Belt retractor

Abstract

To provide a belt retractor which is improved with respect to force restriction.SOLUTION: A belt retractor 10 comprises: a rotatably supported belt reel 12 which can receive a webbing; an operation blocking mechanism which can block rotation of the belt retractor 10 in a loosening direction of the webbing; a force restriction mechanism 16 in which a first portion of a torsion rod 18 is releasably coupled to the belt reel 12, and a second portion is firmly connected to the belt reel 12; a release mechanism 30 for releasing releasable connection between the torsion rod 18 and the belt reel; and a rotatably supported stop member 40 which is located coaxially with the belt reel 12 and / or the torsion rod 18, the stop member 40 restricting rotation of the belt reel 12 in the loosening direction to a prescribed rotation speed when activating the release mechanism 30.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a belt retractor provided with a force limiting mechanism for a seat belt system of a motor vehicle.

Background Art

[0002] When a vehicle is decelerated, under normal circumstances, a seat belt system ensures that it restrains a vehicle occupant. In a belt retractor, during strong deceleration of the vehicle and simultaneous complete blocking of the belt retractor by a locking pawl, a force limiting device is used, for example, to prevent an excessively large load from being applied to the vehicle occupant by the seat belt.

[0003] Generally, a force limiting device allows that when a torque acting on a belt reel caused by a large tension in the seat belt exceeds a certain magnitude, even if the belt reel itself is locked, the belt reel can be rotated against a large resistance force in the unwinding direction, so that a certain length of webbing can be unwound from the belt reel. This allows the vehicle occupant to move further forward, thereby reducing the load. It is known to use one or more torsion bars as a force limiting device, which can be twisted themselves when a large torque acts thereon, connected to the belt reel at one end and connected to the locking mechanism at the other end. However, the rotation of the belt reel when the belt retractor is locked is mechanically limited, and the belt reel can only rotate a few turns.

[0004] The problem with this situation is that even with a relatively small deceleration of the vehicle that leads to locking of the belt retractor, the belt reel can rotate to a certain extent, which is unnecessary when the deceleration is relatively small. When the belt retractor is locked during a subsequent large deceleration of the vehicle, the belt reel can only rotate a small amount. It is necessary to replace the belt retractor to eliminate this problem, which incurs high costs. [Overview of the project] [Problems that the invention aims to solve]

[0005] Therefore, an object of the present invention is to provide a belt retractor that has been improved with respect to force limiting. [Means for solving the problem]

[0006] In accordance with the present invention, this objective is achieved by a belt retractor comprising: a rotatably supported belt reel capable of receiving webbing; an action-restricting mechanism capable of preventing rotation of the belt retractor in the loosening direction of the webbing; a force-limiting mechanism for limiting the restraining force of the belt retractor, the force-limiting mechanism comprising a torsion rod having a first part and at least another second part, wherein the first part of the torsion rod has greater rigidity than the second part, the first part of the torsion rod is releasably coupled to the belt reel, and the second part is firmly coupled to the belt reel; a release mechanism for releasing the releasable connection between the torsion rod and the belt reel; and a rotatably supported stop member disposed coaxially with the belt reel and / or the torsion rod, the stop member limiting the rotation of the belt reel in the loosening direction to a predetermined number of rotations when the release mechanism is activated.

[0007] According to the present invention, the stop member restricts the rotation of the belt reel only when the release mechanism is activated.

[0008] In cases of mild vehicle deceleration, the stop member does not rotate when the release mechanism is not activated (for example, when the vehicle collides with an obstacle at low speed). This has the advantage that sufficient forward displacement of the vehicle occupants is still possible in the next deceleration when the release mechanism is activated.

[0009] The different stiffnesses of the first and second portions of the torsion rod create two different force levels within the belt retractor. During activation at the higher force level, the force limiting mechanism is not activated if the belt reel is prevented from moving. This further suppresses the rotation of the stop member when the rotation mechanism is not activated.

[0010] According to one embodiment, a torsion rod is releasably connected to a belt reel via a sleeve that is coupled to the torsion rod in a way that at least partially surrounds the torsion rod and is rotatably fixed (non-rotatable) in a first portion. This means that a second portion of the torsion rod can be bridged by the sleeve. Specifically, the sleeve is releasably coupled to the belt reel.

[0011] In this context, a disconnectable connection is understood as a connection that can be disconnected without requiring the disassembly of the belt retractor.

[0012] A releasable connection between the first portion of the torsion rod and the belt reel allows for two distinct force paths across the belt retractor, one of which extends only through the first portion of the torsion rod, and the second force path extending through both the first and second portions of the torsion rod. Because the first portion of the torsion rod has greater rigidity than the second portion, plastic deformation is avoided, specifically twisting of the torsion rod, as long as the force path extends only through the first portion of the torsion rod. When the force path extends through the second portion of the torsion rod, the lower rigidity of the torsion rod when the belt retractor is prevented from operating allows for twisting of the torsion rod, which in turn activates a force limiting mechanism, allowing for a predetermined forward displacement of the vehicle occupant.

[0013] Preferably, the motion-blocking mechanism comprises a rotatably supported disc coupled to a torsion rod in a manner that it is rotatably fixed, the disc having a limit stop and a threaded section adjacent to the limit stop, and a stop member being rotatably supported on the threaded section, spaced apart from the limit stop, in a manner that it is screw-engaged with the threaded section.

[0014] The stop member is separated from the limit stop, particularly in its initial position, that is, before the release mechanism is activated. This means that a predetermined number of rotations can be precisely performed until the stop member moves from its initial position to the limit stop on the screw section. Therefore, by positioning the stop member at an appropriate distance from the limit stop, the number of rotations of the stop member can be limited to a predetermined number.

[0015] For example, this distance is selected so as to allow the stop member to perform two to three rotations.

[0016] The limit stop is preferably formed by the end face of the disk.

[0017] The threaded section protrudes from the disc as an extension, and in this case, the diameter of the extension is smaller than the outer diameter of the disc.

[0018] The stop member is connected to the belt reel in a manner that is fixed by rotation, so that when the belt reel is rotated relative to the disc, the stop member moves along the screw section to the limit stop. Because the stop member is connected to the belt reel in a manner that is fixed by rotation, as soon as the stop member contacts the limit stop, further rotation of the belt reel in the loosening direction becomes impossible. Therefore, when the action-blocking mechanism is activated, the belt reel can perform the same number of rotations as the stop member.

[0019] The stopping member is, for example, a nut.

[0020] According to an alternative embodiment, the stop member is screw-engaged with the sleeve, and a limit stop spaced apart from the sleeve is provided at the stop member.

[0021] The limit stop is spaced apart from the sleeve, particularly in the initial position, that is, before the release mechanism is activated. This means that the stop member can accurately perform a predetermined number of rotations before it rotates within the sleeve to an extent that brings the limit stop into abutment against the sleeve.

[0022] Preferably, the stop member is connected to the belt reel in a rotationally fixed manner. Here, when the belt reel rotates relative to the sleeve, the stop member is screwed into the sleeve until the limit stop abuts against the sleeve.

[0023] The rotation of the stop member within the sleeve up to the limit stop provides the advantage that as soon as the limit stop abuts against the sleeve, the belt reel is coupled to the sleeve in a rotationally fixed manner in the unwinding direction. Therefore, as soon as the stop member is screwed into the sleeve up to the limit stop, the second portion of the torsion bar is bridged again.

[0024] Another advantage is that, because the force path always extends through the torsion bar, the vehicle structure is only subjected to a small load when the force limiting device is activated. Furthermore, the restraining force acting on the vehicle occupant is also reduced.

[0025] According to this embodiment, for example, the stop member has an external thread, and the sleeve has a corresponding internal thread.

[0026] In order to enable the stop member to move along the threaded section and into the sleeve, the stop member is axially movable relative to the belt reel. Specifically, the belt reel has an axial guide for the stop member.

[0027] According to one embodiment, at least one movably supported movement blocking member is provided, wherein in a first position of the movement blocking member, the belt reel is rigidly coupled to the sleeve via the movement blocking member, and in a second position of the movement blocking member, the belt reel is rotatable relative to the sleeve. Therefore, depending on the position of the at least one movement blocking member, a force path can extend only through the first section of the torsion bar or through both the first and the second sections of the torsion bar. The at least one movement blocking member is, in particular, part of a release mechanism.

[0028] The release mechanism preferably comprises an adjusting collar supported to be rotatable from a blocking position to a releasing position, and a drive element for rotating the adjusting collar, wherein the adjusting collar blocks movement of the at least one movement blocking member from the first position to the second position in the blocking position, and releases movement of the movement blocking member from the first position to the second position in the releasing position. As soon as the adjusting collar reaches the releasing position and a force acts on the belt reel in the unwinding direction, the movement of the belt reel relative to the sleeve can cause the at least one movement blocking member to be moved into disengagement from the belt reel.

[0029] The at least one movement blocking member is supported so as to be displaceable, particularly in the radial direction. Movement from the blocking position to the releasing position is effected, for example, in a radially outward direction.

[0030] The first portion of the torsion rod preferably has a larger diameter than the second portion. In this way, different rigidities of the first and the second portions can be easily obtained.

[0031] Further advantages and features of the present invention will become apparent from the following description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] [Figure 1]This is an exploded view showing a part of the belt retractor according to the present invention, according to the first embodiment of the present invention. [Figure 2] This is a cross-sectional view of the belt retractor in Figure 1 when the release mechanism is not activated. [Figure 3] This is a cross-sectional view of the belt retractor in Figure 1 when the release mechanism is activated. [Figure 4] This is a cross-sectional view of the belt retractor in Figure 1, showing the release mechanism activated after the torsion rod has twisted. [Figure 5] This diagram shows a part of the mechanism for releasing the deactivated state. [Figure 6] This diagram shows the release mechanism for the activated state shown in Figure 5. [Figure 7] This figure shows the force progression when a belt retractor is prevented from operating at a high force level. [Figure 8] This figure shows the force progression when the belt retractor is prevented from operating at a low force level. [Figure 9] This is an exploded view showing a portion of a belt retractor according to another embodiment of the present invention. [Figure 10] This is a cross-sectional view of the belt retractor in Figure 9 when the release mechanism is not activated. [Figure 11] This is a cross-sectional view of the belt retractor in Figure 9 when the release mechanism is activated. [Figure 12] This is a cross-sectional view of the belt retractor in Figure 9, showing the release mechanism activated after the torsion rod has twisted. [Figure 13] Figure 9 shows the change in force when the belt retractor is prevented from operating at a high force level. [Figure 14] Figure 9 shows the force progression when the belt retractor is prevented from operating at a low force level. [Modes for carrying out the invention]

[0033] Figure 1 shows an exploded view of a portion of a belt retractor 10 for a seat belt system in an automobile vehicle.

[0034] The belt retractor 10 includes a belt reel 12 that is rotatably supported on one side, and the webbing can be wound around the belt reel 12.

[0035] In the installed state of the belt retractor 10, the belt reel 12 is rotatably supported within a frame not shown in the diagram for simplicity.

[0036] The belt retractor 10 further comprises a disc 14 that is rotatably supported with respect to a vehicle structure (not shown).

[0037] The disk 14 has a stop 15 and a threaded section 17 adjacent to the stop 15 (see Figure 2). The stop 15 is specifically formed by the end face of the disk 14.

[0038] Furthermore, the belt retractor 10 has a force limiting mechanism 16, and the restraining force acting on the vehicle occupant when restrained can be limited by the force limiting mechanism 16. The force limiting mechanism 16 includes a torsion rod 18 that functions as an energy absorbing member.

[0039] The torsion rod 18 is received or held at its first end 20 so as to be rotatably fixed within the disc 14. Specifically, the torsion rod 18 is securely connected to the disc 14 in a positively fitted or form-fitting manner.

[0040] At its second end 22, the torsion rod 18 is connected to the belt reel 12 in a manner that it is rotatably fixed. Specifically, the torsion rod 18 is securely connected to the belt reel 12 either by a rigid fit or by a form fitting.

[0041] The torsion rod 18 has a first portion 24 and a second portion 26, as can be seen in Figure 2, which shows a cross-sectional view of the belt retractor 10.

[0042] The first portion 24 of the torsion rod 18 has greater rigidity than the second portion 26, which, in the shown embodiment, is achieved by the torsion rod 18 having a larger diameter in the first portion 24 than in the second portion 26. However, it is also conceivable that the first portion 24 be made of a harder material.

[0043] The belt retractor 10 further includes a sleeve 28 that partially encloses the torsion rod 18.

[0044] The sleeve 28 is coupled to the torsion rod 18 at the first portion 24 of the torsion rod 18, in a manner that is particularly rotatably fixed.

[0045] Furthermore, the sleeve 28 is releasably coupled to the belt reel 12, and as a result, the first portion 24 of the torsion rod 18 is releasably coupled to the belt reel 12. Insofar as the torsion rod 18 is coupled to the belt reel 12 via the sleeve, the second portion 26 of the torsion rod 18 is bridged, as shown by the force path plotted in Figure 2.

[0046] The belt retractor 10 further includes a release mechanism 30, which will be described in more detail later herein in relation to Figures 5 and 6. Specifically, the release mechanism 30 is configured to release a releasable connection between the torsion rod 18 and the belt reel 12.

[0047] The release mechanism 30 comprises two motion-blocking members 32 supported so as to be displaceable in the radial direction, and one adjustment collar 34.

[0048] The adjustment collar 34 is fixed axially on the extension portion 41 of the belt reel 12 by the spring washer 36.

[0049] Furthermore, a stop member 40 is provided, and the step member 40 limits the rotation of the belt reel 12 in the loosening direction to a predetermined number of rotations when the release mechanism 30 is activated. In the shown embodiment, the stop member 40 is a nut.

[0050] The stop member 40 is arranged coaxially with the belt reel 12 and the torsion rod 18.

[0051] The stop member is rotatably supported, specifically rotatably supported with respect to the disk 14 and the sleeve 28.

[0052] Figure 2 shows a cross-sectional view of the belt retractor 10 shown in Figure 1. Specifically, Figure 2 shows the belt retractor 10 in its initial state, in which the vehicle occupant can manually loosen the webbing.

[0053] In this state, the belt retractor 10 is supported so as a whole that it can rotate around its longitudinal axis L. To support the belt retractor 10 so that it can rotate, the extension portion 39 of the disc 14 and the extension portion 41 of the belt reel 12 are supported, for example, in corresponding bearings.

[0054] Figure 2 shows the motion-blocking mechanism 42, which can prevent the belt retractor 10 from rotating in the direction of webbing loosening.

[0055] The operating mechanism 42 has a locking pole 44 that can prevent the rotation of the disk 14 and, consequently, the rotation of the belt retractor 10.

[0056] Furthermore, Figure 2 clearly shows that a toothed portion 46 is provided at the transition point from the first portion 24 to the second portion 26 of the torsion rod 18, and that the torsion rod 18 is connected to the sleeve 28 in a manner that allows it to rotate and be fixed via the toothed portion 46.

[0057] In the state shown in Figure 2, the motion-blocking member 32 is engaged with the sleeve 28 and the belt reel 12, meaning that the sleeve 28 and the belt reel 12 are connected to each other in such a way that they are rotatably fixed via the motion-blocking member 32.

[0058] The stop member 40 is rotatably supported on the threaded section 17, spaced apart from the stop 15, by being screw-engaged with the threaded section 17.

[0059] The stop member 40 is connected to the belt reel 12 in a manner that allows it to rotate and be fixed in place.

[0060] However, the stop member 40 can be displaced axially with respect to the belt reel 12.

[0061] If the vehicle in which the belt retractor 10 is installed undergoes a sudden deceleration while in operation, the motion-blocking mechanism 42 prevents the rotation of the belt retractor 10 in the direction of webbing loosening by, for example, a locking pole 44 that engages with a structural component of the vehicle and thus prevents the rotation of the disc 14.

[0062] As long as the vehicle's deceleration is below a certain level, the release mechanism 30 is not activated, meaning the belt reel 12 is engaged within the sleeve 28 via the motion-blocking member 32 as shown in Figure 2. Such deceleration occurs, for example, when the vehicle collides with an obstacle at a relatively low speed, such as a maximum of 15 km / h.

[0063] In this example, the restraining force acting on the vehicle occupants is transmitted to the vehicle structure via the force path plotted in Figure 2.

[0064] In this case, the torsion rod 18 does not undergo plastic deformation because the force path extends only along the first portion 24 of the torsion rod 18, which has higher rigidity than the second portion 26. This means that the force limiting mechanism 16 does not become activated. Specifically, the torsion rod 18 is not twisted, and the stop member 40 remains in its initial position.

[0065] Figure 3 shows the belt retractor 10 in a different cross-sectional view. Unlike in Figure 2, the motion-blocking member 32 is not engaged with the sleeve 28, and as a result, the belt reel 12 can rotate relative to the sleeve 28.

[0066] This applies when the vehicle's deceleration exceeds a certain level and the release mechanism 30 is activated.

[0067] In this example, the restraining force acting on the vehicle occupants is transmitted to the vehicle structure via the force path plotted in Figure 3, where the force path also extends along the second portion 26 of the torsion rod 18.

[0068] Because the second part 26 has lower rigidity than the first part 24, the belt reel 12 can rotate with respect to the disc 14 in the direction of webbing loosening, causing the torsion rod 18 to plastically deform, specifically to twist, in the second part 26. As a result, the force limiting mechanism 16 is activated, and the vehicle occupant may be displaced forward.

[0069] When the belt reel 12 rotates with respect to the disc 14, the stop member 40 is moved along the screw section 17 by being screw-engaged with the screw section 17.

[0070] Specifically, the belt reel 12 can be rotated until the stop member 40 comes into contact with the stop 15 (see Figure 4). In this state, further rotation of the belt reel 12 relative to the disc 14 is not possible.

[0071] For example, when the release mechanism 30 is activated, the rotation of the belt reel 12 is limited from two rotations to three rotations.

[0072] Because the rotation of the belt reel 12 is limited to a predetermined number of rotations, the vehicle occupants are displaced forward only to the extent that they do not come into contact with the vehicle structure when the operation of the belt retractor 10 is blocked.

[0073] Figure 4 shows another cross-sectional view of the belt retractor 10 in a state where the belt reel 12 is rotated to its maximum extent with respect to the sleeve 28 or / or the disc 14, and the stop member 40 is in contact with the stop 15.

[0074] Figures 5 and 6 show the release mechanism 30. Figure 5 shows the release mechanism 30 when the system is not running, and Figure 6 shows the release mechanism 30 when the system is running.

[0075] When the release mechanism 30 is not activated, the adjustment collar 34 is in the position that prevents movement, and when the release mechanism 30 is released, the adjustment collar 34 is in the release position.

[0076] As is clear from Figures 5 and 6, the adjustment collar 34 has a recess 52.

[0077] When the adjustment collar 34 is in the motion-blocking position, the motion-blocking member 32 is held in the first position by the adjustment collar 34. The belt reel 12 is coupled to the sleeve 28 in such a way that it is rotated and fixed via the motion-blocking member 32.

[0078] When the adjustment collar 34 is in the release position, the recess 52 is aligned with the motion-blocking member 32, and as a result, the motion-blocking member 32 can move radially outward into the recess 52, and thus can be displaced to the second position.

[0079] A drive mechanism is provided to rotate the adjustment collar 34 to the release position, which is simply schematicly shown in Figure 2. The drive mechanism includes a drive member 54 that can be driven by linearly movable pyrotechnic technology, which is specifically a piston. The drive member 54 can act on the adjustment collar 34 in the tangential direction, thereby rotating the adjustment collar 34 to the release position as shown by the arrow in Figure 5.

[0080] The movement of the motion-blocking member 32 from the first position to the second position is achieved by the relative movement between the belt reel 12 and the sleeve 28. Specifically, the motion-blocking member 32 is pushed radially outward by the belt reel 12 until the belt reel 12 and the sleeve 28 are disengaged from each other.

[0081] Figure 7 shows a graph of the change in restraining force at a high force level when the belt retractor 10 is prevented from operating, i.e., when the release mechanism 30 is not activated. Figure 8 shows the change in force at a low force level when the belt retractor 10 is prevented from operating after the release mechanism 30 has been activated. Stop activation (S A ) From this point, that is, when the stop member 40 comes into contact with the stop 15, the restraining force increases rapidly. As shown by the dashed lines in Figures 7 and 8, without using the stop to activate, an equally rapid increase occurs from time G0 when the webbing is completely unwound from the belt reel 12.

[0082] When the release mechanism 30 is not activated, and specifically in the force transition shown in Figure 7, only the theoretical activation of the stop occurs, and no large load is generated that would normally cause the torsion rod 18 to plastically deform in its first part 24 and adjust the stop member 40.

[0083] Figures 9 to 12 show a belt retractor 10 according to another embodiment.

[0084] In the following, the same reference numerals are used for similar structures having similar functions that are known from the embodiments described above. Please refer to the above description for details. To avoid repetition, the differences between each embodiment will be discussed below.

[0085] The belt retractor 10 shown in Figures 9 to 12 differs from the belt retractor shown in Figures 1 to 6 in the shape of the stop member 40.

[0086] Specifically, the stop member 40 is screw-engaged to the sleeve 28 instead of the disc 14.

[0087] For this purpose, the stop member 40 has a male thread and the sleeve 28 has a corresponding female thread.

[0088] A limit stop 56, which is initially spaced apart from the sleeve 28, is provided on the stop member 40 as shown in Figure 10.

[0089] In relation to the first embodiment, when the rotation of the belt retractor 10 described above is prevented by the operation prevention mechanism 42, and furthermore, when the release mechanism 30 is activated, the rotation of the belt reel 12 causes the stop member 40 to be screwed into the sleeve 28, specifically until the limit stop 56 comes into contact with the sleeve 28, as shown in Figure 12.

[0090] As soon as the stop member 40 is fully screwed into the sleeve 28, the belt reel 12 is reconnected to the sleeve 28 in a manner that fixes it in rotation, and as a result, the force path again extends through the first portion 24 of the torsion rod 18 with the second portion 26 of the torsion rod 18 bridged.

[0091] Figure 13 shows a graph illustrating the change in restraining force at high force levels when the belt retractor 10 is prevented from operating, i.e., when the release mechanism 30 is not activated, in the case of the belt retractor 10 as shown in Figures 9 to 12. The restraining force increases sharply from time G0, when the webbing is completely unwound from the belt reel 12.

[0092] Figure 14 shows the force progression when the belt retractor 10 is prevented from operating at a low force level after the release mechanism 30 is activated. From the activation of the stop (SA), that is, when the stop member 40 is brought into contact with the sleeve 28 by its limit stop 56, the restraining force increases to a high force level. A further increase occurs from time G0 when the webbing is fully unwound from the belt reel 12. <Note> [Form 1] A belt retractor (10), A rotatably supported belt reel (12) capable of receiving webbing, An action-blocking mechanism (42) that can prevent the rotation of the belt retractor (10) in the direction of loosening the webbing, A force limiting mechanism (16) for limiting the restraining force of the belt retractor (10), The force limiting mechanism (16) comprises a torsion rod (18) having a first portion (24) and at least one other second portion (26), wherein the first portion (24) of the torsion rod (18) has higher rigidity than the second portion (26), the first portion (24) of the torsion rod (18) is releasably coupled to the belt reel (12), and the second portion (26) is firmly connected to the belt reel (12), A release mechanism (30) for releasing the releasable connection between the torsion rod (18) and the belt reel (12), A rotatably supported stop member (40) is arranged coaxially with the belt reel (12) and / or the torsion rod (18), wherein the stop member (40) limits the rotation of the belt reel (12) in the loosening direction to a predetermined number of rotations when the release mechanism (30) is activated. A belt retractor (10) equipped with [a specific feature]. [Form 2] A belt retractor (10) according to Embodiment 1, characterized in that the torsion rod (18) is releasably connected to the belt reel (12) via a sleeve (28) which is coupled to the torsion rod (18) in such a way that it surrounds the torsion rod (18) at least partially and is rotatably fixed in the first portion (24). [Form 3] A belt retractor (10) according to Embodiment 1 or 2, wherein the motion-blocking mechanism (42) comprises a rotatably supported disc (14), the disc (14) being coupled to the torsion rod (18) in a manner that it is fixed to rotate, the disc (14) comprising a limit stop (15) and a threaded portion (17) adjacent to the limit stop (15), and the stop member (40) being rotatably supported on the threaded section (17) and spaced apart from the limit stop (15) in a manner that it is screw-engaged with the threaded section (17). [Form 4] A belt retractor (10) according to Embodiment 3, characterized in that the stop member (40) is connected to the belt reel (12) in such a manner that it is fixed to rotate, and as a result, when the belt reel (12) rotates with respect to the disc (14), the stop member (40) is moved along the screw section (17) to the limit stop (15). [Form 5] A belt retractor (10) according to Embodiment 2, characterized in that the stop member (40) is screw-engaged with the sleeve (28), and a limit stop (56) that is spaced apart from the sleeve (28) is provided on the stop member (40). [Form 6] A belt retractor (10) according to Embodiment 5, characterized in that the stop member (40) is connected to the belt reel (12) in a manner that is fixed to rotate, and as a result, when the belt reel (12) rotates with respect to the sleeve (28), the stop member (40) is screwed into the sleeve (28) until the limit stop (56) comes into contact with the sleeve (28). [Form 7] A belt retractor (10) according to Embodiment 6, characterized in that the stop member (40) has a male thread and the sleeve (28) has a corresponding female thread. [Form 8] A belt retractor (10) according to any one of embodiments 2 to 7, wherein at least one movable supported motion-blocking member (32) is provided, wherein in a first position of the motion-blocking member (32), the belt reel (12) is firmly coupled to the sleeve (28) via the motion-blocking member (32), and in a second position of the motion-blocking member (32), the belt reel (12) is rotatable with respect to the sleeve (28). [Form 9] A belt retractor (10) according to Embodiment 8, wherein the release mechanism (30) comprises an adjustment collar (34) supported so as to be rotatable from an operation-blocking position to a release position, and a drive element (54) for rotating the adjustment collar (34), wherein the adjustment collar (34) prevents the movement of the operation-blocking member (32) from the first position to the second position at the operation-blocking position, and releases the movement of the operation-blocking member (32) from the first position to the second position at the release position. [Form 10] A belt retractor (10) according to any one of the embodiments 1 to 9, characterized in that the first portion (24) of the torsion rod (18) has a larger diameter than the second portion (26). [Explanation of Symbols]

[0093] 10 Belt Retractor 12 Belt Reels 14 discs 15 Stop 16. Force limiting mechanism 17 Screw Sections 18 Torsion Rod 20 First end 22 Second end 24 Part 1 26. Part 2 28 sleeves 30 Release mechanism 32 Operation blocking member 34 Adjustable Colors 36 Spring Washer 39 Extension part 40 Stopping member 41 Extension part 42 Motion blocking mechanism 44 Rocking Poles 46 Teeth 52 recess 54 Drive Member 56 Limit Stop

Claims

1. A belt retractor (10) for a vehicle seat belt system, A rotatably supported belt reel (12) capable of receiving webbing, An action prevention mechanism (42) that can prevent the rotation of the disc (14) in the loosening direction of the webbing when the vehicle deceleration exceeds a first level, A force limiting mechanism (16) for limiting the restraining force of the belt retractor (10), comprising a torsion rod (18) having a first portion (24) and at least one other second portion (26), wherein the first portion (24) of the torsion rod (18) has greater rigidity than the second portion (26), the first portion (24) of the torsion rod (18) is firmly connected to the disc (14) at one end, and the other end (46) on the second portion (26) side is releasably connected to the belt reel (12), and the second portion (26) is firmly connected to the belt reel (12) at the end (22) on the side furthest from the first portion (24), A release mechanism (30) for activating the force limiting mechanism (16) by releasing the connection between the first portion (24) of the torsion rod (18) and the belt reel (12) when the deceleration of the vehicle is greater than the first level, and the first portion (24) of the torsion rod (18) is greater than the second level, A stop member (40) is arranged coaxially with the belt reel (12) and the torsion rod (18), and is supported so as to be axially movable relative to the belt reel (12) while rotating together with the belt reel (12) after the release mechanism (30) is activated, and the stop member (40) strikes the stops (15, 28) to limit the rotation of the belt reel (12) in the loosening direction to a predetermined number of rotations after the release mechanism (30) is activated. Equipped with, The aforementioned motion-blocking mechanism (42) prevents the rotation of the torsion rod (18) in the loosening direction when the deceleration of the vehicle exceeds the first level. The release mechanism (30) is When the operation blocking mechanism (42) is activated, if the deceleration of the vehicle is below the second level, the force limiting mechanism (16) is not activated, thereby preventing the connection between the first portion (24) of the torsion rod (18) and the belt reel (12) from being released, preventing the belt reel (12) from rotating in the loosening direction, and preventing the rotation of the stop member (40). When the operation blocking mechanism (42) is activated, if the deceleration of the vehicle is at or above the second level, the force limiting mechanism (16) is activated, thereby releasing the connection between the first portion (24) of the torsion rod (18) and the belt reel (12), causing the second portion (26) of the torsion rod (18) to twist, which in turn allows the belt reel (12) to rotate in the loosening direction, and the rotation of the belt reel (12) causes the stop member (40) to rotate, in a belt retractor (10).

2. A belt retractor (10) according to claim 1, characterized in that the torsion rod (18) is releasably connected to the belt reel (12) via a sleeve (28) which is coupled to the torsion rod (18) in such a way that it surrounds the torsion rod (18) at least partially and is rotatably fixed in the first portion (24).

3. A belt retractor (10) according to claim 1 or 2, wherein the motion-blocking mechanism (42) comprises a rotatably supported disc (14), the disc (14) being coupled to the torsion rod (18) in a manner that it is fixed to rotate, the disc (14) comprising a limit stop (15) as the stop and a threaded portion (17) adjacent to the limit stop (15), and the stop member (40) being rotatably supported on the threaded section (17) and spaced apart from the limit stop (15) in a manner that it is screw-engaged with the threaded section (17).

4. A belt retractor (10) according to claim 3, characterized in that the stop member (40) is connected to the belt reel (12) in such a manner that it is rotatably fixed, and as a result, when the belt reel (12) rotates with respect to the disc (14), the stop member (40) is moved along the screw section (17) to the limit stop (15).

5. A belt retractor (10) according to claim 2, characterized in that the stop member (40) is screw-engaged with the sleeve (28), the stop is provided on the end face of the sleeve (28), and a limit stop (56) spaced apart from the end face of the sleeve (28) is provided on the stop member (40).

6. A belt retractor (10) according to claim 5, characterized in that the stop member (40) is connected to the belt reel (12) in a manner that it is rotatably fixed, and as a result, when the belt reel (12) rotates with respect to the sleeve (28), the stop member (40) is screwed into the sleeve (28) until the limit stop (56) comes into contact with the sleeve (28).

7. The belt retractor (10) according to claim 6, characterized in that the stop member (40) has a male screw and the sleeve (28) has a corresponding female screw.

8. A belt retractor (10) according to claim 2, claims 3 and 4 which reference claim 2, or any of claims 5 to 7, wherein at least one movably supported motion-blocking member (32) is provided, wherein in a first position of the motion-blocking member (32), the belt reel (12) is firmly coupled to the sleeve (28) via the motion-blocking member (32), and in a second position of the motion-blocking member (32), the belt reel (12) is rotatable with respect to the sleeve (28).

9. A belt retractor (10) according to claim 8, wherein the release mechanism (30) comprises an adjustment collar (34) supported so as to be rotatable from an operation-blocking position to a release position, and a drive element (54) for rotating the adjustment collar (34), wherein the adjustment collar (34) prevents the movement of the operation-blocking member (32) from the first position to the second position at the operation-blocking position, and releases the movement of the operation-blocking member (32) from the first position to the second position at the release position.

10. A belt retractor (10) according to any one of claims 1 to 9, characterized in that the first portion (24) of the torsion rod (18) has a larger diameter than the second portion (26).

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