Pre-tensioner and seat belt retractor

Abstract

The application relates to the technical field of vehicle safety protection devices, in particular to a pre-tightening device and a safety belt retractor. The pre-tightening device comprises a guide pipe and a pre-tightening assembly, the pre-tightening assembly comprises at least one mass body and a spacer, and the spacer is tightly wrapped on the outer side of the mass body. The mass body wrapped by the spacer can be inserted into the inside of the guide pipe, and the mass body and the guide pipe are isolated by the spacer with lower hardness than the two; when the pre-tightening device is not detonated, the pre-tightening assembly is stored in the guide pipe, and the spacer is isolated between the mass body and the guide pipe, so that when the pre-tightening device vibrates due to, for example, vehicle vibration, the collision between the mass body and the guide pipe and the noise generated due to the collision can be reduced to a certain extent; when the mass body is multiple, the wrapping and fixing of the multiple mass bodies by the spacer can also avoid the collision between the multiple mass bodies and the noise generated due to the collision.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle safety protection devices, in particular to a pre-tightening device and a seat belt retractor. BACKGROUND

[0002] The seat belt retractor usually has a pre-tightening function. When the vehicle is in an emergency situation such as a vehicle collision, the retractor can rotate in the direction of the seat belt winding to make the seat belt quickly tighten to enhance the restraint force of the seat belt on the occupant, avoiding the danger of the occupant leaning forward.

[0003] A pre-tightening device in the prior art is to place multiple balls in a pipe provided with a gas generating device. When the pre-tightening device is detonated, the multiple balls will be shot out and sequentially enter the ball socket of the ball wheel of the retractor to impact the ball wheel, so that the ball wheel rotates in the direction of the seat belt winding, and then the seat belt is wound back into the retractor. However, before detonation, the multiple balls are scatteredly installed in the pipe. Due to external vibration such as vehicle vibration, collisions will occur between the multiple balls and between the balls and the pipe wall, thereby generating noise. SUMMARY

[0004] The purpose of the present application is to provide a pre-tightening device and a seat belt retractor to constrain the mass in the guide pipe and reduce noise to some extent.

[0005] The present application provides a pre-tightening device for a seat belt retractor; the pre-tightening device comprises a pre-tightening assembly and a guide pipe;

[0006] The pre-tightening assembly is filled in the guide pipe, and the pre-tightening assembly can move in the guide pipe along the guide direction of the guide pipe;

[0007] The pre-tightening assembly comprises a spacer and at least one mass, the hardness of the spacer is lower than that of the mass and the guide pipe, and the spacer is used to wrap and fix the mass to isolate the guide pipe and the mass;

[0008] When the mass is multiple, the multiple masses are side by side in a string in the spacer.

[0009] Further, the spacer forms a receiving cavity at the position opposite to each mass, respectively, the receiving cavity is matched with the mass, so that the inner side wall of the receiving cavity and the outer side wall of the corresponding mass wrap and fit.

[0010] Further, the receiving cavities at both ends of the length direction of the spacer form a mouth, and the diameter of the mouth is smaller than that of the mass, so as to prevent the mass from falling out of the spacer.

[0011] Further, the spacer is formed by thermoplastic processing.

[0012] Further, a gas generator is arranged at a first end of the length direction of the guide tube, and the second end of the length direction of the guide tube extends to the ball wheel, and the gas generated by the gas generator can push the pre-tightening assembly out of the second end of the guide tube, so that the mass of the pre-tightening assembly can enter the ball socket of the ball wheel in sequence and push the ball wheel to rotate.

[0013] Further, the pre-tightening device further comprises a buffer member.

[0014] The buffer member comprises at least two connected guide ball portions, the guide ball portion at one end of the buffer member is opposite to the port of the second end of the guide tube, and the guide ball portion at the other end of the buffer member is located in the ball socket.

[0015] Further, a limiting portion is arranged between two adjacent guide portions, and a clamping groove is formed on the side wall of the ball wheel, so that the limiting portion of the buffer member entering the ball socket can be inserted into the clamping groove.

[0016] The application further provides a seat belt retractor comprising the pre-tightening device.

[0017] Compared with the prior art, the pre-tightening device has the following beneficial effects:

[0018] The pre-tightening device comprises a guide tube and a pre-tightening assembly, the pre-tightening assembly is filled in the inside of the guide tube, the pre-tightening assembly comprises at least one mass and an isolation member, the isolation member is wrapped outside the mass, so as to be isolated between the mass and the guide tube through the isolation member, and the hardness of the isolation member is less than the hardness of the mass and the guide tube; when the number of the mass is multiple, the multiple masses are arranged in a string in the isolation member. The pre-tightening assembly can move in the guide tube along the length direction of the guide tube, when the pre-tightening device is detonated, the pre-tightening assembly can be launched, so that the mass of the pre-tightening assembly moves along the guide direction of the guide tube to the ball wheel installed on the seat belt retractor, so as to make the ball wheel move around the winding direction of the seat belt, and realize the tightening of the installed belt; when the pre-tightening device is not detonated, the pre-tightening assembly is stored in the guide tube, and the isolation member is isolated between the mass and the guide tube, so that when the pre-tightening device vibrates due to, for example, vehicle vibration, the collision between the mass and the guide tube and the noise generated by the collision can be reduced to a certain extent; when the mass is multiple, the multiple masses can also be fixed by the isolation member, so as to avoid the collision between the multiple masses and the noise generated by the collision.

[0019] The application further provides a seat belt retractor comprising the pre-tightening device, so that the seat belt retractor also has the beneficial effects of the pre-tightening device. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application or the prior art, the accompanying drawings needed to be used in the description of the specific embodiments or the prior art will be briefly introduced. Obviously, the accompanying drawings in the following description represent some embodiments of the present application, and all other drawings obtained by those of ordinary skill in the art without creative work based on these drawings also belong to the protection scope of the present application.

[0021] Figure 1 A structure schematic diagram of the pre-tightening device and the ball wheel assembly provided by the embodiment of the present application;

[0022] Figure 2 A structure schematic diagram of the pre-tightening assembly of the pre-tightening device provided by the embodiment of the present application;

[0023] Figure 3 A structure schematic diagram of the pre-tightening assembly of the pre-tightening device provided by the embodiment of the present application;

[0024] Figure 4 A structure schematic diagram of the buffer of the pre-tightening device in the first state provided by the embodiment of the present application;

[0025] Figure 5 A structure schematic diagram of the buffer of the pre-tightening device in the second state provided by the embodiment of the present application.

[0026] Reference signs:

[0027] 1 - guide tube, 2 - ball wheel, 3 - shell, 4 - ball collecting cavity, 5 - isolation piece, 6 - mass body, 7 - buffer, 71 - ball guiding part, 72 - limiting part. DETAILED DESCRIPTION

[0028] The technical solutions of the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments.

[0029] The components of the embodiments of the present application generally described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application.

[0030] Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the protection scope of the present application.

[0031] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0032] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0033] The following refers to Figures 1 to 5 A pre-tightening device and a seat belt retractor are described according to some embodiments of the present application.

[0034] The present application provides a pre-tightening device for a seat belt retractor, so that the seat belt retractor has a pre-tightening function, and in an emergency such as a vehicle collision, the seat belt retractor can tighten the seat belt to avoid the risk of the occupant leaning forward;

[0035] As Figure 1 shown, the pre-tightening device includes a guide pipe 1 and a pre-tightening assembly, and the structure of the pre-tightening assembly is as Figure 2 shown, the pre-tightening assembly is filled in the inside of the guide pipe 1, the pre-tightening assembly includes at least one mass body 6 and a spacer 5, the spacer 5 is wrapped on the outside of the mass body 6, so as to be isolated between the mass body 6 and the guide pipe 1 through the spacer 5, and the hardness of the spacer 5 is less than the hardness of the mass body 6 and the guide pipe 1; when the number of the mass body 6 is multiple, the multiple mass bodies 6 are arranged in a string in the spacer 5.

[0036] The pre-tightening assembly can move along the length direction of the guide pipe 1 into the guide pipe 1, and when the pre-tightening device is detonated, the pre-tightening assembly can be launched to move the mass body of the pre-tightening assembly along the guide direction of the guide pipe to the ball wheel 2 provided with the seat belt retractor, so as to make the ball wheel 2 move around the retraction direction of the safety belt, and realize the tightening of the seat belt; when the pre-tightening device is not detonated, the pre-tightening assembly is stored in the guide pipe 1, and the isolating piece 5 is isolated between the mass body 6 and the guide pipe 1, so that when the pre-tightening device vibrates due to the vibration of the vehicle, the collision between the mass body 6 and the guide pipe 1 and the noise generated by the collision can be reduced to a certain extent; when the mass body 6 is multiple, the multiple mass bodies 6 can be fixed by the isolating piece 5, and the collision between the multiple mass bodies 6 and the noise generated by the collision can also be avoided.

[0037] At the same time, by wrapping the multiple mass bodies 6 into a string through the isolating piece 5, the extrusion of the multiple mass bodies during the movement after detonation is also avoided, so that the ball wheel cannot be smoothly driven to rotate.

[0038] In this embodiment, preferably, the pre-tightening assembly is matched with the guide pipe 1, so that the pre-tightening assembly can be inserted into the guide pipe 1 in a clearance fit, that is, the outer side wall of the isolating piece 5 is in clearance fit with the inner side wall of the guide pipe 1, so as to further strengthen the constraint of the guide pipe 1 on the movement of the pre-tightening assembly, so that the collision between the balls and the collision between the balls and the pipe of the multiple mass bodies before detonation is not easy to occur, so as to achieve the purpose of reducing noise.

[0039] The isolating piece 5 can be a cylinder as shown in Figure 2 The isolating piece 5 can be a cylinder as shown in Figure 3 The isolating piece 5 can be a cylinder as shown in

[0040] In this embodiment, the ports at the two ends of the length direction of the isolating piece 5 are respectively located on the two end cavities and are formed with a closing opening, and the diameter of the closing opening is smaller than the diameter of the mass body 6, so as to prevent the mass body 6 from falling out of the two end cavities, and the multiple mass bodies 6 are stably sealed in the isolating piece 5.

[0041] In an embodiment of the present application, the material of the isolation member 5 is preferably a plastic film, and the isolation member 5 is formed by thermoplastic processing. Initially, the isolation member 5 is in a cylindrical shape, and the plurality of mass bodies 6 can be sequentially placed in the isolation member 5, and then the isolation member 5 is heated and thermoplastic formed, so that the isolation member 5 is tightly attached to the mass bodies 6, and the two ends of the isolation member 5 are closed to form a gourd shape as shown in Figure 3 from the outside, thereby realizing the wrapping and fixing of the plurality of mass bodies 6.

[0042] In this embodiment, the isolation member 5 is preferably a plastic film with a thickness of 0.05mm-1mm formed by thermoplastic processing.

[0043] In an embodiment of the present application, the pre-tightening device further comprises a gas generator arranged at the first end of the length direction of the guide pipe 1, and the second end of the length direction of the guide pipe 1 extends to the ball wheel 2 of the seat belt retractor and is tangent to the ball wheel 2. When the vehicle encounters an emergency situation causing the gas generator to start, the gas generated by the gas generator can push the pre-tightening assembly in the guide pipe 1 to move, so that the pre-tightening assembly moves along the guide pipe 1 from the first end of the guide pipe 1 to the second end of the guide pipe 1, and the pre-tightening assembly is ejected from the second end of the guide pipe 1 at a high speed. The plurality of mass bodies 6 of the pre-tightening device after being ejected can sequentially enter the ball socket on the outer side wall of the ball wheel 2, and push the ball wheel 2 to rotate around the winding direction of the seat belt to tighten the seat belt.

[0044] It should be noted that, as shown in Figure 1 , the existing seat belt retractor is covered with a shell 3 outside the ball wheel 2, the shell 3 surrounds the ball wheel 2 to form a guide path with a predetermined length, the starting end of the guide path is connected to the second end of the guide pipe 1, so that the plurality of mass bodies 6 ejected from the guide pipe 1 sequentially enter the ball socket of the ball wheel 2 in the guide path and move along the direction of the guide path; the shell 3 forms a ball collecting cavity 4 at the terminal end of the guide path, so that the mass bodies 6 can sequentially enter the ball collecting cavity 4 after pushing the ball wheel 2 to rotate by a predetermined angle for temporary storage. By arranging the guide path, it can be ensured that the mass bodies 6 do not escape from the ball socket, and the mass bodies 6 can stably provide a pushing force to the ball wheel 2 to make the ball wheel 2 rotate to wind the seat belt, thereby ensuring the pre-tightening stability. At the same time, the present application wraps the plurality of mass bodies 6 with the isolation member 5 to strengthen the constraint of the movement of the mass bodies 6, so that a string of mass bodies 6 sequentially enter the guide path and move along the guide path to push the ball wheel 2 to rotate, thereby avoiding the impact of the unconstrained mass bodies 6 on the shell 3 to a certain extent, reducing the friction between the pre-tightening assembly and the shell 3, reducing energy loss, and further ensuring the pre-tightening stability.

[0045] In this embodiment, preferably, as shown in Figure 4 and Figure 5As shown, the pre-tightening device further comprises a buffer 7, the buffer 7 comprises at least two connected ball guide portions 71, the ball guide portions 71 are spherical and adapted to the ball socket, so that each ball guide portion 71 of the buffer 7 can be respectively placed in the ball socket of the ball wheel 2, and one end of the buffer 7 is opposite to the port of the guide tube 1 towards the second end of the ball wheel 2; when the pre-tightening assembly is ejected from the guide tube 1, the first mass body 6 will first collide with the buffer 7, and then enter the ball socket of the ball wheel 2, with the continuous ejection of the mass bodies 6 in the guide tube 1, the mass bodies 6 push the buffer 7 to move forward and push the ball wheel 2 to rotate to realize the tightening of the safety belt; therefore, the movement of the mass bodies 6 is guided by the buffer 7, so that the plurality of mass bodies 6 enter the ball socket of the ball wheel 2 in turn, and the mass bodies 6 in a string are guided by the buffer 7 to enter the ball collecting cavity 4.

[0046] In the process of entering the ball collecting cavity 4, since the plurality of mass bodies 6 of the present application are fixed by the isolation member 5, the movement of each mass body 6 is limited to a certain extent, avoiding the mass bodies 6 from being squeezed and stuck in the ball collecting cavity 4 in the movement process, thereby avoiding the subsequent mass bodies 6 from being unable to continue to move and push the ball wheel 2 to continue to move due to the blockage, and ensuring the pre-tightening stability.

[0047] Meanwhile, the plurality of mass bodies 6 wrapped in a string move as a whole, avoiding the rapid movement of the buffer 7 caused by the impact of the subsequent mass bodies 6, so that the buffer 7 will not move to the pipe opening of the guide tube 1 before all the mass bodies 6 are out of the guide tube 1, and the buffer 7 will not cause blockage at the pipe opening of the guide tube 1, affecting the ejection of the mass bodies 6 and causing the ball wheel 2 to be unable to normally rotate.

[0048] In this embodiment, preferably, the buffer 7 comprises two ball guide portions.

[0049] Preferably, a limiting portion 72 is arranged between the adjacent ball guide portions of the buffer 7, and a clamping groove is formed around the ball wheel 2 on the side wall of the ball socket of the ball wheel 2, when the ball guide portion 71 of the buffer 7 is placed in the ball socket of the ball wheel 2, the limiting portion 72 of the buffer 7 can be inserted into the clamping groove, so as to ensure that the buffer 7 can stably guide the pre-tightening assembly.

[0050] The present application also provides a safety belt retractor comprising the pre-tightening device of any one of the above embodiments.

[0051] In this embodiment, the safety belt retractor comprises the pre-tightening device, so the safety belt retractor has all the beneficial effects of the pre-tightening device, which will not be repeated here.

[0052] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A pretensioner for a seat belt retractor; characterized by, The pre-tightening device comprises a pre-tightening assembly and a guide tube; The pre-tightening assembly is filled in the guide tube and can move in the guide tube along the guide direction of the guide tube; The pre-tightening assembly comprises an isolating piece and at least one mass, the hardness of the isolating piece is lower than that of the mass and the guide tube, and the isolating piece is used for wrapping and fixing the mass to isolate the guide tube and the mass; When the mass is multiple, the multiple masses are side by side in the isolating piece.

2. The pre-tensioning device according to claim 1, characterized in that The isolating piece forms a receiving cavity at the position opposite to each mass, the receiving cavity is matched with the mass, so that the inner side wall of the receiving cavity is wrapped and fitted with the outer side wall of the corresponding mass.

3. The pre-tensioning device according to claim 2, characterized in that The receiving cavities at both ends of the length direction of the isolating piece form a necking, and the pass line of the necking is smaller than that of the mass, so as to prevent the mass from falling out of the isolating piece.

4. The pre-tensioning device of claim 1, wherein The isolating piece is a plastic film isolating piece, and the isolating piece is formed by thermoplastic processing; The thickness of the isolating piece is 0.05-1mm.

5. The pre-tensioner according to claim 1, characterized in that The first end of the length direction of the guide tube is provided with a gas generator, the second end of the length direction of the guide tube extends to the ball wheel of the safety belt retractor, and the gas generated by the gas generator can push the pre-tightening assembly out of the second end of the guide tube, so that the mass of the pre-tightening assembly can enter the ball socket of the ball wheel and push the ball wheel to rotate.

6. The pre-tensioning device according to claim 5, characterized in that Further comprising a buffer piece; The buffer piece comprises at least two connected guide ball parts, the guide ball part at one end of the buffer piece is opposite to the port of the second end of the guide tube, and the guide ball part at the other end of the buffer piece is located in the ball socket.

7. The pre-tensioning device according to claim 6, characterized in that A limiting part is arranged between the two adjacent guide ball parts, and a clamping groove is formed on the side wall of the ball wheel, so that the limiting part of the buffer piece entering the ball socket can be inserted into the clamping groove.

8. A seat belt retractor characterized by, The pre-tightening device comprises a pre-tightening assembly and a guide tube; The pre-tightening assembly is filled in the guide tube and can move in the guide tube along the guide direction of the guide tube; The pre-tightening assembly comprises an isolating piece and at least one mass, the hardness of the isolating piece is lower than that of the mass and the guide tube, and the isolating piece is used for wrapping and fixing the mass to isolate the guide tube and the mass; When the mass is multiple, the multiple masses are side by side in the isolating piece. The isolating piece forms a receiving cavity at the position opposite to each mass, the receiving cavity is matched with the mass, so that the inner side wall of the receiving cavity is wrapped and fitted with the outer side wall of the corresponding mass. The receiving cavities at both ends of the length direction of the isolating piece form a necking, and the pass line of the necking is smaller than that of the mass, so as to prevent the mass from falling out of the isolating piece. The isolating piece is a plastic film isolating piece, and the isolating piece is formed by thermoplastic processing; The thickness of the isolating piece is 0.05-1mm. The first end of the length direction of the guide tube is provided with a gas generator, the second end of the length direction of the guide tube extends to the ball wheel of the safety belt retractor, and the gas generated by the gas generator can push the pre-tightening assembly out of the second end of the guide tube, so that the mass of the pre-tightening assembly can enter the ball socket of the ball wheel and push the ball wheel to rotate. Further comprising a buffer piece; The buffer piece comprises at least two connected guide ball parts, the guide ball part at one end of the buffer piece is opposite to the port of the second end of the guide tube, and the guide ball part at the other end of the buffer piece is located in the ball socket. A limiting part is arranged between the two adjacent guide ball parts, and a clamping groove is formed on the side wall of the ball wheel, so that the limiting part of the buffer piece entering the ball socket can be inserted into the clamping groove. The pre-tightening device comprises a pre-tightening assembly and a guide tube;

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