Method for manufacturing arc tube body and core used in the method

Abstract

To form an arc tube body including a main tube portion to be a discharge space and thin tube portions for accommodating electrodes, a core ( 6 ) is disposed in a hollow space formed by a pair of arc tube body formation molds ( 7 ) and ( 8 ) and thereafter, a slurry ( 12 ) is injected into a space between the molds ( 7 ), ( 8 ) and the core ( 6 ). In the core ( 6 ), portions for forming the internal shape of the thin tube portions of the arc tube body are provided with a shaft ( 3 ).

1 - 9 . (canceled)  
   
   
       10 . A core used for manufacturing an arc tube body, which comprises a main tube portion to be a discharge space and thin tube portions for accommodating electrodes, using a pair of molds and a material to be injected thereinto, the core being disposed in a hollow space formed by the pair of molds before injecting the material, comprising: 
 portions for forming an internal shape of the thin tube portions;    a portion for forming an internal shape of the main tube portion; and    a shaft disposed in the portions for forming an internal shape of the thin tube portion.    
   
   
       11 . The core used for manufacturing an arc tube body according to  claim 10 , 
 wherein the portion for forming an internal shape of the main tube portion is formed of a fusible material or a combustible material.    
   
   
       12 . The core used for manufacturing an arc tube body according to  claim 10 , 
 wherein the core comprises two portions for forming an internal shape of the thin tube portions, one of the two portions facing the other portion with the portion for forming the main tube portion intervening therebetween, and    a shaft present at one of the two portions and a shaft present at the other portion are defined by one common shaft.    
   
   
       13 . The core used for manufacturing an arc tube body according to  claim 10 , 
 wherein the core comprises at least two shafts.    
   
   
       14 . The core used for manufacturing an arc tube body according to  claim 10 , 
 wherein the portions for forming an internal shape of the thin tube portions are formed by forming a layer of a fusible material or a combustible material around the shaft.    
   
   
       15 . The core used for manufacturing an arc tube body according to  claim 10 , 
 wherein the shaft is formed of a metallic material, a resin material, or a ceramic material.    
   
   
       16 . The core used for manufacturing an arc tube body according to  claim 10 , 
 wherein the shaft is formed of a material that generates heat when an electric current is applied thereto.