CN219029352U - Diffuser for a gas generator, gas generator and airbag - Google Patents

Abstract

The present application relates to a diffuser for a gas generator, comprising a hollow cylinder (1) and a gas inlet (2), the cylinder having a central axis (L) and a side wall (11) surrounding the central axis, a plurality of gas outlet holes (3) being provided in the side wall of the cylinder, at least one of the plurality of gas outlet holes being configured and oriented such that gas discharged from the inside of the cylinder through the at least one gas outlet hole is discharged from the at least one gas outlet hole in a direction deviating from a radial direction with reference to the central axis. The present application also relates to a gas generator comprising the diffuser and an airbag comprising the gas generator. The diffuser can optimize the outflow of gas and reduce the mechanical impact and thermal shock of gas flow to the gas bag.

Description

Diffuser for a gas generator, gas generator and airbag

Technical Field

The present application relates to a diffuser for a gas generator, a gas generator comprising a diffuser and an airbag.

Background

Airbags are widely used as safety protection devices for occupants in vehicles, in particular land vehicles, in particular motor vehicles. The airbag may include a folded airbag and a gas generator. At predetermined conditions of the vehicle, such as in the event of a collision of a motor vehicle, the gas generator can be activated to rapidly generate gas, which fills the airbag, causing the folded airbag to expand and pop out, providing cushioning to the occupant, preventing the occupant's head or other body part from striking a hard or sharp object. The gas generator may also be referred to as an inflator. The airbag may be, for example, a driver airbag installed in a steering wheel, a passenger airbag installed in an instrument panel, a curtain airbag, or the like.

In vehicle technology, inflatable restraint systems, such as airbags, have been developed to complement conventional seat belt restraint systems. Typically, when an airbag is activated, an occupant in a vehicle is protected by absorbing physical impact due to a vehicle collision with the elasticity of an inflated airbag, wherein in the event of a collision the airbag is deployed into the space between the occupant and an interior object or surface in the vehicle, the deployed airbag provides cushioning to the occupant, reducing the likelihood of occupant injury due to the occupant undesirably contacting the interior object or surface of the vehicle.

Whether an airbag can be deployed in place within a prescribed time is directly related to the life safety of the occupant. The diffuser serves as a connection point for the flow-guided connection of the gas generator in the airbag to the airbag, for delivering the gas generated or stored in the gas generator when the gas generator is activated into the airbag, which is critical for the smooth deployment of the airbag.

Currently, diffusers known in practice are provided with a plurality of exhaust openings in the cylindrical side wall, in which the air flow flowing in the axial direction of the diffuser is deflected and flows out substantially in the radial direction of the diffuser. The inventors of the present application found in research and development of products that known diffusers have the following:

In the assembled state, the diffuser is arranged substantially parallel to the gas bag and the gas bag is relatively tightly abutted against the diffuser, and when the gas generator is activated, the high-temperature and high-pressure gas provided by the gas generator flows out along the radial direction of the diffuser and acts on the gas bag substantially vertically, so that large mechanical impact and thermal shock can be brought to the gas bag, and the mechanical impact and the thermal shock can cause ablation or even hole breaking of the gas bag. For this purpose, it is generally necessary to provide a gas-conducting bag between the diffuser and the gas bag in order to achieve a faster diversion of the gas flow to the different gas bag regions. The air bag is required to have relatively high rigidity and heat resistance in order to withstand the corresponding mechanical impact and thermal shock, for example, the air bag is applied with a heat-insulating coating, thereby resulting in an increase in structural complexity and manufacturing cost of the air bag, and also an increase in the volume of the air bag, which is disadvantageous in light weight and compact size of the air bag.

Disclosure of Invention

The object of the present application is to propose a diffuser for a gas generator, a gas generator comprising a diffuser and an airbag, wherein the diffuser is capable of reducing the mechanical and thermal impact of the gas flow on the airbag.

A first aspect of the present application relates to a diffuser for a gas generator, the diffuser comprising a hollow cylinder and a gas inlet, the cylinder having a central axis and a side wall surrounding the central axis, a plurality of gas vents being provided in the side wall of the cylinder, at least one of the plurality of gas vents being configured and oriented such that gas exiting from the interior of the cylinder through the at least one gas vent exits from the at least one gas vent in a direction that deviates from a radial direction with reference to the central axis.

By the technical measure of the present application, an improved diffuser may be achieved. By allowing the gas to flow out of the diffuser in a diffuse manner obliquely with respect to the radial direction of the diffuser, on the one hand, the area of action of the gas on the gas or gas-conducting bag can be increased, and the mechanical and thermal impact of the gas on the gas or gas-conducting bag can be reduced, so that either the gas-conducting bag can be dispensed with, or the use of a coating of the gas-conducting bag can be at least reduced, or even completely eliminated, even in the case of gas-conducting bags, which can optimize the manufacturing costs, and reduce the volume and weight of the gas-conducting bag; on the other hand, the gas can be quickly shunted to different areas of the gas bag, and the gas fills the gas bag more quickly, thereby achieving better diffuser performance.

In some embodiments, the direction offset from the radial direction of the reference central axis may form an angle with the radial direction, which may be not less than 5 °, or not less than 10 °, or not less than 15 °, or not less than 20 °, or not less than 25 °, or not less than 30 °. Preferably, the included angle may be no greater than 85 °, or no greater than 80 °, or no greater than 75 °, or no greater than 70 °, or no greater than 65 °, or no greater than 60 °. For example, the included angle may be 15 ° to 60 °, preferably 30 ° to 60 °, for example about 45 °.

In some embodiments, the at least one vent may be configured and oriented such that gas vented from the interior of the barrel through the at least one vent vents exits the at least one vent in an axial plane containing the central axis. In other words, the air flow exiting the at least one exhaust hole may have substantially no tangential component with reference to the central axis, but only an axial component and a radial component.

In some embodiments, the outlet direction of the at least one vent may have an included angle that is not equal to zero with respect to the radial direction of the reference central axis in an axial plane containing the central axis. Preferably, the included angle may be not less than 5 °, or not less than 10 °, or not less than 15 °, or not less than 20 °, or not less than 25 °, or not less than 30 °. Preferably, the included angle may be no greater than 85 °, or no greater than 80 °, or no greater than 75 °, or no greater than 70 °, or no greater than 65 °, or no greater than 60 °. For example, the included angle may be 15 ° to 60 °, preferably 30 ° to 60 °, for example about 45 °.

In some embodiments, a plurality of rows of vent holes may be provided in the sidewall of the cylinder, the rows of vent holes being successive to each other in an axial direction with reference to the central axis, at least one row of vent holes among the rows of vent holes being configured and oriented such that gas discharged from the inside of the cylinder through the at least one row of vent holes is discharged from the at least one row of vent holes in a direction that is offset from the radial direction with reference to the central axis.

The same row of ventilation openings can be arranged at approximately the same axial position and distributed, in particular uniformly distributed, in the circumferential direction. The exhaust holes of adjacent two columns may have the same layout in the circumferential direction, or may be staggered from each other in the circumferential direction. The same row of vents may be identically or differently configured.

In some embodiments, three rows of vent holes may be provided in the sidewall of the cylinder, a first row of vent holes toward the gas inlet and a third row of vent holes away from the gas inlet being configured and oriented such that gas vented from the interior of the cylinder through the respective vent holes is vented from the respective vent holes in a direction that is offset from the radial direction of the reference central axis, and a second, centered row of vent holes being configured and oriented such that gas vented from the interior of the cylinder through the respective vent holes is vented from the respective vent holes in a radial direction of the reference central axis.

In some embodiments, the outlet direction of the first row of vent holes and the outlet direction of the third row of vent holes face away from each other in an axial direction with reference to the central axis. The outlet direction of the first row of gas outlet holes may be oriented obliquely in a direction towards the gas inlet and have an angle of not less than 30 ° in an axial plane containing the central axis with respect to the radial direction of the reference central axis, for example an angle of 30 ° to 60 °, for example an angle of about 45 °. The outlet direction of the third row of gas outlet openings may be oriented obliquely in a direction away from the gas inlet opening and have an angle of not less than 30 °, for example an angle of 30 ° to 60 °, for example an angle of about 45 °, in an axial plane containing the central axis with respect to the radial direction of the reference central axis.

In some embodiments, two rows of vent holes may be provided in the sidewall of the cylinder, a first row of vent holes toward the gas inlet and a second row of vent holes away from the gas inlet being configured and oriented such that gas exiting the interior of the cylinder through the respective vent holes exits the respective vent holes in a direction that is offset from the radial direction of the reference central axis.

In some embodiments, the outlet direction of the first row of vent holes and the outlet direction of the second row of vent holes may face each other in an axial direction with reference to the central axis. The outlet direction of the first row of exhaust holes may have an angle of not less than 30 ° with respect to the radial direction of the reference central axis in an axial plane containing the central axis, for example, an angle of 30 ° to 60 °, for example, an angle of about 45 °. The outlet direction of the second row of exhaust holes may have an angle of not less than 30 ° with respect to the radial direction of the reference central axis in an axial plane containing the central axis, for example, an angle of 30 ° to 60 °, for example, an angle of about 45 °.

In some embodiments, a row of vent holes may be provided in the sidewall of the cylinder, the row of vent holes being distributed in a circumferential direction with reference to the central axis, the row of vent holes being oriented such that gas discharged from the inside of the cylinder through the row of vent holes is discharged from the row of vent holes in a direction deviating from a radial direction with reference to the central axis.

In some embodiments, the cylinder may be configured as a body of revolution, and in particular the entire diffuser may be configured as a body of revolution.

In some embodiments, the barrel may comprise a hollow ellipsoid. In some embodiments, the ellipsoid is rotationally symmetric about the longitudinal axis of the cylinder, the ellipsoid being circular on the equator.

In some embodiments, the diffuser may include a base integrally formed with the barrel, the base defining the gas inlet, the base configured for installation of the diffuser in a gas generator.

In some embodiments, the barrel may be convexly configured, such as generally ellipsoidal; or may be generally cylindrically configured; or may be formed so as to be retracted and thus have a constriction or neck. In principle, the cylinder can be formed as a hollow body of any desired shape.

In some embodiments, the cylinder is configured convexly, wherein the first row of vent holes is disposed at an axial position between the gas inlet and the equator having the largest dimension and oriented obliquely to the gas inlet with respect to a radial direction of the reference central axis, the second row of vent holes is disposed at the equator and oriented in a radial direction of the reference central axis, and the third row of vent holes is disposed at an axial position between the equator and the top of the cylinder and oriented obliquely to the radial direction of the reference central axis away from the gas inlet.

In some embodiments, the cylinder is configured to be tapered, wherein the cylinder has a converging portion of minimum size, a first row of vent holes is disposed in a first taper expanding from the converging portion toward the gas inlet, and a second row of vent holes is disposed in a second taper expanding from the converging portion in a direction away from the gas inlet.

In some embodiments, the at least one gas outlet opening may be provided with a respective gas guide, which is configured on the side wall such that gas can be discharged from the respective gas outlet opening in a predetermined direction via the respective gas guide.

In some embodiments, the gas guide may be formed of a material punched out of the side wall, and the at least one vent hole is formed by punching out the gas guide from the side wall.

In some embodiments, the gas guide may be configured as a tongue punched out of the side wall and protruding into the cavity of the cylinder at a free end, the at least one vent hole being formed by punching out the tongue from the side wall, the tongue protruding into the cylinder at its free end.

In some embodiments, the plurality of vent holes may form a row of vent holes and each be provided with a tongue, the row of vent holes being distributed in a circumferential direction with reference to the central axis of the cylinder, each tongue having an alternating direction, or being directed in a direction towards the gas inlet, or being directed away from the gas inlet.

In some embodiments, the at least one vent hole may be tetrahedral, wherein the at least one vent hole has a triangular profile on an outer surface of the side wall, the gas guide portion is connected with two sides of the triangular profile, extends along the two sides, extends from the side wall toward the inside of the cylinder, and has a free edge opposite to the other side of the triangular profile, the free edge and the other side enclosing an entrance opening of the corresponding vent hole.

In some embodiments, the two rows of vent holes may each be tetrahedral, each having a triangular profile on the outer surface of the side wall, the gas guide portion being connected to two sides of the triangular profile, extending along the two sides, from the side wall towards the interior of the barrel, and having a free edge opposite the other side of the triangular profile, the free edge and the other side enclosing the entry opening of the respective vent hole.

In some embodiments, the edge in the gas guide may form an acute angle of more than 60 ° with the radial direction.

In some embodiments, the same row of vents may have the same orientation and the two rows of vents may have different orientations from one another.

In some embodiments, with reference to the central axis of the cylinder, the first row of vent holes may have an upright triangular profile and the second row of vent holes may have an inverted triangular profile, the other side of each of the triangular profiles being the base side, respectively.

In some embodiments, the total area of the plurality of exhaust holes may be at least 1.2 times, for example 1.5 to 2 times, the area of the gas inlet.

In some embodiments, the sidewall may have a curvilinear profile at least partially in a longitudinal section of the diffuser, and the plurality of vent holes may be disposed in a section of the sidewall having the curvilinear profile.

In some embodiments, the sidewall may have at least one peak and/or at least one valley in a section having a curvilinear profile in a longitudinal section of the diffuser, the plurality of vent holes being configured at or beside the peak or the valley, respectively.

In some embodiments, the sidewall may have a wavy curve in a longitudinal section of the diffuser, including at least one peak and at least one trough.

In some embodiments, the plurality of exhaust holes may be constructed and arranged such that the resultant force of the airflow to the diffuser as the airflow exits the diffuser may be substantially zero. For example, in an exemplary version of the three rows of vents, the resultant of the air flows of the second, centered row of vents may itself be substantially zero, and the resultant of the air flows of the first row of vents may cancel out the resultant of the air flows of the third row of vents, whereby the resultant of the air flows of the three rows of vents may be substantially zero. In an exemplary embodiment, the total area of the first row of vent holes may be substantially equal to the total area of the third row of vent holes. Furthermore, it is also possible to design the distribution of the gas flow according to a predetermined total force, for example the total area of the first row of gas vents may form a ratio 6 to the total area of the third row of gas vents: 4 or 7:3, or vice versa.

In some embodiments, the vent may have a polygonal, circular, semi-circular, or oval shape. Preferably, the exhaust hole may be a circular hole having a diameter corresponding to a wall thickness of the diffuser.

In some embodiments, the cylinder of the diffuser may be cylindrically configured, and the sidewall of the cylinder is perforated with shaped holes, and the axial direction of the shaped holes forms an included angle with the radial direction of the cylinder of the diffuser, for example, an included angle of 30 ° to 60 °, so that the air flow can flow out at an acute angle or an obtuse angle with the sidewall, the impact area of the air flow on the air bag is increased, and the impact on the air bag locally is finally reduced. In this case, since the axial direction of the shaped hole and the radial direction of the cylinder of the diffuser may have a large angle, it is possible to achieve a diffuse diversion of the air flow to different areas of the air bag. In this embodiment, the air guiding bag can be omitted, and the air flow can be split into different air bag areas while the impact of the air flow on the air bag is reduced.

A second aspect of the present application relates to a gas generator comprising a diffuser for a gas generator according to any one of the embodiments of the present application. Typically, the gas generator may comprise an ignition system, which may comprise a squib or initiator, which is capable of igniting the charge in the charge chamber, thereby generating a high temperature, high pressure gas, and a charge chamber.

In some embodiments, the gas generator may be configured as a hybrid gas generator, which may comprise a pressure vessel, in particular a tube, in which a compressed gas, in particular an inert gas, is accommodated. When the gas generator is activated, the hot gas generated by the burning of the powder may be mixed with the cold compressed gas, and the mixed gas may be output through the diffuser.

A third aspect of the present application relates to an airbag comprising a gas generator according to the second aspect of the present application.

In some embodiments, the airbag may not have a gas-conducting bag; or the airbag has a gas-conducting pouch and the gas-conducting pouch has no coating.

The technical features mentioned above, the technical features to be mentioned below and the technical features shown in the drawings alone may be arbitrarily combined with each other as long as the combined technical features are not contradictory. All possible combinations of features are specifically described herein. Any one of the plurality of sub-features contained in the same sentence may be applied independently, and not necessarily with other sub-features.

Drawings

The present application is explained in more detail below with the aid of exemplary embodiments with reference to the accompanying drawings. The drawings are briefly described as follows:

fig. 1 shows a schematic perspective view of a diffuser according to a first embodiment of the present application.

Fig. 2 shows a schematic perspective view of the diffuser of fig. 1 in partial cutaway.

Fig. 3 shows a schematic perspective view of a diffuser according to a second embodiment of the present application.

Fig. 4 shows a schematic perspective view of the diffuser of fig. 3 in partial cutaway.

Fig. 5 shows a schematic view of the outflow of gas from a prior art diffuser.

Fig. 6 shows a schematic view of the gas flow from the diffuser of fig. 3.

Fig. 7 shows a schematic perspective view of a diffuser according to a third embodiment of the present application.

Fig. 8 shows a schematic perspective view of the diffuser of fig. 7 in partial cutaway.

Fig. 9 shows a schematic perspective view of a diffuser according to a fourth embodiment of the present application.

Fig. 10 shows a schematic perspective view of the diffuser of fig. 9 in partial cutaway.

Fig. 11 shows a schematic perspective view of a gas generator according to an embodiment of the present application.

Fig. 12 shows a schematic view of an airbag according to an embodiment of the present application.

Detailed Description

Exemplary embodiments will now be described more fully with reference to the accompanying drawings. It should be appreciated that elements not necessary for an understanding of the present application may be omitted from the drawings for ease of illustration and understanding. In the drawings, like reference numbers indicate identical or functionally identical elements. In the following description, numerous specific details are set forth, such as examples of specific components, devices, and methods, in order to provide a thorough understanding of embodiments of the present application. It will be apparent to one skilled in the art that it is not necessary to employ all of these specific details. The exemplary embodiments should not be construed as limiting.

A prior art diffuser 10a known from practice is first schematically described with reference to fig. 5. Typically, the diffuser 10a is configured in a cylindrical shape, a plurality of exhaust holes (not shown) are opened in a sidewall of the diffuser 10a, the air flow 200 flows out from the inside of the diffuser 10a in a radial direction with reference to the central axis L of the diffuser 10a, and the air flow 200 impacts the air bag or the air guide bag 300 substantially vertically and frontally, an acting area 400 between the air flow 200 and the air bag or the air guide bag 300 is small, and the air flow 200 causes strong mechanical impact and thermal shock to the air bag strap or the air guide bag 300.

In contrast, as can be seen from fig. 6, the diffuser 10 according to the present application is capable of optimizing the outflow of gas to reduce the mechanical impact and thermal shock of the gas flow discharged from the diffuser 10 into the gas pocket to the gas pocket or the gas guide pocket. By the measures of the application, on one hand, the action area of the gas on the air bag or the air guide bag can be increased, and the mechanical impact and thermal shock of the gas on the air bag or the air guide bag are weakened, so that the air guide bag can be omitted, or even if the air guide bag is adopted, the use of a coating of the air guide bag can be at least reduced, even completely eliminated, the manufacturing cost can be optimized, and the volume of the air guide bag is reduced; on the other hand, the gas can be filled with gas more rapidly, thus achieving better diffuser performance.

As shown in fig. 6, the diffuser 10 according to the present application can diffuse the gas 200 to flow out, thereby increasing the gas flow path that the gas needs to pass before acting on the gas or air guide 300 and increasing the acting area 400 of the gas on the gas or air guide 300. In an advantageous embodiment, the side walls of the diffuser 10 can have a curved profile, which can increase the distance between a suitably arranged exhaust opening and the gas or gas guide bag, thereby additionally increasing the area of action of the gas on the gas or gas guide bag 300.

A number of different embodiments of a diffuser 10 according to the present application are described in more detail below in connection with fig. 1-4 and 7-10. In the illustrated embodiment, the diffuser 10 may be substantially configured as a solid of revolution. It will be appreciated that the diffuser 10 may not be configured as a solid of revolution, for example, may be configured as a hollow body having a rounded rectangular cross-section.

In a first embodiment of the diffuser 10 as shown in fig. 1 and 2, the diffuser 10 comprises a hollow cylinder 1 and a base 13 made integrally with the cylinder 1, for example made of plastic and/or metal, for example by injection moulding and/or sheet metal forming processes. The bowl 1 has a side wall 11 which encloses a diffuser chamber 5. The base 13 defines a gas inlet 2 through which gas generated by the gas generator and/or stored gas may flow into the diffuser chamber 5 of the diffuser 10 when the gas generator is activated. The base 13 may be configured for connection with a corresponding component of a gas generator. For example, in the case where the gas generator is configured as a hybrid gas generator (see fig. 7, which has a pipe body as a pressure vessel), the base 13 may be connected with the pipe body of the gas generator 100, more specifically, may be installed at one axial end portion of the pipe body. The gas inlet 2 may be closed with a rupture membrane and the rupture membrane can be broken by shock waves and/or pressure changes of the gas when the gas generator is activated.

A plurality of exhaust holes 3 may be configured in the sidewall 11 of the cylinder 1 of the diffuser 10. For clarity, only two vent holes are provided with reference numeral 3. Gas can flow out of the diffuser chamber 5 via the plurality of exhaust holes 3. No vent holes are provided in the top 12 of the diffuser 10 opposite the gas inlet 2, for example to avoid high velocity gas streams rushing out of the top 12 of the diffuser 10 directly in an axial direction and to create a large axial force on the diffuser 10 and the overall gas generator comprising the diffuser, thereby causing an undesirable so-called "rocket effect".

In the first embodiment, the cylindrical body 1 of the diffuser 10 is formed in a convex shape and has a substantially elliptical shape. In other words, the side wall 11 has a curved profile in the longitudinal section of the diffuser 10, which in the present embodiment is substantially circular arc-shaped protruding outwards, so as to form a bulging side wall 11. The curved profile of the side wall 11 in longitudinal section has a peak 14 (equator) furthest from the central axis L of the diffuser 10, the angle between the normal direction of the side wall 11 and the radial direction of the diffuser 10 increasing from this peak 14 in the axial direction towards the ends of the diffuser 10. Vent holes are provided at the peak 14 and on both sides of the peak 14, respectively. Thus, three rows of vent holes are provided in the side wall 11 of the cylinder 1, wherein the first row of vent holes toward the gas inlet 2 and the third row of vent holes away from the gas inlet 2 are configured and oriented such that gas discharged from the inside of the cylinder 1 through the respective vent holes is discharged from the respective vent holes in a direction deviating from the radial direction of the reference central axis L, and the second row of vent holes in the middle is configured and oriented such that gas discharged from the inside of the cylinder 1 through the respective vent holes is discharged from the respective vent holes in the radial direction of the reference central axis L.

The first row of vent holes is arranged at an axial position between the gas inlet 2 and the equator (peak 14) having the greatest dimension and oriented obliquely with respect to the radial direction of the reference central axis L towards the gas inlet 2, the second row of vent holes is arranged at an equatorial (peak 14) and oriented in the radial direction of the reference central axis L, and the third row of vent holes is arranged at an axial position between the equator (peak 14) and the closed top 12 of the cylinder 1 and oriented obliquely with respect to the radial direction of the reference central axis L away from the gas inlet 2.

Since the gas is discharged from each of the gas discharge holes 3 substantially along the normal direction of the side wall 11, the first and third rows of gas discharge holes 3 provided on both sides of the equator (peak 14) enable the gas to flow out of the diffuser chamber 5 obliquely with respect to the radial direction. As a result, the gas flowing out from the diffuser 10 can be expanded in the axial direction of the diffuser 10 to act on the gas bag or the gas guide 300, the area of the gas acting on the gas bag or the gas guide 300 increases, and the impact applied to the gas bag or the gas guide 300 locally decreases. The side wall 11 may have a curvature which is suitably designed in longitudinal section so that the normal of the partial section of the side wall 11 forms a suitable angle with the radial direction of the diffuser 10. Preferably, the vent holes 3 are provided in the following sections of the side wall 11: the angle between the normal of said section of the side wall 11 and the radial direction of the diffuser 10 is not less than 30 °, preferably between 30 ° and 60 °, for example about 45 °.

It can also be seen that the distance between the curved profile of the side wall 11 and the central axis L of the diffuser 10 decreases gradually from the peak 14 towards both ends of the diffuser 10, so that the vent holes 3 arranged on both sides of this peak 14 have a relatively large distance with respect to the gas or gas guide bag 300 arranged around the diffuser 10, compared to the vent holes 3 arranged on this peak 14, whereby it is also possible to increase the area of action of the gas on the gas or gas guide bag 300 to a certain extent and to attenuate the impact of the gas or gas guide bag 300.

Each row of vent holes 3 is evenly distributed in the circumferential direction of the sidewall 11 to ensure that the diffuser 10 is uniformly stressed in the radial direction, and thus the resultant force of the air flow of each row of vent holes 3 may be substantially zero, or may be substantially axial. Preferably, adjacent rows of the exhaust holes 3 may be arranged to be staggered in the circumferential direction so that the flow of air out of the diffuser 10 is more uniform. Advantageously, the first and third rows of exhaust holes 3 are oppositely oriented in the axial direction of the diffuser 10. Advantageously, in order to achieve a force balance of the diffuser 10 in the axial direction, it can be provided that the side wall 11 together with the exhaust openings 3 provided on the side wall 11 are configured symmetrically with respect to the peak 14 (equator), and that the first and third rows of exhaust openings 3 have substantially the same total exhaust area. However, it is also conceivable that the first and third rows of exhaust openings 3 have different total exhaust areas, so that the gas flows out in opposite directions in the axial direction of the diffuser 10 are different, in order to achieve an intentional flow distribution. For example, the ratio of the total exhaust area of the first and third rows of exhaust holes 3 may be set to 6:4 or 7:3, or the opposite ratio 4 may be set: 6 or 3:7.

Fig. 3 and 4 show schematic perspective views of a diffuser 10 according to a second embodiment of the present application. The side wall 11 of the cylinder 1 of the diffuser 10 has a curved profile in a longitudinal section through the central axis L, which curved profile comprises an inwardly concave circular arc shape, so that the side wall 11 has at least partially an inwardly concave section. The curved profile of the inwardly recessed side wall 11 has a valley 15 at the closest distance from the central axis L of the diffuser 10, the angle between the normal to the side wall 11 and the radial direction of the diffuser 10 increasing from this valley 15 in the axial direction towards both ends of the diffuser 10. The exhaust holes 3 are provided at both sides of the valley 15, respectively. In other words, the cylinder 1 is configured to be contracted, wherein the cylinder 1 has a converging portion (valley 15) of a minimum size, the first row of exhaust holes 3 is provided in a first tapered surface that expands from the converging portion toward the gas inlet 2, and the second row of exhaust holes 3 is provided in a second tapered surface that expands from the converging portion in a direction away from the gas inlet 2.

Since the gas is discharged from the corresponding gas discharge holes 3 substantially along the normal direction of the side wall 11, the two rows of gas discharge holes 3 provided on both sides of this valley 15 can make the gas flow out of the diffuser chamber 5 diffusely. The side wall 11 may have a suitable recess depth such that the normal of the partial section of the side wall 11 forms a large angle, preferably an angle of more than 30 °, with the radial direction of the diffuser 10 (radial direction with reference to the central axis L).

In the second embodiment, two rows of air vents 3 arranged on both sides of the constriction of the side wall 11 are particularly advantageous compared to cylindrical cylinders known in practice, since they have an increased distance from the air bag or air guide 300 arranged around the diffuser 10, whereby the area of action of the air on the air bag or air guide 300 can be additionally increased, and the impact on the air bag or air guide 300 is reduced.

In the second embodiment, each row of exhaust holes 3 may be uniformly distributed in the circumferential direction of the side wall 11 to ensure that the diffusers 10 are uniformly stressed in the radial direction, so that the resultant force of the airflows of each row of diffusers may be substantially axial force. Advantageously, the two rows of exhaust holes 3 are oriented opposite in the axial direction of the diffuser 10, which advantageously allows a stress balance of the diffuser 10 in the axial direction, in other words, the axial forces of the air flows of the two rows of exhaust holes can substantially cancel each other. Advantageously, the side walls 11 of the cylinder 1 of the diffuser 10 are configured substantially symmetrically with respect to the valleys 15 (constrictions) and the two rows of exhaust holes 3 have substantially the same total exhaust area.

Fig. 7 and 8 show schematic perspective views of a diffuser 10 according to a third embodiment of the present application. The hollow cylinder 1 of the diffuser 10 is formed cylindrically here and has a row of exhaust openings 3 which are arranged uniformly around the central axis L. On the outer circumferential surface of the cylinder 1, the vent hole 3 has an elongated, preferably substantially rectangular, contour and extends substantially axially.

Each of the exhaust holes 3 is provided with a tongue as a gas guide 4 extending from the side wall 11 into the diffuser chamber 5. The direction of extension of the tongues can be inclined at a defined angle relative to the radial direction of the diffuser 10, so that the gas can flow out of the respective exhaust holes 3 under the guidance of the tongues in a defined direction, in particular substantially corresponding to the direction of inclination of the tongues. Preferably, the tongue extends at an angle of not less than 30 ° to the radial direction of the diffuser. The tongue may be formed, for example, from a material punched out of the side wall 11 when the vent hole 3 is manufactured. With reference to the central axis L of the cylinder 1, the row of vent holes is arranged distributed in the circumferential direction, with the tongues having alternating orientations, either towards the gas inlet (tongues extending from the edge of the vent hole facing away from the gas inlet 2 towards the gas inlet), or away from the gas inlet (tongues extending from the edge of the vent hole facing towards the gas inlet 2 towards the top 12 of the cylinder 1).

Fig. 9 and 10 show schematic perspective views of a diffuser 10 according to a fourth embodiment of the present application. The hollow cylinder 1 of the diffuser 10 is formed cylindrically here and has two rows of exhaust openings 3 which are arranged uniformly around the central axis L. Each vent hole 3 is substantially tetrahedral. The exhaust hole 3 has a substantially triangular outline on the outer peripheral surface of the cylinder 1. Preferably, the triangle may be substantially an isosceles triangle, such as an equilateral triangle. Each of the exhaust holes 3 is provided with one gas guide 4 formed of a material punched out of the side wall 11, and the exhaust holes 3 are formed by punching out the gas guide 4 from the side wall 11. The gas guide 4 is connected to two sides 21, 22 of the triangular contour, extends along the two sides 21, 22, extends from the side wall 11 towards the interior of the cylinder 1, and has a free edge opposite the other side 23 of the triangular contour, which free edge encloses with the other side 23 an entry opening for the respective vent hole 3. The edge 24 in the gas guide 4 may form an acute angle of more than 60 ° with the radial direction.

The same row of vent holes 3 has the same orientation, and the two rows of vent holes 3 have different orientations from each other. Referring to the central axis L of the cylinder 1, the first row of vent holes 3 has an upright triangular profile and the second row of vent holes has an inverted triangular profile, the other side 23 of each of the triangular profiles being the base side, respectively. As shown in fig. 9 and 10, the bottom edges 23 each extend with reference to the central axis L in a radial plane perpendicular to the central axis L.

It should be noted that the embodiments described in connection with the drawings are respectively exemplary. It will be appreciated by those skilled in the art that the various geometric features of the diffuser 10, such as the length of the diffuser, the particular type of profile of the curve (e.g., the number of peaks or valleys, the curvature of the curve, etc.), the number of vents, the shape of the vents, the size of the vents, and the placement of the vents on the side walls, can be modified according to actual needs without departing from the scope of the present application. The vent holes may, for example, have a polygonal, circular, semi-circular or oval shape. Preferably, the vent holes may be circular holes, the diameter of which may be approximately equal to the wall thickness of the barrel of the diffuser, for example the wall thickness of the side wall of the barrel.

It will be appreciated that the embodiments described in connection with the figures can be combined with each other. The following are exemplary of several combinations not shown:

1) The barrel of the diffuser may include a first axial section of convex configuration and a second axial section of concave configuration, the first axial section may be configured similarly to the first embodiment shown in fig. 1 and 2, and the second axial section may be configured similarly to the second embodiment shown in fig. 3 and 4.

2) The bowl of the diffuser may be constructed similarly to the second embodiment shown in fig. 3 and 4, with the modified converging portion having an increased axial dimension and the converging portion being provided with a central row of vent holes in the first embodiment shown in fig. 1 and 2.

3) The body of the diffuser may be cylindrically configured and include two rows of vents, one of which may be similarly configured as in the third embodiment shown in fig. 7 and 8, with the tabs of the one row of vents modified to have the same orientation, and the other row of vents may be similarly configured as in the fourth embodiment shown in fig. 9 and 10.

Fig. 11 shows a schematic perspective view of a gas generator 100 according to an embodiment of the present application. The gas generator 100 is configured as a hybrid gas generator, for example, and includes a tube body 20 as a pressure vessel in which a pressure vessel for compressing gas is formed. The diffuser 10 may be mounted at one axial end of the tube 20. At the other axial end of the tube 20, an ignition system and a pyrotechnic chamber, not shown, may be mounted.

Fig. 12 shows a schematic view of an airbag according to an exemplary embodiment of the present application. The airbag may include a gas generator 100, a gas bag 500, and a gas guide bag 300. The airbag 500 is only partially depicted. The air guide bag 300 is schematically shown in phantom. The gas generator 100 may include a diffuser 10 as shown in fig. 9 and 10. The air flow exiting the diffuser 10 can be deflected at a large angle relative to the radial direction so that the air flow is rapidly deflected to flow mainly in the axial direction of the diffuser, whereby the air flow can be better directed to different areas of the air bag, enabling a rapid filling of the air bag. Thus, even the air guide bag 300 can be eliminated. In the case of using the air guide 300, the design requirement of the air guide 300 can be reduced, and for example, it is unnecessary to apply a coating on the air guide 300.

It is noted that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be understood that the terms "comprises" and "comprising," and other similar terms, when used in this specification, specify the presence of stated operations, elements, and/or components, but do not preclude the presence or addition of one or more other operations, elements, components, and/or groups thereof. The term "and/or" as used herein includes all arbitrary combinations of one or more of the associated listed items. In the description of the drawings, like reference numerals always denote like elements.

The thickness of elements in the drawings may be exaggerated for clarity. It will also be understood that if an element is referred to as being "on", "coupled" or "connected" to another element, it can be directly on, coupled or connected to the other element or one or more intervening elements may be present therebetween. Conversely, if the expressions "directly on … …", "directly coupled to … …" and "directly connected to … …" are used herein, it is intended that there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted similarly such as "between … …" and "directly between … …", "attached" and "directly attached", "adjacent" and "directly adjacent", and so forth.

Terms such as "top," "bottom," "over," "under," and the like are used herein to describe one element, layer or region's relationship to another element, layer or region as illustrated in the figures. It will be understood that these terms are intended to encompass other orientations of the device in addition to the orientation depicted in the figures.

It will be understood that, although the terms "first," "second," etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, a first element could be termed a second element without departing from the teachings of the present application.

It is also contemplated that all of the exemplary embodiments disclosed herein may be arbitrarily combined with one another. Finally, it is pointed out that the above embodiments are only for the understanding of the present application and do not limit the scope of protection of the present application. Modifications to the above would be obvious to those of ordinary skill in the art, but would not bring the invention so modified beyond the scope of the present application.

Claims (29)

1. A diffuser for a gas generator, the diffuser comprising a hollow cylinder (1) and a gas inlet (2), the cylinder having a central axis (L) and a side wall (11) surrounding the central axis, characterized in that a plurality of gas outlet holes (3) are provided in the side wall of the cylinder, at least one of the plurality of gas outlet holes being configured and oriented such that gas discharged from the inside of the cylinder through the at least one gas outlet hole is discharged from the at least one gas outlet hole in a direction deviating from a radial direction with reference to the central axis.

2. The diffuser of claim 1, wherein the at least one vent is configured and oriented such that gas exiting the interior of the barrel through the at least one vent exits the at least one vent in an axial plane containing the central axis.

3. The diffuser of claim 1, wherein the outlet direction of the at least one exhaust orifice has an included angle that is not equal to zero in an axial plane containing the central axis relative to a radial direction of the reference central axis.

4. A diffuser for a gas generator as claimed in claim 3 wherein the included angle is not less than 10 ° and/or not more than 80 °.

5. A diffuser for a gas generator as set forth in claim 3, wherein said included angle is 15 ° to 60 °.

6. A diffuser for a gas generator as set forth in claim 3, wherein said included angle is 30 ° to 60 °.

7. A diffuser for a gas generator according to any one of claims 1 to 6, wherein a plurality of rows of gas discharge holes are provided in a side wall of the cylinder, the rows of gas discharge holes being successive to each other in an axial direction with reference to the central axis, at least one row of gas discharge holes among the rows of gas discharge holes being configured and oriented such that gas discharged from the inside of the cylinder through the at least one row of gas discharge holes is discharged from the at least one row of gas discharge holes in a direction deviating from a radial direction with reference to the central axis.

8. A diffuser for a gas generator according to claim 7, wherein three rows of gas discharge holes are provided in a side wall of the cylinder, a first row of gas discharge holes toward the gas inlet and a third row of gas discharge holes away from the gas inlet are configured and oriented such that gas discharged from the inside of the cylinder through the respective gas discharge holes is discharged from the respective gas discharge holes in a direction deviated from a radial direction of the reference central axis, and a second row of gas discharge holes in the center are configured and oriented such that gas discharged from the inside of the cylinder through the respective gas discharge holes is discharged from the respective gas discharge holes in a radial direction of the reference central axis.

9. The diffuser of claim 8, wherein the outlet direction of the first row of gas discharge holes and the outlet direction of the third row of gas discharge holes are directed away from each other in an axial direction with reference to the central axis.

10. A diffuser for a gas generator according to claim 7, wherein two rows of gas discharge holes are provided in a side wall of the cylinder, a first row of gas discharge holes facing the gas inlet and a second row of gas discharge holes facing away from the gas inlet being configured and oriented such that gas discharged from the inside of the cylinder through the respective gas discharge holes is discharged from the respective gas discharge holes in a direction deviating from a radial direction with reference to the central axis.

11. The diffuser of claim 10, wherein the outlet direction of the first row of exhaust holes and the outlet direction of the second row of exhaust holes face each other in an axial direction with reference to the central axis.

12. A diffuser for a gas generator as claimed in any one of claims 1 to 6 wherein a row of gas discharge holes is provided in the side wall of the barrel, the row of gas discharge holes being distributed in the circumferential direction of the reference central axis, the row of gas discharge holes being oriented such that gas discharged from the interior of the barrel through the row of gas discharge holes is discharged from the row of gas discharge holes in a direction offset from the radial direction of the reference central axis.

13. A diffuser for a gas generator as set forth in any one of claims 1 to 6, wherein said cylinder is constituted as a revolution body.

14. A diffuser for a gas generator according to any of the claims 1-6, characterized in that the diffuser comprises a base (13) made integrally with the cylinder, said base defining said gas inlet, said base being configured for the installation of the diffuser (10) in a gas generator.

15. A diffuser for a gas generator according to any one of claims 1 to 6, wherein said cylinder is convexly or cylindrically or invaginally formed.

16. A diffuser for a gas generator according to claim 8 or 9, characterized in that the cylinder is convexly constructed, wherein the first row of gas vents is arranged at an axial position between the gas inlet and the equator having the largest dimension and oriented obliquely towards the gas inlet with respect to the radial direction of the reference central axis, the second row of gas vents is arranged at the equator and oriented in the radial direction of the reference central axis, and the third row of gas vents is arranged at an axial position between the equator and the top (12) of the cylinder and oriented obliquely away from the gas inlet with respect to the radial direction of the reference central axis.

17. A diffuser for a gas generator according to claim 10 or 11, wherein the cylinder is configured to be contracted, wherein the cylinder has a converging portion of a minimum size, the first row of gas discharge holes being provided in a first tapered surface expanding from the converging portion toward the gas inlet, and the second row of gas discharge holes being provided in a second tapered surface expanding from the converging portion in a direction away from the gas inlet.

18. A diffuser for a gas generator according to any one of claims 1 to 6, characterized in that said at least one gas discharge hole is provided with a respective gas guide (4) configured on said side wall such that gas can be discharged from the respective gas discharge hole in a predetermined direction via the respective gas guide.

19. The diffuser of claim 18 wherein the gas guide is formed from a material punched out of the side wall and the at least one vent hole is formed by punching out the gas guide from the side wall.

20. The diffuser of claim 19, wherein the gas guide is configured as a tab punched from the side wall and extending into the cavity of the cylinder at a free end thereof, and the at least one vent hole is formed by punching the tab from the side wall, the tab extending into the cylinder at the free end thereof.

21. The diffuser of claim 20, wherein the plurality of gas discharge holes form a row of gas discharge holes and are respectively provided with tongues, the row of gas discharge holes being distributed in a circumferential direction with reference to a central axis of the cylinder, each tongue having an alternating direction, or being directed in a direction toward the gas inlet, or being directed away from the gas inlet.

22. The diffuser of claim 19 wherein the at least one vent hole is tetrahedral in shape, wherein the at least one vent hole has a triangular profile on an outer surface of the side wall, the gas guide is connected to two sides of the triangular profile, extends along the two sides, extends from the side wall toward the interior of the barrel, and has a free edge opposite the other side of the triangular profile, the free edge and the other side surrounding an entry opening of the corresponding vent hole.

23. A diffuser for a gas generator according to claim 10 or 11, wherein the two rows of gas discharge holes are tetrahedrally shaped, respectively, wherein the two rows of gas discharge holes each have a triangular profile on the outer surface of the side wall, the gas guide portion being connected to two sides of the triangular profile, extending along the two sides, from the side wall towards the inside of the cylinder, and having a free edge opposite the other side of the triangular profile, the free edge and the other side enclosing the inlet opening of the respective gas discharge hole.

24. The diffuser of claim 23 wherein the same row of vents has the same orientation and the two rows of vents have different orientations from each other.

25. The diffuser of claim 24 wherein the first row of vents has an upright triangular profile and the second row of vents has an inverted triangular profile with reference to the central axis, the other side of each of the triangular profiles being the bottom side.

26. The diffuser of any one of claims 1 to 6, wherein the total area of the plurality of gas discharge holes is at least 1.2 times the area of the gas inlet.

27. A gas generator, characterized in that it comprises a diffuser according to any one of claims 1 to 26 for a gas generator.

28. An airbag comprising an airbag and a gas generator connected in a flow-guiding manner to the airbag, characterized in that the gas generator is a gas generator according to claim 27.

29. The airbag of claim 28 wherein the airbag is devoid of a gas-conducting bag; or the airbag has a gas-conducting pouch and the gas-conducting pouch has no coating.

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