FR2950294A1 - Seat backrest inclination control device for e.g. car, has control unit determining retardation rule based on value taken by parameters, in case of receiving of alarm signaling impact or possibility of impact in rear part of vehicle - Google Patents

Abstract

The device (D) has a control unit (MC) permitting unlocking of rotation of a backrest (DS) of a seat (SI) of a vehicle (V) by action of a locking mechanism (MV), and determining a retardation rule based on a value taken by parameters, in case of receiving of alarm signaling an impact or possibility of impact in a rear part (PR) of the vehicle. A retardation unit (MF) e.g. electromagnetic or hydraulic retardation unit, retards the rotation of the backrest along the determined retardation rule. The rule defines retardation intensity to be applied between support and stop positions. The parameters represent valuation of relative speed of the impact, force subjected by the seat of the vehicle when the seat supports a person, and inclination of the backrest with respect to a reference position. The control unit is in the form of electronic circuit and/or software or computer module.

Description

The invention relates to the safety systems which are fitted to certain vehicle seats, possibly of automobile type, and more specifically those which act on a vehicle seat. seat in case of shock or possibility of shock at a rear part of the vehicle they equip. As known to those skilled in the art, when a person is supported by a reclining seat of a vehicle, including automotive type, which is subject to a shock at its rear, this no one suddenly finds himself pressed against the back and therefore exerts on the latter a backward force whose intensity depends on the intensity of the shock. The rotation of the backrest is, at the moment of impact, locked relative to the seat in a selected support position by means of a locking mechanism, the person is suddenly blocked and can then suffer more or less serious lesions, including level of his spine and neck. To reduce the intensity of the shock suffered by the person it has been proposed to use a locking mechanism provided with protuberances housed in defined lights in at least one flange secured to the backrest or seat cushion and can be sectioned when the intensity of the shock is greater than a predefined threshold. Such a solution is described in particular in US Pat. No. 5,676,421.

This solution has at least two disadvantages. Indeed, it acts in a binary way: i) blocking of the rotation when the intensity of the shock is lower than the predefined threshold, which can nevertheless induce certain lesions, or ii) release of the rotation when the intensity of the shock is greater than the predefined threshold (which currently corresponds to a relative rear collision speed greater than 15 km / h), which no longer makes it possible to control the rotational drive and therefore often leads to serious injuries when the intensity of the shock is much higher than the predefined threshold. In addition, when the protuberances have been cut, the locking mechanism must be replaced (at least partially). It has also been proposed to provide the seat with an electric motor intended to control the inclination of its backrest and in particular to incline it forwards early in case of detection of a rear impact. This solution has at least three disadvantages. Indeed, it is not sufficiently responsive because of the relatively slow response of the electric motor when a person is sitting in his seat. Moreover, in case of high intensity shock the motor may not be able to maintain the locking rotation in the pre-inclined position and thus the rotation of the folder can become almost free. In addition, pre-inclination of the backrest forward is not suitable for rear impact. The invention therefore aims to at least partially overcome the aforementioned drawbacks.

It proposes for this purpose a device, dedicated to the control of the inclination of a vehicle seat comprising a backrest rotatably mounted on a seat and a mechanism for locking the rotation in a selected support position. This control device is characterized in that it comprises: braking means arranged (or designed) for braking the rotation according to a given law, and control means arranged, in the event of reception of an alarm signaling a shock or a possibility of impact in a rear part of the vehicle, to cause the unlocking of the rotation by action on the locking mechanism and to determine the braking law as a function of a value taken by at least one parameter. The control device according to the invention can comprise other characteristics that can be taken separately or in combination, and in particular: its control means can be arranged to determine the braking law as a function of a value taken by a first parameter which is representative of an estimate of the relative speed of shock and / or a value taken by a second parameter which is representative of a force experienced by the seat when it supports a person; the value of the first parameter may be derived from a shock sensor which is implanted in the vehicle or from an object detector which is located in the rear part of the vehicle; • the shock sensor can be part of a system of triggering of airbags (or "airbags") of the vehicle; • the object detector can be part of a vehicle parking assist system; the value of the second parameter can come from a sensor which is implanted in the seat; its control means can be arranged to determine the braking law as a function also of a value taken by a third parameter which is representative of the inclination of the backrest relative to a reference position, when in the position support; its control means can be arranged to determine a braking law which defines the intensity of the braking to be applied between the support position and a chosen stop position; its braking means may be of the electromagnetic type and arranged to apply an electromagnetic braking law to parts of the seat which are involved in the rotation of the backrest, or of the hydraulic type and arranged to apply a hydraulic braking law to parts of the seat that are involved in the rotation of the folder. The invention also proposes a vehicle, possibly of automobile type, and comprising at least one seat, comprising a backrest rotatably mounted on a seat and a mechanism for locking the rotation in a selected support position, and at least one locking device. tilt control of the type of that presented above and associated with the seat. Other features and advantages of the invention will appear on examining the detailed description below, and the accompanying drawing, in which the single figure schematically and functionally illustrates a motor vehicle with an associated reclining seat backrest to an exemplary embodiment of a control device according to the invention. The attached drawing may not only serve to complete the invention, but also contribute to its definition, if any. The invention aims to provide a device (D) for controlling the inclination of a seat backrest (DS) (SI) vehicle (V) in case of detection of a shock or opportunity in a rear part (PR) of this vehicle (V). In what follows, it is considered, by way of non-limiting example, that the vehicle (V) is automotive type, such as a car. But, the invention is not limited to this type of vehicle. It concerns indeed any type of vehicle (V) equipped with at least one seat (SI) comprising a backrest (DS) rotatably mounted on a seat (AS) and intended to support (or accommodate) a person in a position oriented towards the front part (PV) of the vehicle (V).

It is schematically and functionally represented in the single figure a vehicle V, here of automotive type, equipped with a single seat SI backrest DS tilting, to avoid overloading. Of course, a vehicle may have several reclining seats. Note that in the non-limiting example illustrated, the seat SI is located in the front part of the passenger compartment of the vehicle V (where the driver is located) and therefore is part of the row 1 of said vehicle V. But, it could be implanted in any rank of a vehicle, and in particular in an intermediate rank between the front and rear of its passenger compartment. Although this appears only functionally in the single figure, the DS seat DS backrest is rotatably mounted on the rear part of the seat AS, by means of rotating parts PT. The latter (PT) comprise, for example, two stamped metal profiles respectively secured to the backrest DS and the seat AS and cooperating together to rotate the backrest DS relative to the seat AS.

The SI seat is also equipped with an MV mechanism that is responsible for locking the rotation of the DS backrest to a support (or home) position that has been chosen by a person and that defines the inclination of the DS backrest relative to at a reference position (defined in relation to the AS seat). The term "support position" is understood here to mean the position that allows a person to sit comfortably on the SI seat facing the road. For example, the lock mechanism MV is arranged to immobilize the rotating parts PT relative to each other. By way of non-limiting example, the locking mechanism MV may comprise a first serrated sector secured to the backrest DS and fitting into a corresponding second notched sector which is integral with the seat AS. A control lever can then make it possible to dissociate these two serrated sectors in order to free rotate the DS backrest relative to the seat AS. When the locking mechanism MV is not actuated, it locks the rotation. This locking mechanism MV comprises, for example, a lever implanted in an upper lateral part of the backrest DS, secured to a cable or linkage and which, when actuated manually, allows the unlocking of the rotation of the backrest DS relative to the backrest. AS seat, and thus its tilt forward (or backward in case of recovery). The invention proposes to associate with at least one seat IF a tilt control device D. As illustrated, the latter (D) comprises at least MF braking means and control means MC. The braking means MF are secured to the seat SI, for example in the immediate vicinity of the rotating parts PT, and are arranged to slow the rotation (of the DS folder) according to a specific law. These braking means MF may for example be of the electromagnetic type. They are then arranged to apply an electromagnetic braking law to the rotating parts PT SI seat (which are involved in the rotation of the DS folder). By way of non-limiting example, it may for example be jaws mounted on PT rotating parts, in suitable locations for this purpose, and whose spacing is controlled electromagnetically. It will be understood that the smaller the spacing, the greater the braking intensity. It will be noted that it is also possible to provide a transverse stress (in Y) of the seat AS relative to the backrest DS so as to induce friction. In an alternative embodiment, the braking means MF may be for example hydraulic type. They are then arranged to apply a hydraulic braking law to the rotating parts PT SI seat (which are involved in the rotation of the DS folder). By way of non-limiting example, it may for example be a friction damping device mounted on the rotating parts PT, in suitable places for this purpose, and whose damping is controlled hydraulically. . It will be understood that the higher the friction damping, the greater the braking intensity. Note that the hydraulic force is applied to the elements that are in contact with the friction damper to vary the damping.

Other embodiments can still be envisaged. Thus, it is possible to use cylinders connecting the DS backrest to the AS seat on the two sides of the SI seats (for example on their side flanges), these two jacks being jointly controlled by a solenoid valve ensuring the control of the opening speed. SI headquarters.

The control means MC intervenes each time they receive an alarm which signals a shock or a possibility of impact in a rear part PR of the vehicle V. When such a situation occurs, they (MC) are arranged in such a way as to cause releasing the rotation by action on the locking mechanism MV and determining the braking law, which must be immediately applied by the braking means MF, as a function of a value taken by at least one parameter. Here, the term "action on the locking mechanism MV" means generating an instruction likely to immediately cause the uncoupling of the locking mechanism MV of the rotating parts PT. The unlocking of the locking mechanism MV can for example be ordered by the control means MC by means of either a dedicated message that they send to the on-board computer OB of the vehicle V (possibly via a computer bus), which is It is then necessary to send an unlocking request to the locking mechanism MV (possibly via a computer bus), or to a dedicated message that addresses "directly" to the locking mechanism MV (possibly via a computer bus).

The term "braking law" is used herein to mean a law that defines the temporal variation of the braking intensity during a period of application. It will be noted that this braking intensity may be either constant or variable during its duration of application.

Furthermore, the duration of application of a braking law may for example depend on the angular difference between the support position (initial ù before the shock) and a chosen stop position. The stop position is the angular position (or inclination) of the DS backrest at the end of the braking phase. It is indeed advantageous to optimize the stopping position of the DS backrest so as to limit as far as possible the injuries that may be caused by a rear impact. This stopping position can be either predetermined (and therefore always the same), or variable depending on the situation encountered, including the energy to be dissipated and the starting angle of the DS folder. In the latter case, it is the control means MC which is responsible for determining the stopping position. The (initial) support position may for example be determined by a position sensor (not shown) which is implanted in the immediate vicinity of the rotating parts PT. The measurement of the support position can be transmitted by the position sensor to the control means MC of the device D is "directly" (possibly via a computer bus), or indirectly via the on-board computer OB and a possible computer bus. It will be noted that the values of a first parameter can be transmitted to the control means MC of the device D or "directly" by the triggering system of the SDC airbags or by the parking assistance system SAS, for example via a computer bus of the vehicle V, or indirectly by the on-board computer OB of the vehicle V (possibly via a computer bus). Several parameters can be used here, separately or in combination (at least partially), by the control means MC to determine the braking law which is adapted to the current situation of the vehicle V. Thus, the control means MC can by for example, determining the braking law as a function of a value taken by a first parameter which is representative of the estimate of a relative impact speed and / or of a value taken by a second parameter which is representative of a force suffered by the SI headquarters when supporting a person. The term "relative speed of shock" here refers to the relative velocity of the vehicle V relative to the object that will enter (or enter) collide with its rear part PR. This object is, for example, another vehicle which follows the vehicle V equipped with the device D. In a first approximation (corresponding to a purely axial impact), this relative speed of impact is therefore equal to the speed difference between the vehicle V and the vehicle. follower object.

It will be understood that the higher the relative speed of impact, the greater the force experienced by the seated person and therefore the higher the upper body may exert significant pressure on the DS folder. Therefore, the higher the pressure on the AS seat, the higher the braking force intensity (opposite to the rotation of the DS backrest), at least at the beginning of the control phase. tilt of the DS folder. The values of the first parameter (representative of the estimate of the relative speed of impact) may for example be derived from a shock sensor CC which is implanted in the vehicle V, and which is part of a loaded SDC system, for example. to trigger the almost instant inflation of airbags (or "airbags") after expelling them from their homes. In this case, the values of the first parameter can be transmitted to the control means MC of the device D or "directly" by the triggering system of the SDC airbags or by the parking assistance system SAS, for example via a data bus of the vehicle V, or indirectly by the on-board computer OB of the vehicle V (possibly via a computer bus). Alternatively or additionally, the values of the first parameter may for example be derived from an object detector DO which is implanted in the rear part PR of the vehicle V, which is part of a system for assisting the vehicle. In this case, the SAS parking aid system may either communicate the value of the first parameter when the value of the distance separating the vehicle V from the follower object is less than a chosen threshold, or communicating the value of the first parameter and the value of the distance separating the vehicle V from the follower object, and it is then either the control means MC or the on-board computer OB which compares the distance value received with the threshold chosen to know whether or not the value of the first received parameter is used to determine a braking law to be applied. It will be noted that the values of a first parameter can be transmitted to the control means MC of the device D or "directly" by the triggering system of the SDC airbags or by the parking assistance system SAS, for example via a computer bus of the vehicle V, or indirectly by the on-board computer OB of the vehicle V (possibly via a computer bus). The values of the second parameter (representative of a force experienced by the seat IF due to the presence of a seated person) may for example be derived from a CP sensor implanted in the SI seat. Such a sensor CP may for example be arranged to measure the pressure exerted on the DS folder by the seated person (in particular because of its weight). It will be understood that the greater the pressure placed on the DS backrest by the seated person, the higher the weight of the sitter, and therefore the higher the upper body may exert a significant pressure on the DS backrest in the event of a shock. rear. Therefore, the higher the initial pressure on the DS backrest, the greater the amount of braking force (as opposed to the rotation of the DS record), at least at the beginning of the control phase of the DS. tilt of the DS folder. It should be noted that the weight of the person remaining constant over time, it is only the effort suffered which decreases due to the absorption of energy by the system. It will be noted that the values of a second parameter can be transmitted to the control means MC of the device D or "directly" by the sensor CP, for example via a computer bus of the vehicle V, or indirectly by the on-board computer OB of the vehicle V (possibly via a computer bus). The control means MC may also and possibly take into account the value taken by a third parameter which is representative of the inclination of the backrest DS relative to a reference position, in order to determine the brake law. It will be understood that the greater the initial inclination (before impact) of the DS backrest, the higher the upper body of the person initially exerts significant pressure on the backrest DS, and therefore the greater the strength of the force of the braking (opposite to the rotation of the DS backrest) should be high. As indicated above, the weight of the person remaining constant over time, it is only the effort suffered which decreases due to the energy absorption by the 1 o system. Note also that the control means MC may optionally be arranged to choose from among a predetermined set of braking laws the braking law to be applied in view of the current situation.

It will also be appreciated that when the device D has been used, it is advantageous that it can be deactivated in order to allow the DS folder to be repositioned and locked in its support position, and then it can be reactivated in order to be able to be re-activated. again used automatically (possibly via a reset by a technician). A warning light 20 or a message can then for example be displayed on a screen of the vehicle V to remind the driver that he must reactivate the device D. It is important to note that the control means MC can be implemented in different places of the vehicle V, and in particular in the SI seat or in the dashboard or in the on-board computer OB, as shown in non-limiting manner in the single figure. However, it is preferable that they be positioned as close as possible to the SI seat to reduce the risk of disconnection during a shock. Therefore, they (MC) can be realized in the form of electronic circuits, software (or computer) modules, or a combination of electronic circuits and software modules. The invention is not limited to the control device and vehicle embodiments described above, only by way of example, but encompasses all the variants that can be envisaged by those skilled in the art.

Claims (12)

REVENDICATIONS1. Tilt control device (D) for a vehicle seat (S) (V) comprising a backrest (DS) rotatably mounted on a seat (AS) and a mechanism (MV) for locking the rotation in a position of support selected, characterized in that it comprises i) braking means (MF) arranged to brake said rotation according to a given law, and ii) control means (MC) arranged, in case of reception of a signaling alarm a shock or a possibility of impact in a rear part (PR) of said vehicle (V), to cause unlocking of the rotation by action on the locking mechanism (MV) and to determine said braking law as a function of a value taken by at least one parameter. 2. Device according to claim 1, characterized in that said control means (MC) are arranged to determine said braking law 15 as a function of a value taken by a first parameter representative of an estimate of the relative speed of shock and / or a value taken by a second parameter representative of a force experienced by said seat (SI) when it supports a person. 3. Device according to claim 2, characterized in that said value of the first parameter is derived from a shock sensor (CC) implanted in said vehicle (V) or an object detector (DO) implanted in the rear portion (PR) of said vehicle (V). 4. Device according to claim 3, characterized in that said shock sensor (CC) is part of a system for triggering airbag 25 (SDC) of said vehicle (V). 5. Device according to one of claims 3 and 4, characterized in that said object detector (DO) is part of a parking aid system (SAS) of said vehicle (V). 6. Device according to one of claims 2 to 5, characterized in that said value of the second parameter is derived from a sensor (CP) implanted in said seat (SI). 7. Device according to one of claims 2 to 6, characterized in that said control means (MC) are arranged to determine said brake loid also a value taken by a third parameter representative of the inclination of said folder (DS) relative to a reference position. 8. Device according to one of claims 1 to 7, characterized in that said control means (MC) are arranged to determine a braking law defining the braking intensity to be applied between said support position and a position of chosen stop. 9. Device according to one of claims 1 to 8, characterized in that said braking means (MF) are electromagnetic type and are arranged to apply an electromagnetic braking law to parts of said seat (SI) involved in the Folder rotation (DS). 10. Device according to one of claims 1 to 8, characterized in that said braking means (MF) are of hydraulic type and are arranged to apply a hydraulic braking law to parts of said seat (SI) involved in the Folder rotation (DS). 11. Vehicle (V) comprising at least one seat (SI) having a backrest (DS) rotatably mounted on a seat (AS) and a mechanism (MV) for locking the rotation in a selected support position, characterized in that it further comprises at least one tilt control device (D) associated with said seat (S1) according to any one of the preceding claims. 12. Vehicle according to claim 11, characterized in that it is automotive type.