Blasting apparatus

Abstract

A blasting cartridge includes a generally cylindrical blasting container, a blasting substance filled in the blasting container, a pair of leadwires contained in the blasting container, and a single thin metal wire connected to tip portions of the pair of leadwires. The leadwires and the thin metal wire are positioned within the blasting substance within the blasting container. The blasting substance is nitromethane, and the thin metal wire is formed of tungsten. With an electric discharge impact blasting apparatus, since the thin metal wire has a higher heating value than a copper wire because of its higher resistance and vaporizes at higher temperatures, it is possible to obtain a greater blasting force at lower voltages than with a blasting apparatus using a copper wire.

1 . A blasting cartridge to be used in a blasting apparatus that blasts an object, comprising:
 a self-reactive blasting substance;   a container that contains said blasting substance;   a thin tungsten wire disposed within said blasting substance; and   a pair of leadwires whose one ends are connected to both ends of said thin tungsten wire and whose other ends are connected to a power supply device outside said container.   
     
     
         2 . The blasting cartridge according to  claim 1 , wherein,
 said thin tungsten wire is formed of a single thin metal wire or two or three stranded thin metal wires.   
     
     
         3 . The blasting cartridge according to  claim 1  or  2 , wherein
 said thin tungsten wire has a length greater than or equal to 10 mm and less than or equal to 120 mm and a cross-sectional area greater than or equal to 0.03 mm 2  and less than or equal to 0.13 mm 2 . 
 
     
     
         4 . The blasting cartridge according to any one of  claims 1  to  3 , wherein
 said blasting substance is nitromethane. 
 
     
     
         5 . A blasting apparatus that blasts an object, comprising:
 a blasting cartridge according to any one of  claims 1  to  4 ;   a capacitor connected to said pair of leadwires;   a power supply part that supplies electric energy to said capacitor; and   a discharge switch that discharges electric energy accumulated in said capacitor to said thin tungsten wire through said pair of leadwires.   
     
     
         6 . The blasting apparatus according to  claim 5 , wherein
 a discharge voltage applied to said thin tungsten wire is greater than or equal to 1500 V and less than or equal to 3000 V.   
     
     
         7 . The blasting apparatus according to  claim 5  or  6 , wherein
 said capacitor has an electrostatic capacitance greater than or equal to 100 μF and less than or equal to 1000 μF. 
 
     
     
         8 . A blasting method for blasting an object, comprising the steps of:
 a) housing a self-reactive blasting substance in a recessed portion formed in an object, such that a thin tungsten wire whose both ends are connected to a pair of leadwires is positioned within said blasting substance; and   b) causing said thin tungsten wire to melt and vaporize by supplying electric energy to said pair of leadwires and blasting said object by an impact force caused by said blasting substance.