Coiling shaft, end cover, safety belt coiling device and safety belt assembly

[0041] In the following description, many specific details are explained in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described here, and those skilled in the art can make similar popularizations without violating the connotation of the present invention. Therefore, the present invention is not limited by the specific implementation disclosed below.

[0042] Please see figure 2 , image 3 with Figure 4 ,among them, figure 2 It is a schematic diagram of an embodiment of a reel for a seat belt retractor according to the present invention. image 3 for figure 2 Sectional view along the axis of the reel; Figure 4 An exploded view of the assembly of the reel and torsion bar.

[0043] The reel 2 includes a mandrel 2-1 and end caps detachably disposed at both ends of the mandrel 2-1: a left end cover 2-2a and a right end cover 2-2b. The mandrel 2-1 is used to wind the webbing of the safety belt, and it can rotate along its axis to wind the webbing on it or release the webbing. The core shaft 2-1 is provided with a through hole 2-3 along its axis, and the inner wall of the through hole 2-3 is provided with internal teeth.

[0044] Two outwardly extending pins 2-6 are respectively provided on both ends of the mandrel 2-1, which are called force limiting pins 2-6.

[0045] The mandrel 2-1 is also provided with an elongated fixing groove 2-4 for passing through and fixing the end of the webbing and a weight reducing groove 2-5 for reducing weight.

[0046] The outer peripheries of the two end covers are provided with external teeth, such as Figure 4 As shown, the outer circumference of the left end cover 2-2a is provided with external teeth 2-2a-1, and the outer circumference of the right end cover 2-2b is provided with an outer gear ring 2-2b-1, and the teeth on both ends are equal It is a one-way tooth, facing the rotation direction of the core shaft 2-1 when the webbing is released, and the outer teeth on the outer periphery of the two end covers are matched with the inner tooth sections of the two through holes on the frame 1.

[0047] On the end faces of the two end covers facing the mandrel 2-1 corresponding to the position of the force limiting pin, pin holes are also provided, such as Figure 4 The pin hole 2-2b-2 on the right end cover 2-2b shown in. Cover at both ends as figure 2 When the illustrated method is set on the two end faces of the mandrel 2-1, the force limiting pin is inserted into the corresponding pin hole. In addition, the force limiting pin may also be arranged inside the end cover, and a pin hole may be arranged at a corresponding position on the end surface of the mandrel 2-1. The force limiting pin 2-6 is mainly used to withstand the shear force when the mandrel rotates, and break when the shear force exceeds a threshold. The setting positions of the force limiting pins at the two ends of the mandrel are staggered by a fixed angle in the circumferential direction, which can be used for positioning when the end cover is assembled with the mandrel 2-1 to prevent the left and right end covers from being assembled incorrectly, and can also make the two end faces The outer teeth of the end cover are staggered by a certain angle to meet the actual condition that the retractor is slightly tilted when the retractor is in the locked state, ensuring that the outer teeth of the end cover can mesh with the inner ring gear of the frame in the locked state.

[0048] A central concave hole with internal teeth (hereinafter referred to as a concave hole) is also provided on the center of the end face of the two end covers facing the mandrel 2-1, such as Figure 4 The recessed hole 2-2b-3 on the right end cap 2-2b shown in. In this embodiment, the concave holes of the two-end covers are arranged on the bosses protruding from the side where they are located. The corresponding end surface of the mandrel is provided with a stop for accommodating the boss.

[0049] On the outer end surface (that is, the end surface away from the mandrel 2-1) of the two end caps, an outwardly protruding extension shaft is provided along the center of the end surface (the extension shaft can be integrally formed with the end cap ). Such as figure 1 The right extension shaft shown in 2-2b-5 and as shown in Figure 4 The left side protruding shaft shown in 2-2a-5. Among them, the left-side extension shaft 2-2a-5 is connected with the sensitive element, and the right-side extension shaft 2-2b-5 is provided with teeth on the outer circumference, which is connected with the coil spring.

[0050] The through hole 2-3 on the core shaft 2-1 is used for accommodating the torsion bar 3 constituting the seat belt reel. The following further describes the reel of this embodiment in conjunction with the matching relationship with the torsion bar 3. However, the torsion bar 3 described in this embodiment is not a part of the reel described in this embodiment.

[0051] Such as Figure 4 The torsion bar 3 shown in the figure is rod-shaped, and external teeth are provided along the circumferential direction at both ends and the middle.

[0052] The structure of the torsion bar 3 and the reel 2 is as follows figure 2 , 3 As shown in and 4, the torsion rod 3 is inserted and passed through the through hole 2-3 of the mandrel 2-1, and the external teeth in the middle of its axial direction and the through hole 2-3 of the mandrel 2-1 The internal teeth provided on the inner wall mesh. The left end cover 2-2a and the right end cover 2-2b respectively cover the two ends of the mandrel 2-1 from the left and right sides, and the force limiting pins at the corresponding positions correspond to the pin holes. The two ends of the torsion rod 3 are respectively inserted into the concave holes of the left and right end caps, and the outer teeth of the ends thereof mesh with the inner teeth of the corresponding concave holes. In this embodiment, such as Figure 4 As shown, a friction reducing ring 4b is also provided between the bosses of the two end covers and the stop of the mandrel 2-1. The anti-friction ring 4b is generally made of low-friction plastics, which can provide a transition for the matching position of the stop between the end cap 2-2 and the opposite end surface of the mandrel 2-1, so that the metal surface of the stop position will not directly contact , To avoid the influence of the gluing caused by the friction between the metal surfaces on the normal operation of the torsion bar.

[0053] Such as Figure 4 As shown, an annular boss ( Figure 4 The annular boss 2-2b-6 on the right end cover shown in Figure 2), the corresponding position of the end face of the mandrel 2-1 is provided with an escape stop that matches the annular boss; by setting the annular boss And the avoidance stop structure can reduce the friction area when the end surface of the mandrel 2-1 and the end cover rotate relative to each other, thereby reducing the friction between the mandrel and the end cover, and improving the stability of the force limiting effect.

[0054] When the reel described in this embodiment is applied to a retractor, it also needs to be used in conjunction with the retractor frame. The following further describes the reel of this embodiment in conjunction with the matching relationship between the retractor frame and the reel of this embodiment.

[0055] Please see figure 1 , Which is a schematic diagram of the structure of the retractor formed by the cooperation of the retractor frame and the reel. The retractor frame 1 is U-shaped and includes two opposite side walls: a first side wall 1-1 and a second side wall 1-2. It also includes two third walls 1-4 connecting the first side wall 1-1 and the second side wall 1-2. Corresponding positions on the first side wall 1-1 and the second side wall 1-2 are respectively provided with a circular first through hole 1-1a and a second through hole 1-2a, on the two through holes Internal tooth segments 1-3 ( figure 1 Only shows the case where the internal tooth segment is provided on the second through hole 1-2a). The inner tooth section 1-3 is used to cooperate with the outer teeth on the reel to lock the reel, so the setting position of the inner tooth section 1-3 is the position corresponding to the traction direction of the webbing wound on the reel. As mentioned figure 1 In the frame shown in the figure, the webbing is drawn out from the inner top of the third wall 1-4, so the inner tooth section 1-3 is arranged at the top of the two through holes.

[0056] The frame 1 is also provided with other structures, such as weight-reducing holes on the two side walls, interfaces of the reinforcing ribs connecting the two side walls, etc., which will not be repeated here.

[0057] The reel 2 is integrally arranged in the frame 1, and two ends of the reel 2 are respectively placed in the through holes of the side wall of the frame 1. In the free state, the reel 2 can be rotatably and floatably arranged in the retractor frame 1, and the external teeth on the end cover of the reel 2 are not in contact with the internal teeth of the through hole on the retractor frame 1. The reel 2 is supported by the protruding shafts on the outer sides of the two ends of the end cover. The reel 2 can rotate freely to realize the winding and release of the webbing. When locked, the external teeth of the cover at both ends of the reel 2 mesh with the internal teeth of the corresponding position on the frame 1, and the reel 2 cannot rotate.

[0058] In this embodiment, the center of the end cover of the reel is not provided with a through hole, and an integral extension shaft is provided on the outside. When used in conjunction with the torsion bar 3, the two ends of the torsion bar 3 are arranged at the end caps of the reel without passing through the end caps, that is, compared to the torsion bar in the background art, the length of the torsion bar in this embodiment is shortened . The shortened part is replaced by an extension shaft provided on the outside of the end cap. When a collision occurs, the webbing drives the mandrel to rotate, which in turn drives the torsion bar to rotate. The two-end covers are locked on the frame, and the two-end covers engage both ends of the torsion bar at the same time, so that the two ends of the torsion bar cannot rotate. The middle part of the torsion bar 3 meshes with the inner teeth of the mandrel 2-1 through the outer teeth of the middle part, so that it can bear the tension of the webbing, and the two ends are due to the outer teeth of the end part and the gears on the inner end face of the end cover 2-2. When the tension of the webbing reaches a certain level, the torsion bar 3 undergoes torsional deformation, so that the core shaft 2-1 rotates at a certain angle and releases part of the webbing. The torsional deformation characteristics of the torsion bar 3 The webbing can be properly released to control the binding force of the webbing to the human body at a predetermined value, avoiding damage to the human body due to excessive binding force; at the same time, the webbing will not be released for a long distance to cause failure of the human body restraint.

[0059] In this embodiment, due to the shortened length of the torsion bar and the setting of the boss on the inner side of the end cover and the stop of the mandrel, it only bears the force from the mandrel and the reaction force of the end cover, avoiding the torsion bar from directly bearing the traction of the webbing Therefore, the force condition is simple and controllable, and the force limiting pin that meets the force limiting requirement can be designed as required, and it is safe and stable during use. In addition, torsion in the middle section of the torsion bar is easier to produce uniformly distributed deformation, avoiding local stress and fracture failure; at the same time, the left and right sides respectively bear half of the limit force value, which can reduce the required diameter of the torsion bar. Since the material of the torsion bar needs to meet special torsion requirements, its cost is high, and the manufacturing requirements are high, the use of a short torsion bar in this embodiment can significantly save costs.

[0060] In addition, in the above-mentioned embodiment of the present invention, the inner tooth section 1-3 is provided on the through hole of the retractor frame, and the position of the inner tooth section 1-3 corresponds to the traction direction of the webbing wound on the reel. s position. Compared with the structure in which internal teeth are provided for the entire circle of the through hole, the structure of this embodiment can ensure that the reel is locked at a certain position when locking, that is, the position where the internal tooth segments 1-3 are provided.

[0061] Secondly, in the embodiment of the present invention, the force limiting pins 2-6 provided at both ends of the mandrel of the reel 2 are as described above. When the reel 2 is locked, the mandrel 2-1 receives the force The tension of the webbing will generate a tendency to rotate relative to the end caps on both sides, and the force limiting pin 2-6 and the external teeth 3-1 in the middle of the torsion bar 3 will prevent it from rotating. The force limiting pin 2-6 receives the shearing force of the end cap and the mandrel 2-1. In the event of a collision, the traction force of the webbing has a rapid loading process of traction force from small to large. In this process, when the traction force is less than the bearing threshold of the force limiting pin 2-6, the traction force borne by the mandrel 2-1 is loaded on the force limiting pin 2-6, and the torsion bar 3 does not bear or is not important Undertake the traction; when the traction value increases to exceed the tolerance threshold of the force limiting pin 2-6, the force limiting pin 2-6 will break, and the torsion bar 3 begins to fully assume the webbing transmitted through the mandrel 2-1 Traction force, and then the torsion bar 3 distortion process occurs. Therefore, the force limiting pin 2-6 can adjust the force limiting threshold of the seat belt.

[0062] In this embodiment, the external teeth in the middle of the torsion bar 3 are provided with gaps, which are called avoiding tooth gaps; Picture 11 The avoidance tooth shown in is missing 3-1-1. Picture 10 It is a schematic diagram of a torsion bar with a central external tooth that avoids tooth gap 3-1-1 is inserted into the core shaft 2-1, and the external tooth part matches the core shaft through hole. by Picture 10 It can be seen that the position of the avoiding tooth gap 3-1-1 on the torsion bar 3 satisfies that after the torsion bar 3 is inserted into the through hole of the mandrel 2-1, the avoiding tooth gap 3-1-1 is aligned or roughly Align the fixing grooves 2-4 provided on the mandrel 2-1 for passing through and fixing the webbing 6. The fixing groove 2-4 is an elongated through hole, which is arranged to meet the requirement that the webbing passing direction is perpendicular to the central axis of the core shaft 2-1 and needs to be as close as possible to the central axis. The avoidance tooth gap 3-1-1 provides a space for the webbing 6 to pass through the fixing grooves 2-4, so as to prevent the webbing 6 from interfering with the teeth due to the provision of teeth there, and causing the webbing 6 to be there. It is far away from the center line of the core shaft 2-1, which is not conducive to the stability of the core shaft 2-1 when the webbing 6 is tightened. In the embodiment of the present invention, the torsion bar 3 is further provided with anti-error toothing. Such as Figure 5 As shown, one end of the torsion bar 3 (in this embodiment, the right side is taken as an example) is provided with a misalignment tooth gap 3-2b-1, and the other side does not need to be provided with the tooth gap. Correspondingly, the concave hole on the end cover of the reel at this end also needs to be provided with a matching structure. Such as Figure 4 As shown in the figure, the corresponding error prevention port 2-2b-4 is provided in the recessed hole 2-2b-3 of the end cap 2-2b. The reason for the provision of the above-mentioned anti-error tooth gap 3-2b-1 is that due to the above-mentioned avoiding tooth gap 3-1-1, the torsion bar 3 must be inserted into the through hole 2-3 of the mandrel at an appropriate angle to prevent the error-proof tooth The lack of 3-2b-1 can ensure a successful operation of inserting the torsion bar 3 during assembly.

[0063] Image 6 Shown as Figure 5 The end tooth shape of the left end 3-2a of the torsion rod 3 shown, Figure 7 Shows the matching diagram of the left end 3-2a of the torsion bar 3 inserted into the concave hole of the left end cover 2-2a; Figure 8 for Figure 5 The end tooth shape of the right end 3-2b of the torsion bar 3 shown, you can see the error prevention notch 3-2b-1 provided at the end, Picture 9 It shows a mating diagram where the right end 3-2b of the torsion bar 3 is inserted into the concave hole of the right end cover 2-2b.

[0064] The provision of the error prevention notch 3-2b-1 at the right end of the torsion bar 3 results in different numbers of teeth at the left and right ends, which in turn will cause the torsion bar 3 to bear the same torsion force when the torsion bar 3 is twisted. Therefore, in the present invention, the problem is solved in the following manner.

[0065] The outer teeth 3-1 in the middle of the torsion bar 3 is inclined to the right end 3-2b (that is, the end where the anti-error gap is provided), so that the middle of the torsion bar 3 is provided with the anti-error teeth on the outer tooth surface. 3-1-1 one end is overall offset. Picture 11 with Picture 12 Shows a perspective view and a cross-sectional view of the torsion bar 3 respectively, by Picture 11 with Picture 12 It can be seen that the teeth 3-1-2 are inclined. By arranging the external teeth 3-1 to incline to the right, it is beneficial to balance the force exerted by the mandrel 2-1 on the torsion rod 3, so that the overall force is balanced.

[0066] In addition, the torsion bar 3 is a separate two-stage structure, such as Figure 13 An exploded view showing the assembly of the reel component and the torsion bar.

[0067] The torsion bar includes two sections arranged coaxially: a first section 3a and a second section 3b. The two sections have the same axial length, and the ends of each section are provided with external teeth along the axial direction. When the group is integrated, the two ends of the torsion bar are butted together, the end faces abut, and the outer teeth of the opposite ends correspond to the teeth, which are not bad teeth. The entire outer teeth of the opposite ends correspond to the peripheral outer teeth of the middle part of the above-mentioned integrated torsion bar. Its function and connection with the mandrel are the same as the above-mentioned embodiment. The other ends of the two sections of torsion rods are respectively inserted into the recessed holes of the end cover of the reel, and the connection method is the same as that described in the above-mentioned embodiment, and will not be repeated here. In addition, the outer teeth of the opposite ends of the two sections of torsion bars are provided with avoiding tooth gaps, and the positions of the two avoiding tooth gaps are the same and corresponding to the fixing grooves on the mandrel passing through and fixing the ends of the webbing. The avoidance tooth gap is the same as the function of the avoidance tooth gap of the central external teeth of the torsion bar in the embodiment, and will not be repeated here. The other parts except the torsion bar in this embodiment are the same as the above-mentioned embodiment.

[0068] Setting the torsion bar as two separate sections has the following effect: two torsion bar sections with the same diameter or different diameters can be combined to form multiple limit force values, so that fewer torsion bars can be used to form multiple The force-limiting retractor meets the different requirements of different automobile manufacturers for the force-limiting value of seat belts. Such as Figure 14 with 15 The schematic diagrams respectively showing the torsion bar segments with the same diameter and the torsion bar segment groups with different diameters are torsion bars. In addition, torsion bars of the same material or different materials can also be used in combination, and different force limiting effects can also be obtained.

[0069] In addition, because the torsion bar is made of special materials and processed by cold heading, a separate mold is required for each diameter of the torsion bar, and its manufacturing equipment and molds are expensive. Using the two-section torsion bar of this embodiment, it is possible to combine the torsion bar sections processed by a limited processing mold to form a torsion bar with multiple limiting force values, thereby reducing the number of mold openings and saving manufacturing costs. In addition, the shorter size of the torsion bar is easier to process, the processing qualification rate is higher, and the cost of each mold is relatively lower.

[0070] In addition, changing the material of the torsion bar segment and changing the diameter can be used at the same time to combine more changes. I won't repeat it here.

[0071] The present invention also protects a seat belt assembly, which uses the retractor described in the above embodiment and can obtain the beneficial effects brought by the retractor in the above embodiment. The assembly of the retractor, the webbing and other related parts can refer to the existing technology, which will not be discussed here.

[0072] Although the present invention is disclosed as above in preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be subject to the scope defined by the claims of the present invention.