Gas generator

Abstract

The present invention provides an end-face-burning gas generator having a simple internal structure for easy manufacture, in which the amount of generated gas can be varied during gas discharge. The present invention provides a gas generator including a housing provided with a gas discharge port, an ignition device provided within the housing, a gas generating agent formed in a lump form and provided within the housing such that the gas generating agent is ignited and burnt, by the ignition device, in an end surface thereof, the gas generating agent having a form or a structure such that a combustion surface area thereof changes as the gas generating agent is being burned.

1 . A gas generator, comprising: 
 a housing provided with a gas discharge port;    an ignition device provided within the housing;    a gas generating agent formed in a lump form and provided within the housing for generating a gas by burning, the gas generating agent including a combustion starting end surface that start a combustion thereof by the ignition device and having a form or a structure such that a combustion surface area varies as the gas generating agent is being burned; and    combustion-restricting means provided on all surfaces of the gas generating agent other than the combustion starting end surface, the combustion -restricting means restricting the combustion of the all surfaces other than the combustion starting end surface.    
   
   
       2 . The gas generator according to  claim 1 , wherein the combustion-restricting means defines a gas generating agent chamber for accommodating therein the gas generating agent, and an outer peripheral surface, an inner peripheral surface, and an opposite side end surface to the combustion starting end surface of the gas generating agent all contact the combustion restricting means such that the gas generating agent is formed substantially columnar form having a through hole which penetrates in an axial direction thereof.  
   
   
       3 . The gas generator according to  claim 2 , wherein the combustion-restricting means includes an inner member and an outer member provided in the inner peripheral surface and the outer peripheral surface of the gas generating agent, respectively, and at least one of an inner diameter of the outer member and an outer diameter of the inner member varies in an axial direction of the housing.  
   
   
       4 . The gas generator according to  claim 1 , wherein the combustion-restricting means defines a gas generating agent chamber for accommodating therein the gas generating agent, and an outer peripheral surface and an opposite side end surface to the combustion starting end surface of the gas generating agent all contact the combustion-restricting means such that the gas generating agent is formed substantially columnar form without having a through hole.  
   
   
       5 . The gas generator according to  claim 4 , wherein the combustion-restricting means includes an outer member provided in the outer peripheral surface of the gas generating agent, and an inner diameter of the outer member varies in an axial direction of the housing.  
   
   
       6 . A gas generator, comprising: 
 a housing provided with a gas discharge port;    an ignition device provided within the housing;    a gas generating agent formed in a lump form and provided within the housing such that the gas generating agent is ignited and burnt, by the ignition device, in an end surface thereof, the gas generating agent having a form or a structure such that a combustion surface area thereof changes as the gas generating agent is being burned.    
   
   
       7 . The gas generator according to  claim 6 , wherein the combustion surface area of the gas generating agent orthogonal to a combustion progression direction thereof varies in the combustion progression direction of the gas generating agent.  
   
   
       8 . The gas generator according to  claim 3 , further comprising: 
 an ignition device chamber provided in an inside of the inner member, 
 wherein the ignition device includes an operation-starting means for starting an operation of the gas generator and are disposed in the ignition device chamber at one axial end side thereof, and  
 the combustion starting end surface exists on the opposite side of the gas generating agent chamber to the operation starting device.  
   
   
   
       9 . The gas generator according to  claim 2 , wherein the gas generating agent exists in a container formed by a member forming the gas generating agent chamber, or in a container stored in the gas generating agent chamber.  
   
   
       10 . The gas generator according to  claim 1 , wherein the gas generating agent contains a fuel and an oxidant, 
 the fuel includes at least one type selected from the group consisting of RDX, HMX, 5-nitrotetrazole, 1H-tetrazole, 5-aminotetrazole, 1H-tetrazole-1,5-diamine, guanidine nitrate, mono-amine guanidine nitrate, carbodihydrazide, triamine guanidine nitrate, 1,2,4-triazole-3-on, 5,5′-bi-1H-tetrazole, dicyandiamide, azodicarbonamide, glycine, semicarbazone, 1H-1,2,4-triazole-3,5-diamine, 4-amino guanazole, and guanylurea nitrate, and    the oxidant includes at least one selected from the group consisting of potassium perchlorate, ammonium perchlorate, sodium perchlorate, strontium perchlorate, potassium nitrate, ammonium nitrate, sodium nitrate, and strontium nitrate.    
   
   
       11 . The gas generator according to  claim 1 , wherein one of the following combustion accelerators (i) and (ii) is mixed into and dispersed throughout the gas generating agent: 
 (i) a combustion accelerator which contributes directly to combustion of the gas generating agent by burning itself in order to further raise the combustion temperature; and    (ii) a combustion accelerator which does not contribute directly to combustion of the gas generating agent, but provides conditions for accelerating the combustion.    
   
   
       12 . The gas generator according to  claim 11 , wherein the combustion accelerator comprises one of the following bases (a) through (c), and the average particle diameter of one particle thereof is between 1 and 1000 μm: 
 (a) a base including a fuel and an oxidant and having a higher combustion temperature than the gas generating agent in which the base is mixed and dispersed;    (b) a base including hollow micro-particles, which accelerates combustion of the gas generating agent by increasing the combustion surface area of the gas generating agent at one of the combustion stages of the gas generating agent in which the base is mixed and dispersed; and    (c) a base comprising metallic particles.    
   
   
       13 . The gas generator according to  claim 1 , further comprising: 
 a reinforcing member for preventing breakage at the combustion starting end surface is provided at the combustion starting end surface.    
   
   
       14 . The gas generator according to  claim 1 , further comprising: 
 an ignition aid containing a material that has a greater ignitability than the gas generating agent is provided at the combustion starting end surface.    
   
   
       15 . The gas generator according to  claim 14 , wherein the ignition aid is a film-form member coated on one surface or both surfaces thereof with a transfer charge.  
   
   
       16 . The gas generator according to  claim 14 , wherein the ignition aid is a porous thin plate member impregnated with a transfer charge.  
   
   
       17 . The gas generator according to  claim 14 , wherein the ignition aid is a slurry-form substance mixed with a transfer charge, which is cured on the combustion starting end surface of the gas generating agent.  
   
   
       18 . A method of manufacturing a gas generator including therein a gas generating agent that generates a gas when burned and an ignition device for igniting and burning the gas generating agent in the interior of a housing having a gas discharge port, comprising the steps of: 
 charging a gas generating agent chamber provided within the housing with a fluid-state gas generating agent; and    curing the fluid-state gas generating agent to form a lump-form gas generating agent having a combustion starting end surface and a form or a structure such that a combustion surface area thereof varies as the gas generating agent is burned.    
   
   
       19 . The gas generator according to  claim 6 , further comprising: 
 combustion-restricting means provided within the housing, and attaching to and restricting a combustion of all surfaces of the gas generating agent other than the end surface.    
   
   
       20 . The gas generator according to  claim 6 , wherein the gas generating agent contains a fuel and an oxidant, 
 the fuel includes at least one type selected from the group consisting of RDX, HMX, 5-nitrotetrazole, 1H-tetrazole, 5-aminotetrazole, 1H-tetrazole-1,5-diamine, guanidine nitrate, mono-amine guanidine nitrate, carbodihydrazide, triamine guanidine nitrate, 1,2,4-triazole-3-on, 5,5′-bi-1H-tetrazole, dicyandiamide, azodicarbonamide, glycine, semicarbazone, 1H-1,2,4-triazole-3,5-diamine, 4-amino guanazole, and guanylurea nitrate, and    the oxidant includes at least one selected from the group consisting of potassium perchlorate, ammonium perchlorate, sodium perchlorate, strontium perchlorate, potassium nitrate, ammonium nitrate, sodium nitrate, and strontium nitrate.    
   
   
       21 . A method of manufacturing the gas generator according to  claim 18 , further comprising: 
 providing, within the housing, a combustion-restricting means such that the combustion-restricting means attach to and restrict a burning of all surfaces of the gas generating agent other than the combustion starting end surface.