Sensor and seat belt retractor

Abstract

The invention describes a sensor (12) for activating a vehicle-sensitive locking mechanism (14) of a seat belt retractor (10), the sensor comprising a suspended inertial body (26) and a support (28) for supporting the inertial body (26), the support (28) comprising a receiving space (58) for receiving a lubricant. The invention further describes a seat belt retractor (10).

Description

[0001] The present invention relates to a sensor for activating a vehicle-sensitive locking mechanism of a seat belt retractor and a seat belt retractor.

[0002] Sensors for activating a vehicle-sensitive locking mechanism of a seat belt retractor are known. In the case of positive or negative vehicle acceleration and when the vehicle is in a specific inclined position, an inertial body starts to move and causes a sensor lever to pivot. As a result, a blocking pawl is lifted, whereby in different ways a blocking mechanism is activated which is adapted to block a take-up shaft and prevent the webbing from extending.

[0003] In order to reduce the noise emission which the vehicle occupants may perceive as disturbing, lubricant is usually provided on the contact surfaces of the suspended inertial body. Due to the frequent movement of the inertial body, during the service life of the sensor, the inertial body may shift from a predetermined position.

[0004] Therefore, the object of the present invention is to provide a sensor for a vehicle-sensitive vehicle occupant restraint system such that noise emission is avoided particularly reliably and over a long period.

[0005] According to the invention, this object is achieved by a sensor for activating a vehicle-sensitive locking mechanism of a seat belt retractor, which sensor comprises a suspended inertial body and a support for the inertial body, the support comprising a receiving space for receiving lubricant. This object is further achieved by an assembly group comprising a seat belt retractor and a sensor designed appropriately.

[0006] The presence of the receiving space can contribute to providing a sufficient amount of lubricant in the support of the sensor to damp noise particularly reliably and over a long period. Specifically, the lubricant present in the receiving space serves as a supply which can diffuse in the support when part of the lubricant has been discharged from the support due to the frequent movement of the inertial body.

[0007] The lubricant serves as a damping for the inertial body. In addition, the lubricant reduces the friction between the inertial body and the support, which has a beneficial effect on the service life of the sensor.

[0008] For example, the lubricant is a solid lubricant, grease, etc.

[0009] According to one embodiment, the support has a support housing and a sphere retained in the support housing. In this way, the inertial body is pivotally mounted and in particular can swing in all directions similarly.

[0010] For example, the receiving space is formed by at least partially circumferential grooves in the support housing. Specifically, the grooves are provided on the contact surface between the support housing and the sphere, for example, the grooves extend along the equator of the sphere. In this way, an increased amount of lubricant can be present along the equator of the sphere, so that when the sphere moves within the support, the lubricant in the receiving space can be evenly diffused on the surface of the sphere.

[0011] Preferably, the grooves are circumferential throughout the support housing.

[0012] The support housing is preferably formed by two half - shells specifically put together. Alternatively or additionally, the support housing can be bonded or welded. This makes the manufacture of the support particularly simple.

[0013] The inertial body can be fixed to the sphere. Accordingly, the inertial body can be integrally manufactured with the sphere or can be subsequently fixed to the sphere, for example, fixed to the sphere by a pin that is fixed to both the sphere and the inertial body. By fixing the inertial body to the sphere, the inertial body is reliably held in the support.

[0014] The inertial body can include a metal body, and an insert made of plastic extends through the metal body. In particular, the sphere is part of the insert. That is to say, the insert is part of the support. The metal body ensures a sufficiently high weight to guarantee the proper oscillating behavior of the inertial body. The insert made of plastic in turn ensures proper frictional behavior (especially on the contact surface between the sphere and the support housing).

[0015] For example, the plastic insert is injected into the metal body. In this way, the metal body is bound to the plastic insert.

[0016] According to an embodiment, in the support housing, a first opening through which the inertial body extends and a second opening facing the first opening are provided, and the second opening communicates with a lubricant reservoir. The second opening is used on the one hand to fill the support housing with lubricant. In a lubricant reservoir that is preferably separated from the receiving space, an excess amount of lubricant can be additionally provided, and if necessary, when the sensor operates, the lubricant can flow into the receiving space. For this purpose, the lubricant reservoir is, for example, funnel - shaped.

[0017] The second opening is specifically arranged above the first opening and accordingly above the sphere, and is in direct communication with the lubricant reservoir, so that the lubricant can be continuously conveyed from the lubricant reservoir to the support by gravity.

[0018] A collar configured to retain a support housing in a seat belt retractor can be integrally formed on the support housing. The collar is inserted into a mating guide, such as in the housing of a seat belt retractor. As a result, additional fasteners for fastening the sensor can be dispensed with, allowing the sensor to be installed in a particularly simple and inexpensive manner.

[0019] According to one embodiment, the sensor includes a triggering element that can be moved out of an idle position by the movement of an inertia body, thereby activating a vehicle occupant restraint system, wherein the inertia body is pivotable about a fixed pivot point. The pivotable mounting of the inertia body helps to avoid excitation in the vertical direction, thus preventing any interfering noise from being generated by the sensor during operation.

[0020] The triggering element is configured to, for example, engage a blocking pawl in the locking teeth of a locking mechanism. In this way, the vehicle occupant restraint system can be activated such that when a tension acts on the webbing of the take-up spool, the take-up spool is blocked.

[0021] Other advantages and features of the present invention will be apparent from the following description and from the accompanying drawings, in which:

[0022] - Figure 1 A seat belt retractor according to the present invention is shown in an exploded view,

[0023] - Figure 2 A part of the seat belt retractor is shown in a side view,

[0024] - Figure 3 Another side view of the seat belt retractor is shown,

[0025] - Figure 4 A cross-section through the seat belt retractor is shown,

[0026] - Figure 5 Shows Figure 4 a detailed view of

[0027] - Figure 6 Another cross-section through the seat belt retractor is shown,

[0028] - Figure 7 A part of the sensor is shown in an exploded view,

[0029] - Figure 8 The sensor in an assembled state is shown, and

[0030] - Figure 9 and Figure 10 a half-shell of the support is shown.

[0031] Figure 1The seatbelt retractor 10 is shown in an exploded view and includes a sensor 12 for activating a vehicle-sensitive locking mechanism 14 of the seatbelt retractor 10.

[0032] In addition to the sensor 12 and the locking mechanism 14, the seatbelt retractor 10 further includes a housing 16, a webbing spool 18 around which a webbing can be wound, and a cover 20 that covers the sensor 12 and the locking mechanism 14.

[0033] The locking mechanism 14 includes locking teeth 22 that are connected to the webbing spool 18 via a spring mechanism, and a blocking pawl 24 that can engage in the locking teeth 22 to trigger a blocking mechanism that blocks rotation of the webbing spool 18.

[0034] The sensor 12 includes a suspended, specifically pivotally mounted inertial body 26 that is suspended in a support 28. The sensor 12 is specifically designed as an oscillating sensor.

[0035] The support 28 is formed by a two-piece support housing 30 and a sphere 32 that is rotatably held in the support housing 30. The sphere 32 is tightly connected to the inertial body 26, specifically formed integrally with the inertial body.

[0036] In addition, the sensor 12 includes an adjustably mounted trigger element 34 that is tightly connected to the blocking pawl 24. In an embodiment, the trigger element 34 is formed integrally with the blocking pawl 24. However, it is also conceivable that the trigger element 34 is movable relative to the blocking pawl 24.

[0037] The trigger element 34 is specifically a pivotally mounted sensor lever.

[0038] In addition to the blocking pawl 24, a wing arm 36 that is also formed integrally with the trigger element 34 is provided on the trigger element 34. The wing arm 36 is designed such that the trigger element 34 is balanced.

[0039] Figure 2 A side view of the sensor 12 is shown, which is pre-assembled in the cover 20 of the seatbelt retractor 10.

[0040] The sensor 12 includes a collar 38 formed on the support housing 30 that is inserted into a mating seat 40 in the cover 20.

[0041] In Figure 2 a non-activated state of the sensor 12 is shown, in which the inertial body 26 is not deflected. In this state, the blocking pawl 24 is disengaged from the locking teeth 22.

[0042] Figure 3Also shown is a side view of the sensor 12 in the lid 20, in which the locking teeth 22 of the locking mechanism 14 are also shown.

[0043] Figure 3 The sensor 12 in the activated state is shown, in which the inertial body 26 is deflected. In the deflected state of the inertial body 26, the blocking pawl 24 of the triggering element 34 engages in the locking teeth 22, thereby preventing the take-up spool 18 from rotating.

[0044] For an adjustable, specifically pivotal mounting of the triggering element 34, the triggering element 34 includes an integrally formed sleeve 42, which is attached to a journal 44 formed in the lid 20. As an alternative, the journal 44 can be formed on the triggering element 34 and the sleeve 42 can be formed on the lid 20.

[0045] Figure 4 A cross-section through the seatbelt retractor 10 is shown, which extends through the center of the inertial body 26. Figure 5 Shows Figure 4 A detailed view of the region of the inertial body 26 in the cross-section of

[0046] From Figure 4 and Figure 5 the structure and the support of the inertial body 26 become clear.

[0047] For a suspended mounting of the inertial body 26, the sphere 32 is received in the two-piece support housing 30 in such a way that the support housing 30 wraps around the sphere 32 along the equator of the sphere.

[0048] The inertial body 26 can thus pivot about a fixed pivot point.

[0049] Furthermore, it is evident from the cross-sectional view that the inertial body 26 has a metal body 46, and an insert 48 made of plastic extends through the metal body. The insert 48 extends specifically to the lower side 50 of the inertial body 26 and forms the lower side 50. The sphere 32 is also made of plastic and is integrally formed with the insert 48.

[0050] Thus, the contact surfaces of the inertial body 26 and the sphere 32 that contact other surrounding components are made of plastic.

[0051] At the end 52 of the triggering element 34 that contacts the inertial body 26, the triggering element 34 is hemispherical.

[0052] The triggering element 34 abuts specifically against the lower side 50 of the inertial body 26.

[0053] It is further evident from the cross-sectional view that a recess 54 is formed on the lower side 50 of the inertial body 26, and the hemispherical end of the triggering element 34, specifically the triggering element 34, projects into the recess.

[0054] More precisely, the inertial body 26 includes, on its lower side 50, a geometry that is wavy when viewed in a longitudinal section passing through the center of the inertial body 26, wherein a projection 56 is formed at the center of the lower side 50, specifically at the center of the recess 54.

[0055] When the sensor 12 is not activated, the end 52 of the trigger element 34 abuts against the projection 56 at the center of the recess 54.

[0056] The outer surface of the projection 56 extends concentrically around the center M of the sphere 32, and the center M also corresponds to the pivot point about which the inertial body 26 can pivot.

[0057] As seen in Figure 6 When the inertial body 26 deflects, the trigger element 34 can pivot about the pivot point R.

[0058] To reduce the friction within the support 28, a lubricant (not shown in the figures for clarity) is present in the support housing 30.

[0059] To receive the lubricant, the support includes a receiving space 58. The receiving space 58 is specifically formed by a circumferential groove 60 in the support housing 30. The groove 60 extends particularly along the equator of the sphere 32.

[0060] The support housing 30 includes two openings, specifically a first opening 62 through which the inertial body 26 extends and a second opening 64 facing the first opening 62.

[0061] The second opening 64 communicates with a lubricant reservoir 66 formed in the support 28.

[0062] Via the second opening 64, after the sensor 12 is assembled, the lubricant can be filled (specifically through a nozzle) into the receiving space 58.

[0063] In the lubricant reservoir 66, an excess of lubricant can be provided, which is continuously conveyed into the receiving space 58 if needed.

[0064] In Figure 7 The support 28 and the inertial body 26 are shown in an exploded view. It is evident from Figure 7 that the support housing 30 is formed by two parts of two half - shells 68, 70, and the two half - shells 68, 70 are put together to form the support 28.

[0065] The two half - shells 68, 70 can be identical.

[0066] Figure 8 The inertial body 26 suspended in the support 28 is shown in the assembled state.

[0067] InFigure 9 and Figure 10 In FIGS. Figure 9 and Figure 10 , the half shells 68, 70 of the support 28 are shown from different perspectives. It can be seen in these figures that in this embodiment, the pendulum is mounted essentially separately. For this purpose, two protrusions 74 designed in the form of spherical segments are formed in each of the half shells 68, 70. The sphere 32 rests on the protrusions 74. In this embodiment, a total of four protrusions 74 are provided for mounting the sphere. In different designs of the support housing, particularly when the construction is not mirror-inverted, ideally, three evenly distributed protrusions are used for mounting the sphere. However, alternatively, mounting via more than four protrusions, or alternatively, annular or planar mounting on the sphere surface is also possible. Hereinafter, the function of the sensor 12 will be described.

[0068] When the vehicle equipped with the sensor 12 accelerates, the inertial body 26 deflects, as shown in FIGS. and

[0068] . Figure 3 and Figure 6 shown.

[0069] Depending on the magnitude of the acceleration force acting on the inertial body 26, the inertial body 26 rotates more or less. In FIGS. and

[0069] , the inertial body 26 is shown in the maximum deflection position. Figure 3 and Figure 6 shown.

[0070] Preferably, the locking mechanism 14 of the seat belt retractor 10 is not activated until the inertial body 26 has reached approximately its maximum deflection. In the case of low acceleration, activation of the locking mechanism 14 is generally not desired.

[0071] This activation behavior is achieved by the geometric shape that is already wavy on the lower side of the inertial body 26.

[0072] Since the outer surface of the protrusion 56 is concentric with the center M of the sphere 32, when the inertial body 26 is activated, the inertial body initially moves relative to the trigger element 34 without deflecting the trigger element. For example, the inertial body 26 can deflect up to 11° without the trigger element 34 moving.

[0073] Only in the case of a large deflection does the inertial body 26 move the trigger element 34 out of its idle position, causing the trigger element 34 to pivot about the pivot point R.

[0074] The pivoting of the trigger element 34 causes the blocking pawl 24 to engage in the locking teeth 22 of the locking mechanism 14 (see FIG. Figure 3 ), which triggers the blocking mechanism. Specifically, another locking pawl (not visible in the figure) extends, causing the outer teeth formed on one side of the take-up shaft 18 to engage in the teeth 72 within the housing 16 (see FIG. Figure 1 ), thereby blocking the rotation of the take-up shaft 18. In this way, the vehicle occupant restraint system is activated.​​​​

Claims

1. A sensor (12) for a vehicle-sensitive locking mechanism (14) for actuating a seat belt retractor (10), the sensor comprising a suspended inertial body (26) and a support (28) for supporting the inertial body (26), wherein, The support member (28) includes a receiving space (58) for receiving a lubricant, wherein the support member (28) includes a support housing (30) and a sphere (32) retained in the support housing (30), and in the support housing (30), a first opening (62) through which the inertial body (26) extends and a second opening (64) facing the first opening (62) are provided, and the second opening (64) communicates with a lubricant reservoir (66).

2. The sensor (12) according to claim 1, characterized in that, The receiving space (58) is formed by at least partially circumferential grooves (60) in the support housing (30).

3. The sensor (12) according to claim 1 or 2, characterized in that, The support housing (30) is formed by two half-shells (68, 70) put together.

4. The sensor (12) according to claim 1 or 2, characterized in that, The inertial body (26) is fixed to the sphere (32).

5. The sensor (12) according to claim 1 or 2, characterized in that, The inertial body (26) includes a metal body (46), and an insert (48) made of plastic extends through the metal body, wherein the sphere (32) is part of the insert (48).

6. The sensor (12) according to claim 1 or 2, characterized in that, A collar (38) for retaining the support housing (30) in the seat belt retractor (10) is integrally formed on the support housing (30).

7. The sensor (12) according to claim 1 or 2, characterized in that, The sensor (12) includes a trigger element (34) that can be moved out of an idle position by the movement of the inertial body (26), thereby activating the vehicle occupant restraint system in this way, wherein the inertial body (26) is pivotable about a fixed pivot point (M).

8. The sensor (12) according to claim 7, characterized in that, The trigger element (34) is configured to engage a blocking pawl (24) in a locking tooth (22) of a locking mechanism (14).

9. A seat belt retractor (10) comprising a vehicle-sensitive locking mechanism (14) and a sensor (12) according to any one of claims 1 to 8.

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