A torque limiting nutrunner for a seat belt retractor retaining bolt

Abstract

The utility model discloses a torque limiting screwing head of safety belt retractor fixed bolt relates to the installation technical field of automobile safety equipment, including the main body sleeve for the fixed bolt of the sleeve connection safety belt retractor, the inside of main body sleeve is provided with the inner hole of fixed bolt outside profile adaptation, its characterized in that: the outside fixed connection of main body sleeve has the friction cover layer, and the main body sleeve of fixed with friction cover layer is detachable installation in the inside of outside sleeve, the inside of outside sleeve is provided with a plurality of movable friction block, one side fixed connection of friction block has extrusion spring. The utility model provides the limitation of torque through setting the friction between friction cover layer and friction block, can according to need, make the friction of different number of friction block and friction cover layer contact to provide different degree of friction, and then to adjust different torque limitation, improve the use effect of the device, enhance the practicality of the device.

Description

Technical Field

[0001] This utility model relates to the field of automotive safety equipment installation technology, specifically a torque-limiting tightening head for a seat belt retractor fixing bolt. Background Technology

[0002] In the automotive manufacturing and assembly field, seat belts, as one of the most important passive safety devices, directly affect the overall safety performance of the vehicle through their installation quality. The seat belt retractor is a core component of the seat belt system, typically installed on the B-pillar or floor of the vehicle body using fixing bolts. To ensure reliable connection and prevent structural damage or functional failure due to overtightening or loosening, the tightening process of these fixing bolts must strictly control the preset torque value. Therefore, this invention proposes a torque-limiting tightening head for the seat belt retractor fixing bolts. Utility Model Content

[0003] Technical problems to be solved The purpose of this invention is to overcome the shortcomings of the existing technology and provide a torque-limiting tightening head for a seat belt retractor fixing bolt.

[0004] Technical solution

[0005] To achieve the above objectives, this utility model provides the following technical solution: a torque-limiting tightening head for a seatbelt retractor fixing bolt, comprising a main sleeve for fitting the fixing bolt of the seatbelt retractor, the main sleeve having an inner hole adapted to the outer contour of the fixing bolt, a friction sleeve layer fixedly connected to the outside of the main sleeve, the main sleeve with the friction sleeve layer fixedly installed detachably inside the outer sleeve, a plurality of movable friction blocks being provided inside the outer sleeve, a compression spring being fixedly connected to one side of each friction block, and pressing blocks being fixedly connected to both sides of each friction block, a movable limiting rod being provided inside the pressing block, and limiting holes for installing the limiting rod being provided on both sides of the outer sleeve. The torque is limited by setting the friction force between the friction sleeve layer and the friction blocks. During use, different numbers of friction blocks can be made to contact the friction sleeve layer to provide different degrees of friction force, thereby adjusting different torque limits, improving the effectiveness of the device, and enhancing its practicality.

[0006] Preferably, the outer sleeve has an internal mounting cavity for mounting the friction block, and the friction block is independently mounted inside the mounting cavity.

[0007] Preferably, a torsion bar is connected to one side of the outer sleeve.

[0008] Preferably, the pressing block has an internal mounting hole for installing a limiting rod, and a spring is fixedly connected to one side of the limiting rod.

[0009] Preferably, a plurality of compression springs are fixedly connected to one side of each of the friction blocks.

[0010] Preferably, the main sleeve has multiple specifications, and the outer contours of the main sleeves of different specifications are equal in size, while the inner holes have different specifications.

[0011] Beneficial effects

[0012] Compared with existing technologies, the torque-limiting tightening head of this seatbelt retractor fixing bolt has the following advantages: This invention provides torque limitation by setting the friction force between the friction sleeve layer and the friction block. In use, different numbers of friction blocks can be made to contact the friction sleeve layer to provide different degrees of friction force, thereby adjusting different torque limits, improving the use effect of the device and enhancing its practicality. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the test cross-sectional structure of this utility model; Figure 3 For the present utility model Figure 2 Enlarged schematic diagram of the structure at point A in the middle; Figure 4 This is a cross-sectional structural diagram of the present invention.

[0015] In the picture: 1. Main sleeve; 2. Inner hole; 3. Friction sleeve layer; 4. Outer sleeve; 5. Friction block; 6. Compression spring; 7. Pressing block; 8. Limiting rod; 9. Limiting hole; 10. Torsion rod; 401. Mounting cavity; 701. Mounting hole; 801. Spring II. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] Please see Figures 1-4 As shown, this utility model provides a technical solution: a torque-limiting tightening head for a seat belt retractor fixing bolt, including a main sleeve 1 for fitting the fixing bolt of the seat belt retractor. The main sleeve 1 has an inner hole 2 that matches the outer contour of the fixing bolt. A friction sleeve layer 3 is fixedly connected to the outside of the main sleeve 1. The main sleeve 1 with the friction sleeve layer 3 is detachably installed inside an outer sleeve 4. The outer sleeve 4 has multiple movable friction blocks 5 inside. A compression spring 6 is fixedly connected to one side of the friction block 5. Pressing blocks 7 are fixedly connected to both sides of the friction block 5. A movable limiting rod 8 is provided inside the pressing block 7. Limiting holes 9 for installing the limiting rod 8 are opened on both sides of the outer sleeve 4. The torque is limited by setting the friction force between the friction sleeve layer 3 and the friction blocks 5. In use, different numbers of friction blocks 5 can be made to contact the friction sleeve layer 3 to provide different degrees of friction force, thereby adjusting different torque limits, improving the use effect of the device, and enhancing the practicality of the device.

[0018] Please refer to the following carefully. Figure 1 and Figure 4 The outer sleeve 4 has an internal mounting cavity 401 for mounting the friction block 5. Multiple compression springs 6 are fixedly connected to one side of the friction block 5. The friction block 5 is independently mounted inside the mounting cavity 401. A torsion bar 10 is connected to one side of the outer sleeve 4.

[0019] Please refer to the following carefully. Figure 2 and Figure 3 The pressing block 7 has an installation hole 701 for installing the limiting rod 8 inside, and a spring 801 is fixedly connected to one side of the limiting rod 8.

[0020] Please refer to the following carefully. Figure 1 and Figure 4 The main sleeve 1 has various specifications. The outer contours of the main sleeve 1 of different specifications are equal, while the inner holes 2 have different specifications.

[0021] Working principle: In use, align the inner hole 2 of the main sleeve 1 with the head of the fixing bolt of the seat belt retractor and slip it on. A friction sleeve layer 3 is fixed on the outer surface of the main sleeve 1, and the main sleeve is detachably installed inside the outer sleeve 4. The outer sleeve 4 is provided with multiple radially movable friction blocks 5. Each friction block 5 is pre-compressed by a compression spring 6, which makes it tend to move inward, so that it can contact the surface of the friction sleeve layer 3 and generate friction.

[0022] When an external torque is applied through the torsion bar 10 for tightening, the torque is transmitted to the main sleeve 1 via the outer sleeve 4, friction block 5, and friction sleeve layer 3, and finally acts on the bolt. During this process, if the applied torque is less than the maximum static friction torque between the friction block 5 and the friction sleeve layer 3, the power is transmitted smoothly and the bolt is tightened.

[0023] Once the applied torque reaches the preset limit, the friction between the friction pairs is overcome, and the friction block 5 and the friction sleeve layer 3 slide relative to each other, interrupting the power transmission. At this point, even if force continues to be applied, the main sleeve 1 and the bolt will no longer receive additional torque, thereby achieving the torque limiting function and preventing over-tightening.

[0024] The torque limit can be changed by adjusting the number of friction blocks 5 involved in contact. By operating the pressing block 7 and utilizing the cooperation between the limiting rod 8 and the limiting hole 9, some friction blocks 5 can be selectively locked in the retracted position, disengaging them from contact with the friction sleeve layer 3. The more friction blocks involved in contact, the greater the total friction force and the higher the torque required to overcome, thus achieving multi-level torque settings.

[0025] In addition, the main sleeve 1 is designed in various specifications, with its inner hole 2 size adapted to different bolt head models, while the outer contour remains uniform, ensuring compatibility with the outer sleeve 4 and improving the tool's versatility and ease of replacement.

[0026] In summary, this device achieves adjustable torque limiting through a modular friction pair structure, and has advantages such as accurate response, flexible adjustment, and reliable structure. It is suitable for applications requiring high assembly precision, such as automotive seat belt retractors.

[0027] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0028] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A torque-limiting tightening head for a seatbelt retractor fixing bolt, comprising a main sleeve (1) for fitting the fixing bolt of the seatbelt retractor, wherein the main sleeve (1) has an inner hole (2) adapted to the outer contour of the fixing bolt, characterized in that: The main sleeve (1) is fixedly connected to a friction sleeve layer (3). The main sleeve (1) with the friction sleeve layer (3) fixedly connected is detachably installed inside the outer sleeve (4). The outer sleeve (4) is provided with a plurality of movable friction blocks (5). A compression spring (6) is fixedly connected to one side of the friction block (5). Pressing blocks (7) are fixedly connected to both sides of the friction block (5). A movable limiting rod (8) is provided inside the pressing block (7). Limiting holes (9) for installing the limiting rod (8) are opened on both sides of the outer sleeve (4).

2. The torque-limiting tightening head for a seatbelt retractor fixing bolt according to claim 1, characterized in that: The outer sleeve (4) has an installation cavity (401) for installing the friction block (5), and the friction block (5) is installed independently inside the installation cavity (401).

3. The torque-limiting tightening head for a seatbelt retractor fixing bolt according to claim 1, characterized in that: A torsion bar (10) is connected to one side of the outer sleeve (4).

4. The torque-limiting tightening head for a seatbelt retractor fixing bolt according to claim 1, characterized in that: The pressing block (7) has an installation hole (701) for installing the limiting rod (8) inside, and a spring (801) is fixedly connected to one side of the limiting rod (8).

5. The torque-limiting tightening head for a seatbelt retractor fixing bolt according to claim 1, characterized in that: Each of the friction blocks (5) has a plurality of compression springs (6) fixedly connected to one side.

6. The torque-limiting tightening head for a seatbelt retractor fixing bolt according to claim 1, characterized in that: The main sleeve (1) has various specifications. The outer contours of the main sleeves (1) of different specifications are equal in size, while the inner holes (2) have different specifications.

Images