Self-locking seatbelt retractor

Abstract

Self-locking seatbelt retractor with -a belt winding shaft (1) rotatably mounted in a frame (2) that can be permanently attached to a vehicle, and -a locking system (3) for the belt winding shaft (1) that is controlled at least by the vehicle, in which, in the event of triggering, a vehicle-sensitive sensor mass (5) moves a locking lever with its engagement tip into engagement with a toothing (9) of a control disc (4) into a trigger position, thereby stopping the control disc (4) in its common rotational movement with the belt winding shaft (1) and activating the locking system (3), wherein -the sensor mass (5) is arranged in a carrier part (6) on a support surface and, in the event of vehicle accelerations, is inertially controlled from a neutral position to the trigger position in the carrier part (6) on the support surface, wherein -the carrier part (6) with the sensor mass (5) arranged therein is arranged in a housing (11) comprising the control disk (4) with a first ring toothing (13), wherein -a fastening ring (12) with a second ring toothing (14) is provided, and -the housing (11) with the carrier part (6) and the sensor mass (5) arranged therein can be attached to the belt winder in different rotational angle positions relative to the control disc (4) by means of an engagement of the first ring toothing (13) with the second ring toothing (14) of the fastening ring (12), wherein -the fastening ring (12) has at least one first fastening projection (16) with which it is attached to the frame (2) of the belt retractor, and -the retaining ring (12) has at least one second retaining projection (17) to which the housing (11) is attached by an engagement of the first ring toothing (13) with the second ring toothing (14), characterized in that -the second fastening point (17) is formed by an annular radially projecting collar, and -the housing (11) has one or more locking edges (7) with which the housing (11) is positively locked to the collar, and -the housing (11) has a first ring wall (8) encompassing the fastening ring (12) with several recesses (10), and -the locking edges (7) are formed by radially inwardly directed projections of the first ring wall (8) in the area of ​​the recesses (10), and -the housing (11) has a second annular wall (20) which defines an annular space (21) to the first annular wall (8), into which the retaining ring (12) with the first ring toothing (13) projects.

Description

[0001] The invention relates to a self-locking seatbelt retractor with a blocking system for a seatbelt winding shaft that can be controlled at least in a vehicle-sensitive manner, in which, in the event of triggering, a vehicle-sensitive sensor mass moves a locking lever with its engagement tip into engagement with the toothing of a control disc into a triggering position, thereby stopping the control disc in its common rotational movement with the seatbelt winding shaft and activating the blocking system, wherein the sensor mass is arranged on a support surface of a carrier part and, in the event of vehicle accelerations, can be moved from a neutral position to the triggering position on the support surface of the carrier part in an inertially controlled manner, wherein the carrier part with the sensor mass arranged therein is arranged in a housing encompassing the control disc.

[0002] A belt retractor with the aforementioned features is described in DE 195 39 619 C2. The locking lever is positively connected at the end opposite the engagement tip to a sensor mass, which in turn is pivotably mounted on a support surface, forming a bearing.

[0003] A common problem with seatbelt retractors is that, for them to function correctly, the sensor mass must be positioned in a specific orientation in space and relative to the mounting surface. This ensures that the sensor mass only moves from the neutral position to the activation position when the vehicle deceleration exceeds a predefined threshold. The orientation of the sensor mass and the mounting surface also depends on the retractor's installation position within the vehicle, which is determined by the body structure and the designated mounting location. Therefore, the sensor and its mounting surface must be individually aligned with the retractor for its specific installation position, ensuring that the sensor mass and the mounting surface maintain the correct orientation in space and relative to the vehicle.

[0004] It is known from WO 2009 / 143 984 A1 to provide a ring toothing on the inside of a sensor cap that covers the sensor on the outside, in which the sensor can be held in various angular orientations relative to the control disc. The ring toothing on the sensor cap creates a mounting point on which the sensor, with its mass and bearing surface, can be positioned in various orientations and arrangements relative to the control disc without requiring any structural modifications to the belt retractor. For this purpose, a complementary toothing is also provided on the sensor, which presses the sensor into the toothing of the sensor cap at a predetermined angular orientation. The sensor is then subsequently fixed in place circumferentially by the positive engagement of the toothing.The sensor cap with the sensor inside is then attached to the frame of the belt retractor, so that the sensor is securely clamped between the sensor cap and the frame of the belt retractor.

[0005] From publication DE 10 2016 202 383 B4, a belt retractor is also known in which the sensor cap, referred to therein as the housing, has a first annular toothing on its radially outer edge, which is arranged on the side facing away from the frame. Furthermore, a retaining ring with a second toothing is provided, which is placed on the outside and fixes the housing, i.e., the sensor cap, in a defined orientation by the engagement of the teeth. Thus, the housing is secured by first being positioned and held in a defined orientation, and then the retaining ring is placed on it so that its teeth engage with the teeth of the housing and are subsequently fastened.Securing the housing therefore requires aligning and holding it in the defined orientation, without fixing it in place during this phase. If, for example, the housing shifts or rotates slightly after alignment and while being held, it will subsequently be fixed not in the defined orientation but in the rotated orientation. This represents a potential source of error that can only be eliminated through increased manufacturing effort.

[0006] The object of the invention is to create an improved self-locking belt retractor in which the alignment of the sensor to the control disc can be adjusted with simplified means and with high accuracy during the assembly process.

[0007] The invention solves this problem with the features of independent claim 1. Further advantageous embodiments of the invention can be found in the dependent claims, the figures and the accompanying description.

[0008] According to the basic idea of ​​the invention, it is proposed that the second fastening element is formed by an annular radially projecting collar, and that the housing has one or more detent edges with which the housing is positively locked to the collar, and that the housing has a first annular wall encompassing the fastening ring with several recesses, and that the detent edges are formed by radially inwardly directed projections of the first annular wall in the area of ​​the recesses, and that the housing has a second annular wall which delimits an annular space to the first annular wall into which the fastening ring with the first annular teeth projects.

[0009] The proposed solution differs fundamentally from the prior art solution in that the mounting ring is first attached to the frame via the first mounting point and itself forms the support for the housing via the second mounting point. Thus, instead of first placing the housing in the predetermined orientation and then securing it with the mounting ring, as in the prior art, the mounting ring is attached first, and then the housing is aligned in the predetermined orientation and attached to the mounting ring. This allows the housing to be aligned and secured in a single step and eliminates the need to hold it in the aligned position until it is secured by the mounting ring. The proposed solution therefore enables a significantly simplified assembly process with a reduced probability of misalignment of the housing.

[0010] It is further proposed that the second mounting point is formed by an annular, radially projecting collar, and that the housing has one or more detent edges with which the housing is positively locked to the collar. By designing the second mounting point as an annular collar, the housing can be attached to the mounting point, and thus to the belt retractor, in any desired rotational orientation. Furthermore, due to its closed design, the annular collar forms a particularly dimensionally stable mounting point and thus a particularly secure hold for the housing.

[0011] It is further proposed that the housing has a first annular wall encompassing the retaining ring, with several recesses, and that the locking edges are formed by radially inward-facing projections of the first annular wall in the area of ​​the recesses. When the housing is placed, the annular wall effectively acts as a guide, simplifying the sliding process, alignment in the predetermined rotational position, and finally the locking action on the annular collar. Furthermore, recesses are provided in the annular wall in which the locking edges are formed by radially inward-facing projections that provide the mating surface for the locking action. Due to the recesses, the locking edges can be integrally molded onto the housing in a single injection molding process.Furthermore, the ring wall is slightly weakened in the area of ​​the detent edges by the recesses, so that the housing can more easily perform the spring movements required for detent engagement in these areas of the ring wall.

[0012] It is further proposed that the housing has a second annular wall, which defines an annular space relative to the first annular wall, into which the retaining ring with the first annular teeth projects. The second annular wall further improves the guidance of the housing when it is placed onto the retaining ring. In addition, the second annular wall forms an additional radially internal stop surface for the housing, thus limiting any possible radial movement of the housing relative to the retaining ring.

[0013] It is further proposed that the first and second ring teeth are formed by face teeth oriented axially in the mounting direction of the housing. The proposed design of the two ring teeth simplifies the engagement movement with respect to the mounting direction of the housing to the frame, i.e., with respect to the sliding movement of the housing onto the frame. Due to the proposed design of the ring teeth, during the sliding movement, they first engage face-to-face with the tips of their tooth flanks and then, during the subsequent increasing tooth engagement, align themselves automatically with each other until the tooth flanks of the rings are in full contact.

[0014] It is further proposed that the first and / or second ring teeth are laterally bounded by a boundary wall on the radial inner and / or radial outer side. This lateral boundary of the ring teeth secures the other ring teeth against slipping out laterally, thus fixing the ring teeth radially to each other.

[0015] The first and second ring teeth can each preferably be laterally bounded by a boundary wall, the boundary walls preferably being arranged on different sides of the ring teeth. This fixes the ring teeth to each other both radially inwards and radially outwards.

[0016] The invention is explained below with reference to preferred embodiments and the accompanying figures. Fig. 1: a self-locking belt retractor with a blocking system with a sensor mass without a housing; and Fig. 2: the housing as a single component in different views; and Fig. 3: a mounting ring with the housing; Fig. 4: An enlarged section of the mounting ring with and without housing in various sectional views.

[0017] In the Fig. Figure 1 shows a self-locking seatbelt retractor according to the invention, comprising a frame 2 that can be mounted to the vehicle and a seatbelt winding shaft 1 rotatably mounted in the frame 2. A seatbelt (not shown) can be wound onto the winding shaft 1, which serves to restrain an occupant in a vehicle. The winding shaft 1 is pre-tensioned in the winding direction by a torsion spring (not shown), so that the seatbelt, when fastened, lies against the occupant with minimal slack and is securely wound into the parked position when unbuckled.

[0018] Furthermore, the belt retractor has a locking system 3 with a control disc 4 and a locking pawl (not shown), which, upon activation, engages a locking toothing 19 in the frame and thereby blocks the belt winding shaft 1 against further belt extension. The locking system 3 also includes a control disc 4 rotatably mounted on the belt winding shaft 1, which is spring-loaded relative to the belt winding shaft 1 in the unwinding direction. A control contour is provided on the control disc 4, into which the locking pawl (not shown) engages with a pin. If the control disc 4 is stopped relative to the belt winding shaft 1 during the extension movement of the seat belt, the control contour forces the locking pawl to move outwards into the locking toothing 19, thereby blocking the belt winding shaft 1 in the belt extension direction.

[0019] Furthermore, the locking system 3 comprises a sensor mass 5, which is designed here as a stationary mushroom-shaped mass, and a support part 6. The support part 6 has a bearing surface on which the sensor mass 5 rests. The locking system 3 also includes a locking lever against which the sensor mass 5 rests. If the sensor mass 5 is pivoted from a neutral position to a release position due to vehicle deceleration exceeding the predetermined limit value, the locking lever is deflected to such an extent that its engagement tip engages the toothing 9 of the control disc 4, thereby stopping the control disc 4 relative to the belt winding shaft 1 to trigger the locking action.Furthermore, an inertial mass (not shown in detail) is arranged on the control disc 4, which is spring-loaded relative to the control disc 4 in the winding direction and is deflected relative to the control disc 4 when a predetermined limit value of the belt extension acceleration is exceeded, and engages in a WS toothing of the housing and thereby stops the control disc 4 relative to the belt winding shaft 1.

[0020] To ensure that the sensor, with sensor mass 5 and carrier part 6, blocks the belt retractor shaft 1 only when the predetermined vehicle deceleration threshold is exceeded, it is important that the sensor mass 5 is in a predetermined upright position in the neutral position. In this position, the locking lever does not engage the teeth 9 of the control disc 4, and the control disc 4, together with the belt retractor shaft 1, can rotate freely. To allow the same belt retractor to be used in as many vehicles as possible, in different installation orientations, the carrier part 6 and the sensor mass 5 it holds must be individually aligned with the belt retractor for each vehicle. In the respective installation position of the belt retractor, the sensor mass 5 is in the neutral position below the predetermined vehicle deceleration threshold, allowing the belt retractor shaft 1 to rotate freely.

[0021] The belt retractor further comprises a housing 11 and a fastening ring 12, which are located in the Fig. Figure 3 shows that the housing 11 encompasses the control disc 4 on the outside in the fixed position. The fastening ring 12 is attached to the frame 2 of the belt retractor and in turn serves to fasten the housing 11.

[0022] Case 11 is in the Fig. 2 can be seen as a separate component in different views. The housing 11 has a receptacle 15, which is shaped such that the carrier part 6 with the sensor mass 5 therein is arranged on the housing 11 in only one predetermined orientation. For assembly, the subassembly consisting of the carrier part 6 and the sensor mass 5 is inserted into the housing 11 and fixed. The housing 11 also has an axially aligned first annular wall 8 on its radial outer surface, in which several window-shaped recesses 10 are provided.

[0023] The one in Fig. The 3 identifiable fastening ring 12 has several first fastening projections 16 which protrude axially on the rear of the fastening ring 12 and are arranged such that the fastening ring 12 can be fastened in only one orientation in corresponding fastening openings 18 on the frame 2.

[0024] The fastening ring 12 has a first ring toothing 13 on its end face, which is bounded on the radial outer side by a limiting wall 23. The housing 11 has a [feature] as shown in the lower illustration of the Fig. 4. A second ring wall 20 can be identified, which is arranged at a radially inward distance to the first ring wall 8 and delimits an annular space 21 to the first ring wall 8. In the base of the annular space 21, a second ring toothing 14 is arranged on the second ring wall 20, which in the Fig. 2, which can also be seen through the recesses 10. The second ring wall 20 thus forms a radially inner boundary wall 22 for the second ring toothing 14. The first and second ring toothing 13 and 14 are designed as ring-shaped face teeth with axially directed teeth and are arranged such that, in the fixed position on the belt winder, they are aligned concentrically to the axis of rotation of the belt winding shaft 1. Due to their face tooth design, when the housing 11 is placed onto the mounting ring 12, the ring toothing 13 and 14 first engage with their tooth tips and then automatically align themselves with each other during the further placement movement until they are in full contact. Their movement relative to each other is limited radially inwards by the boundary wall 22 of the second ring wall 20 and radially outwards by the boundary wall 23 of the mounting ring 12.This defines the housing 11 in its radial orientation both towards the radial inside and the radial outside and limits its movement in terms of motion.

[0025] The retaining ring 12 is first attached to the frame 2 via the first mounting lugs 16 and then projects from the frame 2 with its first ring teeth 13. The retaining ring 12 also has a second mounting lug 17 on its radial outer surface in the form of an annular, projecting collar. The collar has a conical shape with a diameter that increases in the mounting position towards the frame 2 or towards the first mounting lugs 16.

[0026] The housing 11 has detent edges 7 in the area of ​​the recesses 10 in the form of radially inwardly directed projections, which are formed by a thickening of the edge sides of the recesses 10 facing the free edge of the first ring wall 8. The detent edges 7 are conically shaped with a wall thickness that decreases towards the free edge of the first ring wall 8, so that the inner diameter of the housing 11 increases in this area towards the free side of the first ring wall 8. The detent edges 7 are deliberately provided in the area of ​​the recesses 10 so that the housing 11 can be manufactured as a one-piece plastic part in a single injection molding operation as a mass-produced part. Furthermore, the recesses 10 deliberately weaken the housing 11 in the area of ​​the detent edges 7, so that it can more easily perform the detent movement, which will be explained in more detail below, when being secured to the retaining ring 12.

[0027] To attach the housing 11, the mounting ring 12 is first attached to the frame 2 via the first mounting points 16. The mounting ring 12 then forms a separate mounting point 17 for the housing 11 with its annular collar. The housing 11 is then pre-assembled with the sensor and placed onto the mounting ring 12 in a predefined rotational orientation by sliding it onto the mounting ring 12 with the annular space 21. In this process, the housing 11, with its conical inner surfaces 25, comes to rest under the recesses 10 against the conical outer surface 24 of the second mounting point 17 formed by the annular, protruding collar.During the further sliding movement of the housing 11, the housing 11 is slightly deformed outwards in the area of ​​the projections 7, and the retaining ring 12 is slightly deformed inwards in these areas, until the housing 11 with the projections 7 behind the second retaining lug 17 is in the . Fig. The position shown in the middle illustration is locked. The middle illustration shows the Fig. 4 A sectional view of a section through the housing 11 and the retaining ring 12 in the area of ​​the cutouts 10 of the housing 11. In the lower view of the Fig.Figure 4 shows a sectional view through a section of the housing 11 and the retaining ring 12 between the recesses 10 in the area of ​​the interlocking first ring teeth 13 and second ring teeth 14. The housing 11 is pushed onto the retaining ring 11 and fixed by its attachment to the second mounting projection 17 to such an extent that the first ring teeth 13 engage with the second ring teeth 14, thus fixing the housing 11 in its rotational position relative to the retaining ring 12. Furthermore, the housing 11 is supported by the inner side of the first ring wall 8 against the outer side of the second mounting projection 17 formed by the collar, thus also fixing it in this direction.

[0028] The fastening ring 12 is positioned between the frame 2 and the housing 11 in the fastening position and forms a support for the housing 11 together with the second fastening projection 17.

[0029] The second fastening element 17 on the fastening ring 12 is deliberately designed as an annular, preferably closed, collar, so that the housing 11 can be fastened to the fastening ring 12 in a variety of preferably arbitrary angular positions. Furthermore, this achieves improved sealing of the belt retractor with regard to the ingress of foreign bodies or dust particles, as the housing 11 and the fastening ring 12 form a type of labyrinth seal.

[0030] The sensor is inserted into the housing 11 before the housing 11 is assembled and is then protected by the housing 11 during the fastening process to the belt retractor. The alignment of the housing 11 in the predetermined rotational angle position can then be carried out in rotational angle increments, which are defined by the tooth spacing of the gears 13 and 14. Thus, the finer the gearing of the gears 13 and 14, the finer the adjustment of the sensor's rotational angle relative to the axis of rotation of the belt retractor shaft 1.

[0031] The fastening ring 12 is arranged in the fastening position between the frame 2 and the housing 11 and forms a holder for the housing 11 with a positive locking fastening or latching together with the second fastening projection 17.

Claims

[1] Self-locking seatbelt retractor with -a belt winding shaft (1) rotatably mounted in a frame (2) that can be permanently attached to a vehicle, and -a locking system (3) for the belt winding shaft (1) which is controlled at least by the vehicle, in which, in the event of triggering, a vehicle-sensitive sensor mass (5) moves a locking lever with its engagement tip into engagement with a toothing (9) of a control disc (4) into a trigger position, whereby the control disc (4) is stopped in its common rotational movement with the belt winding shaft (1) and the locking system (3) is activated, wherein -the sensor mass (5) is arranged in a carrier part (6) on a support surface and, in the event of vehicle accelerations, is inertially controlled from a neutral position to the trigger position in the carrier part (6) on the support surface, wherein -the carrier part (6) with the sensor mass (5) arranged therein is arranged in a housing (11) comprising the control disk (4) with a first ring toothing (13), wherein -a fastening ring (12) with a second ring toothing (14) is provided, and -the housing (11) with the carrier part (6) and the sensor mass (5) arranged therein can be attached to the belt winder in different rotational angle positions relative to the control disc (4) by means of an engagement of the first ring toothing (13) with the second ring toothing (14) of the fastening ring (12), wherein -the fastening ring (12) has at least one first fastening projection (16) with which it is attached to the frame (2) of the belt retractor, and -the retaining ring (12) has at least one second retaining projection (17) to which the housing (11) is attached by an engagement of the first ring teeth (13) with the second ring teeth (14). characterized by, that -the second fastening point (17) is formed by an annular radially projecting collar, and -the housing (11) has one or more locking edges (7) with which the housing (11) is positively locked to the collar, and -the housing (11) has a first ring wall (8) encompassing the fastening ring (12) with several recesses (10), and -the locking edges (7) are formed by radially inwardly directed projections of the first ring wall (8) in the area of ​​the recesses (10), and -the housing (11) has a second annular wall (20) which defines an annular space (21) to the first annular wall (8), into which the retaining ring (12) with the first ring toothing (13) projects. [2] Self-locking seatbelt retractor according to claim 1, characterized by -the first and second ring teeth (13,14) are formed by face teeth directed axially in the mounting direction of the housing (11). [3] Self-locking seatbelt retractor according to claim 2, characterized by , that -the first and / or second ring teeth (13,14) are laterally limited to the radial inside and / or to the radial outside by a limiting wall (22,23). [4] Self-locking belt retractor according to claim 3, characterized by , that -the first ring toothing (13) and the second ring toothing (14) are each laterally limited by a boundary wall (22, 23), and -the boundary walls (22,23) are arranged on different sides of the ring teeth (13,14).

Images