Silencer for pneumatic device

Abstract

The present invention provides a silencer, which is coupled to a pneumatic device to reduce noise. The silencer ( 10 ) of the present invention has a double pipe structure, which includes an inner casing ( 11 ), which is coupled to an outlet of the pneumatic device, and an outer casing ( 12 ), which is coaxially provided around the inner casing ( 11 ). A space ( 18 ) is defined between the inner casing and the outer casing. The space communicates with an air guide hole ( 15 ), which is formed in one end of the inner casing. Furthermore, an acoustical absorbent ( 22 ) is provided in the space ( 18 ). Preferably, the acoustical absorbent has a spiral shape. Thus, compressed air, which has passed through the pneumatic device, passes through the acoustical absorbent of the silencer. At this time, almost all noise is absorbed by the acoustical absorbent.

1 . A silencer for a pneumatic device, comprising: an inner casing opened at a first end thereof and closed at a second end thereof, with transverse air guide means formed in the open end or the closed end of the inner casing, the air guide means communicating with an outlet in the pneumatic device; an outer casing provided around the inner casing coaxially such that a space for communicating with the air guide means is defined between the inner casing and the outer casing, with an exhaust hole formed in the outer casing at a position opposite the air guide means, the exhaust hole communicating with the space; and an acoustical absorbent provided in the space defined between the inner casing and the outer casing. 
   
   
       2 . The silencer for the pneumatic device according to  claim 1 , wherein the acoustical absorbent has a spiral shape, so that the space forms a spiral passage. 
   
   
       3 . The silencer for the pneumatic device according to  claim 1 , wherein the air guide means comprises at least one hole. 
   
   
       4 . The silencer for the pneumatic device according to  claim 1 , wherein the outer casing is supported at opposite ends thereof by respective flanges, which are provided around the open end and the closed end of the inner casing, respectively. 
   
   
       5 . The silencer for the pneumatic device according to  claim 1 , wherein the exhaust hole is formed through a sidewall of the outer casing. 
   
   
       6 . The silencer for the pneumatic device according to  claim 4 , wherein the exhaust hole is formed in the flange disposed opposite the air guide means. 
   
   
       7 . The silencer for the pneumatic device according to  claim 5 , wherein orientation of the exhaust hole is changed by rotating the outer casing. 
   
   
       8 . The silencer for the pneumatic device according to  claim 1 , wherein a tool holding part is provided on the closed end of the inner casing, so that the silencer is coupled to or removed from the pneumatic device by rotating the tool holding part.