Seat belt retractor for vehicle seat belt

Abstract

The invention relates to a belt retractor (10) for a vehicle safety belt, comprising a frame (14), a belt reel (16), which is rotatably mounted on the frame (14) and has a winding body (20) on which a belt strap (12) of the safety belt can be received, and a safety system (18), which has a locking mechanism (46), the safety belt reel (16) can be locked relative to the frame (14) by means of the locking mechanism. Here, the winding body (20) has a receptacle (24), in which the locking mechanism (46) is at least mostly arranged.

Description

Technical Field

[0001] The invention relates to a seat belt retractor for a vehicle seat belt, the seat belt retractor comprising a frame, a seat belt reel which is rotatably supported on the frame and comprises a winding body on which a seat belt strip of the seat belt can be received, and a safety system comprising a locking mechanism by which the seat belt reel can be locked relative to the frame. Background Art

[0002] Seat belt retractors with a belt reel are known and are used to provide a vehicle occupant with a seat belt. In normal operation, the vehicle occupant can freely withdraw the seat belt from the belt reel against the action of a transmission spring, and the belt reel rewinds the seat belt again, for example, when the vehicle occupant unfastens the buckle. Depending on external parameters, such as the deceleration of the vehicle or the rotational acceleration of the belt reel when the seat belt is withdrawn, a locking mechanism is activated, by means of which the belt reel can be locked in the frame.

[0003] If the belt reel is locked in the frame, no further belt can be withdrawn from the belt reel until a predetermined force level is reached in the belt; if minimal bending due to the inherent elasticity of all components in the force flow is not taken into account, the belt reel cannot be twisted relative to the frame of the belt retractor.

[0004] Modern vehicles, in particular autonomous vehicles, offer a variety of different seating positions for vehicle occupants. In order to ensure the protective effect of the seat belt in all possible seating positions, the seat belt retractor must be positioned in the seat.

[0005] The known seat belt retractors have the disadvantage that they require a relatively large installation space. Therefore, they can only be arranged in the seat with great compromises in design and function. Summary of the invention

[0006] The object of the present invention is to provide a seat belt retractor which is of particularly compact design and which at the same time provides important safety-related functions.

[0007] In order to achieve this object, a belt retractor for a vehicle seat belt is provided, which has a frame, a belt reel which is rotatably mounted on the frame and has a winding body on which the belt strip of the seat belt can be received, and a safety system which has a locking mechanism by which the belt reel can be locked relative to the frame. The winding body has a receptacle in which the locking mechanism is at least mostly arranged. In the sense of the invention, the term "mostly" is understood to mean more than 50%, in particular at least 75%. By arranging the main part of the locking mechanism inside the winding body, i.e. radially inside the winding surface of the winding body, on which the belt strip is wound, the belt retractor can be designed particularly compactly in the axial direction. Such a belt retractor is particularly well suited for positioning in a vehicle seat, since it offers particularly large degrees of freedom in the design and function of the seat and the vehicle due to its axially flat design.

[0008] In order to make the seat belt retractor more compact, the safety system is at least mostly arranged in the receiving portion. As mentioned above, in the sense of the present invention, the term "mostly" is understood to mean more than 50%, in particular at least 75%.

[0009] In one embodiment, the locking mechanism does not protrude axially beyond the axial end of the reel, so that the locking mechanism is arranged axially completely within the reel or the receptacle. In this way, the belt retractor can have a particularly small axial width.

[0010] In order to provide a receptacle with the required installation space for the locking mechanism or the entire safety system, the belt reel can have a larger diameter than conventional belt retractors. The diameter of the winding body or the diameter of the winding surface can be at least 150%, in particular at least 200%, of the width of the belt webbing for which the belt retractor is intended. The axial width of the winding surface usually defines for which belt webbing width the belt retractor is intended.

[0011] In another embodiment, the frame has at least one section arranged in the receptacle. In this case, the section forms a bearing section and / or a locking section, by means of which the belt reel is rotatably supported on the frame and on which the locking mechanism acts in order to lock the belt reel relative to the frame. In this way, the bearing of the belt reel on the frame and, additionally or alternatively, the locking function of the locking mechanism are arranged inside the receptacle. As a result, the belt retractor can be designed to be particularly compact.

[0012] The at least one section can extend axially from an axially outer side of the frame into the receptacle. As a result, the belt reel can be supported on the frame and / or locked there without the belt reel and / or the locking mechanism having to extend in the axial direction beyond the respective axial outer side of the frame.

[0013] In particular, the at least one section can be part of a frame region with an S-shaped cross section. Due to the S-shaped cross section, the frame can have an at least partially pot-shaped recess in the corresponding axial outer side. The structural space surrounded by the pot-shaped recess can be used particularly efficiently as a receiving portion for parts of the safety system.

[0014] It can be provided that the safety system is configured to provide at least one of the following functions: belt tensioning, belt retraction, force limitation. This has the advantage that the corresponding functions are directly integrated into the belt retractor and can therefore be provided reliably.

[0015] According to one specific embodiment, the safety system has a belt tensioner, by means of which belt slack can be eliminated and the belt can be re-tensioned against the occupant.

[0016] Furthermore, the safety system can have a transmission spring which is provided as a drive for retracting the belt strap.

[0017] According to another embodiment, the belt retractor has a motor, in particular an electric motor, by means of which the belt reel can be driven relative to the frame.

[0018] In particular, as part of an Active Control Retractor (ACR), a motor may be provided for tensioning the seat belt webbing in order to improve the comfort and safety effect of the vehicle occupants.

[0019] In one embodiment, the motor is part of or forms the safety system.

[0020] In an alternative embodiment, the motor comprises an outer rotor and a base. In this case, the outer rotor is part of the winding body or forms the winding body. In this case, the base is part of the safety system or forms the safety system. In this way, the main part and the function of the seat belt retractor can be formed by the motor. This has the advantage that the number of components and the size of the seat belt retractor can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Further advantages and features emerge from the following description and from the drawings. In these drawings:

[0022] Figure 1The seat belt retractor according to the invention is shown in a side view.

[0023] Figure 2 In the front view shown Figure 1 Seat belt retractor,

[0024] Figure 3 The sectional view along the plane AA shows the first embodiment. Figure 1 Seat belt retractor,

[0025] Figure 4 The sectional view along the plane AA shows the second embodiment. Figure 1 Seat belt retractor,

[0026] Figure 5 The belt retractor according to the invention is shown in a side view according to a third embodiment, and

[0027] Figure 6 In the cross-sectional view along plane AA, Figure 5 Seat belt retractor. DETAILED DESCRIPTION

[0028] exist Figures 1 to 3 1 shows a seat belt retractor 10 for a vehicle seat belt together with a seat belt strip 12. The seat belt retractor 10 has a frame 14, a seat belt reel 16 which is rotatably supported in the frame 14 about a rotation axis R (see Figure 3 ) and security system 18.

[0029] The belt reel 16 has a winding body 20 with a radially outer winding surface 22 , against which the belt strap 12 rests or is wound in the wound state.

[0030] The winding surface 22 extends in a circumferential direction U around the axis of rotation R and can be partially interrupted in the circumferential direction U and / or in the axial direction.

[0031] Radially inside the winding surface 22 , the winding body 20 has a receptacle 24 which is formed by a cavity in the belt reel 16 .

[0032] In the present embodiment, the receiving portion 24 has a main cavity 26 adjacent to a first axial end 28 of the wound body 20 and a secondary cavity 30 adjacent to an opposite second axial end 32 of the wound body 20 .

[0033] In principle, the receiving part 24 can have any desired number of chambers 26 , 30 , which in particular can be connected to one another.

[0034] The frame 14 has a first and a second axial side section 34 , 36 , between which the winding body 20 is arranged in the axial direction.

[0035] The axial side sections 34, 36 are connected by a base section 38 (see Figure 1 ) are connected to each other, whereby the frame 14 has a U-shaped profile.

[0036] The first axial side section 34 has a pot-shaped first section 40 (see Figure 3 ), the first section extends into the main cavity 26.

[0037] In contrast to the cup-shaped first section 40 , the second axial side section 36 has a cup-shaped second section 42 which extends into the auxiliary space 30 .

[0038] Due to the pot-shaped sections 40 , 42 , the axial side sections 34 , 36 each have a region with an S-shaped cross section 44 .

[0039] The frame 14 is a one-piece formed part made of sheet metal. The pot-shaped sections 40, 42 can be produced by deep drawing.

[0040] The safety system 18 is provided for providing the comfort functions and safety functions described below and for this purpose comprises a locking mechanism 46 , a force limiter 48 and a transmission spring 50 .

[0041] The locking mechanism 46 comprises a locking plate 52 , a locking pawl 54 , a clutch plate 56 , and a belt strap-side acceleration sensor 58 and a vehicle-side acceleration sensor 60 , which are functionally coupled to the locking pawl 54 via the clutch plate 56 .

[0042] The belt webbing-side acceleration sensor 58 is formed by an inertia disk.

[0043] The vehicle-side acceleration sensor 60 may be an electrical sensor or a mechanical sensor, such as a ball sensor.

[0044] The locking mechanism 46 is provided for locking the belt reel 16 relative to the frame 14 when the belt strap-side acceleration sensor 58 and / or the vehicle-side acceleration sensor 60 detects an acceleration exceeding a fixed threshold value. In this case, the locking pawl 54 is triggered by the clutch disk 56 and engages with the locking section 62 of the frame 14, whereby the belt reel 16 is locked relative to the frame 14.

[0045] In this case, the locking section 62 is part of the pot-shaped first section 40 and is arranged completely within the main chamber 26 .

[0046] Due to this design, the locking means 46 is arranged completely in the receptacle 24 and does not protrude beyond the axial ends 28 , 32 of the winding body 20 in the axial direction.

[0047] In order to protect the locking mechanism 46 from environmental influences, the belt retractor 10 has a housing cover 64 which, in the present exemplary embodiment, is also completely accommodated within the main chamber 26 .

[0048] The force limiter 48 connects the locking disk 52 to the belt reel 16 and is provided to allow a limited rotation of the belt reel 16 relative to the locking disk 52 and thus relative to the frame 14 when the locking mechanism 46 is triggered. In other words, the force limiter 48 provides force limitation.

[0049] The force limiter 48 is arranged completely inside the receiving part 24 .

[0050] The belt reel 16 furthermore has a shaft section 66 , by means of which it is supported rotatably about an axis of rotation R on a bearing section 68 of the frame 14 .

[0051] In this case, the bearing section 68 is part of the pot-shaped second section 42 and is arranged completely within the auxiliary space 30 .

[0052] Furthermore, a transmission spring 50 is arranged in the auxiliary chamber 30 , which connects the belt reel 16 to the frame 14 under pretension and is provided as a drive for retracting the belt webbing.

[0053] The transmission spring 50 is arranged completely inside the receiving portion 24 .

[0054] In order to protect the transmission spring 50 from environmental influences, the belt retractor 10 comprises a spring cover 70 which, together with a thrust washer 72 , forms a housing for the transmission spring 50 .

[0055] The thrust plate 72 is provided as a low-friction bearing for the transmission spring 50 in order to reduce noise during operation of the transmission spring 50 , and is made of plastic, for example.

[0056] In an alternative embodiment, the safety system 18 can also be provided for providing belt tensioning, for example by means of a pyrotechnic belt tensioner, which is preferably arranged completely in the receptacle 24 .

[0057] In order to provide a receptacle 24 with sufficient installation space for the safety system 18, the wound body 20 has a corresponding outer diameter D on the winding surface 22 (see Figure 2 ).

[0058] Since the safety system 18 is arranged completely radially inside the winding surface 22 and in particular completely in the receptacle 24 , the belt retractor 10 has an axial width B which is determined by the axial outer sides 74 , 76 of the frame 14 .

[0059] Due to this configuration, the axial width B of the belt retractor 10 is less than 125% of the width b of the belt webbing 12 .

[0060] In this embodiment, the seat belt strip 12 has a width b of 55 mm, and the seat belt retractor 10 has an axial width B of 65 mm. When the retractor width is 55 mm, the seat belt strip width may also be 48 mm.

[0061] Of course, in an alternative embodiment, the belt retractor 10 can have any desired dimensions, in particular dimensions that are coordinated with the corresponding belt strap 12 .

[0062] In all embodiments, however, at least the locking mechanism 46 (preferably the entire safety system 18 ) is at least largely arranged in the receiving part 24 .

[0063] In order to effectively limit the width B of the belt retractor 10 , it is advantageous if the locking mechanism 46 (preferably the entire safety system 18 ) does not protrude axially beyond the axially outer sides 74 , 76 of the frame 14 .

[0064] Now with the help of Figure 4 A seat belt retractor 10 according to a second embodiment will now be described. For components known from the above embodiments, the same reference numerals are used and reference is made to the above explanations in this regard.

[0065] In contrast to the preceding embodiment, the safety system 18 of the belt retractor 10 according to the second embodiment has a motor 78 .

[0066] The motor 78 is an electric motor which may be electrically connected to a voltage source, for example, via sliding contacts or friction contacts (not shown).

[0067] In this case, the voltage source and the electrical lines between the voltage source and the electric motor are not part of the safety system 18 and therefore have no influence on which parts of the safety system 18 are arranged within the receiving unit 24 .

[0068] In the present exemplary embodiment, the motor 78 is arranged more than 95% in the receiving portion 24 and completely between the axial outer sides 74 , 76 .

[0069] The motor 78 is arranged between the locking disk 52 and the belt reel 16 and between the locking disk 52 and the force limiter 48 and is functionally coupled thereto.

[0070] The motor 78 is provided here as a belt tensioner, which is part of a belt tensioner in the form of an ACR. The ACR is provided for regulating the belt webbing extension and can in this way retract or tension the belt webbing 12.

[0071] In an alternative embodiment, the motor 78 can be provided for other functions of the safety system 18 , such as retraction of the belt strap, whereby, for example, the transmission spring 50 can be omitted.

[0072] Now with the help of Figure 5 and 6 A seat belt retractor 10 according to a third embodiment will now be described. For components known from the above embodiments, the same reference numerals are used and reference is made to the above explanations in this regard.

[0073] In this embodiment, the seat belt retractor 10 has an outer rotor motor 80 with a base 82 and an outer rotor 84 , wherein the base 82 includes a stator of the outer rotor motor 80 .

[0074] The external rotor motor 80 also has an electrical connection 86 , via which the external rotor motor 80 can be electrically connected to a voltage source.

[0075] The base 82 is mounted in the frame 14 in a rotationally fixed manner.

[0076] In the present exemplary embodiment, the base 82 is fixed to the second axial side section 36 by means of three screws 88 .

[0077] In this case, the outer rotor 84 forms the belt reel 16 with the winding body 20 , which is mounted rotatably about an axis of rotation R on the frame 14 via a base 82 .

[0078] In an alternative embodiment, the outer rotor 84 may form part of the belt reel 16 and / or part of the winding body 20 .

[0079] The safety system 18 is formed here by a base 82 which, depending on the operating mode of the outer rotor motor 80, can tension or retract the seat belt webbing 12, provide force limitation and / or can lock the seat belt reel 16 relative to the frame 14. The base 82 thus combines the functions of the seat belt webbing tensioner, the transmission spring 50, the force limiter 48 and the locking mechanism 46.

[0080] In an alternative embodiment, the base 82 may form part of the safety system 18 , for example by providing a single function by a corresponding device provided in addition to the outer rotor motor 80 .

[0081] In this case, the receptacle 24 is formed in a radially inner region of the outer rotor 84 .

[0082] Since the outer rotor 84 has an axial width e which is only slightly smaller than the axial width E of the base 82 , the base 82 and thus the safety system 18 are arranged mostly within the receptacle 24 .

[0083] In each case, by receiving a large portion of the safety system 18 or the locking mechanism 46 radially inwardly of the reel 20 , the axial width B of the seatbelt retractor 10 can be reduced.

[0084] In this way, in all embodiments a particularly flat belt retractor 10 can be provided, whose maximum axial width B is at most 150%, in particular at most 125%, of the width b of the belt webbing 12 for which the belt retractor 10 is provided.

[0085] The invention is not limited to the embodiments shown. In particular, individual features of one embodiment may be combined as desired with features of other embodiments, in particular independently of other features of the respective embodiment.

Claims

1. A seat belt retractor for a vehicle seat belt, the seat belt retractor comprising a frame (14), a seat belt reel (16) and a safety system (18), the seat belt reel being rotatably supported on the frame (14) and having a winding body (20), on which a seat belt strip (12) of the seat belt can be received, the safety system having a locking mechanism (46), by means of which the seat belt reel (16) can be locked relative to the frame (14), characterized in that: The winding body (20) has a receiving portion (24) in which the locking mechanism (46) is at least largely arranged.

2. The seat belt retractor according to claim 1, characterized in that: The safety system (18) is at least largely arranged in the receiving part (24).

3. The seat belt retractor according to claim 1 or 2, characterized in that: The locking mechanism (46) does not protrude beyond the axial ends (28, 32) of the winding body (20) in the axial direction.

4. The seat belt retractor according to any one of the preceding claims, characterized in that The frame (14) has at least one section (40, 42) arranged in the receiving portion (24), the section (40, 42) forming a bearing section (68) and / or a locking section (62), by which the belt reel (16) is rotatably supported on the frame (14), and a locking mechanism (46) acts on the locking section in order to lock the belt reel (16) relative to the frame (14).

5. The seat belt retractor according to claim 4, characterized in that: The at least one section (40, 42) extends axially from an axially outer side (74, 76) of the frame (14) into the receiving portion (24), in particular, the at least one section (40, 42) is part of a frame region having an S-shaped cross section (44).

6. The seat belt retractor according to any one of the preceding claims, characterized in that The safety system (18) is configured to provide at least one of the following functions: belt tensioning, belt retraction, and force limitation.

7. The seat belt retractor according to any one of the preceding claims, characterized in that The safety system (18) has a seat belt tensioner (78, 80).

8. The seat belt retractor according to any one of the preceding claims, characterized in that The safety system (18) has a transmission spring (50, 80) which is provided as a drive device for retracting the safety belt strap.

9. The seat belt retractor according to any one of the preceding claims, characterized in that The seat belt retractor (10) has a motor (78, 80), in particular an electric motor.

10. The seat belt retractor according to claim 9, characterized in that: The motor (78, 80) is part of or forms the safety system (18).

11. The seat belt retractor according to claim 9, characterized in that: The motor (80) includes an outer rotor (84) and a base (82), wherein the outer rotor (84) is part of the winding body (20) or forms the winding body (20), and the base (82) is part of the safety system (18) or forms the safety system (18).

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