JP4919980B2 - End face combustion type gas generator - Google Patents

Description

  The present invention relates to an end face combustion type gas generator used for, for example, a side thruster of a flying object including a solid rocket motor and a spacecraft.

  The end face combustion type gas generator is configured such that, for example, a cylindrical combustor is filled with a gas generating agent so that the shape of the gas generating agent is a columnar shape, and this gas generating agent is end face burned to advance combustion in the axial direction. The combustion gas generated by the combustion is introduced from a combustor into a functional part such as a nozzle. As such an end face combustion type gas generator, a rocket motor or the like loaded with a solid propellant as a gas generating agent is generally known.

  However, in the above end face combustion type gas generator, when the gas generating agent has a cylindrical shape, the value obtained by dividing the axial length by the combustion speed is the combustion time, and the gas generating agent is proportional to the combustion time. The length in the axial direction increases. For this reason, there is a problem that the shape of the gas generating agent is naturally determined with respect to the required combustion time and the supply amount of the combustion gas, and the degree of freedom in design is limited. In addition, for example, it is difficult to extend the combustion time and increase the efficiency of filling the gas generating agent under the design condition that the cylinder diameter of the combustor can be increased but the total length cannot be increased.

  In order to solve these problems, the applicant of the present invention previously created and applied for the reciprocating end face combustion type gas generator of Patent Document 1.

  As shown in FIG. 9, the “reciprocating end face combustion type gas generator” of Patent Document 1 fills a plurality of layers of gas generant 50 into a combustor 54 via a restrictor 59, and end face combustion is sequentially performed in each layer. The reciprocating end face combustion type gas generator A1 in which the gas generating agent 50 of each layer is continuously arranged in a progressing state is realized, and the combustion time is greatly extended without increasing the overall length of the combustor 54, and the degree of freedom of design is greatly increased. It is to improve.

Japanese Patent Application Laid-Open No. 2002-204947, “Reciprocating End Face Combustion Gas Generator”

  In the reciprocating end face combustion type gas generator described above, the end face combustion type gas generating agent 50 whose side face is restricted by the restrictor 59 is filled into the combustor 54 in an annular state in a state bent from the inside to the outside. It is. Thereby, the gas generating agent 50 is formed in two layers in the cross section shown in the figure, and has an exposed end face 51 on one end side of the combustor 4 on the right side of the figure, and the inner layer and the outer layer are continuously formed on the other end side. Yes.

However, in the gas generating device of Patent Document 1, the combustion at the outer periphery is slower than the inner periphery at the folded portion, and the combustion area is different before and after the folding. Therefore, if it is going to implement | achieve the same combustion area with the shape of a propellant, it will have to be a complicated shape.
That is, the restrictor 59 of this gas generator has a shape that is three-dimensionally bent from the inside to the outside, and the shape of the propellant is complicated, so that the filling rate of the gas generating agent is low and the filling process is complicated. There was a problem of requiring.

  The present invention has been developed to solve the above-described problems. That is, the object of the present invention is to greatly extend the combustion time without increasing the total length, and to generate a stable gas amount with little variation in the combustion area over the entire combustion time. An object of the present invention is to provide an end face combustion type gas generator that has a high filling rate of propellant and is easy to fill.

According to the present invention, a hollow cylindrical combustor;
A propellant that is concentrically filled in the combustor and is packed densely without having a large space in the internal cross section, and the cross-sectional area of each layer is equal;
A partition wall that separates the plurality of layers from each other and is connected only by a folded portion at an axial end,
The folded portion includes an end skin that continuously surrounds the end portions of the inner and outer propellants, and a fuel speed increasing member that is provided along the inner surface of the end shell and increases the combustion speed of the propellant. Become
The propellant is subjected to end face combustion sequentially from the outermost layer through a turn-up portion, and an end face combustion type gas generator is provided.

According to a preferred embodiment of the present invention, the shape of the end skin is configured such that the variation of the combustion area at the turned-up portion is within a range of +/− 10% or less .

  The fuel speed increasing member is preferably a wire, foil, or net member made of a metal having high thermal conductivity and a high melting point.

  The inner surface of the end skin has an insulation with low thermal conductivity and high heat resistance, and the fuel speed increasing member is provided directly or floating on the inner surface of the insulation, and the inner surface is filled with propellant. ing.

  Alternatively, an insulation having low thermal conductivity and high heat resistance is provided on the inner surface of the end outer plate, and a thin gas generating film made of a propellant containing a fuel speed increasing member is attached to the inner surface of the insulation. The inner surface is filled with propellant.

  The fuel speed increasing member is preferably a high fuel speed propellant having a higher combustion speed than the propellant.

  An insulation having low thermal conductivity and high heat resistance is provided on the inner surface or outer surface of the partition wall, and a heat resistant and flexible relief boot is provided on the surface of the insulation other than the folded portion.

  The combustor has a nozzle that discharges gas generated by combustion of the propellant at one or both ends in the axial direction, and the nozzle communicates with an end face of the outermost layer or the innermost layer propellant.

  It is preferable that the combustor is configured to be detachable at one end or both ends in the axial direction so that the propellant can be directly filled therein.

  According to the configuration of the present invention, the propellant is concentrically filled in the hollow cylindrical combustor and the layers are densely packed without having a large space in the inner cross section, and the partition walls separate the layers of the propellant from each other. And since it connects only by the folding | returning part of an axial direction edge part, an end surface combustion can be carried out sequentially from an outermost layer via a folding | returning part, and combustion time can be extended significantly, without increasing full length.

  Moreover, since the cross-sectional area of each layer of the propellant is equal, there is little variation in the combustion area in each layer.

  Also, according to a preferred embodiment of the present invention, the folded portion is provided along the end skin that continuously surrounds the ends of the inner and outer propellants, and along the inner surface of the end shell. And the shape of the end skin is configured so that the combustion area at the folded portion is substantially constant. A stable amount of gas can be generated over time.

  Further, by providing a fuel speed increasing member for increasing the combustion speed at the outer peripheral portion, it is possible to easily achieve the same combustion area at the outer periphery from the inner periphery in the folded portion in the shape of the propellant.

  Furthermore, according to a preferred embodiment of the present invention, the propellant is filled in the hollow cylindrical combustor concentrically and in a plurality of layers without gaps, so the filling rate of the gas generating agent (propellant) is high.

  In addition, the inner and outer surfaces of the partition wall have insulation and relief boots, and the combustor is configured so that one end or both ends in the axial direction are detachable. is there.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is an overall configuration diagram of an end face combustion type gas generator of the present invention.
In this figure, the end face combustion type gas generator 10 of the present invention includes a combustor 12, a propellant 14, a partition wall 16, and an igniter 18.

The combustor 12 is a hollow cylindrical airtight container made of metal or FRP with an insulation such as rubber attached to the inner surface. Further, in this example, the combustor 12 has a nozzle 12a that discharges gas generated by combustion of the propellant 14 at one end in the axial direction (left end in the drawing). The nozzles 12a may be provided at both ends in the axial direction or at other locations.
In this example, the nozzle 12 a communicates with the exposed end surface 14 a of the outermost layer propellant 14 through a cavity inside the combustor 12. In this case, the end face 14b of the innermost layer propellant 14 is closed by a closing plate 19 made of FRP or a metal or an insulation such as rubber or the like applied to the surface.

  Further, the combustor 12 has a connecting portion 12b (for example, a flange) at one end in the axial direction of the trunk portion, and is configured so that one end in the axial direction is detachable so that the propellant can be directly filled therein. In addition, you may provide the connection part 12b in the both ends of a trunk | drum.

The propellant 14 is concentrically filled in the combustor 12 into a plurality of layers, and the cross-sectional area of each layer is set equal. In this example, the propellant 14 is composed of a double layer of an inner layer and an outer layer. In addition, this invention is not limited to a double layer, The multilayer of 3 layers or more may be sufficient.
In addition, the thin broken line shown in the propellant 14 of FIG. 1 has shown typically the combustion surface for every unit combustion distance (2.5 cm) of end surface combustion.

The propellant 14 is not particularly limited, but when used in a spacecraft, a gas generating agent having self-combustibility is preferable, and a solid propellant used for a rocket motor can be used.
The igniter 18 (igniter) is provided in the combustor 12 so as to face the exposed end surface 14a of the propellant 14, and can ignite the exposed end surface 14a to start end surface combustion.

The partition wall 16 is made of, for example, FRP, and separates the plural layers of the propellant 14 from each other and is connected only by the folded portion 17 at the axial end portion. Further, in this example, the partition wall 16 and the closing plate 19 are fixed with a plurality of arms 15 spaced from the inner wall of the combustor 12.
A part of metal or FRP constituting the combustor 12 may be used as a part of the partition wall 16. Hereinafter, this case is referred to as a partition wall 16.

  By the ignition by the igniter 18 described above, the propellant 14 is subjected to end face combustion sequentially from the outermost layer or the innermost layer via the turn-back portion 17.

In FIG. 1, the folded portion 17 includes an end outer plate 16 a and a fuel speed increasing member 20 (shown by a thick broken line).
The end skin 16a continuously surrounds the end portions of the inner and outer propellants 14. The shape of the end outer plate 16a is configured such that the combustion area in the folded portion 17 is substantially constant.
The shape of the end outer plate 16a will be described in detail in an embodiment described later.

The fuel speed increasing member 20 is provided along the inner surface of the end outer plate 16 a and has a function of increasing the combustion speed of the propellant 14.
In this example, the fuel speed increasing member 20 is a wire, foil, or net member made of a metal having high thermal conductivity and a high melting point. As such a metal, silver, copper, tungsten, or the like can be used. It is known that silver wire, silver foil, and silver net have a function of increasing the burning rate of the propellant 14 in contact therewith by about 5 times.

FIG. 2 is a relationship diagram between the combustion distance and the combustion area of FIG. In this figure, the horizontal axis represents the combustion distance [cm], and the vertical axis represents the combustion area [cm ² ].
In this example, the propellant 14 is composed of a double layer of an inner layer and an outer layer, and each has a cross-sectional area of about 1000 cm ² . The length of the propellant 14 is 50 cm from the exposed end surface 14 a to the entrance of the folded portion 17, the inner layer is 51 cm from the end surface 14 b to the exit of the folded portion 17, and the implemented length of the folded portion 17 is 8 cm.
From this figure, it can be seen that the combustion area fluctuates in the range of +/− 10% or less at the position of the turn-back portion 17, but the combustion area is substantially constant before and after that.

FIG. 3 is a diagram for explaining the principle of the present invention.
FIG. 3A shows a case where the fuel speed increasing member 20 (in this case, a silver wire) is located at the center of the propellant 14. Moreover, the thin broken line shown in the figure schematically shows the combustion surface for each unit combustion distance of end surface combustion.
Since the fuel speed increasing member 20 is made of a metal having a high thermal conductivity and a high melting point, the propellant 14 in contact with the fuel speed increasing member 20 is heated early by heat transfer from the fuel speed increasing member 20. Therefore, the burning rate of the propellant 14 in contact with this can be increased.
As described above, the silver wire, the silver foil, and the silver net have a function of increasing the burning rate of the propellant 14 in contact therewith by about 5 times. Hereinafter, the increase rate of the combustion speed is referred to as “fuel speed magnification”.
In this example, since the combustion of the part which contacts the fuel speed increase member 20 (silver wire) is accelerated, the combustion surface has a mountain shape in the combustion direction along the silver wire.

FIG. 3B shows a case where the fuel speed increasing member 20 (in this case, a silver film) is located on the outer surface of the propellant 14.
In this example, the combustion surface is V-shaped in the combustion direction because the portion in contact with the fuel speed increasing member 20 (silver film) burns faster.

FIG. 3C is a view when the combustion increasing member is located only in the upper half and not in the lower half, and FIG. 3D is a combustor in which the right side portion of FIG. 3C is bent downward. It is the figure applied to the end surface shape.
From FIGS. 3C and 3D, it is possible to predict the change of the combustion surface in the folded portion 17 of FIG.
However, if the shape of FIGS. 3C and 3D is used as it is, the combustion area of end face combustion rises abnormally in the folded-back portion 17, and it is necessary to adjust the propellant outer diameter to suppress this.
The shape of the end outer plate 16a for this adjustment will be described later.

  FIG. 4 is a diagram showing a first embodiment of the folded portion of the present invention.

  In this figure, (A) is a figure which shows the change of the combustion surface in the folding | returning part 17, (B) is a figure which shows the change of the combustion area in the folding | turning part 17. FIG.

FIG. 4 shows a case where the end outer plate 16a of the folded portion 17 is inclined in two steps at an angle of 30 ° and 60 ° with respect to the axis, and the axial length of the folded portion 17 is 10 cm.
The fuel speed increasing member 20 is provided along the inner surface of the end skin 16a and the inner wall of the partition wall 16 that is continuous with the end skin 16a.
The thin broken line shown in FIG. 4A schematically shows the combustion surface for each unit combustion distance (0.5 cm) of end surface combustion. In addition, the circles indicated by the numbers 0 to 11 in the figure indicate the front end of the combustion surface that burns at the fuel speed multiplication factor 5 by the fuel speed increasing member 20.
From FIG. 4 (B), it can be seen that in this example, the combustion area in the folded portion 17 reaches a maximum of about 1500 cm ² .

FIG. 5 shows a case where the end portion outer plate 16a of the folded portion 17 is inclined at an angle of 50 ° with respect to the axis, and the axial length of the folded portion 17 is 8 cm.
Other configurations are the same as those in FIG.
From FIG. 5 (B), it can be seen that in this example, the variation of the combustion area in the folded portion 17 falls within the range of about 1000 cm ² +/− 10%.
1 described above corresponds to the case of FIG.

When the combustion magnification is 5 times from the above-described embodiment, as shown in FIG. 5, the angle formed by the end outer plate 16a of the folded portion 17 with respect to the axis is most preferably 50 °, and the axial length of the folded portion 17 Is most preferably 6.4 cm to 8 cm.
Further, in this case, it can be seen that the combustion area in the folded portion 17 can be in a range of about 1000 cm ² +/− 10%.
In addition, this invention is not limited to these structures, It is good to determine the shape of the edge part outer plate | plate 16a so that the combustion area in the folding | turning part 17 may become substantially constant.

FIG. 6 is a diagram showing a specific example of the present invention. This figure has shown the cross section of the parallel wall surface and end part wall surface (right side) of a combustor. Hereinafter, the means for attaching the fuel speed increasing member will be described with reference to FIG.
The reason for increasing the combustion rate (fuel rate) of the propellant along the fuel speed increasing member (for example, silver wire) is that the heat of the combustion flame is quickly transmitted to the propellant through the metal. Therefore, if the adhesive layer is not interposed between the silver wire and the propellant, the fuel speed magnification is large and the quality is stable.

6A, the inner surface of the end outer plate 16a has an insulation 21 with low thermal conductivity and high heat resistance, and a fuel speed increasing member 20 (silver wire or net) is formed on the inner surface of the insulation 21. The propellant 14 is filled on the inner surface directly.
In the case of a silver film, it can be firmly adhered to the insulation 21 with an adhesive, but it is difficult to adhere to the propellant 14 without an adhesive with high strength.
However, in the case of silver wires or silver nets, if they are placed on the insulation 21 and the adhesive on the insulation surface is hard and does not cover the lines or nets, by pouring the propellant 14, Adhesion between the insulation 21 and the propellant 14 can be reliably performed. In addition, partial fixation of a silver wire or a silver net is necessary.

In FIG. 6 (B), the fuel speed increasing member 20 (silver wire or net) floats on the inner surface of the insulation 21 and is filled with the propellant 14 inside.
Thus, when the adhesive on the insulation surface is a viscous liquid, the propellant 14 can be poured after the silver net is lifted from the insulation 21 and stretched.

In FIG. 6C, a thin gas generating film 22 made of a propellant containing the fuel speed increasing member 20 is attached to the inner surface of the insulation 21, and the inner surface is filled with the propellant 14.
That is, in this example, a thin propellant containing a silver wire or a silver film is manufactured in advance as the gas generating film 22, which is attached to the insulation 21 of the fuel speed increasing portion, and then the propellant 14 is poured.

In FIG. 6 (D), the fuel speed increasing member is a high fuel speed propellant 23 having a combustion speed higher than that of the propellant 14, and the high fuel speed propellant 23 is directly attached to the inner surface of the insulation 21. The propellant 14 is filled on the inner surface.
That is, the high fuel speed propellant 23 is attached to the insulation 21 of the fuel speed increasing portion, and then the propellant is poured. This high fuel speed propellant is only required to have good adhesion and high fuel speed, and the propulsion performance is not limited.

FIG. 7 is a view showing a specific example of the combustor of the present invention.
In the example of FIG. 1, the partition wall 16 and the closing plate 19 are fixed with a plurality of arms 15 spaced apart from the inner wall of the combustor 12, but as shown in FIG. 16 and the closing plate 19 may be fixed to the combustor 12, and the generated gas may be taken out from both sides of the central pipe 24.
In this embodiment, since the inner propellant is supported by the central pipe 24, an arm as shown in FIG. 1 is not necessary, and only a flexible material such as rubber can be used as the material of the partition wall.

7B, the inner surface or the outer surface of the partition wall 16 has an insulation 21 with low thermal conductivity and high heat resistance, and the surface of the insulation 21 is heat resistant and flexible except for the folded portion. A sex relief boot 25 is provided.
That is, in addition to the usual form in which the relief boot is attached to the inside of the combustor 12, the insulation 21 + relief boot 25 is attached to the inner and outer periphery of the partition wall 16 (for example, a hard core material such as CFRP) to prevent the propellant from cracking. It is good.

In FIG. 7C, the combustor 12 is configured such that one end (or both ends) in the axial direction is detachable so that the propellant 14 can be directly filled therein.
With this configuration, one end in the axial direction is removed and the propellant 14 is poured, and finally a closing plate can be applied to the end of the inner propellant.

FIG. 8 shows an embodiment of a method for fixing the partition wall when the outer propellant is folded back to the inner propellant. In this figure, (A) is a longitudinal sectional view similar to FIG. 7 (A), and (B) is a view taken along arrow BB in FIG. 8 (A).
In this example, the end face of the inner propellant block is fixed to the motor case as shown. The nozzle 12a is disposed around the motor. When this motor is used as a gas generator, the number of nozzles 12a may be one. However, when a propulsion device is used, a plurality of (four in this example) nozzles are provided if necessary.

The above-described end face combustion type gas generator of the present invention has the following characteristics.
(1) The propellant 14 is a gas generator (motor) with a high packing density that does not have an inner hole, and the propellant is divided into an outer layer and an inner layer in the example of FIG.
(2) As for the combustion mode, in the example of FIG. 1, the outer layer propellant is first burned by the end face combustion method, and when the combustion surface reaches the outer layer end, the combustion surface is automatically turned back to the inner layer propellant. Is burned from the end face.
(3) A silver film (or silver net) is stuck on the outer periphery of the outer layer propellant on the folded portion 17 of the combustion surface, and the burning rate of the propellant is higher than the base burning rate (for example, about The combustion surface is folded using the property of (5 times).
(4) In the example of FIG. 5, the variation of the combustion area at the turn-back point can be +/− 10% or less, and the pressure before and after the turn-back (combustion area) is configured to be substantially constant.
(5) Instead of silver, other high heat conductivity and high melting point metals such as copper and tungsten may be used.
Further, the same effect can be obtained by using a metal net instead of the metal film.
The net has the merit that it can be easily attached to a curved shape propellant or insulation surface.
Further, instead of the metal film, it is possible to use a propellant that has a high combustion speed even if the performance is low.
A multi-stage folding motor having a plurality of folding points can also be designed.
(6) The gas generator (motor) of the present invention can be manufactured by direct filling with the boundary between the outer layer propellant and the inner layer propellant as a relief boot.

  As described above, according to the configuration of the present invention, the propellant 14 is densely filled in the hollow cylindrical combustor 12 concentrically and in a plurality of layers without having a large space in the inner cross section, and the partition 16 is propelled. Since the multiple layers of the medicine are separated from each other and connected only by the folded portion 17 at the axial end, the propellant can be sequentially end-burned from the outermost layer through the folded portion, and the combustion time can be increased without increasing the overall length. Can be extended significantly.

  Moreover, since the cross-sectional area of each layer of the propellant 14 is equal, the fluctuation of the combustion area in each layer is small.

  Further, according to a preferred embodiment of the present invention, the folded portion 17 is provided along the end skin 16a that continuously surrounds the ends of the inner and outer propellants, and along the inner surface of the end shell. It is composed of a fuel speed increasing member 20 that increases the combustion speed of the medicine, and the shape of the end skin is such that the combustion area in the folded portion is substantially constant, so that the variation in the combustion area in the folded portion is also small. A stable gas amount can be generated over the entire combustion time.

  Further, by providing a fuel speed increasing member for increasing the combustion speed in the outer peripheral portion, it is possible to easily achieve the same combustion area in the folded portion from the outer layer to the inner layer in the shape of the propellant.

  Furthermore, according to a preferred embodiment of the present invention, the propellant 14 is filled in the hollow cylindrical combustor 12 concentrically and in a plurality of layers without gaps, so the filling rate of the gas generating agent (propellant) is high. .

  Further, since the insulation 21 and the relief boot 25 are provided on the inner surface or the outer surface of the partition wall 16 and the combustor 12 is configured to be detachable at one end or both ends in the axial direction, the propellant can be directly filled therein. Easy to fill.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be variously modified without departing from the gist of the present invention.

It is a whole block diagram of the end face combustion type gas generator of the present invention. FIG. 2 is a relationship diagram between a combustion distance and a combustion area in FIG. 1. It is a principle explanatory view of the present invention. It is a figure which shows 1st Embodiment of the folding | turning part of this invention. It is a figure which shows 2nd Embodiment of the folding | turning part of this invention. It is a figure which shows the specific example of the partition part of this invention. It is a figure which shows the specific example of the combustor of this invention. It is an Example of the fixing method of a partition in the case of turning back from an outer propellant to an inner propellant. It is a block diagram of the gas generator of patent document 1. FIG.

Explanation of symbols

10 end face combustion type gas generator,
12 combustor, 12a nozzle, 12b connecting part,
Propellant 14, exposed end face 14a, end face 14b,
15 arm, 16 partition, 16a end skin,
17 Folding part, 18 igniter (igniter), 19 closing plate,
20 Fuel speed increasing member (wire, foil, mesh member, high fuel speed propellant),
21 insulation, 22 gas generating membrane,
23 high fuel propellant, 24 center pipe, 25 relief boots

Claims (9)

A hollow cylindrical combustor;
A propellant that is concentrically filled in the combustor and is packed densely without having a large space in the internal cross section, and the cross-sectional area of each layer is equal;
A partition wall that separates the plurality of layers from each other and is connected only by a folded portion at an axial end,
The folded portion includes an end skin that continuously surrounds the end portions of the inner and outer propellants, and a fuel speed increasing member that is provided along the inner surface of the end shell and increases the combustion speed of the propellant. Become
The propellant is subjected to end face combustion sequentially from the outermost layer through a turn-up portion, and is an end face combustion type gas generator. 2. The end face combustion type gas generator according to claim 1, wherein a shape of the end portion outer plate is configured such that a variation in a combustion area in the folded portion falls within a range of +/− 10% or less. . 2. The end face combustion type gas generator according to claim 1 , wherein the fuel speed increasing member is a wire, foil, or net member made of a metal having high thermal conductivity and a high melting point.   The inner surface of the end skin has an insulation with low thermal conductivity and high heat resistance, and the fuel speed increasing member is provided directly or floating on the inner surface of the insulation, and the inner surface is filled with propellant. The end face combustion type gas generator according to claim 3, wherein   The inner surface of the end portion outer plate has an insulation with low heat conductivity and high heat resistance, and a thin gas generating film made of a propellant containing a fuel speed increasing member is attached to the inner surface of the insulation. The end face combustion type gas generator according to claim 3, wherein the inner surface is filled with a propellant. 2. The end face combustion type gas generator according to claim 1 , wherein the fuel speed increasing member is a high fuel speed propellant having a higher combustion speed than the propellant.   It has insulation with low heat conductivity and high heat resistance on the inner surface or outer surface of the partition wall, and has a heat resistant and flexible relief boot on the surface of the insulation other than the folded portion. The end face combustion type gas generator according to claim 1.   The combustor has a nozzle for discharging gas generated by combustion of the propellant at one or both ends in the axial direction, and the nozzle communicates with an end face of the outermost layer or the innermost layer propellant. The end face combustion type gas generator according to claim 1.   2. The end face combustion type gas generator according to claim 1, wherein the combustor is configured to be detachable at one end or both ends in the axial direction so that the propellant can be directly filled therein.

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