FR3058952A1 - SUSPENSION DEVICE FOR SEAT FRAME FOR MOTOR VEHICLE SEAT - Google Patents

Abstract

The invention relates to a suspension device for a seat frame comprising a base (30), a suspended frame (40) for supporting said seat frame (10) and a compression spring (50) whose ends are respectively coupled to said base and to said frame, said frame being hingedly mounted on said base via a first pair of front bells (42) and a second pair of rear bails (44), both of which ends are respectively articulated to said base and said frame, the intersection between the plane (PA) defined by the transverse axes of articulation (A1, A2) of the front links and that (PB) defined by the transverse axes of articulation ( B1, B2) rear links constituting the instantaneous transverse axis of rotation (AIR) of said suspended frame, said rods being further arranged so that said instantaneous axis of rotation (AIR) is systematically located in a and above said frame (40).

Description

Holder (s): PEUGEOT CITROEN AUTOMOBILES SA Société anonyme.

Extension request (s)

Agent (s): PEUGEOT CITROEN AUTOMOBILES SA Public limited company.

FR 3 058 952 - A1 (54) SUSPENSION DEVICE FOR A SEAT FRAME OF A MOTOR VEHICLE.

©) The invention relates to a suspension device for a seat seat frame comprising a base (30), a suspended frame (40) intended to support said seat frame (10) and a compression spring (50), the ends are respectively coupled to said base and to said chassis, said chassis being mounted articulated on said base by means of a first pair of front connecting rods (42) and a second pair of rear connecting rods (44), of which the two ends are respectively articulated to said base and to said chassis, the intersection between the plane (P _A ) defined by the transverse articulation axes (A- ,, A ₂ ) of the front links and that (P _B ) defined by the transverse articulation axes (B _h B ₂ ) of the rear links constituting the instantaneous transverse axis of rotation (A | _R ) of said suspended chassis, said links being further arranged so that said instantaneous axis of rotation (A | _R ) or systematically ement located in front of and above said chassis (40).

SUSPENSION DEVICE FOR. MOTOR VEHICLE SEAT FRAME

Field of the invention

The present invention relates generally to a suspension device for a seat frame of a vehicle seat, in particular of the automobile type.

Invention background

In the rolling phase of a vehicle, the roughness of the road generates vibrations which partially affect the seats and negatively impact the comfort level of the occupants of this vehicle.

In addition, in the long term, the repetition of these vibrations can have consequences on their state of health, for example by causing trauma to the lumbar region.

In order to limit these vibrations, it is known to provide a suspension device for the seat frame of such a seat.

Patent application EP 0600855A4 proposes such a suspension device comprising a basic structure intended to be moored to the floor of the vehicle and a suspended structure intended to support the seat frame of said seat.

Several link arms arranged in scissors connect the structures together, overlapping cam tracks which have profiles in which engage rollers fixed to springs anchored on the basic structure. During the movement of the structures towards each other, the springs extend as the rollers move along the cam tracks in order to apply a restoring force on the structures.

When the vehicle is subjected to a significant deceleration in the event of a front impact or dry braking, it turns out that the passenger tends to slip under the lap strap of the seat belt.

This phenomenon known as submarining tends to cause injuries to the passenger's abdomen and lumbar spine.

Subject and summary of the invention

The present invention therefore aims to provide a suspension device for a vehicle seat improving passenger safety.

To this end, it proposes a suspension device for a seat frame of a vehicle seat comprising a base intended to be moored to the floor of said vehicle, a suspended chassis intended to support said seat frame and suspension means mounted between said base and said chassis;

characterized in that said suspension means comprise a compression spring, the two ends of which are respectively coupled to said base and to said chassis, and in that said chassis is mounted articulated on said base by means of a first pair of rods symmetrical front side and a second pair of symmetrical rear side links, the first and second ends of which are respectively articulated to said base and to said chassis along transverse axes, the intersection between the plane defined by the transverse articulation axes of the rods front and the plane P _B defined by the transverse articulation axes of the rear links constituting the instantaneous transverse axis of rotation of said chassis suspended with respect to said base, said front and rear links being further arranged so that said instantaneous axis of rotation is systematically located in front and above s of said chassis.

This particular arrangement of the two pairs of front and rear links makes it possible, when the vehicle is subjected to a significant deceleration in the event of a front impact or dry braking, to cause the rear part of the chassis to tip down (and therefore that of the seat frame) opposing the sliding under the lap strap of the seat belt of the passenger seated on this seat frame.

According to preferred characteristics of the suspension device, taken alone or in combination:

- Said front and rear links are arranged so that the longitudinal spacing between said instantaneous axis of rotation and said seat frame is at least twice greater than their spacing in height;

- The links of at least one of the two said pairs of front and rear links have an adjustable length or positioning so as to vary the position of said instantaneous transverse axis of rotation;

- Said suspension device comprises an electronic control module capable of automatically ensuring the length adjustment or the positioning of said links;

- Said suspension device comprises a manual control system capable of allowing the length adjustment or the positioning of said links;

- Said suspension means further comprise a damper comprising a piston rod movably mounted in a cylindrical body, the free ends of said rod and of said body being respectively coupled to said base and to said chassis or vice versa; and or

- Said base is provided with two lateral rails mounted movable to slide along the two longitudinal slides intended to be fixed to the floor of said vehicle.

The invention also relates in a second aspect to a seat frame comprising such a suspension device and a seat frame supported by said suspended frame.

According to advantageous characteristics taken alone or in combination:

- Said front and rear links are arranged so that said instantaneous axis of rotation is systematically located in front of and above said seat frame; and or

- Said seat frame is connected to said chassis by means of a raising device making it possible to adjust the height of said seat frame with respect to said chassis.

Brief description of the drawings

The description of the invention will now be continued with the detailed description of an exemplary embodiment, given below by way of illustration but not limitation, with reference to the appended drawings, in which:

- Figure 1 shows an exploded perspective view of a seat frame provided with a suspension device according to the invention; and

- Figure 2 is a side view of the seat frame of Figure 1.

Detailed description of an embodiment

The terms "front", "rear", "top", "bottom", "upper", "lower", "lateral", "longitudinal" and "transverse" used in the remainder of this description are defined with respect to the mounting position of a motor vehicle seat in the passenger compartment of this vehicle.

Figures 1 and 2 show a seat frame 1 of a motor vehicle seat according to a preferred embodiment of the invention.

This frame 1 comprises a seat frame 10 supported by a suspension device 20 according to the invention.

The seat frame 10 comprises two lateral flanges 11, 12 arranged facing one another, between the front ends of which which extends a tubular bar of transverse front connection 13 and between the rear ends of which extends a rear transverse connecting tubular bar 14.

The two transverse connecting bars 13, 14 support an elastic suspension sheet 15 which comprises several crenellated metal wires 16 extending between the latter and arranged at regular intervals over the width of the seat frame 10.

The elastic ply 15 further comprises a plurality of hooks 17 disposed at the two ends of each of the wires 16 and making it possible to secure their attachment to the two connecting bars 13, 14.

These metal wires 16 are also joined together by connecting spacers 18 making it possible to better distribute the forces exerted on the latter when a passenger is seated on the seat.

The suspension device 20 comprises a metal base 30 provided with two side rails mounted 31, 32 movable to slide along the two longitudinal rails 33, 34 intended to be fixed to the floor of a vehicle, so as to allow a longitudinal adjustment of the position of the seat while maintaining this basic structure 30 moored to this floor.

The suspension device 20 also comprises a suspended metal frame 40 overhanging the base 30 and supporting the seat frame 10.

This device 20 further comprises a compression spring shown schematically in the drawings by the cylinder 50 and which may be of the mechanical, pneumatic or hydraulic type. Its two lower and upper ends are respectively coupled to the front part of the base 30 and to that of the suspended chassis 40.

The lower end of the spring 50 is rigidly linked to a first element pivotally mounted on the base 30 around a transverse axis Ci (Figure 2) while its upper end 52 is rigidly linked to a second element pivotally mounted on the chassis suspended 40 around a transverse axis C ₂ .

The suspension device 20 finally comprises a double-acting pneumatic or hydraulic shock absorber 60 conventionally comprising a piston rod 61 movably mounted in a cylindrical body 62.

The free end of the piston rod 61 constituting the lower end of the damper 60 is coupled to the rear part of the base 30 while the free end of the cylindrical body 62 constituting the upper end of this damper 60 is coupled to the rear part of the suspended chassis 40.

More specifically, the free end of the piston rod 61 is pivotally mounted on the base 30 around a transverse axis Di while the free end of the cylindrical body 62 is pivotally mounted on the suspended chassis 40 around a transverse axis D ₂ (Figure 2).

The presence of this damper 60 makes it possible to improve the comfort of suspension by limiting the amplitude of the elastic return forces transmitted to the suspended chassis 40 via the spring 50.

The suspended chassis 40 is articulated on the base 30 by means of a first pair of symmetrical front side links 41, 42 and a second pair of symmetrical rear side links 43, 44.

More specifically, the first ends of the front links 41, 42 are articulated in rotation on the base 30 around a first transverse axis Ai, while their second ends are articulated in rotation on the suspended chassis 40 around a second axis transverse A ₂ .

The first ends of the rear links 43, 44 are articulated in rotation on the base 30 around a third transverse axis Bi, while their second ends are articulated in rotation on the suspended chassis 40 around a fourth transverse axis B ₂ .

The intersection between the plane P _A defined by the transverse articulation axes Ai, A ₂ of the front links 41, 42 and the plane P _B defined by the transverse articulation axes Bi, B ₂ of the rear links 43, 44 constitutes thus the instantaneous transverse axis of rotation A _IR of the suspended chassis 40 vis-à-vis the base 30, axis whose position varies as a function of the position of the front links 41, 42 and rear 43, 44 and therefore of the spacing between the chassis 40 and the base 30.

The arrangement of the front links 41, 42 and rear link 43, 44 is defined so that this instantaneous axis of rotation A _IR is systematically located in front of and above the chassis 40.

Thanks to this particular configuration, and unlike existing devices, the suspension device 20 makes it possible to cause the seat frame 10 to tilt downwards when the vehicle is subjected to a significant deceleration in the event of a front impact or dry braking, which contributes to improving passenger safety by preventing them from slipping under the lap strap of the seat belt and from being injured (anti-submarining function).

Advantageously, the front links 41, 42 and rear 43, 44 are arranged so that this instantaneous axis of rotation Air is also located at the front (advantageously from 30 to 120 cm) and above (advantageously from 15 to 60 cm) of the seat frame 10. This arrangement makes it possible to provide better suspension comfort for the passenger seated on this seat frame.

Preferably, the front links 41, 42 and rear 43, 44 are also arranged so that the longitudinal spacing between this instantaneous axis of rotation Air and the seat frame 10 is at least twice as large as their spacing in height .

Such a configuration makes it possible to limit the longitudinal movement of the passenger seated on this seat frame 10, the displacement of which is essentially vertical, which is particularly advantageous when the suspension device is installed on a driver's seat because the distance between the pedals and the driver's legs varied little.

The seat frame 10 is connected to the suspended frame 40 by means of a raising device 70 making it possible to adjust the height of this seat frame 10 with respect to the frame 40.

This raising device comprises a first pair of front symmetrical side connecting rods 71, 72 and a second pair of rear symmetrical side connecting rods 73, 74 mounted articulated between the seat frame 10 and the suspended chassis 40.

More specifically, the first ends of the front connecting rods 71, 72 are articulated in rotation on the suspended chassis 40 about a transverse axis Ei, while their second ends are articulated in rotation on the seat frame 10 around an axis transverse E ₂ .

The first ends of the rear connecting rods 73, 74 are articulated in rotation on the suspended chassis 40 about a transverse axis Fi, while their second ends are articulated in rotation on the seat frame 10 around a transverse axis F ₂ .

The raising device 70 further comprises a control mechanism cooperating with the rear connecting rod 74 to drive it in rotation (as well as the other three connecting rods 71, 72, 73 due to the intrinsic rigidity of the seat frame 10) of so as to cause a variation in the height of the seat frame 10.

This control mechanism comprises a pinion disposed on the internal side of the lateral flange 12 and driven with a toothed sector situated on the periphery of a protrusion 74A presented by the rear link 74 (the pinion and the toothed sector not being visible in the figures. because hidden by the side flange 12).

This pinion is connected by a shaft passing through the lateral flange 12 to an adjustment wheel 75 arranged on the external side of this flange 12 so that the rotation of this wheel 71 by a user causes that of the pinion and therefore that of the rear toothed connecting rod. 74.

According to an alternative embodiment not shown, the links of at least one of the two pairs of front links 41, 42 and rear 43, 44 have an adjustable length or positioning so as to vary the position of the transverse axis instantaneous rotation A _ÎR of the suspended chassis 40 in order to adapt it to the morphology and mass of the passenger or to different types of driving (sporty, comfort, etc.).

This adjustment can either be carried out directly by the seat passenger via a manual control system, or carried out automatically by an electronic control module connected to a plurality of sensors installed in the vehicle and capable of evaluating the driving context.

According to other embodiments not shown, the suspension device does not include a shock absorber or the latter is single acting.

According to yet other alternative embodiments not shown, the compression spring is arranged around the cylindrical body and a part of the piston rod of the shock absorber: its upper and lower ends being fixed respectively to an upper cup integral with the piston rod and to a lower cup secured to the cylindrical body.

Finally, it should be remembered that the present invention is not limited to the embodiments described and shown, but that it encompasses any variant within the reach of the skilled person.

Claims (10)

1. Suspension device for a seat frame of a vehicle seat comprising a base (30) intended to be moored to the floor of said vehicle, a suspended chassis (40) intended to support said seat frame (10) and means for suspension (50, 60) mounted between said base (30) and said chassis (40); characterized in that said suspension means comprise a compression spring (50) the two ends of which are respectively coupled to said base (30) and to said chassis (40), and in that said chassis (40) is mounted articulated on said base (30) by means of a first pair of symmetrical front side links (41, 42) and of a second pair of symmetrical rear side links (43, 44), the first and second ends of which are articulated respectively to said base base (30) and said chassis (40) along transverse axes (Ai, A ₂ , Bi, B ₂ ), the intersection between the plane (P _A ) defined by the transverse articulation axes (Ai, A ₂ ) front links (41, 42) and the plane (P _B ) defined by the transverse articulation axes (Bi, B ₂ ) of the rear links (43, 44) constituting the instantaneous transverse axis of rotation (Air) of said chassis suspended (40) with respect to said base (30), said links with ant (41, 42) and rear (43, 44) being further arranged so that said instantaneous axis of rotation (Air) is systematically located in front and above said chassis (40). 2. Suspension device according to claim 1, characterized in that said front links (41, 42) and rear (43, 44) are arranged so that the longitudinal spacing between said instantaneous axis of rotation (Air) and the said seat frame (10) is at least twice as large as their spacing in height. 3. Suspension device according to one of claims 1 or 2, characterized in that the links of at least one of the two so-called pairs of front and rear links have an adjustable length or positioning so as to vary the position of said instantaneous transverse axis of rotation (Air). 4. Suspension device according to claim 3, characterized in that it comprises an electronic control module capable of automatically ensuring the length adjustment or the positioning of said rods. 5. Suspension device according to claim 3, characterized in that it comprises a manual control system capable of allowing the length adjustment or the positioning of said rods. 6. Suspension device according to one of claims 1 to 5, characterized in that said suspension means further comprises a damper (60) comprising a piston rod (61) movably mounted in a cylindrical body (62), the free ends of said rod (61) and said body (62) being respectively coupled to said base (30) and to said chassis (40) or vice versa. 7. Suspension device according to one of claims 1 to 5, characterized in that said base (30) is provided with two lateral rails (31, 32) mounted movable to slide along the two longitudinal slides (33, 34) intended to be fixed to the floor of said vehicle. 8. Seat frame comprising a suspension device according to one of claims 1 to 7 and a seat frame (10) supported by said suspended frame (40). 9. Seat frame according to claim 8, characterized in that said front links (41, 42) and rear (43, 44) are arranged so that said instantaneous axis of rotation (Air) is systematically located in front and at above said seat frame (10). 10. Seat frame according to one of claims 8 or 9, characterized in that said seat frame (10) is connected to said chassis (40) by means of a raising device (70) making it possible to adjust the height of said seat frame (10) with respect to said frame (40).