Motor vehicle seat and method for limiting forces on a motor vehicle seat

Abstract

The invention relates to a motor vehicle seat (20) comprising a seat frame (22) and a backrest structure (24), which are connected to one another at a connection point (28). A deformation element (50) and a retaining element (64) operatively connected to the deformation element (50) are arranged at the connection point (28) between the seat frame (22) and the backrest structure (24). It is provided that the deformation element (50) has a connecting flange (52), a body (55), a bead (60) and a predetermined breaking point (76) and the holding element (64) has a pocket (70) for receiving the bead (60) of the deformation element (50), wherein the connecting flange (52) of the deformation element (50) and the holding element (64) are connected to the seat frame (22). The invention further relates to a method for limiting forces on such a motor vehicle seat (20).

Description

[0001] The invention relates to a motor vehicle seat and a method for limiting forces on a motor vehicle seat according to the preamble of the independent patent claims.

[0002] The passive safety of motor vehicles has been continuously improved over the past decades. Through defined deformation zones on a vehicle, which absorb energy through deformation during an impact, the risk of injuries and fatal accidents has been significantly reduced. The development of seat belts, particularly in combination with airbags, has also further increased the passive safety of motor vehicles. The vehicle seat also contributes to passive safety, as the seat structure, in conjunction with other safety elements such as seat belts and airbags, helps protect the occupants of a vehicle from serious injuries. Despite all the passive safety elements present, a rear-end collision with a vehicle can result in the head being accelerated at a different rate than the torso, which can lead to well-known injuries such as whiplash.

[0003] A rear-end collision is characterized by three-phase acceleration. In the first phase, the upper body is pressed into the seat, while the head remains in its position due to inertia, potentially causing a critical S-shaped deformation of the cervical spine. In the second phase, the head is thrown forward after impact against a headrest. In a third phase, the head is further accelerated forward while the upper body is restrained by the seatbelt, creating another severe load on the cervical spine.

[0004] DE 10 2007 018 715 A1 discloses a seat for a motor vehicle comprising a first energy absorber for absorbing kinetic energy of a vehicle seat user by deforming and / or destroying the first energy absorber, and a second energy absorber for absorbing kinetic energy of the vehicle seat user by deforming and / or destroying the second energy absorber in the event of a rear-end collision. The second energy absorber is designed to absorb more kinetic energy than the first energy absorber.

[0005] DE 10 2014 004 440 A1 describes a seat structure for a motor vehicle seat, comprising a seat cushion support part and a backrest part, which is pivotably mounted on the seat cushion support part about a pivot axis relative to the seat cushion support part, and comprising at least one energy absorption element for targeted energy absorption through plastic deformation. If an accident-related force is applied, for example as a result of a rear-end collision of the motor vehicle, the backrest part pivots relative to the seat cushion support part. The second subregion pivots along with the backrest part relative to the seat cushion support part, resulting in the aforementioned plastic deformation. This allows kinetic energy to be passively absorbed in the seat structure by means of the energy absorption element acting as a deformation element.As a result of the accident-related pivoting of the backrest part relative to the seat cushion support part and the energy absorption of the geometry of the energy absorption element, which is designed as a deformation element, a failure, in particular breakage, of a web of the energy absorption element also occurs.

[0006] The invention is based on the object of reducing the loads on a passenger in the event of a rear-end collision and at least partially overcoming the disadvantages known from the prior art.

[0007] This object is achieved by a motor vehicle seat having a seat frame and a backrest structure, which are connected to one another at a connection point. A deformation element and a retaining element operatively connected to the deformation element are arranged at the connection point between the seat frame and the backrest structure. According to the invention, the deformation element has a connecting flange, a body, a bead, and a predetermined breaking point, and the retaining element has a pocket for receiving the bead of the deformation element, wherein the connecting flange of the deformation element and the retaining element are connected to the seat frame.

[0008] In this context, a seat frame is understood to be a frame that is connected to the body, in particular to a rail on which the position of the motor vehicle seat relative to the steering wheel and pedals can be adjusted. The seat frame supports a seat surface on which a vehicle occupant sits while the motor vehicle is moving and on which the weight of the torso rests. A backrest structure is understood to be a structure that supports and stiffens a seat back of the motor vehicle seat. The backrest structure is preferably adjustable relative to the seat frame, in particular in order to be able to adjust the inclination of the backrest relative to the seat surface. In this context, a deformation element is understood to be an element that deforms in a defined manner during an accident in order to absorb the impact energy and / or specifically transmit it to other structural components of the seat.In this context, a holding element is understood to be an element that holds the deformation element in a defined position, in particular by means of a positive connection. In this context, a bead is understood to be a bulge on the deformation element facing the holding element and / or a projection on the deformation element facing the holding element. In this context, a pocket is understood to be a surface that is retracted relative to the remaining surface of the holding element and is designed to create a positive connection with the deformation element and, in particular, to limit movement of the deformation element counter to the primary direction of movement in the event of a crash through the positive connection. The motor vehicle seat according to the invention reduces the forces and accelerations acting on a vehicle occupant, so that the consequences of an accident, in particular in the event of a rear-end impact, are mitigated.This can reduce the risk of whiplash, giving the vehicle occupant a better chance of surviving the accident unharmed or with only very minor injuries. In particular, the engagement of the deformation element's bead in the pocket of the retaining element reduces the vehicle backrest and headrest from rebounding, thus mitigating the so-called whiplash effect, which is an overextension of the cervical spine caused by the head accelerating forward while the torso is simultaneously held in place by the seat belt. The injury criteria relevant to the whiplash load case are also lower because the forward acceleration of the head is reduced by the hold of the backrest structure and the headrest connected to the backrest structure.While concepts known from the prior art pursue the solution principle of absorbing a maximum amount of energy and / or a defined force level in the event of an impact, the concept according to the invention pursues a different approach, namely a force-displacement identifier in the event of a crash. In this case, force maxima are limited, with the progression of the forces being staggered by the free path of the deformation element after a fracture at the predetermined breaking point. The deformation concept of the motor vehicle seat according to the invention pursues the goal of accelerating the head and torso as evenly as possible in order to avoid hyperextension or compression of the cervical spine. Thanks to the deformation element, the motor vehicle seat according to the invention is able to absorb the energy in the event of an accident and absorb it efficiently.

[0009] The additional features mentioned in the dependent claims enable advantageous improvements and further developments of the motor vehicle seat mentioned in the independent claim.

[0010] In a preferred embodiment of the invention, the predetermined breaking point is designed as a web that connects the connecting flange to the body of the deformation element. By using a web as the predetermined breaking point, the body of the deformation element tears away from the fastening flange when a defined threshold value is exceeded. The body of the deformation element initially slides off the holding element and is then caught by the positive connection between the bead of the deformation element and the pocket of the holding element. The web is designed such that it tears away in such a way that the head and torso acceleration are advantageously coordinated in time. This allows particularly efficient absorption of energy in the event of an accident and reduces the risk of injury to vehicle occupants.Furthermore, the proposed structural design of the deformation element enables the deformation element to provide a restraining effect during deformation. In combination with the deformation path defined by the deformation element and the holding element, the restraining effect of the deformation element ensures that the energy stored in the backrest structure is not released again and that the backrest structure does not accelerate the backrest further forward. By restraining the backrest structure, the occupant's torso and head are accelerated forward less strongly, which means that the forces acting on the occupant's body are lower overall. The lower load on the head and the resulting lower rebound speed are achieved through the combination of the deformation element, the holding element, and a corresponding structural design of the seat frame and the backrest structure.

[0011] In an advantageous embodiment, the connecting flange is welded to a sheet metal part of the seat frame. This allows for particularly simple attachment of the connecting flange. Furthermore, it can be ensured that any impermissible relative movement between the seat frame and the backrest structure will result in a tear at the predetermined breaking point, thus reducing the forces and accelerations acting on the vehicle occupants as described in the previous sections.

[0012] In a further preferred embodiment of the invention, a guide element is formed on the deformation element, which guide element is guided in or on a guide contour of the retaining element. This allows the deformation element to be displaced relative to the retaining element in such a way that it slides along a predetermined path to reduce the forces and accelerations on the retaining element and is then reliably captured and held in a form-fitting manner by its bead in the pocket of the retaining element.

[0013] In an advantageous embodiment of the motor vehicle seat, an end stop for the deformation element is formed on the retaining element. This allows the maximum travel of the deformation element to be limited, so that the force-locking absorption of energy is followed by further absorption through plastic deformation, allowing additional kinematic energy to be absorbed and absorbed. Furthermore, the stop element prevents the deformation element from sliding over the retaining element, ensuring that the bead is reliably received in the pocket of the retaining element.

[0014] According to an advantageous embodiment of the invention, a ramp is formed on the retaining element, along which the bead or a ramp of the deformation element slides in the event of a crash, creating a frictional connection. The ramp allows the pressure between the deformation element and the retaining element to be continuously increased as the elements slide against each other, creating a force plateau that limits the forces and accelerations acting on the vehicle occupants. This allows the effects of an accident, particularly a rear-end collision, to be controlled and limited.

[0015] In a preferred embodiment of the motor vehicle seat, the deformation element has a lower flexural rigidity than the retaining element. The fact that the deformation element has a lower flexural rigidity than the retaining element means that the deformation element undergoes greater plastic deformation in a crash than the retaining element. This means that the deformation element can, in particular, exhibit plastic compression, which causes the bead to be pressed into the pocket of the retaining element. This ensures that, even with maximum energy absorption by the deformation element, acceleration acting counter to the direction of the crash is minimized by the elasticity of the seat back and the energy stored therein. This further minimizes the risk of hyperextension of the cervical spine.

[0016] In an advantageous embodiment of the invention, an opening is provided in the body of the deformation element, wherein a connecting element, in particular a wedding screw, which connects the seat frame to the backrest structure, is inserted into the opening. The use of a connecting element, in particular a screw, for fastening the backrest structure to the seat frame enables simple integration of the deformation element into a motor vehicle seat. By tearing off at the predetermined breaking point, the backrest is no longer attached to the seat frame without play after the deformation element has been triggered and a tearing off at the predetermined breaking point, so that a triggering of the deformation element can be easily and reliably detected and the affected motor vehicle seat or seat component can be replaced.

[0017] In an advantageous embodiment of the motor vehicle seat, the motor vehicle seat is designed as an integral belt seat. The backrests of integral belt seats are significantly more rigid than the backrests of motor vehicle seats where the belt is attached to the B-pillar or C-pillar of the motor vehicle, since all forces acting on the belt must be dissipated via the backrest structure. The increased rigidity and the generally associated higher mass of the backrest structure of an integral belt seat mean that more energy is stored in the backrest through elastic deformation in the event of an impact, so that the counter-acceleration is greater than with conventional motor vehicle seats where the belt is attached to the B-pillar or C-pillar of the body.As a result, integral seat belts have a higher acceleration potential in a rebound direction opposite to the primary direction of acceleration in an accident, accelerating the torso and head toward the steering wheel and windshield or dashboard. Without additional measures, the load on the cervical spine is particularly high in such integral seat belts. A vehicle seat with a deformation element and an associated retaining element can demonstrably significantly reduce the whiplash effect in an integral seat belt.

[0018] In an advantageous embodiment of the motor vehicle seat, it is provided that the motor vehicle seat is designed as a belt integral seat.

[0019] Another aspect of the invention relates to a method for limiting forces on a motor vehicle seat described in the preceding paragraphs. The method comprises the following steps: - Tearing off the connecting flange connected to the seat frame at the predetermined breaking point if a force acting on the deformation element exceeds a first threshold value, - sliding of the bead of the deformation element or a ramp formed on the deformation element on a ramp of the holding element, - Holding the bead of the deformation element in a pocket of the holding element in order to minimize springback of the backrest structure and a headrest connected to the backrest structure.

[0020] In a rear-end collision with a motor vehicle, the movement of the upper body and head of a vehicle occupant can be divided into three phases. In the first phase, also known as retraction, the upper body is pressed against the back of the vehicle seat by the rear impact. The head initially remains in position due to inertia. This can cause a critical S-shaped deformation of the cervical spine. The goal in this phase is to achieve equal acceleration of the head and upper body so that no shear forces act on the cervical spine. In a second phase, which is caused by a rebound effect of the seat backrest springing back, the head and upper body are accelerated forward. This acceleration can be mitigated by the deformation element absorbing the energy from the impact.Furthermore, rebound, i.e., the springing back of the seatback and headrest, can be reduced by holding the seatback firmly. In a third phase, the upper body is caught by the seat belt and pressed against the seatback again. The head is not caught and moves further forward, causing a renewed shear load on the cervical spine.

[0021] By using a motor vehicle seat according to the invention with a deformation element, the time of contact of the head with the headrest can be influenced in the first phase, whereby the deformation element changes the time of contact between head and headrest so that the acceleration of the head approaches the acceleration of the torso. In the second phase, the rebound effect can be mitigated by a multi-stage deformation element because, on the one hand, the energy is absorbed upon impact and, on the other hand, the backrest is held in place so that the acceleration of the head and body is reduced compared to the initial acceleration in a rear-end impact. In the third phase, the shear forces acting on the head are also mitigated because the head is accelerated forwards to a lesser extent and, when the upper body is caught by the seat belt, a lower shear load acts on the cervical spine.

[0022] In an advantageous embodiment of the method, when the bead of the deformation element or the ramp of the deformation element slides along the ramp of the retaining element, the frictional force at the contact surface is increased such that a second threshold value is exceeded and plastic deformation occurs at the deformation element and / or the retaining element. The plastic deformation can also dissipate kinetic energy, thereby further reducing the forces and accelerations acting on the vehicle occupants.

[0023] The various embodiments of the invention mentioned in this application can be advantageously combined with one another, unless stated otherwise in the individual case.

[0024] The invention is explained below in exemplary embodiments with reference to the accompanying drawings. They show: Fig. 1 a motor vehicle with a motor vehicle seat according to the invention, Fig. 2 a schematic representation of a motor vehicle seat according to the invention with a seat frame and a backrest structure, which are connected to each other by a deformation element, Fig. 3 a schematic representation of a deformation element and a holding element, Fig. 4 a preferred embodiment of a deformation element, Fig. 5 a preferred embodiment of a holding element for receiving the deformation element, Fig. 6 - 10 further embodiments of deformation elements according to the invention and matching holding elements, and Fig. 11 a force-displacement diagram of a deformation element on a motor vehicle seat according to the invention.

[0025] Fig. 1 shows a motor vehicle 10 with a motor vehicle seat 20 according to the invention. The motor vehicle 10 has a front section 12, a side part 14, and a rear section 18. A door 16 is provided in the side part 14 to facilitate entry and exit into a vehicle interior of the motor vehicle. The motor vehicle seat 20 comprises a seat frame 22 and a backrest structure 24, on which a headrest 26 is formed or attached. The seat frame 22 and the backrest structure 24 are connected to one another at a connection point 28. The motor vehicle seat 20 is preferably designed as an integral belt seat 40 and additionally comprises a holding and retracting device for a safety belt 30.

[0026] Furthermore, in Fig. 1 shows a vehicle occupant 32, in particular a driver of the motor vehicle 10, sitting on the motor vehicle seat 20. A torso 34 of the vehicle occupant 32 is supported on a seat surface 44 located on the seat frame 22 and on a backrest surface 46 surrounding the backrest structure 24. Furthermore, a support surface 48 for the head 36 of the vehicle occupant 32 is formed on the headrest 26. The head 36 and the torso 34 are connected by a cervical spine 38.

[0027] Fig. 2 shows a motor vehicle seat 20 according to the invention with a seat frame 22 connected to the motor vehicle structure and a backrest structure 24 connected to the seat frame 22 via a connection point 28. A headrest 26 is also attached to the backrest structure 24. Alternatively, the backrest structure 24 and the headrest 26 can also be formed as a single piece. A deformation element 50 is arranged at the connection point 28, which absorbs energy in the event of an accident, in particular an impact with the vehicle rear 18. The motor vehicle seat 20 is preferably designed as an integral belt seat 40 and additionally comprises a holding and retracting device for a safety belt 30.

[0028] Furthermore, in Fig. 2 shows a vehicle occupant 32, in particular a driver or front passenger of the motor vehicle 10, sitting on the motor vehicle seat 20. The torso 34 of the vehicle occupant 32 is supported on a seat surface 44 located on the seat frame 22 and on a backrest surface 46 surrounding the backrest structure 24. The motor vehicle seat 20 according to the invention can also be used for other seats in a motor vehicle 10 and is not limited to the seats in the first row of seats. Furthermore, a support surface 48 for the head 36 of the vehicle occupant 32 is formed on the headrest 26. The head 36 and the torso 34 are connected by a cervical spine 38.

[0029] In a rear-end collision, the torso 34 is pressed against the backrest 46 of the motor vehicle seat 20 in a first phase. Due to its inertia, the head 36 of the vehicle occupant 32 initially remains in its position, which could result in a dangerous S-shaped deformation of the cervical spine 38. By tearing off the deformation element 50 at the web 54, the increase in force in this first phase is limited, causing the head 36 and the torso 34 to accelerate similarly and minimizing the shearing between the head 36 and the torso 34.

[0030] In a second phase of the rear impact, the head 36 and torso 24 are accelerated forward due to a rebound effect. The rebound effect can be amplified or mitigated by the contact of the head 36 with the headrest 26, with the deformation element 50 being designed to absorb energy during this phase to minimize the rebound effect.

[0031] In a third phase, the torso 24 is caught by the safety belt 30 and pressed again against the backrest surface 46, but the head continues to accelerate unbraked toward the steering wheel or windshield. During this phase, a critical shear load can again occur on the cervical spine 38. By absorbing the kinetic energy by the deformation element 50 and catching the bead 60 of the deformation element 50 in the pocket 70 of the holding element 64, on the one hand, the kinetic energy of the impact is dissipated and only a small portion is stored by elastic deformation of the backrest structure 24. On the other hand, the rebound effect is minimized, so that the head 36 and torso 34 of the vehicle occupant 32, which are supported on the backrest surface 46 or headrest 26, are only minimally accelerated forward.The restraining effect is enhanced by the fact that the backrest structure 24 is captured by the deformation element 50, allowing less stored energy to be re-dissipated to the torso 34 of the vehicle occupant 32. This can significantly reduce the load on the cervical spine 38, thus mitigating dangerous accident consequences.

[0032] In Fig. 3 schematically shows a movement of a deformation element 50 relative to a holding element 64 of the motor vehicle seat 20. The deformation element 50 has, as in Fig. 4, a connecting flange 52 is shown for the materially or positively connecting the connecting flange to the seat frame 22. The deformation element 50 has a web 54, which serves as a predetermined breaking point 76 in the event of an accident. The deformation element 50 further comprises a body 55, in which an opening 56 is formed for receiving a connecting element 41, in particular a wedding screw 42 for connecting the seat frame 22 to the backrest structure 24. A bead 60 is also formed on the body 55, which serves to form a positively locking connection between the deformation element 50 and the holding element 64. Furthermore, a guide element 58 is formed on the body 55 in order to guide the deformation element 50 during a relative movement between the deformation element 50 and the holding element 64 and to ensure a controlled sliding of the deformation element 50 on the holding element 64.

[0033] The holding element 64 has, as in Fig. 5, a reinforcing plate 66 is shown, with which the holding element 64 is fastened to one of the backrest structures 24 of the motor vehicle seat 20. The holding element 64 further comprises an end stop 68 for the deformation element 50, with which a path is limited when the body 55 of the deformation element 50 slides along a ramp 72 of the holding element 64. The holding element 64 further comprises a guide contour 74, which comes into operative connection with the guide element 58 on the deformation element 50 when the body 55 of the deformation element 50 slides along the holding element 64. An opening 75 is formed in the reinforcing plate 66 in order to insert the connecting element 41 for connecting the seat frame 22 to the backrest structure 24 into the deformation element 50. The deformation element is as shown in Fig. 3, the connecting flange 52 is integrally connected to an outer sheet 62 of the seat frame 22.

[0034] In the Fig. 3, the deformation element 50 tears off at the web 54 in the event of an accident and moves in the direction of the arrow relative to the stationary holding element 64. A connecting element 41 is inserted into the opening 55 of the deformation element 50, which connects the seat frame 22 to the backrest structure 24 and also moves when the web 54 tears off. The bead 60 of the deformation element 50 slides down a ramp 72 of the holding element 64, so that kinetic energy is absorbed under frictional engagement. The further the deformation element 50 is displaced in the direction of the arrow, the stronger the contact force when the bead 60 rises up the ramp 72. The bead 60 is finally caught in the pocket 70 of the holding element 64, thereby preventing the deformation element from rising along the ramp 72.If a pressure on the contact surface 80 between the deformation element 50 and the holding element 64 is exceeded, plastic deformation of the elements 50, 64 may occur, whereby additional kinetic energy is absorbed.

[0035] In the Fig. 6 to 10 show further preferred embodiments of a deformation element 50 and a holding element 64 for a motor vehicle seat 20 according to the invention. The design variants of the Fig. 6 to 10, particularly in the contour of the deformation element 50.

[0036] The Fig. The deformation element 50 shown in Figure 6 has an S-shape. Such an S-shape leads to a slow increase in force along the deformation path s and does not form a force plateau. Furthermore, such an S-shape leads to a strong elastic deformation of the deformation element 50.

[0037] The Fig. The deformation element 50 shown in Figure 7 has an L-shape and is laterally connected to the holding element 64. Such an L-shape also leads to a slow increase in force along the deformation path and thus to a low acceleration of the head 36 and torso 34. However, the force F is not limited by a plateau in this embodiment and can lead to a plastic deformation of the deformation element 50. Furthermore, the Fig. 7 shown contour to a force jump when the bead 60 engages in the pocket 70 and thus to a “hard” engagement of the deformation element 50 on the holding element 64.

[0038] The Fig. The deformation element 50 shown in Figure 8 is a further development of the Fig. 7 and additionally has a wave. The shaping leads to a staggered force increase with the formation of a force plateau and a slight plastic deformation of the deformation element 50. Furthermore, the Fig. 8 leads to a force jump when the bead 60 engages in the pocket 70 and thus to a “hard” engagement of the deformation element 50 on the holding element 64.

[0039] The Fig. 9 and Fig. The deformation elements 50 shown in Figure 10 each have a D-shape, which leads to a rapid increase in force along the deformation path s. Furthermore, the D-shape of the deformation element 50 leads to the formation of a force plateau and a plastic deformation of the deformation element 50. The D-shape enables a comparatively soft locking of the bead 60 in the pocket 70 of the holding element 64.

[0040] In Fig.Figure 11 shows a force-displacement diagram of the deformation element 50 during a crash event. The force F is plotted against the deformation displacement s. Force F is the force acting on the deformation element 50. Displacement s is the distance traveled by the deformation element 50. In a first phase I of the deformation, the deformation element 50 tears when a first threshold value F is exceeded. S1the force F on the web 54 and thus triggers the deformation mechanism. In a second phase II, the force F increases slowly, while the bead 60 or a ramp 78 on the deformation element 50 slides along the ramp 72 of the holding element 64. In the second phase II, the force increases slowly until it reaches a plateau, from which the force remains essentially constant. In order to achieve a small increase in the force F, the deformation mechanism works with friction. Friction has the advantage that by building up surface contact on the contact surface 80 and enlarging the contact surface 80, the force F is constantly built up and maintained at the plateau. In phase III, the surface contact on the contact surface 80 is maximized during friction, for example by enlarging the contact surface 80, changing a surface structure, or using appropriate material pairings.Additionally, in phase III, deformation of the deformation element 50 and / or the retaining element 64 can occur in the elastic or plastic range. In phase IV, the bead 60 on the deformation element 50 is captured in the pocket 70 of the retaining element 64, and a positive fit is established. The elastic deformation slows down the backrest structure 24 and returns it to its original position, so that the torso 34 and the head 36 are accelerated forward with only a slight acceleration. List of reference symbols 10 motor vehicle 12 Front section 14 Side panel 16 Door 18 Rear of vehicle 20 motor vehicle seat 22 Seat frame 24 Backrest structure 26 Headrest 28 connection point 30 seat belt 32 vehicle occupants 34 Torso / Upper Body 36 heads 38 Cervical spine 40 Belt-integrated seat 41 Connecting element 42 Wedding Screw 44 Seat 46 backrest area 48 contact surface 50 deformation element 52 connecting flange 54 jetty 55 bodies 56 Opening (in the deformation element) 58 Guide element 60 bead 62 Outer sheet 64 Holding element 66 Reinforcing plate 68 End stop 70 bag 72 Ramp 74 Guide contour 75 Opening (in the reinforcement plate) 76 predetermined breaking point 78 Ramp 80 contact area QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2007 018 715 A1

[0004] DE 10 2014 004 440 A1

[0005]

Claims

[1] Motor vehicle seat (20) with a seat frame (22) and a backrest structure (24) which are connected to one another at a connection point (28), wherein a deformation element (50) and a holding element (64) which is operatively connected to the deformation element (50) are arranged at the connection point (28), characterized by that the deformation element (50) has a connecting flange (52), a body (55), a bead (60) and a predetermined breaking point (76) and the holding element (64) has a pocket (70) for receiving the bead (60) of the deformation element (50), wherein the connecting flange (52) of the deformation element (50) and the holding element (64) are connected to the seat frame (22). [2] Motor vehicle seat (20) according to claim 1, characterized by that the predetermined breaking point (76) is designed as a web (54) which connects the connecting flange (52) to the body (55) of the deformation element (50). [3] Motor vehicle seat (20) according to claim 1 or 2, characterized by that a guide element (58) is formed on the deformation element (50), which is guided in or on a guide contour (74) of the holding element (64). [4] Motor vehicle seat (20) according to one of claims 1 to 3, characterized by that an end stop (68) for the deformation element (50) is formed on the holding element (64). [5] Motor vehicle seat (20) according to one of claims 1 to 4, characterized by that a ramp (72) is formed on the holding element (64), on which ramp the bead (60) or a ramp (78) of the deformation element (50) slides in the event of a crash event, producing a frictional connection. [6] Motor vehicle seat (20) according to one of claims 1 to 5, characterized by that the deformation element (50) has a lower flexural rigidity than the holding element (64). [7] Motor vehicle seat (20) according to one of claims 1 to 6, characterized bythat an opening (56) is made in the body (55) of the deformation element (50), wherein a connecting element (41) which connects the seat frame (22) to the backrest structure (24) is inserted into the opening (56). [8] Motor vehicle seat (20) according to one of claims 1 to 7, characterized by that the motor vehicle seat (20) is designed as a belt integral seat (40). [9] Method for limiting the force on a motor vehicle seat (20) according to one of claims 1 to 7, comprising the following steps: - tearing off the connecting flange (52) connected to the seat frame (22) when a force acting on the deformation element (50) exceeds a first threshold value (T S1 ) exceeds - sliding of the bead (60) or a ramp (78) formed on the deformation element (50) on a ramp (72) of the holding element (64), - Holding the bead (60) of the deformation element (50) in a pocket (70) of the holding element (64) in order to minimize a backward movement of the backrest structure (24) and a headrest (26) connected to the backrest structure (24). [10] Method for limiting forces on a motor vehicle seat (20) according to claim 9, characterized by that when the bead (60) or the ramp (78) of the deformation element (50) slides along the ramp (72) of the holding element (64), the force on a contact surface (80) is increased such that a second threshold value (T S2 ) is exceeded and plastic deformation occurs on the deformation element (50) and / or the holding element (64).

Images