WO2020119405A1

WO2020119405A1 - Rotary tightening device for safety belt, and piston for same

Info

Publication number: WO2020119405A1
Application number: PCT/CN2019/119470
Authority: WO
Inventors: 拉尔森莱纳斯·卡尔·阿克塞尔; 虞悦; 许志源; 文卡提什沙迦·巴萨拉鲁; 乌拉·莎菲
Original assignee: 奥托立夫开发公司
Priority date: 2018-12-12
Filing date: 2019-11-19
Publication date: 2020-06-18
Also published as: CN111301340A; KR20210124208A

Abstract

A rotary tightening device (100) for a safety belt, and a piston (110) for the same. The piston body (110) is constructed to drive a mass (130) in a pipe (120) of the rotary tightening device (100) to exit the pipe (120) and to enter a drive wheel of the rotary tightening device (100), such that the drive wheel rotates in a direction that tightens the safety belt. A pressing end surface (C) of the piston (100) for pressing the mass body (130) is designed as a planar surface perpendicular to an axial direction of the piston (110) or as a convex surface protruding toward the mass (130). The structure of the piston (110) achieves an excellent seal, thereby enabling reliable operation of the rotary tightening device (100).

Description

Rotary tightening device for safety belt and its piston body

Technical field

The invention relates to a rotary tightening device for a safety belt and its piston body.

Background technique

There is a safety belt in the prior art, which is equipped with a pre-tightening device on a rotary tightening device. When a collision occurs, especially in the early stage of the collision, once the deceleration detected by the sensor is higher than the threshold, the gas generator is triggered to generate reactive gas, causing the rotation tightening device to rotate in the direction of tightening the seat belt. After that, when the peak of impact force has passed or the occupant has been protected by the airbag, the seat belt should be properly relaxed.

FIG. 1 is a schematic diagram of a rotary tightening device in the prior art. The process of tightening the seat belt by the rotary tightening device is described below with reference to FIG. 1. When the gas generator (not shown) located in the end 11 of the pipe 1 is activated by the electronic igniter, the gas generator releases gas by the explosive explosion. This gas exerts a force on the mass body 2 in the pipe 1 via the piston body stored in the pipe 1, so the mass body 2 is driven out of the pipe via the outlet 13 near the other end 12 of the pipe and enters the groove of the drive wheel 3 31. The mass body 2 is continuously driven into the groove 31 of the driving wheel 3 in contact with each other, so that the driving wheel 3 rotates, so that the take-up shaft 4 fixed with the driving wheel 3 rotates in the direction of tightening the seat belt Therefore, the rotating tightening device tightens the seat belt on the take-up shaft.

In the early stage of a collision, in order to enable the gas generated by the gas generator to successfully drive the mass body away from the pipe, it is desirable to form a seal between the piston body and the inner wall of the pipe, so that almost all the gas generated by the gas generator acts on the piston body Without leakage.

However, in the prior art rotary tightening device, there is a problem that when the piston body moves inside the pipe to the bent portion of the pipe, the piston body is easily inclined with respect to the pipe to cause the seal between the piston body and the pipe to fail, As a result, the mass body cannot successfully leave the pipeline without receiving sufficient force. Therefore, reliable operation of the tightening seat belt of the rotary tightening device cannot be ensured.

Therefore, it is desirable to provide a rotary tightening device that can be reliably operated.

Summary of the invention

The object of the present invention is to provide a rotary tightening device capable of reliable operation.

According to an aspect of the present invention, there is provided a piston body for a rotation tightening device of a safety belt,

The piston body is configured to drive the mass body in the pipe of the rotary tightening device to leave the pipe and enter the drive wheel of the rotary tightening device when a collision occurs, so that the drive wheel is tightened Rotating in the direction of the seat belt;

The abutting end surface of the piston body for abutting the mass body is designed as a flat surface perpendicular to the axial direction of the piston body or a convex surface swelling toward the mass body.

According to an embodiment of the present invention, when the abutting end face is a convex surface, in a longitudinal section passing through the axis of the piston body, the contour curve of the abutting end face is an arc.

According to an embodiment of the invention, the radius of the arc of the profile curve abutting the end face is greater than 5.4 mm.

According to an embodiment of the present invention, the radius of the arc of the profile curve abutting the end face is 15 mm.

According to an embodiment of the present invention, the piston body includes at least a first stepped side surface and a second stepped side surface, and the first stepped side surface is farther away from the abutting end surface than the second stepped side surface The outer diameter of the first stepped side is designed to be larger than the outer diameter of the second stepped side.

According to an embodiment of the present invention, the size of the first stepped side surface in the axial direction of the piston body is designed to be half the size of the piston body in the axial direction thereof.

According to an embodiment of the present invention, the piston body further includes a third stepped side surface between the first stepped side surface and the second stepped side surface, and an outer diameter of the third stepped side surface It is designed to be larger than the outer diameter of the second step side and smaller than the outer diameter of the first stepped side.

According to an embodiment of the present invention, a groove is provided on the side of the piston body.

According to an embodiment of the present invention, the piston includes a first groove, a second groove, and a third groove, and the first groove, the second groove, and the third groove are located at The circumferential direction of the piston body is evenly spaced.

According to an embodiment of the present invention, a sealing lip is provided on a circumferential edge of the first stepped side surface of the piston body away from the abutting end surface.

According to another aspect of the present invention, there is provided a rotary tightening device for a safety belt, which includes a pipe and a mass body contained in the pipe,

It also includes any of the aforementioned piston bodies accommodated in the pipe, and the abutting end face of the piston body is for abutting against the mass body, wherein,

The piston body is configured to drive the mass body in the pipe of the rotary tightening device to leave the pipe and enter the drive wheel of the rotary tightening device to cause the drive when a collision occurs The wheel rotates in the direction of tightening the seat belt.

According to an embodiment of the present invention, the piston body includes at least a first stepped side and a second stepped side, the first stepped side is farther from the mass body than the second stepped side, the The outer diameter of the first stepped side is designed to be larger than the outer diameter of the second stepped side and the inner diameter of the pipe, and the outer diameter of the second stepped side is designed to be smaller than the inner diameter of the pipe.

According to an embodiment of the present invention, a side surface of the piston body is provided with a first groove, and the first groove is arranged to face the diameter of the pipe when the piston body is located in the curved portion of the pipe Inward.

According to an embodiment of the invention, the radius of the arc determined by the bend of the pipe is 20 mm-25 mm.

The rotary tightening device of the present invention can achieve a good seal, thereby being able to operate reliably.

BRIEF DESCRIPTION

The present invention is exemplarily explained by the exemplary embodiments in the drawings, and will be described in detail below with reference to the drawings.

Fig. 1 shows a schematic diagram of a rotary tightening device in the prior art.

2 is a piston body according to an embodiment of the present invention.

3 is a rotary tightening device according to an embodiment of the present invention.

detailed description

Specific embodiments of the rotary tightening device for a safety belt and its piston body according to the present invention will be described below with reference to the drawings. The following detailed description and drawings are used to exemplify the principle of the present invention. The present invention is not limited to the described preferred embodiments, and the protection scope of the present invention is defined by the claims.

In addition, space-related terms (such as "upper", "lower", "left", and "right", etc.) are used to describe the relative positional relationship between an element shown in the drawings and another element. Therefore, spatially related terms can be applied to directions different from those shown in the drawings when used. Obviously, for ease of explanation, all of these spatially related terms refer to the directions shown in the drawings, but those skilled in the art can understand that directions different from those shown in the drawings can be used.

2 is a piston body according to an embodiment of the present invention. The piston body according to the present invention will be described below with reference to FIG. 2. It should be understood that the piston body according to the present invention can be used for a rotation tightening device of a seat belt. As already mentioned above, the piston body according to the embodiment of the present invention is configured to drive the mass body in the pipe of the rotary tightening device to leave the pipe and enter the driving wheel of the rotary tightening device in the event of a collision, so that The drive wheel rotates in the direction of tightening the seat belt.

As shown in FIG. 2, the piston body 110 includes an abutting end surface C, a first stepped side 111 and a second stepped side 112. The abutting end face C for abutting the mass body is designed as a convex surface (shown as a convex surface convex downward in FIG. 2 ), specifically, in a longitudinal section passing through the axis of the piston body 110, The contour curve against the end surface C is an arc (that is, the curve indicated by the arrow C is a circular arc). The first stepped side surface 111 is farther away from the abutting end surface C than the second stepped side surface 112, and the outer diameter of the first stepped side surface 111 is designed to be larger than the outer diameter of the second stepped side surface 112, so that the entire piston body 110 It appears to narrow as the axial direction of the piston body 110 is downward. In addition, the size of the first stepped side surface 111 in the axial direction of the piston body 110 is designed to be half the size of the piston body 110 in the axial direction thereof, that is, the first stepped side surface 111 and the second stepped side surface 112 The dimensions in the axial direction of the piston body 110 are equal.

As shown in FIG. 2, three grooves are provided on the side of the piston body 110, namely, the first groove 114, the second groove and the third groove (neither the second groove nor the third groove is shown in FIG. 2 (Shown), and the first groove 114, the second groove, and the third groove are evenly spaced in the circumferential direction of the piston body 110 (ie, in the circumferential direction of the piston body, the three grooves are 120 degrees apart from each other) . Those skilled in the art can understand that in the event of a collision, when the peak impact force has passed or the occupant has been protected by the airbag, the seat belt will be properly relaxed, at this time, the mass body that previously entered the drive wheel will return to the pipeline . In order for the mass body to be successfully returned into the pipeline, the groove provided on the side of the piston body is used to release the gas in the pipeline after the mass body is successfully driven away from the pipeline into the drive wheel.

In addition, as shown in FIG. 2, the circumferential edge of the first stepped side surface 111 of the piston body 110 away from the abutting end surface C (that is, the axial edge of the top surface of the first stepped side surface 111 shown in FIG. 2) Provided with a sealing lip 113. The sealing lip 113 can be used to form a seal with the pipe.

The working process of the piston body 110 shown in FIG. 2 in the rotary tightening device for a seat belt is incorporated in the following description of the rotary tightening device.

3 is a rotary tightening device according to an embodiment of the present invention. The rotary tightening device according to the present invention will be described below with reference to FIG. 3. It should be understood that the rotating tightening device shown in FIG. 3 shows a situation where the rotating tightening device needs to rotate in the direction of tightening the seat belt (hereinafter referred to as a pre-tightening phase) when a collision occurs. In this case, the mass The body drives the gas generated by the gas generator out of the pipe via the piston body. Correspondingly, it is necessary to form a seal between the piston body and the pipeline, so that almost all the gas generated by the gas generator acts on the piston body without leakage, and the gas generated by the gas generator can successfully drive the mass body Leave the pipeline.

As shown in FIG. 3, the rotary tightening device 100 includes a piston body 110, a pipe 120 and a mass body 130. The specific structure of the piston body 110 has been described in detail with reference to FIG. 2 and will not be repeated here to avoid redundancy. It should be noted that, for the first stepped side 111 and the second stepped side 112 included in the piston body 110, the outer diameter of the first stepped side 111 is not only designed to be larger than the second stepped side 112 as described with reference to FIG. And the outer diameter of the second stepped side surface 112 is smaller than the inner diameter of the pipe 120. In addition, the piston body 110 is specifically installed in the rotary tightening device 100 as follows: the abutting end surface C of the piston body 110 is used to abut against the mass body 130, and the first groove 114 provided on the side surface of the piston body 110 is positioned as When the piston body 110 is located in the curved portion of the pipe 120, it faces the radially inner side of the curved portion P of the pipe 120. A person skilled in the art can understand that “radially facing the curved portion of the pipe” refers to the plane in which the bent portion P of the pipe 120 is located, that is, in the paper plane of FIG. 3, pointing to the upper right of the pipe 120 direction. Similarly, the radially outer direction of the curved portion of the pipe is directed to the lower left of the pipe, and the first groove 114 on the side of the piston body 110 is positioned to face the position indicated by the arrow of the curved portion P of the pipe 120 (may It is understood that the portion indicated by the arrow of the bending portion P is the radially inner side of the bending portion, and the portion opposite to this portion is the radially outer side of the bending portion). At the same time, a sealing lip is provided radially outward of the bent portion to assist in providing a seal between the piston body and the pipe. Moreover, the radius of the arc determined by the bent portion P of the pipe 120 is 20 mm-25 mm.

In the rotary tightening device according to the present invention, the abutment end face of the piston body is designed as a convex surface, and the contact of the piston body with the mass body at the bent portion of the pipe makes the piston body still aligned with the pipe without being relative to the center of the pipe The line is skewed. Therefore, the rotary tightening device of the present invention can ensure that the piston body forms a good seal between the bent portion of the pipe and the pipe.

Alternatively, in the rotary tightening device according to the present invention, the abutting end surface of the piston body may be designed as a flat surface perpendicular to the axial direction of the piston body. This design can also make the piston body form a good seal between the pipe bend and the pipe.

In addition, since the outer diameter of the first stepped side is designed to be larger than the inner diameter of the pipe, when the piston body is installed in the pipe, the first stepped side of the piston is tightly pressed on the inner surface of the pipe, therefore, The first stepped side can be used to form a seal with the pipe. At the same time, the sealing lip can also form a seal with the pipe.

Based on the above description, the rotary tightening device of the present invention can achieve a good seal, thereby being able to operate reliably.

Preferably, in a longitudinal section through the axis of the piston body, the radius of the arc of the profile curve abutting the end face is greater than 5.4 mm.

Preferably, in a longitudinal section passing through the axis of the piston body, the radius of the arc of the profile curve abutting the end face is 15 mm.

The embodiment shown in FIG. 2 is only an example of the piston body for the rotation tightening device of the safety belt according to the present invention. The piston body of the present invention is not limited to the above example. For example, the piston body of the present invention may also be designed such that the piston body further includes a third stepped side surface between the first stepped side surface and the second stepped side surface, and The outer diameter of the three stepped side is designed to be larger than the outer diameter of the second stepped side and smaller than the outer diameter of the first stepped side. For another example, the piston body of the present invention may not be provided with a sealing lip. For another example, the contour curve of the abutting end surface of the piston body of the present invention in the longitudinal section passing through the axis of the piston body is not limited to an arc, but may also be other convex contour curves, such as a parabola.

The embodiment shown in Fig. 3 is only an example of a rotary tightening device for a safety belt according to the present invention. The rotary tightening device of the present invention is not limited to the above example. For example, the rotary tightening device of the present invention may also be designed such that the piston body further includes a third stepped side between the first stepped side and the second stepped side And, the outer diameter of the third stepped side is designed to be larger than the outer diameter of the second stepped side and the inner diameter of the pipe and smaller than the outer diameter of the first stepped side. For another example, the grooves on the side of the piston body of the rotary tightening device of the present invention may not be set to three, for example, more or less grooves are provided, but it is necessary to ensure that one groove is positioned as the first groove 114 With the above arrangement of the pipe 120.

As described above, although the exemplary embodiments of the present invention have been described with reference to the drawings, the present invention is not limited to the above specific embodiments, and the scope of protection of the present invention should be defined by the claims and their equivalents.

Claims

A piston body used for a rotation tightening device of a safety belt,

The piston body is configured to drive the mass body in the pipe of the rotary tightening device to leave the pipe and enter the drive wheel of the rotary tightening device when a collision occurs, so that the drive wheel is tightened Rotating in the direction of the seat belt;

among them,

The abutting end surface of the piston body for abutting the mass body is designed as a flat surface or a convex surface perpendicular to the axial direction of the piston body.
The piston body according to claim 1, wherein, when the abutting end surface is a convex surface, in a longitudinal section passing through the axis of the piston body, the contour curve of the abutting end surface is an arc.
The piston body according to claim 2, wherein the radius of the arc of the profile curve abutting the end face is greater than 5.4 mm.
The piston body according to claim 3, wherein the radius of the arc of the profile curve abutting the end face is 15 mm.
The piston body according to claim 4, wherein the piston body includes at least a first stepped side surface and a second stepped side surface, and the first stepped side surface is farther away than the second stepped side surface For the abutting end surface, the outer diameter of the first stepped side surface is designed to be larger than the outer diameter of the second stepped side surface.
The piston body according to claim 5, wherein the dimension of the first stepped side surface in the axial direction of the piston body is designed to be half the dimension of the piston body in the axial direction thereof.
The piston body according to claim 5, wherein the piston body further includes a third stepped side surface between the first stepped side surface and the second stepped side surface, and, the The outer diameter of the three stepped side is designed to be larger than the outer diameter of the second stepped side and smaller than the outer diameter of the first stepped side.
The piston body according to claim 6, wherein a groove is provided on a side surface of the piston body.
The piston body according to claim 8, wherein the piston includes a first groove, a second groove, and a third groove, and the first groove, the second groove, and the first groove The three grooves are evenly spaced in the circumferential direction of the piston body.
The piston body according to claim 9, wherein a sealing lip is provided on a circumferential edge of the first stepped side surface of the piston body away from the abutting end surface.
A rotary tightening device for a safety belt, which includes a pipe and a mass body contained in the pipe,

among them,

Also included is the piston body according to claim 1 accommodated in the pipe, the abutting end face of the piston body is for abutting the mass body, wherein,

The piston body is configured to drive the mass body in the pipe of the rotary tightening device to leave the pipe and enter the drive wheel of the rotary tightening device to cause the drive when a collision occurs The wheel rotates in the direction of tightening the seat belt.
The rotary tightening device according to claim 11, wherein when the abutting end face is a convex surface, in a longitudinal section passing through the axis of the piston body, the contour curve of the abutting end face is an arc.
The rotary tightening device according to claim 12, wherein the piston body includes at least a first stepped side and a second stepped side, and the first stepped side is compared to the second stepped type The side surface is away from the abutting end surface, and the outer diameter of the first stepped side surface is designed to be larger than the outer diameter of the second stepped side surface.
The rotary tightening device according to claim 13, wherein the dimension of the first stepped side surface in the axial direction of the piston body is designed to be half the dimension of the piston body in the axial direction thereof.
The rotary tightening device according to claim 13, wherein the piston body further includes a third stepped side surface between the first stepped side surface and the second stepped side surface, and The outer diameter of the third stepped side is designed to be larger than the outer diameter of the second stepped side and smaller than the outer diameter of the first stepped side.
The rotary tightening device according to claim 14, wherein a groove is provided on the side of the piston body.
The rotary tightening device according to claim 16, wherein the piston includes a first groove, a second groove, and a third groove, and the first groove, the second groove, and the groove The third grooves are evenly spaced in the circumferential direction of the piston body.
The rotary tightening device according to claim 17, wherein a sealing lip is provided on a circumferential edge of the first stepped side surface of the piston body away from the abutting end surface.
The rotary tightening device according to claim 11, wherein the outer diameter of the first stepped side is designed to be larger than the outer diameter of the second stepped side and the inner diameter of the pipe, and the second The outer diameter of the stepped side is designed to be smaller than the inner diameter of the pipe.
The rotary tightening device according to claim 12, wherein the first groove is provided on the side of the piston body, and the first groove is provided such that when the piston body is located in the pipe The curved portion faces the radially inner side of the pipe.