FR2829727A1 - Power operated adjustable seat for motor vehicle, has common synchronized drive for seat squab and backrest - Google Patents

Abstract

The power operated adjustable seat (1) for a motor vehicle has a squab (4) and a backrest (2) adjustable with respect to the squab. The backrest is mounted at the sides of the squab by bearings each with a transmission (7,8). The transmission passes drive to the backrest for tilting. The adjusters for the seat squab and the backrest have synchronized electric regulators (30,31) with a common control (33).

Description

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Technical area
The present invention relates to a vehicle seat comprising a seat surface and a seat back structure, adjustable relative thereto, this structure being received in two bearings provided on each side of the seat surface, these bearings each comprising a transmission device transmitting the pivoting movement of a drive to the seat back structure.

 The seats of vehicles, for example of motor vehicles, are currently often equipped with electric adjustment drives to allow individual adjustment of the seating position. It is sought to use only one adjustment drive per adjustment plane for reasons of economy and size.

State of the art
Document DE 92 04 166.3 U describes a device for adjusting the height of the seat by an electric motor, in particular for a vehicle seat. The device comprises an electric motor and two lifting transmissions driven by the latter and symmetrically associated with the seat surface; these transmissions each comprise a threaded sleeve driven by the electric motor and which rotates in the direction of vertical alignment in the housing. The threaded sleeve is supported by its upper front face, by means of a compression spring, axially against the housing. There is also a coaxial pin which screws into the threaded sleeve; the end of this pin projecting from the housing is integrally connected to the lower side of the seat and has a stop fixed near the end of the pin. The stop is applied against a counter-stop provided in the spindle adjustment stroke to axially limit the inward movement of the spindle. The counter-stop freely protrudes from the upper wall of the housing surrounding the spindle and is joined integrally by the latter by an annular washer provided between the upper face of the threaded sleeve and the compression spring.

 Document DE 31 29 101 A1 relates to a device adjustable in length for adjusting the position of a vehicle seat. In this device provided in particular for adjusting the height and / or the inclination of the vehicle seat and which comprises a driven sleeve, axially blocked but rotating relative to the housing, and having an internal thread engaged with the external thread of a part , depending on the direction of rotation of the sleeve, this part will move in the inward or outward direction

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 to allow the greatest possible length of the stroke to be achieved relative to the length of the device. For this, the part guided in the sleeve is produced in two parts, namely in the form of an external sleeve with an external thread and an internal thread, the internal thread being engaged with a threaded rod constituting with the sleeve, a rod telescopic which can lengthen or shorten by relative movement.

 Document DE 199 22 645. 8 relates to a manual and / or automatic adjustment device for a vehicle seat comprising several elements. Adjustment means act on the elements of the vehicle seat; these seat elements consist of at least a seat cushion and a seat back. The adjustment means act on the seat elements so that by adjusting the backrest, the ratio between the length of the seat backrest and the length of the seat cushion is adjusted.

 DE 198 60 190 A1 relates to a vehicle seat with a seat frame and a base frame. The base frame has two longitudinal guides adjustable by a motor; these guides are constituted each time by a floor rail and a seat rail; the seat frame is carried by the two rails. Each of the two longitudinal guides is equipped with its own motor for its longitudinal displacement so that at least one longitudinal guide is associated with an installation detecting the relative position of its seat rail relative to its floor rail.

 According to the state of the art, motorized backrest tilt adjustment installations are known. In these installations, either a shaft transverse to the two back frames is used which transmits the drive torque from the motor to the two nutation movement transmissions, or else an offset transmission shaft is used which is located above the points. articulation between the backrest and the seat cushion or seat. These two solutions according to the state of the art have in common the need for space at the back cushion and thus limit the comfort that the seat can give because of the limited suspension possibilities of the seat or seat surface. In addition, the installation of an offset transmission shaft or an elongated transmission shaft does not make it possible to produce slender and thin back frames.

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Statement of the invention
The present invention aims to remedy the drawbacks of known solutions and to this end relates to an adjustable seat of a motor vehicle of the type defined above, characterized in that an electric adjustment drive is associated with each transmission device fitted to the seat surface, these adjustment drives being capable of being electrically synchronized.

 Preferably, the transmission devices are nutation movement transmissions.

 The solution according to the invention makes it possible to use the overall depth available at the level of the backrest frame in the tilting / suspension range of the backrest frame because the drive torque drive shaft is removed from the adjustment drive. to the other side of the seat. Mechanical synchronization of nutation movement transmissions producing backrest adjustment with respect to the seating surface becomes unnecessary because the respective pivoting bearings of the seat backrest structure made in several parts are associated each time with separate adjustment drives.

 The adjustment drives can be integrated mainly in the vertical mounting position in the seat back structure; the drive shaft is eliminated because the synchronization of the two adjustment drives takes place below the seat back construction to achieve a regular pivoting movement and at the same time reach intermediate positions along the pivoting stroke or the abutted against an abutment surface, proceeding analogically, for example by a potentiometer or digitally by the use of Hall sensors. A mechanical connection in the form of a drive shaft limiting the volume of construction below the seat surface of a vehicle seat can thus be eliminated.

 The transmission shaft offset from the pivot range, known from the prior art certainly results in an increase in the volume available below the seat surface but, due to its raised mounting position, is limited , the tilting range of the seat back structure pivotally mounted on the seat surface. The solution proposed according to the invention and consisting in providing an adjustment drive acting directly on each of the nutation movement transmissions, is less dependent on the

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 mounting editions and provides a more flexible swivel range for a seat back structure.

 The respective pivoting strokes of the nutation movement transmissions at the pivoting bearing points of the seat back structure on the seat surface can be detected in a control device, processing and processing the analog digital potentiometer signals Hall sensors, to determine the pivoting stroke of the seat back structure.

 Thus, the invention provides a control device associated with the electrical adjustment drives, this device comparing the rotations of the two electrical adjustment drives with each other. In addition, potentiometers or Hall elements are associated with the electric adjustment drives and / or the transmission devices, elements detecting the rotations of the adjustment drives and / or the pivoting movement of the seat back structure.

In addition, thanks to the solution of the invention, the arrangement of the two adjustment drives on the pivot bearings of the seat back structure can be saved for the last adjusted seat back position. The storage of the last seat position adjusted can be saved in memory and can be called up according to an access or identification code for the driver or passenger, so as to allow automatic recognition of that person and position as requested.

According to other advantageous features: - the seat back structure made in several parts, including a part of the shoulders capable of being bent and a headrest connected to it, is equipped with a third drive of adjustment as well as another adjustment drive, the multi-part seat back structure being pivotable relative to the seating surface via the first and second adjustment drives; - the part of the shoulders capable of being folded, is moved by means of a driven connecting rod, guided in a slide, relative to the back part, above the point of flexion of the seat back structure in several parts; - the first and second adjustment drives associated with the transmission devices, the adjustment drives associated with the part of the shoulders that can flex and another adjustment drive ensuring

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 the longitudinal adjustment (A), are controlled by a central control; - the adjustment positions of the adjustment drives are saved in a memory associated with the command and these adjustment positions can be called up in this memory.

- la figure 3 est une vue de côté de l'arbre de transmission mécanique installé dans la structure de dossier de siège, - la figure 4 est une vue de dessus de la structure de dossier de siège selon la figure 3, - la figure 5 montre l'entraînement proposé selon l'invention d'une structure de dossier de siège à deux entraînements de réglage, - la figure 6 est une structure de dossier de siège en plusieurs parties dont le mouvement de pivotement est produit par deux entraînements de réglage. drawings
The present invention will be described below in more detail with the aid of exemplary embodiments shown in the appended drawings in which: - Figure 1 shows a drive for adjusting a seat back structure in one single part with a drive shaft, the assembly being seen from the front, - Figure 2 is a side view of the seat back adjustment drive of Figure 1,

- Figure 3 is a side view of the mechanical drive shaft installed in the seat back structure, - Figure 4 is a top view of the seat back structure according to Figure 3, - Figure 5 shows the drive proposed according to the invention of a seat back structure with two adjustment drives, - Figure 6 is a seat back structure in several parts whose pivoting movement is produced by two adjustment drives.

Description of the embodiments
FIG. 1 shows an adjustment drive for a seat back structure in one piece, this drive acting by means of a drive shaft on a nutation movement transmission provided opposite the adjustment drive in below the structure of the backrest seat.

 According to Figure 1, the vehicle seat 1 comprises a backrest structure 2 equipped with a headrest 3. The headrest 3 can be raised and lowered in the vertical direction relative to the seat backrest structure 2 The seat back structure 2 is delimited by two parts of the back frame 5, in the form of a bead. Perpendicular to the plane of the drawing according to Figure 1 there is a seat surface 4 which is also adjustable relative to the floor of the vehicle. The seat surface 4 incorporates an adjustment drive 6 constituted in the view of FIG. 1 in the form of an electric motor 10 installed in the vertical position

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 down. The adjustment drive 6 acts via a transmission flange on a first nutation movement transmission 7 acting through a transmission shaft 9 passing transversely under the seat surface 4 on a second transmission with nutation movement 8. The transmission shaft 9 extends from the first nutation movement transmission 7 to the second nutation movement transmission 8 so as to synchronize the two nutation movement transmissions via of the transmission shaft 9 so that it performs practically the same tilting movements dependent on the speed of rotation of the electric motor 10. The transmission shaft 9 which extends from the first transmission with nutation movement 7 until the second nutation movement transmission 8 passes over the surface 4 of the seat and thus greatly limits the space available for the suspension d e the lower area of the backrest.

 FIG. 2 is a side view of the seat back adjustment drive according to the view in FIG. 1.

 The seat back structure 2 configured in one piece in Figure 1 includes in the upper area the headrest 3 sliding in the vertical direction. The seat back structure 2 according to the view in FIG. 2 is mounted on a bearing panel 20; this panel is connected by the first nutation movement transmission 7 with the bearing panel 11 to the seat surface 4 for a pivoting movement. The control of the electric motor 10 of the electric adjustment drive 6 supplies a motor torque to the first nutation movement transmission 7 which makes it possible to tilt the seat back structure 2 relative to the seat surface 4. The face upper part of the seat surface 4 bears the reference 12; the reference 13 designates the bead of the back protruding from the back surface of the seat back structure 2. The transmission shaft 9 which transmits the drive torque of the adjustment drive 6 of the first nutation movement transmission 7 to the second nutation movement transmission 8, opposite, is perpendicular to the plane of the drawing in FIG. 2.

 Figure 3 shows a seat structure using an offset mechanical transmission shaft.

 According to the view in Figure 3, the bearing panel 20 connected to the seat back structure 2 is pivotally mounted relative to

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 to the bearing panel 11 of the seat surface 4 not shown here. The bearing panel 11 of the seat surface 4 not shown is fixed by fixing holes 27 in a stationary or sliding manner in housings to allow the vehicle seat to be moved manually or electrically relative to the floor of the vehicle.

 The seat back structure 2, the upper part of which is equipped with the headrest device 3 is adjusted by driving the pinion 22 by means of the adjustment drive 6 not shown in FIG. 3; the pinion 22 meshes with a pinion 21 carried by the transmission shaft 24, offset. The reference 23 designates the tilting movement performed by the bearing panel 20 around the axis of the first or second nutation movement transmission 7,8; by this transmission, the bearing panel 20 of the seat back structure 2 as well as the bearing panel 11 of the seat surface 4 or seat surface, not shown here are pivotally connected.

 FIG. 4 shows a front view of the structure of the seat back in FIG. 3.

 The seat back structure 2 is provided in its rear part with a wire fabric 25 giving the rear face of the seat back structure 2 a certain elasticity. The tension in the wired chassis device 25 is reinforced by the integration of tension spring elements 26. The front view of FIG. 4 shows that the bearing panels 11 which can tilt one relative to the other of the seat surface 4.20 of the seat back structure 2 can be relatively adjusted by the first nutation movement transmission 7 or the second nutation movement transmission 8; in the view of Figure 4, the adjustment movement is provided by an electric motor 10 of the adjustment drive 6 by a transmission shaft 24, offset. Each of the nutation movement transmissions 7,8 comprises a pinion 22 transmitting the drive movement. The diameter of this pinion is a multiple of that of the pinion 21 carried by the end of the transmission shaft 24, offset, integral in rotation and transmitting the engine torque of the electric motor 10 by the transmission shaft 24 offset in the landing panels of the seatback structure 2, pivoting panel relative to the bearing panel 11 of the seating surface 4.

 Figure 5 shows the drive according to the invention of a seat back structure using two adjustment drives.

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 The view of FIG. 5 here shows a structure of the seat back 2, in a single piece whose rear surface of the back is delimited by chassis parts 5 in the form of a bead adapted to the anatomy of the human body. Above the seat back structure 2 in a single part in the view of FIG. 5, there is a headrest 3 adjustable in the vertical direction. Below the seat back structure 2, pivoting, produced in one piece in this case, there is at the rear zone of the seat surface 4 of the vehicle seat 1, a first transmission with nutation movement 7 as well as a second nutation movement transmission 8. Each of the nutation movement transmissions 7,8 comprises a transmission flange 32 on which is fixed a first adjustment drive 30 associated with the first nutation movement transmission 7 and a second adjustment drive 31 associated with the second nutation movement transmission 8.

The adjustment drives 30, 31 consisting of electric motors, are mounted essentially in a vertical position and extend with their length, partially in the bead-shaped chassis parts 5 of the pivoting structure 2 of the seat back.

 To synchronize the first adjustment drive 30 or the second adjustment drive 31, it is possible to use a control device 33 connected by a signal transmission line 34 to the first adjustment drive 30 and to the second adjustment drive 31.

The control device 33 can include either an internal memory part 33.1 with a standby function; it is also possible to use the vehicle's central electronic memory as a memory location.

 The number of rotations of the first adjustment drive 30 or the second adjustment drive 31 can be detected in an analogous manner, for example by potentiometers 35. The potentiometers 35 can be installed both on the outside of transmissions with nutation movement 7 , 8 as between the transmission flanges 32 and the inner side of the nutation movement transmissions 7,8. Another mounting possibility is to install them on the inside of the transmission flanges 32.

 In addition to an analog input of the instantaneous swivel angle of the adjustable seat backrest structure 2 relative to the seat surface 4, one can also enter the swivel angle of the seatback structure adjustable seat 2 in relation to the surface of

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 seat or seat with Hall 36 digital sensors in the adjustment drive. Electrical input (both digital and analog) of the number of rotational speeds of the adjustment drives 30,31 as well as of the pivoting position of the adjustable seat back structure 2 relative to the seat surface 4 allows these positions to be memorized in memory area 33.1 of the control unit 33. A selected seat position, adjusted for once in memory area 33.1 can be adjusted again within the framework of the memory function when the vehicle is accessed if this chosen position has been previously saved in memory area 33.1 and if the position has been modified in the meantime by a person using the vehicle seat. This makes it possible to save individually selected seat back positions in memory area 33.1 and to call them up as part of a memory function by the various users of the vehicle, so that the control unit 33 can restore the desired position, memorized for the seat back by the control of the drives 30, 31.

 FIG. 6 shows a seat back structure in several parts, the pivoting movements of which are produced by two adjustment drives.

 The vehicle seat 1 according to the view in FIG. 6 has a seat back structure 40 formed of several parts. The seat back structure 40 comprises a part of shoulders 41 pivoting around a point of flexion 48 and to this part is associated a headrest 3 which can deploy from this part 41 in the vertical direction. The headrest 3 and the shoulder part 41 pivot around a bending point 48. The bending movement of the shoulder part 41 and the headrest 3 sliding in the vertical direction with respect to this part can be guided relative to a back part 42 of the multi-part back structure 40 by means of a push rod 44 guided in a slide 43 of the shoulder part 41. The slide 43 or the upper end of the connecting rod 44 can be equipped with a third adjustment drive 45 with an electric motor.

 The lower end of the connecting rod 44 is received in the back part 42 of the seat back structure 40 in several parts; the pushing movement of the connecting rod 44 which takes place essentially in the vertical direction, is created by a fourth adjustment drive 46,

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 separate. For this, the lower end of the connecting rod 44 is connected to a pivoted lever by the fourth adjustment drive 46.

 In the position shown in phantom, in the articulation zone of the seat back structure 40 in several parts on the seat surface 4, the transmission devices 7,8 have been indicated; these devices transmit by adjustment drives 30,31 each time separated, avoiding the intermediate connection of a drive shaft, the pivoting movement to the seat back structure 40 in several parts, pivoting relative to the surface d 'seat 4.

 The seat surface or seat surface 4, the upper surface of which bears the reference 12, can be moved relative to a guide rail 49 by another adjustment drive 47 so as to allow the adjustment of the entire structure seat relative to the vehicle floor following the double arrow marked with the reference A.

 By activating the first adjustment drive 30 or the second adjustment drive 31 acting each time on one of the nutation movement transmissions 7,8, the inclination of the backrest can be modified according to the individual request of each driver or passenger; in the case of a seat back structure 40 in several parts, in particular it will be possible to carry out a precise adjustment of the length of the part of the shoulders 41 and of the headrest 3 which equips it according to the double arrow B.

 The fifth adjustment drive 47 makes it possible to move the whole of the vehicle seat 1 relative to the floor of the vehicle along the double arrow A in the longitudinal direction of the vehicle.

 The view of FIG. 6 further shows that both the first adjustment drive 30 and the second adjustment drive 31 can be connected to a central control 51 to ensure the pivoting movement of the seat back structure 2, 40 in one or more parts. In addition, the third drive 45 or the fourth drive 46 are connected to the central control 51. The third drive 45 is used to fold the shoulder portion 41 relative to the back portion 42 of a seat back structure 40 in several parts. In addition, the fifth adjustment drive 47 which ensures the longitudinal sliding of the seat surface 4 and thus that of the entire seat 1, which is also preferably equipped with an electric motor is connected to the central control part. 51. Each of the drive means with an electric motor 30, 31, 45, 46, 47 can be

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 associate, according to the view in FIG. 6, an input installation detecting the speed of rotation as the current position of the adjustment drive by analog channel (potentiometer 35) or a digital installation (Hall sensor 36) detecting the position; thus, all the positions of the electrical adjustment drives 30, 31, 45, 46, 47 can be entered in the central control 51. The storage of the positions taken by the various adjustment drives 30, 31, 45, 46, 47 can be do this in an external memory 52 associated with the command 51. As part of a memory function which must also be carried out in the command 51 or in the control device 33 according to FIG. 5, the occupants can individually store the different seat backrest and seat positions and when using vehicle seat 1, call the adjustment of the individually preset positions, memorized, to replace it with another position specific to the person. Thus, the electric adjustment drives 30, 31, 45, 46, 47 are controlled so as to be able to adjust the desired position of the seating surface 4 and of the seat back structure (whether it is a structure seat 2 in one part or a seat structure 40 in several parts) according to the view of FIG. 6, by an individual implementation.

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 NOMENCLATURE 1 Vehicle seat 2 One-piece seat back structure 3 Headrest 4 Seat or seat surface 5 Back frame 6 Adjustment drive 7 First transmission with nutation movement 8 Second transmission with nutation movement 9 Shaft 10 Electric motor 11 Seat surface bearing panel 12 Upper face of the seat 13 Back pad 20 Seat back structure bearing panel 21 Pinion drive shaft 22 Pinion 23 Pivot range 24 Drive shaft, offset 25 Tensioned wire frame 26 Tension spring 27 Fixing hole 30 First adjustment drive 31 Second adjustment drive 32 Transmission flange 33 Control unit 33.1 Internal memory range 34 Signal transmission line 35 Potentiometer 36 Hall sensor 40 Multi-part seat back structure 41 Shoulder part 42 Seat back part 43 Co ulisse 44 connecting rod

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 45 Third adjustment drive 46 Fourth adjustment drive 47 Fifth adjustment drive 48 Bending point 49 Guide rail 51 Control 52 Memory A Longitudinal direction of vehicle B Extension of shoulder part L Backrest length Sliding range of vehicle seat 1.

Claims (1)

 CLAIMS 1) Vehicle seat comprising a seat surface (4) and a seat back structure (2,40), adjustable relative thereto, this structure being received in two bearings provided on each side of the surface seat (4), these bearings each comprising a transmission device (7,8) transmitting the pivoting movement of a drive to the seat back structure (20,40), characterized in that an adjustment drive (30,31) electric is associated with each transmission device (7,8) equipping the seat surface (4), these adjustment drives being capable of being electrically synchronized.  2) vehicle seat according to claim 1, characterized in that the transmission devices (7,8) are nutation movement transmissions.  3) Vehicle seat according to claim 1, characterized by a control device (33) associated with the electric adjustment drives (30,31), this device comparing between them the rotations of the two electric adjustment drives (30,31).  4) vehicle seat according to claim 3, characterized in that potentiometers (35) are associated with electric adjustment drives (30,31) and / or transmission devices (7,8), potentiometers for detecting rotations adjustment drives (30,31) and / or the pivoting movements of the seat back structure (2, 40).  5) Vehicle seat according to claim 3, characterized in that Hall elements (36) are associated with the electric adjustment drives (30,31) and / or the transmission devices (7,8), elements detecting the rotations of the adjustment drives (30,31) and / or the pivoting movement of the seat back structure (2,40). <Desc / CRUD Page number 15>  6) Vehicle seat according to any one of claims 4 or 5, characterized in that the pivoting position of the seat back structure (2,40) is recorded relative to the seat surface (4) in the memory area (33.1) of the control unit (33) and this position can be called up in the memory.  7) vehicle seat according to claim 1, characterized in that the seat back structure (40) made in several parts, comprising a part of the shoulders (41) capable of being bent and a headrest (3) connected to this, is equipped with a third adjustment drive (45) as well as with another adjustment drive (46), the seat back structure (40) in several parts being pivotable relative to the surface d 'seat (4) via the first and second adjustment drive (30,31).  8) Vehicle seat according to claim 7, characterized in that the part of the shoulders (41) capable of being folded, is moved by means of a rod (44) driven, guided in a slide (43), relative to the backrest part (42), above the bending point (48) of the multi-part seat backrest structure (40).  9) Vehicle seat according to claim 7, characterized in that the first and the second adjustment drive (30,31) associated with the transmission devices (7,8), the adjustment drives (45,46) associated with the part of shoulders (41) which can flex and another adjustment drive (47) ensuring the longitudinal adjustment (A), are controlled by a central control (51).  10) vehicle seat according to claim 9, characterized in that the adjustment positions of the adjustment drives (30,31, 45,46, 47) are recorded in a memory (52) associated with the control (51) and these adjustment positions can be called up in this memory.