Tensioning device for a seat belt component

Abstract

Tensioning device for a safety belt component (3), with - a gas generator for producing a compressed gas, - a piston driven by the compressed gas, - a pull cable (4) connected to the piston, which can be connected to a safety belt component (3) to be set into a tensioning movement, - a tensioner tube (5) for receiving and guiding the piston and - a guide block (1) forming a cable guide, in which a receptacle (2) receiving the gas generator and a pressure chamber fluidically connected to the receptacle (2) are formed, wherein the guide block (1) is connected to the tensioning tube (5) and wherein the traction cable (4) runs straight through the pressure chamber from the tensioning tube (5) in a piston movement direction (6), at least one damping element (9.1, 9.2, 9.3) is formed, which absorbs the kinetic energy of the safety belt component (3) in the event of a load-free tensioning movement, characterized in that a damping element (9.1) is formed by a projection formed on a housing (10) of the tensioning device, which projection deforms and / or breaks for absorption.

Description

[0001] The present invention relates to a tensioning device for a safety belt component, comprising a gas generator for generating a compressed gas, a piston which can be driven by the compressed gas, a traction cable which is connected to the piston and which can be connected to a safety belt component which is to be set in a tensioning movement, a tensioning tube for receiving and guiding the piston and a guide block which forms a cable guide and in which a receptacle which receives the gas generator and a pressure chamber which is fluidically connected to the receptacle are formed, wherein the guide block is connected to the tensioning tube and the traction cable runs in a straight line through the pressure chamber in a piston movement direction from the tensioning tube.

[0002] Such a tensioning device is known, for example, from DE 10 2015 111 083 B4, in which the guide block forms a cable deflection so that the pull cable is deflected from the pressure chamber toward the seat belt component to be tightened by a deflection guide in the guide block transversely to the direction of piston movement. Such a deflection of the pull cable by the guide block was previously necessary because the tensioning device is mounted laterally next to a vehicle seat and the piston movement direction is aligned parallel to the longitudinal axis of the vehicle, with a belt buckle or end fitting of a seat belt being tightened as a safety component via the pull cable. There are now considerations for the pull cable to run through the guide block in a straight line or offset parallel to the straight line in the tensioner tube.However, with such a guide block design, the problem arises that during a load-free tensioning process, the seat belt component connected to the traction cable hits the guide block without braking, which can damage it. If the damage is such that the pressure chamber formed by the guide block is no longer closed, flames can escape from the pressure chamber at unintended locations. Other tensioning devices are known from JP 6 420 474 B2, DE 195 46 280 A1, DE 22 23 061 A, and DE 10 2020 103 157 A1, respectively.

[0003] The object of the present invention is therefore to at least partially eliminate the disadvantages described with reference to the prior art and, in particular, to provide a tensioning device with which flame escape is prevented even during a load-free tensioning process.

[0004] Solutions to this problem are provided by a tensioning device having the features of independent claims 1, 3, 5, and 6. Further tensioning devices and advantageous developments of the tensioning device are specified in the dependent claims and in the description, wherein individual features of the advantageous developments can be combined with one another in a technically expedient manner.

[0005] The problem is solved by a tensioning device for a seat belt component, which can have a gas generator for generating a compressed gas. The tensioning device can also have a piston that can be driven by the compressed gas and to which a pull cable is connected, wherein the pull cable is connectable or connected to a seat belt component that is to be set in a tensioning movement (such as a belt buckle or end fitting). The tensioning device can also comprise a tensioning tube in which the piston is received and which guides the piston during the tensioning movement. The tensioning device can also have a one-part or multi-part guide block in which a receptacle for the gas generator and a pressure chamber fluidically connected to the receptacle are formed.The guide block is in particular connected to the tensioning tube and is in particular designed such that the pull cable runs straight through the pressure chamber from the tensioning tube in a piston movement direction. The guide block can be designed such that the pull cable exits the guide block either transversely to the piston movement direction or parallel, aligned, or offset parallel to the rectilinear piston movement direction. Accordingly, the guide block forms a linear guide adjoining the pressure chamber, which is designed such that the pull cable can be guided out of the guide block parallel to the piston movement direction on the side opposite the tensioning tube. At least one resistance element, described below, can be used in the linear guide to counteract any unintentional movement of the pull cable.

[0006] The tensioning device can in particular have a (flame-protection) housing which at least partially surrounds the guide block and is designed in such a way that flames emerging from the pressure chamber through the guide block along the traction cable are held back.

[0007] The tensioning device can also have at least one resistance element, which is particularly inserted in the guide block and counteracts any unintentional movement of the traction cable. Such a resistance element has, for example, ribs on the surface facing the traction cable, which increase the static friction with the traction cable. In particular, when the traction cable runs completely straight or with a parallel offset from the pressure chamber through the guide block, such a resistance element can ensure that the traction cable is not unintentionally moved by the guide block during normal use. However, when a tensioning process occurs, the resistance element only imparts relatively low sliding friction. Such a resistance element is particularly placed in the guide block transversely to the direction of movement of the traction cable.On the other hand, this also means that gaps remain between the guide block and the resistance element, through which flames could potentially escape during a normal tensioning process. With the previously described (flame-protection) housing, further flame escape can be prevented or at least minimized.

[0008] The guide block typically has an opening, preferably circular and / or particularly extending transversely to the direction of extension of the cable, through which the tensioning device can be attached to the motor vehicle. For example, a fastening element (such as a pre-tensioned screw, possibly with a collar, or a bolt) can be passed through the opening. To make the attachment of the tensioning device to the motor vehicle more stable, a bushing can be inserted into the opening in the guide block, through which the fastening element (screw or bolt) is passed.

[0009] In particular in this context, to further improve the mechanical stability of the tensioning device, it can be provided that the tensioning device has a stabilizing holder as a type of cage. The holder can in particular consist of a metallic material and preferably has a U-shaped cross-section. In addition, the holder in particular has two holes which, in the assembled state, are assigned to the opening in the guide block, so that the opening and the holes in the holder are aligned with one another. Thus, the holder, in particular which is metallic, at least partially surrounds the guide block. To fasten the holder to the tensioning device, the holder can be riveted to the bushing which is passed through the opening in the guide block.

[0010] It can now be provided that the tensioning device has at least one damping element which at least partially absorbs the kinetic energy of the safety belt component in the event of a load-free tensioning movement.

[0011] For example, the seat belt component can be attached directly or by means of a fastening element, in particular to one end of the tension cable. If the seat belt component itself or the fastening element strikes another element of the tensioning device during a load-free tensioning process (i.e., in which the seat belt component is accelerated (almost) without counterforce after the gas generator is triggered), the damping element is designed and arranged in such a way that the kinetic energy of the seat belt component is at least partially absorbed by an intentional deformation or breakage of the damping element. This prevents damage to the area of the guide block forming the pressure chamber, and also prevents flames from escaping from the pressure chamber at unintended locations.

[0012] The damping element is realized in particular by a projection which is formed on a component of the tensioning device and which is deformed or broken off during a load-free tensioning process due to the kinetic energy of the safety belt component.

[0013] Thus, a projection realizing the damping element can be formed in particular on the (flame-retardant) housing, the holder and / or the resistance element.

[0014] If the damping element is formed on the housing of the tensioning device, the projection is particularly designed as a collar surrounding the tension cable. In other words, the tension cable is guided through the housing at a point where the housing has a raised projection extending along the cable. This projection, in particular, completely surrounds the tension cable. In this case, the projection is therefore formed at a point where the seat belt component or its fastening element first comes into contact with the other components of the tensioning device.

[0015] If a damping element is formed on the bracket, it is particularly formed in a section with which the bracket rests against the guide block. In particular, the bracket has two projections, each of which rests against the guide block on one of two opposite sides of the traction cable. The at least one projection is aligned such that the projection can deform, allowing the remaining sections of the bracket to shift toward the pressure chamber or the tensioner tube during the deformation.

[0016] If a damping element is formed on the resistance element, the damping element is realized in particular by the resistance element projecting beyond the guide block. The resistance element thus extends, in particular, along the tension cable beyond an outer contour of the guide block. When the seat belt component or its fastening element then strikes the tensioning device after a load-free tensioning process, the resistance element deforms.

[0017] If the tensioning device has a resistance element, an independent invention is considered independent of the previously described solution if the tensioning device has a holder, wherein the holder fixes the resistance element in the guide block. In particular, it is provided that the holder is positively attached to the guide block by means of a bushing and that the holder is connected to the bushing by means of a rivet connection.

[0018] By securing the resistance element with the bracket, no additional devices are required to securely mount the resistance element inserted into the guide block as part of the tensioning device. Furthermore, this ensures that the resistance element is held in a position that appropriately counteracts any unintentional movement of the pull rope.

[0019] In this regard, it is particularly provided that the resistance element is brought into an operative position by fastening (in particular by riveting) the bracket to the guide block, in which position the resistance element counteracts any unintentional movement of the traction cable. The bracket and the resistance element are thus designed such that, before the riveting process, the resistance element does not yet exert sufficient force on the traction cable to prevent unintentional movement. After the riveting process, the resistance element is offset in the direction of the traction cable such that sufficient force is exerted on the traction cable to prevent unintentional movement.

[0020] The invention and the technical environment are explained below using the figures as examples. They show schematically Fig. 1: a partially exploded view of a tensioning device, Fig. 2: the tensioning device without housing, Fig. 3: a resistance element of the tensioning device, Fig. 4: a bracket for the tensioning device, Fig. 5: the housing of the tensioning device, Fig. 6: the tensioning device without housing and bracket, Fig. 7: the guide block of the tensioning device with the resistance element before fastening the bracket and Fig. 8: the view according to Fig. 7 after riveting the bracket.

[0021] The Fig. The tensioning device shown in an exploded view in Figure 1 comprises a guide block 1 with a receptacle 2 for a gas generator (not shown). A pressure chamber (not visible in the figures) is formed in the guide block 1, into which the gas generated by the gas generator enters.

[0022] The guide block 1 also forms a linear guide 7 for a traction cable 4. A safety belt component 3 is attached to the traction cable 4. The traction cable 4, guided by the linear guide 7, enters a tensioning tube 5 through the pressure chamber, where the traction cable 4 is connected to a non-visible piston. The piston is accelerated in a piston movement direction 6 in the tensioning tube 5 by triggering the gas generator, thereby pulling the traction cable 4 through the guide block 1.

[0023] In addition, a resistance element 8 is inserted into the linear guide 7, which, in the final assembled state, ensures that the pull cable 4 cannot be moved unintentionally by the guide block 1.

[0024] The tensioning device also includes a Fig. 4 shows a bracket 11 shown in detail, which is made of sheet metal and has a U-shaped cross-section. The bracket 11 has two projections, each forming a damping element 9.2, which in the mounted position are fixed to the guide block 1 (see in particular Fig. 2 and Fig. 6). The bracket 11 has holes in its two legs, which serve for connection to a bushing 12. The bushing 12 is pushed through an opening in the guide block 1 and through the holes in the bracket 11, whereby the bushing 12 is riveted to the bracket 9 for fastening.

[0025] The holder 11 and the resistance element 8 are designed in such a way that the resistance element 8 protrudes laterally beyond the guide block 1 before the holder 11 is attached (see Fig. 7).

[0026] During riveting, the resistance element 8 is then pressed onto the pull rope 4 by means of the holder 11 into an active position in which the pull rope 4 is secured against unintentional movement (see Fig. 8).

[0027] The tensioning device also comprises a (flame-protection) housing 10, which, in the mounted position, partially surrounds the guide block 1 and the holder 11. The housing 10 (see in particular Fig. 5) has a collar as a damping element 9.1, which projects from the housing 10 and surrounds the pull cable 4.

[0028] From the Fig. 6 also shows that the resistance element 8 protrudes beyond the guide block 1 with a section forming a damping element 9.3.

[0029] When the tensioning device is triggered and the seat belt component 3 is accelerated with virtually no counterforce due to the absence of an occupant, the seat belt component 3 impacts the damping element 9.1 on the housing 10 almost without braking, which immediately deforms. Subsequently, the damping element 9.3 of the resistance element 8, which protrudes beyond the guide block 1, is also deformed. Furthermore, the damping elements 9.2 of the bracket 11 are also deformed when the bracket 11 is pressed against the guide block 1 by the seat belt component 3. List of reference symbols 1 guide block 2 recording 3 Seat belt component 4 pull rope 5 tensioner tube 6 Piston movement direction 7 Linear guide 8 resistance element 9.1 Damping element 9.2 Damping element 9.3 Damping element 10 housings 11 Bracket 12 socket

Claims

[1] Tensioning device for a safety belt component (3), with - a gas generator for producing a compressed gas, - a piston driven by the compressed gas, - a pull cable (4) connected to the piston, which can be connected to a safety belt component (3) to be set into a tensioning movement, - a tensioner tube (5) for receiving and guiding the piston and - a guide block (1) forming a cable guide, in which a receptacle (2) accommodating the gas generator and a pressure chamber fluidically connected to the receptacle (2) are formed, wherein the guide block (1) is connected to the tensioner tube (5) and wherein the traction cable (4) runs in a straight line from the tensioner tube (5) through the pressure chamber in a piston movement direction (6), wherein at least one damping element (9.1, 9.2, 9.3) is formed which absorbs the kinetic energy of the safety belt component (3) in the case of a load-free tensioning movement, characterized by that a damping element (9.1) is formed by a projection formed on a housing (10) of the tensioning device, which deforms and / or breaks for absorption. [2] Tensioning device according to claim 1, wherein the projection is formed as a collar surrounding the traction cable (4). [3] Tensioning device for a safety belt component (3), with - a gas generator for producing a compressed gas, - a piston driven by the compressed gas, - a pull cable (4) connected to the piston, which can be connected to a safety belt component (3) to be set into a tensioning movement, - a tensioner tube (5) for receiving and guiding the piston and - a guide block (1) forming a cable guide, in which a receptacle (2) accommodating the gas generator and a pressure chamber fluidically connected to the receptacle (2) are formed, wherein the guide block (1) is connected to the tensioner tube (5) and wherein the traction cable (4) runs in a straight line from the tensioner tube (5) through the pressure chamber in a piston movement direction (6), wherein at least one damping element (9.1, 9.2, 9.3) is formed which absorbs the kinetic energy of the safety belt component (3) in the case of a load-free tensioning movement, characterized bythat the tensioning device has a holder (11) and the holder (11) forms at least one damping element (9.2), wherein the damping element (9.2) bears at least partially against the guide block (1). [4] Tensioning device according to claim 3, wherein the damping element (9.2) is designed as a projection and bears against the guide block (1). [5] Tensioning device for a safety belt component (3), with - a gas generator for producing a compressed gas, - a piston driven by the compressed gas, - a pull cable (4) connected to the piston, which can be connected to a safety belt component (3) to be set into a tensioning movement, - a tensioner tube (5) for receiving and guiding the piston and - a guide block (1) forming a cable guide, in which a receptacle (2) accommodating the gas generator and a pressure chamber fluidically connected to the receptacle (2) are formed, wherein the guide block (1) is connected to the tensioner tube (5) and wherein the traction cable (4) runs in a straight line from the tensioner tube (5) through the pressure chamber in a piston movement direction (6), wherein at least one damping element (9.1, 9.2, 9.3) is formed which absorbs the kinetic energy of the safety belt component (3) in the case of a load-free tensioning movement, characterized by that the tensioning device has at least one resistance element (8) which is inserted in the guide block (1) and counteracts an unintentional movement of the traction cable (4) during normal use when no tensioning process takes place, wherein a damping element (9.3) is formed by a section of the resistance element (8) protruding beyond the guide block (1). [6] Tensioning device for a safety belt component (3), with - a gas generator for producing a compressed gas, - a piston driven by the compressed gas, - a pull cable (4) connected to the piston, which can be connected to a safety belt component (3) to be set into a tensioning movement, - a tensioner tube (5) for receiving and guiding the piston and - a guide block (1) forming a cable guide, in which a receptacle (2) accommodating the gas generator and a pressure chamber fluidically connected to the receptacle (2) are formed, - at least one resistance element (8), wherein the resistance element (8) is inserted into the guide block (1) and counteracts an unintentional movement of the traction cable (4) during normal use when no tensioning process takes place, wherein the guide block (1) is connected to the tensioning tube (5) and the traction cable (4) runs in a straight line through the pressure chamber from the tensioning tube (5) in a piston movement direction (6), characterized by , that the tensioning device has a holder (11), wherein the holder (11) fixes the resistance element (8) in the guide block (1) and at least partially surrounds the guide block (1). [7] Tensioning device according to claim 6, wherein the holder (11) is positively secured to the guide block (1) by means of a bushing (12). [8] Tensioning device according to claim 7, wherein the holder (11) is connected to the bushing (12) by means of a rivet connection. [9] Tensioning device according to one of the preceding claims 6 to 8, wherein the resistance element (8) is brought into an operative position by fastening the holder (11) to the guide block (1), in which the resistance element (8) counteracts an unintentional movement of the traction cable (4). [10] Tensioning device according to one of the preceding claims, wherein the guide block (1) forms a linear guide (7) adjoining the pressure chamber, which is designed such that the traction cable (4) can be guided out of the guide block (1) parallel to the piston movement direction (6) on the side opposite the tensioning tube (5). [11] Tensioning device according to claim 10, wherein at least one resistance element (8) is inserted in the linear guide (7), which counteracts an unintentional movement of the traction cable (4) during normal use when no tensioning process takes place.

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