Safety device with a force limiter

Abstract

The present invention relates to a safety device for a motor vehicle, comprising a force limiter (1) and a part (2) which carries out a linear displacement movement when the force limiter (1) is activated, wherein at least one plastically deformable deformation strip (5.1, 5.2) is provided between a first fastening projection (3.1, 3.2) and a second fastening projection (4.1, 4.2), which deformation strip has two partial sections connected to one another by a deflection section (6.1, 6.2), wherein the deflection section (6.1, 6.2) is arranged on the side facing away from the part (2) relative to the first fastening projection (3.1, 3.2) and the second fastening projection (4.1, 4.2).

Description

[0001] Safety device with a force limiter

[0002] Description

[0003] The present invention relates to a safety device for a motor vehicle, comprising a force limiter and a part which executes a linear displacement movement when the force limiter is activated, such as a belt buckle or end fitting.

[0004] Safety devices, and in particular seat belt devices, generally serve to restrain vehicle occupants in the event of an accident. For this purpose, the seat belt devices comprise a seat belt, which can be wound at a first end onto a belt reel of a belt retractor that is rotatably mounted in a frame, the frame of the belt retractor being secured in a motor vehicle. To create a two-point belt, the seat belt can be provided at its second end with a belt tongue that can be locked in a belt buckle that is permanently attached to the vehicle.Furthermore, in order to implement a three-point belt, the safety belt can be fastened at its second end by means of an end fitting on the same side of the vehicle seat as the belt retractor, wherein a movable belt tongue is provided on the safety belt, which can be locked in a belt buckle fastened on the other side of the vehicle seat in order to divide the safety belt into the three-point geometry.

[0005] The belt spool in the belt retractor can be pretensioned in the winding direction by a drive spring supported on the frame, so that the seat belt is automatically wound up after the belt tongue is unlocked. Furthermore, a blocking device with associated sensor devices can be provided, which blocks the belt spool against further rotation in the seat belt extension direction when predetermined values ​​of the belt webbing extension acceleration and / or vehicle deceleration are exceeded, so that the occupant is restrained by the seat belt when the belt spool is blocked and protected from impact with the vehicle's internal structure.

[0006] The safety device may comprise at least one airbag, which may be located at various locations on the vehicle structure and inflates to cover the vehicle structure in the event of an accident. The occupant's restraint is thus achieved through a combination of the seat belt and the airbags.

[0007] Since the occupants are additionally protected from impact with the vehicle structure by the inflated airbags, it may be advisable to incorporate additional force limiters into the seat belt system. These force limiters allow for force-limited belt extension when the belt reel is blocked, thus reducing the occupant load. The force limiters can be attached to the belt buckle, the end fitting, a deflection device, the belt retractor attachment, or the belt reel.

[0008] DE 10 2017 101 807 A1 discloses a force limiter which is arranged on an end fitting or on a belt buckle and comprises a straight deformation tube with a displacement part provided therein. The displacement part is connected to a tension transmission means in the form of a cable, which in turn is connected to a belt transmission means in the form of the belt buckle or a cable loop. The seat belt is thus connected directly or indirectly to the tension transmission means via the belt transmission means and, via this, to the displacement part.

[0009] The deformation tube is formed by a straight tube attached to a fitting, where the tension transmission element is further deflected. In addition to deflecting the tension transmission element, the fitting also serves to attach the force limiter to the vehicle structure. Thus, the attachment point of the deformation tube to the fitting is an interface through which the tension transmission element must pass. To ensure the guidance of the tension transmission element in the area of ​​the interface, an additional connecting element is provided through which the tension transmission element extends. The connecting element is supported on a fitting and also serves to attach the deformation tube to the fitting.

[0010] The disadvantage of this solution is that the displacement part is pulled through the deformation tube with friction during the plastic deformation of the deformation tube and the friction during the force-limited extension of the safety belt is a parameter that is difficult to control.

[0011] Against this background, it is an object of the present invention to provide a safety device with a cost-effective and compact force limiter, wherein the force limiter should have a simplified structure with an improved linear displacement movement.

[0012] A possible solution to this problem is provided by the safety device having the features of claim 1. Further solutions and advantageous developments of the safety device are specified in the preceding and following descriptions as well as in the subclaims. Individual features of the advantageous developments can be combined with one another in a technically expedient manner.

[0013] The object is achieved in particular by a safety device for a motor vehicle, comprising a force limiter and a part that executes a linear displacement movement upon activation of the force limiter, which part can be designed, for example, as a belt buckle, end fitting, deflection device, or attachment for a belt retractor. The force limiter comprises, in particular, a first fastening attachment, with which the force limiter can be fastened to the motor vehicle directly or indirectly, for example by means of a fastening fitting. The force limiter also comprises a second fastening attachment, to which the part of the safety device can be fastened directly or indirectly, for example by means of a fastening wire.

[0014] The invention now provides that at least one, in particular precisely one, plastically deformable deformation strip, which can be designed, for example, as a metal strip, is provided between the first fastening attachment and the second fastening attachment, wherein the at least one deformation strip has two partial sections connected to one another by a deflection section, of which a first partial section is connected directly or indirectly to the first fastening attachment and a second partial section is connected directly or indirectly to the second fastening attachment.

[0015] During a linear displacement movement of the part of the safety device, the deformation strip is plastically deformed, initially in particular in the region of the deflection section and, as the displacement movement continues, in particular also in the region of the second sub-section, so that the energy absorption required for the force-limited movement of the belt is based solely on the deformation work of the deformation strip. In other words: the deformation strip rolls from one sub-section to the other in the deflection section, with one of the sub-sections, in particular the first sub-section, shortening and the other, in particular the second sub-section, lengthening. The length of the force-limited extension of the part corresponds to the length by which one sub-section is lengthened and by which the other sub-section is shortened.

[0016] The force limiter can be manufactured very cost-effectively since it only has the deformation strip as its basic component, which enables the force-limiting extension of the part solely through its shape with the proposed subsections in the proposed arrangement with the deflection section arranged in between and finally the proposed fastening of the subsections.

[0017] It is now further proposed that the deflection section be arranged on the side facing away from the part relative to the first fastening lug and the second fastening lug. The first fastening lug and the second fastening lug are thus arranged on the side of the force limiter facing the part. This allows almost the entire length of the deformation strip to be deformed during the displacement movement, which in turn makes it possible to construct the force limiter shorter and thus more compact in the direction of the linear displacement movement.

[0018] In other words, the basic concept of the invention provides that the deflection section of the deformation strip, which is essentially U-shaped, faces away from the component to be displaced, so that the opening of the U faces toward the part. Since almost the entire deformation strip, or at least the first section, can be deformed, a more compact design is possible.

[0019] To implement the invention, it is sufficient if exactly one deformation strip is provided. However, it is preferred that at least two deformation strips acting in parallel, and particularly preferably exactly two deformation strips acting in parallel, are provided.

[0020] For an even more compact design and a secure connection of the part to the second fastening lugs, it can be provided in this context that the second fastening lugs are arranged between the two first sections of the two parallel-acting deformation strips. The first sections, which are arranged parallel to one another in the initial state, are thus arranged on the outside relative to the second sections, so that the second sections and thus also the second fastening lugs are arranged "inside" between the two outer first sections. This also means that the first sections, initially arranged on the outside, are deformed inward during the sliding movement.

[0021] In this context, it can be provided in particular that the two deformation strips, particularly in the area of ​​the deflection sections and / or the two second sub-sections, abut one another in the initial state and at least also at the beginning of the displacement movement and thus directly touch one another. In this case, the deformation strips can in particular be bent such that the deformation strips abut one another in a linear contact. In this case, it can be provided in particular that the initially U-shaped deflection section is followed by a type of S-shaped design of the deflection section. Through these measures, a relatively even and thus gentle start-up of the force limitation can be brought about.

[0022] Alternatively, it can be provided that the deflection sections and / or the second subsections are held at a predefined distance from one another by a spacer in the initial state and at least at the beginning, and in this case preferably throughout the entire displacement movement. This predefined distance also achieves a uniform force limitation, whereby force limitation, in particular, begins gently at the beginning of the displacement movement.

[0023] In a preferred embodiment, the spacer element has a first leg, a second leg, and a third leg, wherein the first leg is arranged between the second subsections of the two deformation strips, and the second leg and the third leg are each assigned to a deflection section. Provision can be made here for the first leg to be clamped between the two deformation strips, so that the spacer element is carried along by the deformation strips during the displacement movement. Such a T-shaped spacer element is easy to install. The second and third legs preferably each bear against the respective deflection section, ensuring that the spacer element is not pulled uncontrollably between the deflection sections or the second subsections.

[0024] In one embodiment, the part is indirectly connected by a

[0025] A fastening wire is attached to the at least one fastening projection. The fastening wire is guided in a loop-like manner through the part, in particular through the belt buckle, and is attached by its free ends to the at least one first fastening projection of the force limiter. This also makes it possible, in particular, for the at least one first fastening projection to not have to be adapted in its geometry to the part to be moved.

[0026] In particular, in this context, it can preferably be provided that the two ends of the fastening wire are each individually fastened to the respective first fastening projection of the two deformation strips. For example, the ends of the fastening wire can be connected to the fastening projections of the deformation strips in a force-fitting manner.

[0027] Particularly cost-effective and simple production is made possible by the fact that the first fastening projection is / are formed integrally with the first subsection and / or the second fastening projection is / are formed integrally with the second subsection of the deformation strip. In particular, the fastening projection, the second fastening projection, the first and second subsections, and the deflection section are formed integrally, thereby further reducing the number of pieces. In a particularly advantageous embodiment, it can also be provided that two deformation strips and preferably also the fastening projections are all formed integrally.

[0028] In particular, in this context, it can preferably be provided that the two ends of the fastening wire are jointly fastened to the first fastening projections of the deformation strips, which are preferably formed as a single piece. For example, it can be provided that the two ends of the fastening wire are guided through the first fastening projections of the deformation strips, wherein the ends guided through the first fastening projections are connected to one another by means of a sleeve, so that the sleeve rests against the first fastening projections during the linear displacement movement.

[0029] To limit the linear displacement movement, it can be provided that a stop is provided for each deformation strip, which stop is particularly fixed in place. The stop is arranged such that the corresponding deformation strip comes into contact with the stop, thereby terminating the force-limited displacement movement. In this case, it can be provided that the fastening projections and the stops can be jointly attached, particularly indirectly, to the motor vehicle.

[0030] The invention and the technical environment are explained below using the figures as examples. They show schematically

[0031] Figure 1 : a perspective view of a first embodiment of a

[0032] safety device,

[0033] Figure 2: a force limiter of the embodiment of Figure 1 in

[0034] From initial to state,

[0035] Figure 3 : the force limiter during a displacement movement,

[0036] Figure 4: the force limiter at the end of the displacement movement,

[0037] Figure 5: a second embodiment of a safety device, Figure 6: the force limiter of the second embodiment in

[0038] From initial to state,

[0039] Figure 7 : the force limiter during a displacement movement and

[0040] Figure 8 : the force limiter at the end of the displacement movement.

[0041] The embodiments of a safety device illustrated in Figures 1 and 5 each comprise a force limiter 1 and a belt buckle 2 as part of the safety device. The belt buckle 2 is attached to the force limiter 1 by means of a fastening wire 10, while the force limiter 1 can be attached to a motor vehicle by means of a fastening stop 13. The force limiter 1 is enclosed by a housing 12.

[0042] As can be seen in particular from Figures 2 and 6, the force limiters 1 each comprise a first deformation strip 5.1 and a second deformation strip 5.2, each of which comprises a first section 7.1,

[0043] 7.2 and a second section 8.1 , 8.2 and a diversion section 6.1 ,

[0044] 6.2. The deformation strips 5.1, 5.2 are each formed in one piece with a first fastening projection 3.1, 3.2 and a second fastening projection 4.1, 4.2.

[0045] The first fastening projections 3.1, 3.2 can be fastened to the motor vehicle indirectly via the fastening stop. On the other hand, the second fastening projections 4.1, 4.2 are connected to ends 10.1, 10.2 of the wire 10 and thus fastened to the belt buckle 2. The deflection section, which is U-shaped at least in the initial state,

[0046] 6.1 , 6.2 of the deformation strips 5.1 , 5.2 is arranged on the side facing away from the belt buckle 2 with respect to the fastening lugs 3.1 , 3.2, 4.1 , 4.2, wherein the deformation strips 5.1 , 5.2 are shaped such that the second fastening lugs 4.1 , 4.2 are arranged between the outwardly arranged first partial sections 7.1 , 7.2 of the deformation strips 5.1 , 5.2.

[0047] In the embodiment according to Figures 1 to 4, the fastening wire 10 is attached individually, each with its ends 10.1 and 10.2, to a first fastening projection 3.1 and 3.2 by means of a force-locking connection. In the embodiment of Figures 5 to 8, however, the ends 10.1, 10.2 of the wire 10 are jointly attached to the second fastening projections 4.1, 4.2 by passing the ends 10.1, 10.2 through the fastening projections 4.1, 4.2 and connecting them to one another by means of a sleeve 14.

[0048] In the embodiment of Figures 1 to 4, the deformation strips

[0049] 5.1 , 5.2 in the area of ​​the deflection sections 6.1 , 6.2 and the second sections 8.1 , 8.2 are S-shaped so that the deformation strips

[0050] 5.1, 5.2 abut against each other at a linear contact point. In the embodiment of Figures 5 to 8, however, an additional spacer element 9 is provided, which has a first leg 9.1, a second leg 9.2 and a third leg 9.3, wherein the first leg 9.1 is arranged between the deflection sections 6.1, 6.2 and between the second subsections 8.1 and 8.2, while the second and third legs 9.2, 9.3 are arranged on an underside at the respective

[0051] Deflection section 6.1, 6.2. The spacer element 9 thus provides a predefined distance between the deformation strips 5.1, 5.2.

[0052] If, in an accident situation, with the belt tongue inserted into the belt buckle and the belt retractor blocked, the belt buckle 2 is subjected to a high force by the occupant, a deformation of the deformation strips 5.1 , 5.2 takes place in that the deformation strips 5.1 ,

[0053] 5.2 from the second subsection 8.1 , 8.2 into the first subsection 7.1 ,

[0054] 7.2, whereby the first section 7.1, 7.2 shortens and the second section 8.1, 8.2 lengthens. Thus, a deformation process takes place in the deformation strips 5.1, 5.2, which dissipates energy and thus enables force-limited belt extension.

[0055] In the embodiment of Figures 1 to 4, the deformation strips 5.1, 5.2 rest against each other during the sliding movement (see Figure 3). In the embodiment of Figures 5 to 8, the deformation strips 5.1,

[0056] 5.2, however, sets a predetermined distance due to the spacer element 9.

[0057] At the end of the sliding movement, the deformation strips 5.1, 5.2 each come into contact with a stop 11, which limits further extension of the belt buckle 2. The stops 11 are attached together with the first fastening projections 3.1, 3.2 to the fastening stop 13 for fastening to the motor vehicle.

[0058] Since the deflection section 6.1, 6.2 of the deformation strips 5.1, 5.2 is arranged on the side facing away from the belt buckle 2, a very compact / short design of the force limiter in the direction of the displacement movement of the belt buckle 2 is possible. Since the deformation strips 5.1, 5.2 abut one another at least at the beginning of the displacement movement or have a predefined distance from one another, a uniform displacement movement and thus a gentle start to the displacement movement is possible, especially at the beginning.

[0059] List of reference symbols Force limiter Belt buckle First fastening attachment First fastening attachment Second fastening attachment Second fastening attachment Deformation strip Deformation strip Deflection section Deflection section First sub-section First sub-section Second sub-section Second sub-section Spacer element First leg Second leg Third leg Fastening wire First end Second end Stop Housing Fastening stop Sleeve

Claims

Claims 1. Safety device for a motor vehicle, with a force limiter (1) and a part (2) which executes a linear displacement movement upon activation of the force limiter (1), wherein the force limiter comprises a first fastening projection (3.1, 3.2) for fastening the force limiter (1) to the motor vehicle and a second fastening projection (4.1, 4.2) for fastening to the part (2) of the safety belt device, characterized in that between the first fastening projection (3.1, 3.2) and the second fastening projection (4.1, 4.2) at least one plastically deformable deformation strip (5.1, 5.2) is provided, which has two subsections connected to one another by a deflection section (6.1, 6.2), wherein the first subsection (7.1, 7.2) is connected to the first fastening projection (3.1, 3.2) and the second subsection (8.1 , 8.2) is connected to the second fastening attachment (4.1 , 4.2) and the deflection section (6.1 , 6.2) is arranged relative to the first fastening projection (3.1, 3.2) and the second fastening projection (4.1, 4.2) on the side facing away from the part (2).

2. Safety device according to claim 1, wherein at least two parallel acting deformation strips (5.1, 5.2) are provided.

3. Safety device according to claim 2, wherein the second fastening lugs (4.1, 4.2) are arranged between the two first sections (7.1, 7.2) of the two parallel-acting deformation strips (5.1, 5.2).

4. Safety device according to claim 2 or 3, wherein the deflection sections (6.1, 6.2) and / or the second subsections (8.1, 8.2) abut one another in the initial state and at least at the beginning of the displacement movement.

5. Safety device according to claim 2 or 3, wherein the deflection sections (6.1, 6.2) and / or the second subsections (8.1, 8.2) are held at a predefined distance from one another in the initial state and at least at the beginning of the displacement movement by a spacer element (9).

6. Safety device according to claim 5, wherein the spacer element (9) comprises a first leg (9.1), a second leg (9.2) and a third leg (9.3), wherein the first leg (9.1) is arranged between the second partial sections (8.1, 8.2) of the two deformation strips (5.1, 5.2) and the second leg (9.2) and the third leg (9.3) are each assigned to a deflection section (6.1, 6.2).

7. Safety device according to one of claims 1 to 6, wherein the part (2) is fastened to the first fastening attachment (3.1, 3.2) by means of a fastening wire (10).

8. Safety device according to one of claims 2 to 7, wherein the deformation strips (5.1, 5.2) are formed in one piece.

9. Safety device according to claim 7 or 8, wherein both ends (10.1, 10.2) of the fastening wire (10) are fastened together to the first fastening lugs (3.1, 3.2) of the deformation strips (5.1, 5.2).

10. Safety device according to claim 7, wherein the ends (10.1, 10.2) of the fastening wire (10) are each individually fastened to the first fastening projection (3.1, 3.2) of the respective deformation strip (5.1, 5.2).

11. Safety device according to one of the preceding claims, wherein a stop (11) which is stationary even during the displacement movement is provided between the partial sections (7.1, 7.2, 8.1, 8.2).

12. Safety device according to one of the preceding claims, wherein the at least one deformation strip (5.1, 5.2) is formed by a metal strip.

13. Safety device according to one of the preceding claims, wherein the first fastening projection (3.1, 3.2) is / are formed integrally with the first partial section (7.1, 7.2) and / or the second fastening projection (4.1, 4.2) is / are formed integrally with the second partial section (8.1, 8.2) of the deformation strip (5.1, 5.2).

Images