detail below on the basis of advantageous exemplary embodiments which are illustrated in the figures. The invention is however not limited to these exemplary embodiments. In the figures: 
         FIG. 1 : shows schematically a vehicle seat according to the invention, 
         FIG. 2 : shows a longitudinal adjuster according to the invention of the vehicle seat from  FIG. 1 , 
         FIG. 3 : shows a perspective view of a pair of rails of the longitudinal adjuster from  FIG. 2 , 
         FIG. 4 : shows a longitudinal section of the pair of rails from  FIG. 3 , 
         FIG. 5 : shows a perspective illustration, enlarged in detail, of a spindle nut according to a first exemplary embodiment, 
         FIG. 6 : shows a longitudinal section of the spindle nut from  FIG. 5 , 
         FIG. 7 : shows a perspective illustration, enlarged in detail, of a spindle nut according to a second exemplary embodiment, 
         FIG. 8 : shows a longitudinal section of the spindle nut from  FIG. 7 , 
         FIG. 9 : shows a perspective illustration, enlarged in detail, of a spindle nut according to a third exemplary embodiment, 
         FIG. 10 : shows a longitudinal section of the spindle nut from  FIG. 9 , 
         FIG. 11 : shows a perspective illustration, enlarged in detail, of a spindle nut according to a fourth exemplary embodiment, and 
         FIG. 12 : shows a longitudinal section of the spindle nut from  FIG. 11 . 
     
    
    
     A vehicle seat  1  illustrated schematically in  FIG. 1  is described below using three spatial directions running perpendicular to one another. In the case of a vehicle seat  1  installed in the vehicle, a longitudinal direction x runs substantially horizontally and preferably parallel to a vehicle longitudinal direction, which corresponds to the normal direction of travel of the vehicle. A transverse direction y, which runs perpendicularly with respect to the longitudinal direction x, is likewise oriented horizontally in the vehicle, and runs parallel to a vehicle transverse direction. A vertical direction z runs perpendicularly with respect to the longitudinal direction x and perpendicularly with respect to the transverse direction y. In the case of a vehicle seat  1  installed in the vehicle, the vertical direction z runs parallel to the vehicle vertical axis. 
     The positional and directional indications used, such as for example front, rear, top and bottom, relate to a viewing direction of an occupant sitting in the vehicle seat  1  in a normal sitting position, wherein the vehicle seat  1  is installed in the vehicle, in a use position suitable for passenger transport, with an upright backrest  4 , and is oriented in the conventional manner in the direction of travel. The vehicle seat  1  may however also be installed in a different orientation, for example transversely with respect to the direction of travel. 
     The vehicle seat  1  shown in  FIG. 1  for a motor vehicle has a seat part  2  and the backrest  4  which is adjustable in its inclination relative to the seat part  2 . An inclination of the backrest  4  can be adjustable, for example, by means of a latching fitting or a geared fitting. The vehicle seat  1  is mounted on a longitudinal adjuster  10  for adjusting a longitudinal seat position. 
       FIG. 2  shows the longitudinal adjuster  10  according to the invention of the vehicle seat  1 . The longitudinal adjuster  10  has at least one pair of rails, in the present case two pairs of rails.  FIG. 3  shows one of the pairs of rails of the longitudinal adjuster  10  from  FIG. 2 . 
     The pairs of rails are each formed from a first rail  12 , in particular for connection to a seat structure of the vehicle seat  1 , and from a second rail  14 , in particular for connection to a vehicle structure. The rails  12 ,  14  of the pair of rails are displaceable in the longitudinal direction x relative to one another and engage alternately around one another forming an inner channel  16 . A spindle nut  130 ;  230 ;  330 ;  430 , which is mounted on the second rail  14  and in the present case is connected, in particular non-rotatably, to the second rail  14 , and a spindle  20  interacting with the spindle nut  130 ;  230 ;  330 ;  430  are arranged in the inner channel  16 . The spindle  20  extends along a spindle axis S parallel to the longitudinal direction x. A spindle gear  50  which is drivable by means of a motor  60  and which drives the spindle  20  is arranged at a front end of the first rail  12 . The motor  60  is held on a motor carrier  70  mounted between the two spindle gears  50  of the respective pairs of rails and drives the two spindle gears  50  by means of a shaft, not illustrated in  FIG. 2 . 
       FIG. 4  shows a longitudinal section of the pair of rails from  FIG. 3 . The spindle gear  50  supports a front end section  20   a  of the spindle  20 . The spindle nut  130 ;  230 ;  330 ;  430  is arranged centrally along the length of the spindle  20  in the state illustrated here. By rotation of the spindle  20  about the spindle axis S, the spindle nut  130 ;  230 ;  330 ;  430  is screwed, depending on the direction of rotation, along an external thread of the spindle  20  in or counter to the longitudinal direction x and thereby displaces the first seat rail  12  relative to the second seat rail  14 . A relative position between the spindle  10  and the spindle nut  130 ;  230 ;  330 ;  430  is also displaced accordingly. 
       FIGS. 5 and 6  show the spindle nut  130  according to a first exemplary embodiment. The spindle nut  130  has a basic body  132 . The spindle nut  130  has a continuous threaded bore which is oriented in particular parallel to the longitudinal direction x and has an internal thread. The internal thread of the spindle nut  130  is operatively connected to an external thread of the spindle  20 . 
     The spindle nut  130  is connected to the second rail  14  by means of two crash bolts  90 . For this purpose, the second rail  14  has two first openings  14   a , through each of which a crash bolt  90  is passed. Furthermore, a gap  100  is provided around the crash bolts  90 , between the bolts and the second rail  14 . The spindle nut  130  is fixedly connected to the second rail  14  by means of a fixing means  80 , in particular a fixing means  80  arranged centrally between the crash bolts  90 , as viewed in the longitudinal direction x. For this purpose, the second rail  14  has a second opening  14   b  for the fixing means  80 . The inner diameter of the second opening  14   b  is adapted to an outer diameter of the fixing means  80 . The spindle nut  130  has a projection  134  on the basic body  132  in the region of the fixing means  80 , which projection defines a distance between the basic body  132  and the second rail  14 . The spindle nut  130  can, preferably in the event of a crash, be pivotable about a substantially horizontal axis, in particular about an axis running parallel to a transverse direction y. 
     According to the first exemplary embodiment, a shoulder  136  is arranged, in particular integrally formed, on the basic body  132  of the spindle nut  130  in the region of each of the crash bolts  90  and defines a distance between a head  92  of the respective crash bolt  90  and the basic body  132 . In the present case, the head  92  is normally spaced apart from the second rail  14  and only comes into contact with the second rail  14  after the longitudinal adjuster  10  has been deformed under load, in particular in the event of a crash. 
     In the present case, one possibility of movement of the spindle nut  130  corresponding to a degree of freedom is a rotation of the spindle nut  130  about a substantially vertical axis, in particular an axis A of the fixing means  80 . In the region of the crash bolts  90 , the second rail  14  can also move to a limited extent in the vertical direction z between the head  92  and the spindle nut  130 . 
       FIGS. 7 and 8  show the spindle nut  230  according to a second embodiment. The spindle nut  230  has a basic body  232 . The spindle nut  230  has a continuous threaded bore which is oriented in particular parallel to the longitudinal direction x and has an internal thread. The internal thread of the spindle nut  230  is operatively connected to an external thread of the spindle  20 . 
     The spindle nut  230  is connected to the second rail  14  by means of two crash bolts  90 . For this purpose, the second rail  14  has two first openings  14   a , through each of which a crash bolt  90  is passed. Furthermore, a gap  100  is provided around the crash bolts  90 , between the bolts and the second rail  14 . The spindle nut  230  is fixedly connected to the second rail  14  by means of a fixing means  80 , in particular a fixing means  80  arranged centrally, as viewed in the longitudinal direction x. For this purpose, the second rail  14  has a second opening  14   b  for the fixing means  80 . The inner diameter of the second opening  14   b  is adapted to an outer diameter of the fixing means  80 . The spindle nut  230  has a projection  234  on the basic body  232  in the region of the fixing means  80 , which projection defines a distance between the basic body  232  and the second rail  14 . The spindle nut  230  can, preferably in the event of a crash, be pivotable about a substantially horizontal axis, in particular about an axis running parallel to a transverse direction y. 
     According to the second exemplary embodiment, the crash bolts  90  each have a shoulder  236  adjoining a head  92  of the respective crash bolt  90 , which shoulders  236  each define a distance between the head  92  and the spindle nut  230 . In the present case, the head  92  is normally spaced apart from the second rail  14  and only comes into contact with the second rail  14  after the longitudinal adjuster  10  has been deformed under load, in particular in the event of a crash. 
     In the present case, one possibility of movement of the spindle nut  230  corresponding to a degree of freedom is a rotation of the spindle nut  230  about a substantially vertical axis, in particular an axis A of the fixing means  80 . In the region of the crash bolts  90 , the second rail  14  can also move to a limited extent in the vertical direction z between the head  92  and the spindle nut  230 . 
       FIGS. 9 and 10  show the spindle nut  330  according to a third embodiment. The spindle nut  330  has a basic body  332 . The spindle nut  330  has a continuous threaded bore which is oriented in particular parallel to the longitudinal direction x and has an internal thread. The internal thread of the spindle nut  330  is operatively connected to an external thread of the spindle  20 . 
     The spindle nut  330  is connected to the second rail  14  by means of two crash bolts  90 . For this purpose, the second rail  14  has two first openings  14   a , through each of which a crash bolt  90  is passed. Furthermore, a gap  100  is provided around the crash bolts  90 , between the bolts and the second rail  14 . The crash bolts  90  each have a shoulder  336  adjoining a head  92  of the respective crash bolt  90 , which shoulders  336  each define a distance between the head  92  and the spindle nut  330 . In the present case, the head  92  is normally spaced apart from the second rail  14  and only comes into contact with the second rail  14  after the longitudinal adjuster  10  has been deformed under load, in particular in the event of a crash. 
     An elastic means  338  is arranged between the basic body  332  of the spindle nut  330  and the second rail  14 . In the present case, the elastic means  338  is a buffer  338 , in particular a flat buffer  338 , made of a plastic, in particular a rubber. A further buffer  338 , in particular an annular buffer  338 , made of a plastic, in particular a rubber, is arranged between the head  92  of each of the crash bolts  90  and the second rail  14 . 
     In the present case, one possibility of movement of the spindle nut  330  corresponding to a degree of freedom is a rotation of the spindle nut  330  about a substantially vertical axis which is limited by a respective position of the crash bolts  90  in the first openings  14   a  in the second rail  14 . 
     Another possibility of movement of the spindle nut  330  corresponding to the degree of freedom can be a movement of the spindle nut  330  in the vertical direction z, which is influenceable by the elastic properties of the material of the buffers  338 . 
     Another possibility of movement of the spindle nut  330  corresponding to the degree of freedom can be a pivoting of the spindle nut  330  about a substantially horizontal axis, in particular along an imaginary connecting line between the two crash bolts  90 , which is also influenceable by the elastic properties of the material of the buffers  338 . 
       FIGS. 11 and 12  show the spindle nut  30  according to a fourth exemplary embodiment. The spindle nut  430  has a basic body  432 . The spindle nut  430  has a continuous threaded bore which is oriented in particular parallel to the longitudinal direction x and has an internal thread. The internal thread of the spindle nut  430  is operatively connected to an external thread of the spindle  20 . 
     The spindle nut  430  is connected to the second rail  14  by means of two crash bolts  90 . For this purpose, the second rail  14  has two first openings  14   a , through each of which a crash bolt  90  is passed. Furthermore, a gap  100  is provided around the crash bolts  90 , between the bolts and the second rail  14 . The crash bolts  90  each have a shoulder  436  adjoining a head  92  of the respective crash bolt  90 , which shoulders  336  each define a distance between the head  92  and the spindle nut  430 . In the present case, the head  92  is normally spaced apart from the second rail  14  and only comes into contact with the second rail  14  after the longitudinal adjuster  10  has been deformed under load, in particular in the event of a crash. 
     An elastic means is arranged between the basic body  432  of the spindle nut  430  and the second rail  14 . A metal spring  438 , in particular a metallic leaf spring  438 , can be arranged between the basic body  432  of the spindle nut  430  and the second rail  14 . A respective buffer  440 , in particular an annular buffer  440 , can be arranged between the head  92  of each of the crash bolts  90  and the second rail  14 . In the present case, the buffer  440  is made of metal. 
     Alternatively, the buffer  440  can be made of metal on the one hand and plastic or rubber on the other hand. One side of the buffer  440  facing the head  92  can be made of metal and a side of the buffer  440  facing the second rail  14  can be made of plastic and/or rubber. Alternatively, a side of the buffer  440  facing the second rail  14  can be made of metal and a side of the buffer  440  facing the head  92  can be made of plastic and/or rubber. 
     In the present case, one possibility of movement of the spindle nut  430  corresponding to a degree of freedom is a rotation of the spindle nut  430  about a substantially vertical axis which is limited by a respective position of the crash bolts  90  in the first openings  14   a  in the second rail  14 . 
     Another possibility of movement of the spindle nut  430  corresponding to the degree of freedom can be a movement of the spindle nut  430  in the vertical direction z, which is influenceable by the elastic properties of the material of the metal spring  438 . 
     Another possibility of movement of the spindle nut  430  corresponding to the degree of freedom can be a pivoting of the spindle nut  430  about a substantially horizontal axis, in particular along an imaginary connecting line between the two crash bolts  90 , which is also influenceable by the elastic properties of the material of the metal spring  438  and is limited by the dimensions of the first openings  14   a  and the heads  92  of the crash bolts  90 . 
     The features which are disclosed in the description above, in the claims, and in the figures may be of importance, both individually and in combination, for the implementation of the invention in its various configurations. 
     Although the invention has been described in detail in the figures and in the above illustration, the illustrations should be understood as being illustrative and by way of example and not as restrictive. In particular, the selection of the graphically illustrated proportions of the individual elements should not be interpreted as being required or limiting. Furthermore, the invention is in particular not limited to the exemplary embodiments discussed. Further variants of the invention and the implementation thereof are apparent to a person skilled in the art from the preceding disclosure, from the figures and from the claims. 
     Terms such as “comprise”, “have”, “include”, “contain” and the like used in the claims do not rule out further elements or steps. The use of the indefinite article does not rule out a plurality. A single device can perform the functions of a plurality of units or devices mentioned in the claims. 
     LIST OF REFERENCE SIGNS 
     
         
           1  Vehicle seat 
           2  Seat part 
           4  Backrest 
           10  Longitudinal adjuster 
           12  First rail 
           14  Second rail 
           14   a  First opening 
           14   b  Second opening 
           16  Inner channel 
         Spindle 
           20   a  Front end section (of the spindle  20 ) 
           20   b  Rear end section (of the spindle  20 ) 
           50  Spindle gear 
           60  Motor 
           70  Motor carrier 
           80  Fixing means 
           90  Crash bolt 
           92  Head 
           100  Gap 
           130  Spindle nut 
           132  Basic body 
           134  Projection 
           136  Shoulder 
           230  Spindle nut 
           232  Basic body 
           234  Projection 
           236  Shoulder 
           330  Spindle nut 
           332  Basic body 
           336  Shoulder 
           338  Elastic means, buffer 
           430  Spindle nut 
           432  Basic body 
           436  Shoulder 
           438  Spring means, leaf spring 
           440  Buffer 
         S Spindle axis (of the spindle  20 ) 
         A Axis (of the fixing means) 
         x Longitudinal direction 
         y Transverse direction 
         z Vertical direction