Gurtaufroller

Abstract

Belt retractor (10) for a vehicle safety belt, with a belt spool (12) rotatably mounted in a frame (14), a sensor (16) for vehicle-sensitive blocking of the belt spool (12) and a mechanism (17) for deactivating the sensor (16) which interacts with a rocker arm (22), characterized in that the belt spool (12) acts on the mechanism (17) for deactivating the sensor (16) via a gear wheel (18) rotatably mounted on the frame (14) and the rocker arm (22) and can adjust the latter, the gear wheel (18) interacting via an external toothing with a pinion mounted in a rotationally fixed manner on the belt spool (12).

Description

[0001] The invention relates to a belt retractor for a vehicle safety belt, with a belt reel rotatably mounted in a frame, a sensor for vehicle-sensitive blocking of the belt reel and a mechanism for deactivating the sensor.

[0002] Belt retractors for vehicle seat belts are well known in the art. The vehicle seat belt is wound onto or off a belt reel as required.

[0003] For safety reasons, unwinding of the vehicle's seat belt must be prevented in certain situations. This is particularly the case when a vehicle is involved in an accident or is otherwise subject to significant deceleration. In such a case, the vehicle's seat belt must effectively keep the vehicle occupant who is wearing the seat belt in their seat.

[0004] As mentioned at the beginning, conventional belt retractors incorporate a sensor for this purpose. This typically comprises an inertial mass, usually designed as a metal ball. In the event of sudden acceleration or deceleration, this metal ball deflects a sensor lever, thus blocking the belt spool.

[0005] However, this blocking of the belt reel is not desirable in all situations involving sharp acceleration or deceleration, which is why mechanisms for deactivating this sensor are known in the art. Such a mechanism ensures that the vehicle-sensitive sensor can be selectively deactivated, thus preventing the belt reel from being blocked.

[0006] In addition, the sensor's inertial mass typically generates noise when it moves. Such noise can be perceived as annoying by vehicle occupants. This is particularly true if the belt retractor is designed for rear-seat application and installed in the parcel shelf. In this case, the belt retractor is located in the immediate vicinity of the heads of rear-seat occupants. This makes the noise generated by the sensor clearly audible. Sensor deactivation mechanisms are also used to prevent this noise development.

[0007] A belt retractor of the type mentioned above is known from DE 10 2006 037 544 A1. In this belt retractor, a rocker arm is connected to the belt spool via a friction clutch. The rocker arm can thus be driven by a rotational movement of the belt spool via a frictional connection. The rocker arm acts on an adjusting element with which a sensor lever of a sensor for detecting a vehicle condition can be blocked. The sensor lever is blocked in particular when the seat belt is not fastened by a vehicle occupant and when the seat belt is currently being wound onto the belt spool. The sensor lever is therefore only released when the belt spool is rotated in one unwinding direction.

[0008] The generic DE 10 2015 004 972 A1 describes a belt retractor with a rotatably mounted belt reel, a sensor for vehicle-sensitive blocking of the belt reel and a mechanism for deactivating the sensor, which interacts with a rocker arm.

[0009] Another belt retractor with a vehicle-sensitive sensor that can be deactivated is known from US Pat. No. 7,090,304 B2. In this belt retractor, a lever arm, which can block the vehicle-sensitive sensor, is operatively connected to the belt reel via a control disc and a gear.

[0010] Other belt retractors with a mechanism for deactivating the sensor are known, for example, from US 8 66 25 38 B2, EP 2 527 212 A1 and US 5 505 400 A.

[0011] The object of the present invention is to further improve a belt retractor of the type mentioned above. The belt retractor should produce minimal noise. Furthermore, the belt retractor should be simple in design and reliable in its operation.

[0012] This task is solved by a belt retractor of the type mentioned above, in which the belt spool acts on the mechanism for deactivating the sensor via a gearwheel rotatably mounted on the frame and the rocker arm, thereby adjusting the sensor. The gearwheel interacts via external teeth with a pinion mounted on the belt spool in a rotationally fixed manner. Mounted on the frame means that the axis of rotation of the gearwheel is fixed relative to the frame. The gearwheel creates a step-up or step-down ratio between the movement of the belt spool and the rocker arm. This allows the forces acting on the rocker arm and thus on the mechanism for deactivating the sensor to be precisely adjusted. At the same time, the translational and / or rotational paths of these elements can be adjusted. The mechanism for deactivating the sensor is thus actuated very precisely. This makes its function reliable.In addition, the components of the sensor deactivation mechanism are always held in a defined position with a defined force. This prevents unwanted movement of the components, which at least reduces disturbing noise. Thus, vehicle occupants are not disturbed by such noise.

[0013] The gear pairing ensures a simple, reliable, and low-wear functional coupling of the gear to the belt reel. Furthermore, the number of teeth on the gear and / or pinion allows for a gear ratio reduction or increase. Furthermore, the gear pairing reduces disturbing noises because it contains no loose components.

[0014] According to one embodiment, the mechanism for deactivating the sensor comprises a rotatably mounted blocking lever that is adjustable between a deactivation position, in which it engages a holding surface of the sensor, and a release position, in which it is spaced from the holding surface. This provides a simple and reliable way to deactivate the sensor. By engaging the holding surface of the sensor, at least a reduction in the noise generated by the sensor is achieved.

[0015] In one design variant, the rocker arm has a first and a second contact surface that interact with the blocking lever to adjust it between the deactivation position and the release position. The contact surfaces are preferably arranged adjacent to each other. The blocking lever is thus always in a defined position on the rocker arm and thus in a defined position overall. This reliably implements deactivation. Furthermore, the defined positioning reduces noise or prevents it from occurring in the first place.

[0016] Additionally, the rocker arm can include two circumferentially offset stop surfaces to limit rotational movement of the rocker arm relative to the locking lever. The rocker arm and the locking lever are thus in a defined position relative to each other, even with respect to rotation.

[0017] Preferably, the locking lever is preloaded in a direction to deactivate the sensor, preferably by a spring. This effectively prevents disturbing noises from the belt retractor and the mechanism for deactivating the sensor.

[0018] In one embodiment, a rotational movement of the belt spool is coupled to a rotational movement of the rocker arm by means of a friction clutch. The friction clutch contains a spring that preloads at least one friction element such that a predetermined frictional torque is generated between an input and an output of the friction clutch. The spring is preferably a metal spiral spring. Springs, in particular metal spiral springs, are generally designed to exhibit neither fatigue nor settling phenomena. For these reasons, the predetermined frictional torque is kept constant over the entire service life of the belt retractor. This results in consistently reliable function of the belt retractor and the mechanism for deactivating the sensor for vehicle-sensitive blocking of the belt spool.Furthermore, noise emanating from the sensor or the mechanism for deactivating the sensor is avoided or at least reduced so that a vehicle occupant is not disturbed by such noise.

[0019] The friction element can be designed as a single piece with the rocker arm. The friction element and rocker arm can be manufactured, for example, using a plastic injection molding process. This allows for cost-effective production.

[0020] Preferably, the spring is arranged between two friction elements, and the friction elements are preloaded in opposite directions. The force is thus applied essentially symmetrically. This can result in essentially identical behavior of the friction clutch in both directions of rotation. Likewise, the components of the friction clutch are loaded symmetrically or at least uniformly, thus preventing wear and achieving a long service life.

[0021] In a preferred variant, the friction element interacts with a friction surface arranged on the gear. The gear and the friction element are thus coupled in a simple and reliable manner. Furthermore, this results in a compact design.

[0022] Additionally, the gear can be ring-shaped, with the friction surface located on its inner circumference. Consequently, the sensor deactivation mechanism requires only a small amount of installation space. The friction surface is advantageously ring-shaped. This keeps the friction torque constant regardless of the angular or rotational position of the friction clutch's friction surface. Furthermore, consistent friction behavior can be ensured in both directions of rotation. This ensures high reliability of the belt retractor and the sensor deactivation mechanism.

[0023] The friction surface is preferably formed by at least one wall of a circumferential groove, and the groove preferably has a V-shaped cross-section. A groove is a simple and cost-effective way to create the friction surface. The friction behavior of the friction clutch can be further influenced by the angle at which the walls of a V-shaped groove are aligned to each other.

[0024] In one variant, the at least one friction element is at least partially accommodated in the groove, and the sections of the friction element accommodated in the groove are designed to correspond to the cross-section of the groove. This ensures that the friction element is securely mounted even in the event of shocks and vibrations that can occur in the vehicle and can perform its function smoothly. A predetermined friction torque is therefore always generated. Furthermore, there is extensive contact between the friction element and the walls of the groove. This allows a very high friction torque to be generated, yet requires only a relatively small installation space.

[0025] The friction element can be designed as an elastic, circular-arc-shaped friction arm. Such a friction arm is adapted to the friction surface arranged on the inner circumference of the rotating gear. The friction arm can be manufactured from plastic, for example, using an injection molding process. It can thus be manufactured cost-effectively while still being reliable.

[0026] The invention is explained below with reference to the accompanying drawings. They show: - Fig. 1 a belt retractor according to the invention in a perspective view, - Fig. 2a a side view of the belt retractor according to the invention from Fig. 1, in which the sensor is deactivated and some parts are omitted for clarity, - Fig. 2b an excerpt from Fig. 2a, where various components are omitted for clarity, - Fig. 3a a side view of the belt retractor according to the invention from Fig. 1, in which the sensor is not deactivated and in which some parts are omitted for clarity, - Fig. 3b an excerpt from Fig. 3a, where various components are omitted for clarity, - Fig. 4 a friction clutch and a rocker arm of the belt retractor according to the invention Fig. 1, - Fig. 5 an exploded view of the rocker arm and the friction clutch from Fig. 4, - Fig. 6 a view of the rocker arm and the friction clutch of the belt retractor according to the invention from a perspective Fig. 4 opposite perspective, - Fig. 7 a section along the line A - A Fig. 6, and - Fig. 8 a section along the line B - B Fig. 6.

[0027] The Fig. Figure 1 shows a belt retractor 10 with a belt spool 12 rotatably mounted on a frame 14. A housing cover 15 is also attached to the frame 14. A vehicle seat belt is not shown for reasons of clarity.

[0028] The Fig. Figure 2a shows the belt retractor 10 in a side view with the housing cover 15 removed. Here, a sensor 16 for vehicle-sensitive locking of the belt reel and a mechanism 17 for deactivating the sensor 16 can be seen.

[0029] A pinion (not shown) is mounted on the belt reel 12 in a rotationally fixed manner. This pinion interacts with a gear 18. A rocker arm 22 is rotationally connected to the gear 18 via a friction clutch 20 and thus via the friction torque prevailing in the friction clutch 20.

[0030] The rocker arm 22 is coupled to a rotatably mounted blocking lever 24, which is biased toward the rocker arm 22 by a spring 26. The blocking lever 24 represents a deactivation element for the sensor 16 and is a component of the mechanism 17 for deactivating the sensor 16.

[0031] The belt reel 12 thus acts via the gear 18 and the rocker arm 22 on the mechanism 17 for deactivating the sensor 16 and can adjust it.

[0032] Fig. Figure 2b shows the chain of effects from the gear 18 via the friction clutch 20 and the rocker arm 22 to the blocking lever 24 in detail. In addition, the Fig. 2b shows the vehicle-sensitive sensor 16. This can pivot a rotatably mounted sensor lever 30 and thus cause the belt reel 12 to lock.

[0033] In the Fig. 2a and Fig. Figure 2b shows the blocking lever 24 in a deactivation position. In this position, the blocking lever 24 rests against a retaining surface 32 of the sensor lever 30. As a result, the sensor lever 30 cannot be pivoted into a position in which it blocks the belt reel 12.

[0034] In the Fig. 3a is the same section as in the Fig. 2a. However, the blocking lever 24 is in a release position. In this position, the blocking lever 24 is lifted or spaced from the retaining surface 32 of the sensor lever 30.

[0035] Consequently, in this position, the sensor lever 30 is released in such a way that when the sensor 16 is triggered, the sensor lever 30 can be pivoted and the movement of the belt reel 12 can be blocked.

[0036] In the Fig. 3b again shows the chain of effects from the gear 18 to the sensor lever 30 in isolation.

[0037] The Fig. 4 and Fig. 5 shows the rocker arm 22 and the gear 18 in detail. Two arms 34, 36 are arranged on the rocker arm, between which, in the assembled state, a rocker arm of the blocking lever 24 is located (cf. Fig. 2b and Fig. 3b).

[0038] Viewed in the circumferential direction, the arm 34 forms a first stop surface 38 for the blocking lever 24 and the arm 36 forms a second stop surface 40 for the blocking lever 24.

[0039] In the Fig. 2a and Fig. In the deactivation position of the blocking lever 24 shown in Figure 2b, the rocker arm of the blocking lever 24 rests against the stop surface 38.

[0040] In the Fig. 3a and Fig. In the release position of the blocking lever 24 shown in Figure 3b, the rocker arm of the blocking lever 24 rests against the stop surface 40.

[0041] In the radial direction, the rocker arm 22 forms a first contact surface 42 and a second contact surface 44. The rocker arm side of the blocking lever 24 is in the deactivation position according to Fig. 2a and Fig. 2b on the first contact surface 42.

[0042] In the Fig. 3a and Fig. In the release position shown in Figure 3b, the rocker arm of the blocking lever 24 rests against the second contact surface 44.

[0043] Due to the spring load of the blocking lever 24 by the spring 26, the rocker arm of the blocking lever 24 always rests on one of the two contact surfaces 42, 44.

[0044] In the Fig. Figure 5 shows an exploded view of the rocker arm 22 and the gear 18. An annular friction surface 46 is formed on an inner circumference 45 of the gear 18. This friction surface is formed by the walls of a circumferential groove 47.

[0045] Two friction elements 48 corresponding to the geometry of the friction surface are arranged on the rocker arm 22. A cross-section of the friction elements 48 thus essentially corresponds to a cross-section of the groove 47.

[0046] In the illustrated embodiment, the friction elements 48 are designed as one piece with the rocker arm 22.

[0047] The friction elements 48 are preloaded in opposite directions by a coil spring 50. When assembled, the coil spring 50 thus preloads the two friction elements 48 toward the groove base. This also presses the friction elements 48 against the walls of the groove 47, creating a frictional connection there.

[0048] In the Fig. 7 and Fig. 8, the sectional views from the Fig. 6, it can be seen that the groove 47 has a V-shaped cross-section. The friction elements 48 are also V-shaped in section, so that they correspond to the cross-section of the groove 47. The friction elements 48 are designed as elastic, circular-arc-shaped friction arms, so that they can be elastically deformed by the spiral spring 50 and pressed into the groove 47.

[0049] Starting from a release position of the blocking lever 24, which is in the Fig. 3a and Fig. As shown in Figure 3b, the function of the belt retractor and the sensor deactivation mechanism 17 is as follows.

[0050] In the Fig. 3a and Fig. In the release position of the blocking lever 24 shown in Figure 3b, the sensor lever 30 can be moved by the sensor 16. The sensor 16 is therefore not blocked and can thus block the belt reel 12 in a vehicle-sensitive manner.

[0051] By rotating the belt spool 12, the blocking lever 24 can now be moved into a deactivation position. The belt spool 12 acts on the blocking lever 24, which is a component of the mechanism 17 for deactivating the sensor 16, via the gear 18 rotatably mounted on the frame 14 and the rocker arm 22.

[0052] The mechanism 17 for deactivating the sensor 16 can be adjusted via this chain of effects.

[0053] For this purpose, the belt reel 12 is inserted into the Fig. 3a and Fig. 3b is rotated clockwise. Such a rotation corresponds, for example, to the retraction of a vehicle's seat belt. During retraction, deactivation of sensor 16 is desirable to minimize noise.

[0054] The pinion, which is arranged on the belt reel in a rotationally fixed manner, forms a gear pair with the gear 18, so that the gear 18 rotates counterclockwise.

[0055] Since the rocker arm 22 is coupled to the gear 18 via the friction clutch, the rocker arm 22 is also rotated counterclockwise. The rocker arm of the blocking lever 24 slides from the contact surface 44 toward the contact surface 42 and, due to its loading by the spring 26, comes into contact with the contact surface 42.

[0056] As a result, the opposite arm of the blocking lever 24 comes into contact with the holding surface 32 of the sensor lever 30 and thus blocks a deflection of the sensor lever 30. The sensor 16 is thus deactivated.

[0057] If the belt reel 12 and thus the gear 18 are rotated further, the rocker arm 22 is pivoted via the friction clutch 20 until the rocker arm of the blocking lever 24 strikes the stop surface 38 of the rocker arm 22. The rocker arm 22 can then no longer rotate counterclockwise due to the blocking by the blocking lever 24.

[0058] However, the belt reel 12 and the gear 18 can be rotated further, provided that the torque causing this rotational movement is greater than the torque transmittable by the friction clutch 20. The friction clutch 20 then slips, i.e., it opens.

[0059] Starting from this position, in which the blocking lever 24 is in a deactivation position and the Fig. 2a and Fig.2b, the belt reel 12 is rotated counterclockwise, the rocker arm 22 is rotated clockwise via the gear pair of the pinion and the gear 18 as well as via the friction clutch 20.

[0060] The rocker arm of the blocking lever 24 slides from the contact surface 42 toward the contact surface 44 and comes into contact with it. At the same time, the blocking lever 24 is pivoted counterclockwise so that it lifts off the retaining surface 32 of the sensor lever 30.

[0061] This cancels the deactivation of sensor 16.

[0062] If the belt reel 12 and thus the pinion and the gear 18 are rotated further, the rocker arm 22 is driven along in this rotational movement until the rocker arm side of the blocking lever 24 rests against the stop surface 40.

[0063] Thereafter, the friction clutch 20 begins to slip analogously to the above description when the corresponding torque conditions are present.

Claims

[1] Belt retractor (10) for a vehicle safety belt, with a belt reel (12) rotatably mounted in a frame (14), a sensor (16) for vehicle-sensitive blocking of the belt reel (12) and a mechanism (17) for deactivating the sensor (16) which interacts with a drag lever (22), characterized by that the belt reel (12) acts on the mechanism (17) for deactivating the sensor (16) via a gear wheel (18) rotatably mounted on the frame (14) and the drag lever (22) and can adjust the latter, the gear wheel (18) cooperating via an external toothing with a pinion mounted non-rotatably on the belt reel (12). [2] Belt retractor (10) according to claim 1, characterized bythat the mechanism (17) for deactivating the sensor (16) comprises a rotatably mounted blocking lever (24) which is adjustable between a deactivation position in which it engages a holding surface (32) of the sensor (16) and a release position in which it is spaced from the holding surface (32). [3] Belt retractor (10) according to claim 2, characterized by in that the rocker arm (22) has a first and a second contact surface (42, 44) which cooperate with the blocking lever (24) in order to adjust it between the deactivation position and the release position, wherein the contact surfaces (42, 44) are preferably arranged adjacent to one another. [4] Belt retractor (10) according to claim 2 or 3, characterized by that the rocker arm (22) comprises two circumferentially offset stop surfaces (38, 40) for limiting a rotational movement of the rocker arm (22) relative to the blocking lever (24). [5] Belt retractor (10) according to one of claims 2 to 4, characterized by that the blocking lever (24) is pretensioned in a direction for deactivating the sensor (16), preferably by a spring (26). [6] Belt retractor (10) according to one of the preceding claims, characterized by in that a rotary movement of the belt reel (12) is coupled to a rotary movement of the rocker arm (22) by means of a friction clutch (20), wherein the friction clutch (20) contains a spring (50) which pretensions at least one friction element (48) such that a predetermined friction torque is generated between an input and an output of the friction clutch (20), wherein the spring (50) is preferably a spiral spring made of metal. [7] Belt retractor (10) according to claim 6, characterized by that the friction element (48) is designed in one piece with the rocker arm (22). [8] Belt retractor (10) according to claim 6 or 7, characterized bythat the spring (50) is arranged between two friction elements (48) and prestresses the friction elements (48) in opposite directions. [9] Belt retractor (10) according to one of claims 6 to 8, characterized by that the friction element (48) interacts with a friction surface (46) arranged on the gear (18). [10] Belt retractor (10) according to claim 9, characterized by that the gear (18) is annular and the friction surface (46) is arranged on its inner circumference (45). [11] Belt retractor (10) according to claim 10, characterized by that the friction surface (46) is annular. [12] Belt retractor (10) according to one of claims 9 to 11, characterized by that the friction surface (46) is formed by at least one wall of a circumferential groove (47) and the groove (47) preferably has a V-shaped cross-section. [13] Belt retractor (10) according to claim 12, characterized bythat the at least one friction element (48) is at least partially received in the groove (47) and the sections of the friction element (48) received in the groove (47) are designed to correspond to the cross section of the groove (47). [14] Belt retractor (10) according to one of claims 6 to 13, characterized by that the friction element (48) is designed as an elastic, circular-arc-shaped friction arm.

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