Arrangement for igniting gas generators in multiple stages

p0001<b>The invention relates to</b> an arrangement for multi-stage ignition of gas generators according to the preamble of claim 1, 6 or 7th

p0002There are known restraint systems for vehicle occupants having an airbag (airbag) are fitted, which is inflated by one, from a generated in the gas generator. Here, basically two types of gas generators are known which use combustible solid gas-generating propellant for inflating the airbag.

p0003So once gas generators are known, their combustion and filter chamber are arranged in a ring around a ignition. At the center of such a circular inflator is the cylindrical ignition chamber. There, a lighter is mounted, which is activated from the outside by an electrical pulse, and so is the initial spark in transition. The ignition chamber is connected through wall openings with the toroidal combustion chamber in which the flammable gas-generating solid fuel is. Here the actual gas is produced. The gas passes through the connecting channels in a filter chamber, the toroidal combustion chamber encloses. In the filter chamber the gas is cooled and cleaned of impurities. Via the outlet openings on the outer wall of the gas leaving the gas generator and is supplied to the consumer.

p0004On the other hand, gas generators with a cylindrical configuration is known in which an elongated cylinder represents the combustion chamber and a combustion chamber cylinder enclosing this cylinder has the exhaust ports. Inside a pipe such gas generators is the cylindrical ignition chamber. There, a lighter is mounted, which is activated from the outside by an electrical pulse, and so is the initial spark in transition. The ignition chamber is connected through wall openings to the tubular combustion chamber in which the flammable gas-generating solid fuel is. Here the actual gas is produced. The gas passes through the connecting channels in a filter chamber which encloses the tubular combustion chamber. In the filter chamber the gas is cooled and cleaned of impurities. Via the outlet ports in the outer wall of the gas leaving the gas generator and is supplied to the consumer. Also known from EP 0382552 A2 a tubular gas generator is known the two combustion chambers, each with an ignition unit includes. The cylinder-shaped one-piece outer wall at the outflow openings are located, inside has a circular diaphragm, which separates the outer cylinder in the interior into two chambers. In each of these chambers, a cylindrical filter unit is in turn is the cylindrical combustion chamber with the fuel. Inside the combustion chamber, the cylindrical ignition chamber with the igniter. The two open ends of the cylindrical, two-chamber, single-piece outer wall are closed on each side with a lid. On the covers an igniter depending mounted such that it protrudes into the ignition chamber.

p0005<b>A disadvantage of these arrangements</b> however, is that it is not possible during the inflation of the airbag, the amount of influencing the pressure and speed and to adapt to the respective requirements, if only one unit of fuel and an igniter is present. However, a disadvantage of the solution from EP 0382552 A2 that the production of cylindrical, two-chamber, single-piece outer wall is very expensive and can only be implemented for pipe inflators. Also in this process only a maximum of two combustion chambers can be formed, their size can not be changed without increased manufacturing expense.

p0006<b>The invention is therefore based on the object</b> to provide an arrangement for a gas generator of the aforementioned type, which allows the gas generation and thus the Aufblasparameter according to the requirements, flexible, cost-effective and to control with the lowest production costs.

p0007<b>This object is achieved by the characterizing features of claim 1, 6 or. 7</b> Hereinafter, in a pyrotechnic gas generator at least two independent fuel units, each with its own ignition device each in a closed, insertable container, or in a respective combustion chamber area or in each case one separate combustion chambers each of which an independent outside wall having the discharge openings, arranged.

p0008Advantageous developments of the invention result from the dependent claims. Here, the container upon activation of gas generating reaction from the inside to open. These containers may have a sector-shaped cross-section. When inserting all pie-shaped container into the combustion chamber fill the circular combustion chamber from all over. The Anzündeeinheiten and thus the respective fuel can individually be triggered offset together or at different times.

p0009<b>consist The advantages achieved with the invention</b> in particular, that can be realized a wide range of possible gas generations with the specified portioning the fuel and the variable timing ignition spacing. Thus, the amount of gas, the inflation and the pressure in both the airbag and the inflator can be controlled. This parameter can now be set to the respective requirements. It is also possible that a non-ignited fuel / ignition unit forming a closed module in an independent, insertable container can be reused without any effort. Also, by several independent gas-generating reactions to safety are at a malfunction for example, increases in non-triggering, since then a different gas-producing reaction can be activated. The constructions of the invention are cost effective, flexible in multiple stages and production technology easy to implement.

p0010The <b>embodiments</b> the invention and its advantageous developments are set out below with reference to several drawings.<dl id="dl0001" compact="compact"><dt><b>Figure 1:</b></dt><dd>Inventive pyrotechnic inflator round with einlegbarem container</dd><dt><b>Figure 2:</b></dt><dd>Section through the combustion chamber of a pyrotechnic inflator round inventive with pie-shaped, insertable containers</dd><dt><b>Figure 3:</b></dt><dd>Inventive pyrotechnic inflator round with several combustion chamber areas</dd><dt><b>Figure 4:</b></dt><dd>Section through the combustion chamber, forming by radial partitions multiple independent combustion chamber areas</dd><dt><b>Figure 5:</b></dt><dd>Inventive pyrotechnic tubular gas generator having multiple combustion chambers, which has its own independent body with the discharge openings per combustion chamber.</dd></dl>

p0011<b>figure 1</b> shows a pyrotechnic inflator round inventive with einlegbarem container <b>19</b>, In this illustration is one of several Anzünd- / fuel unit<b>8th</b> shown that in the one-piece combustor <b>25</b> is. combustor<b>25</b> is of the combustion chamber wall <b>14</b> bounded laterally. The Anzünd- / fuel unit<b>8th</b> includes an ignition unit consisting of a lighter <b>16</b> and an igniter <b>18</b> and the actual gas-generating fuel <b>1</b>, encases these Anzünd- / fuel unit<b>8th</b> from a reservoir <b>19</b>, The wall material and wall thickness, is designed such that the wall on the one hand by an explosion inside the container <b>19</b> but is destroyed on the other hand from the outside of an explosion withstand in an adjacent fuel / ignition. That is, the one opening of the container<b>19</b> only occurs when an electrical pulse the ignition <b>3</b> the gas-generating reaction of the fuel <b>1</b> has set in motion. The container has a sector-shaped cross-section (see Figure 2) and is inserted during assembly into the combustion chamber, and then fixed as required. The container with its Anzünd- / fuel unit is independent of adjacent containers, that is, the contents of which can be ignited individually without adjacent container influence. After the container opening<b>19</b> the gas escapes through a prefilter <b>13</b>Which also in the combustion chamber <b>25</b>But not in the container, is, through the combustion chamber openings <b>7</b>That in the combustion chamber wall <b>14</b> are, in the filter chamber. Throughout the filter chamber, the hot and polluted gas is first through a coarse filter<b>10</b> and then through a fine filter <b>11</b> purified and cooled. Thereafter, it leaves the gas generator to the discharge openings <b>12</b>Which at the filter chamber wall <b>15</b> . are

p0012<b>figure 2</b> shows a section through the combustion chamber of a pyrotechnic inflator round inventive with pie-shaped, insertable containers. In this sectional view can look at the entire combustion chamber<b>25</b> be granted. Here are two Anzünd- / fuel units smaller<b>8th</b> and a greater <b>9</b>, combustor <b>25</b> is through the combustion chamber wall <b>14</b> bounded laterally. Each of these Anzünd- / fuel unit<b>8th</b> and <b>9</b> has its own Anzündeeinheit <b>3</b> and <b>4</b>Which can be triggered independently. In the illustrated application, the containers<b>19</b> and <b>20</b> vary in size and the amount of fuel <b>1</b> or. <b>2</b> differently. Each of these Anzünd- / fuel unit is housed in a container<b>19</b> or. <b>20</b>, These containers have a sector-shaped section and together again a circle like the pieces of a cake. Therefore, it is also possible any number of containers in the combustion chamber<b>25</b> to arrange long as they all back together have a circular section. If one of the container is opened by an ignition in its interior, so passes the gas when no baffles align the gas stream in the entire pre-filter<b>13</b> and it can all combustion chamber openings along the entire combustion chamber wall <b>14</b> be used, as well as the entire filter chamber. If the Anzünd- / fuel units in the containers can be ignited independently, this means that depending on the requirements of the gas bag only slightly, so only with the gas from the small Anzünd- / fuel unit <b>8th</b>, Medium, ie only with the gas from the large Anzünd- / fuel unit <b>9</b> or heavy, so the gas from both Anzünd- / fuel units <b>8th</b> and <b>9</b> simultaneously, is inflated. With this arrangement, it would be possible to be interpreted in accordance with the pressure in the airbag requirements. In the application example shown the gas generator would be three stages. If one were to fill the combustion chamber with more independent Anzünd- / fuel units, the gas generator could be operated with any number of levels. Also, by a time-delayed release of the two Anzünd- / fuel units accelerates Aufblasdauer the airbag or delayed.

p0013<b>figure 3</b> shows a pyrotechnic inflator round inventive multi-chamber areas. In this illustration, a portion of the one-piece combustor is shown which is divided into a plurality of combustion chamber areas. The subdivision into several areas combustor is described in FIG. 4 A combustor section<b>5</b> includes an ignition unit <b>3</b> consisting of a lighter <b>16</b> and an igniter <b>18</b> and the actual gas-generating fuel <b>1</b>, Here is the pre-filter<b>13</b>, Enclosed wild the combustor section of the common circular combustion chamber wall <b>14</b> and radial partitions <b>21</b> (Shown in Figure 4). The wall material and the wall thickness is designed so that they are not destroyed due to an explosion inside the combustion chamber area and the combustion chamber openings<b>7</b> be opened. By contrast, the combustion chamber openings remain, in an explosion from the outside in an adjacent combustion chamber area, closed (see Figure 4). That is, the gas-generating fuel<b>1</b> in the furnace area will only be ignited when the associated ignition <b>3</b> an electrical pulse the gas-generating reaction of the fuel <b>1</b> triggers. But then open the combustion chamber openings<b>7</b> the combustion chamber area and the gas escapes through a prefilter <b>13</b>, Which is also located in the combustion chamber area, in the filter chamber. In the filter chamber, the hot and polluted gas is first through a coarse filter <b>10</b> and then through a fine filter <b>11</b> purified and cooled. Thereafter, it leaves the gas generator to the discharge openings<b>12</b>Which at the filter chamber wall <b>15</b> . are

p0014<b>figure 4</b> shows a section through the combustion chamber, which is formed by radial partition walls several independent combustion chamber regions. In this sectional view can look at the entire combustion chamber <b>25</b> be granted. Here are two separated combustion chamber areas, a smaller<b>5</b> and a larger <b>6</b>, The entire combustion chamber through the combustion chamber wall<b>14</b> delimited towards the filter chamber. The different sized combustion spaces by radial walls<b>21</b> separated from each other. These partitions<b>21</b> either individually eg be inserted into a groove in the center and in the combustion chamber wall or they are already V-shaped or star-shaped arrangement and are in the combustion chamber <b>25</b> inserted in brackets. The partitions<b>21</b> are designed such that, when the gas generating reaction in a combustion chamber region of the fuel in the combustion chamber adjacent area can not be triggered. The combustion chamber areas<b>5</b> and <b>6</b> are independently of each other. The gas leaves the combustion chamber via openings <b>7</b> to the combustion chamber wall <b>14</b> the combustor section <b>5</b> or. <b>6</b> and is across the filter chamber <b>24</b>, If no baffles are attached, purified and cooled in the illustrated application, the combustion spaces of different sizes. Also, the amount of fuel<b>1</b> or. <b>2</b> differently. As a result, that is only slightly, so inflated with the gas from the small combustion chamber area, medium, ie only with the gas from the large combustion area or heavy, so with the gas from the two combustion chamber areas simultaneously depending on the requirements of the gas bag. With this arrangement, it would be possible to be interpreted in accordance with the pressure in the airbag requirements. In the application example shown the gas generator would be three stages. If one were to the combustion chamber with yet another radial partitions<b>21</b> divide, so the gas generator could be operated with any number of levels. Also, by a time-delayed release of the two Anzünd- / fuel units accelerates Aufblasdauer the airbag or delayed.

p0015<b>figure 5</b> shows a pyrotechnic tubular gas generator according to the invention having multiple combustion chambers, having its own independent body with the outflow openings per combustion chamber. This tubular gas generator forms two independent combustion chambers <b>22</b> and <b>23</b> out. In the two combustion chambers<b>22</b> and <b>23</b> There are different amounts of gas generating fuel <b>1</b> and <b>2</b>, Also extending into each combustion chamber a Anzündeeinheit<b>3</b> and <b>4</b>Whose lighter can be triggered independently. In the combustion chamber still is a prefilter<b>13</b>, Each combustion chamber has its own combustion chamber wall in which the combustion chamber openings<b>7</b> . are Each of the cylindrical combustion chamber is provided with its own filter chamber<b>24</b> surrounded, in which there are the filters. Each filter chamber is outwardly with its own outer wall, the filter wall having the discharge openings<b>12</b>Enclosed. With such a structure is to be connected to each other in principle two independent tubular gas generators<b>26</b>, Furthermore, the combustion chambers are<b>22</b> and <b>23</b> constructed such that can not be ignited by the energy released in the initiation of a fuel in the other combustion chamber. Ignition of the fuel is only possible by the igniter in the respective combustion chamber. After the ignition of the gas generating propellant <b>1</b> and or <b>2</b> the gas escapes through a prefilter <b>13</b> through the combustion chamber openings <b>7</b> is in the filtering chamber in which it is cleaned and cooled. After it leaves through the exhaust ports<b>12</b> the gas generator and enters the consumer z. B. an airbag.

p0016Also in this application example, there is a three-stage gas generator. Upon ignition of the propellant<b>1</b> in the small combustion chamber <b>22</b> is only slightly inflated an airbag. Upon ignition of the propellant<b>2</b> in the large combustion chamber <b>23</b> inflates an airbag mediocre. In the ignition of the entire propellant<b>1</b> and <b>2</b> in the small and large combustion chamber <b>22</b> and <b>23</b> the airbag is overinflated. In this structure, it is possible even more combustion chambers with an ignition unit and a unit of fuel in the generator integrated. Also, by a time-delayed release of the two Anzünd- / fuel units accelerates Aufblasdauer the airbag or delayed.