Heat sink

Abstract

A heat sink includes a pillar member, to which a device that generates heat is to be mounted, and a plurality of heat-dissipating fins arranged on a side surface of the pillar member to dissipate the heat generated by the device. The heat sink further includes a ring-shaped holding member that has a plurality of grooves formed therein. The holding member is mounted to a longitudinal end of the pillar member and has each of the heat-dissipating fins inserted in a corresponding one of the grooves of the holding member, thereby holding the heat-dissipating fins to the pillar member. Each of the heat-dissipating fins has a detachment prevention portion that prevents the heat-dissipating fin from being detached from the pillar member in a direction perpendicular to the longitudinal direction of the pillar member.

What is claimed is: 
     
         1 . A heat sink comprising:
 a pillar member to which a device that generates heat is to be mounted; and   a plurality of heat-dissipating fins arranged on a side surface of the pillar member to dissipate the heat generated by the device,   wherein   the heat sink further comprises a ring-shaped holding member that has a plurality of grooves formed therein,   the holding member is mounted to a longitudinal end of the pillar member and has each of the heat-dissipating fins inserted in a corresponding one of the grooves of the holding member, thereby holding the heat-dissipating fins to the pillar member, and   each of the heat-dissipating fins has a detachment prevention portion that prevents the heat-dissipating fin from being detached from the pillar member in a direction perpendicular to the longitudinal direction of the pillar member.   
     
     
         2 . The heat sink as set forth in  claim 1 , wherein the heat-dissipating fins are joined to the pillar member by brazing. 
     
     
         3 . The heat sink as set forth in  claim 1 , wherein for each of the heat-dissipating fins, the detachment prevention portion is formed by bending the heat-dissipating fin on the pillar member side and along the longitudinal direction of the pillar member, and
 the detachment prevention portion is sandwiched between the side surface of the pillar member and an inner surface of the ring-shaped holding member.   
     
     
         4 . The heat sink as set forth in  claim 1 , wherein each of the heat-dissipating fins has a slit that is formed to extend from a longitudinal end of the heat-dissipating fin in the longitudinal direction of the pillar member,
 the holding member is inserted in each of the slits of the heat-dissipating fins,   for each of heat-dissipating fins, the detachment prevention portion is made up of a portion of the heat-dissipating fin which adjoins the slit from the pillar member side, and   the detachment prevention portion is sandwiched between the side surface of the pillar member and an inner surface of the ring-shaped holding member.   
     
     
         5 . The heat sink as set forth in  claim 1 , wherein the ring-shaped holding member is a first holding member, and the longitudinal end of the pillar member is a first longitudinal end of the pillar member,
 the heat sink further comprises a second ring-shaped holding member that has a plurality of grooves formed therein,   the second holding member is mounted to a second longitudinal end of the pillar member which is opposite to the first longitudinal end in the longitudinal direction of the pillar member, and   the second holding member has each of the heat-dissipating fins inserted in a corresponding one of the grooves of the second holding member, thereby holding the heat-dissipating fins to the pillar member.   
     
     
         6 . A heat sink comprising:
 a pillar member to which a device that generates heat is to be mounted; and   a plurality of heat-dissipating fins arranged on a side surface of the pillar member to dissipate the heat generated by the device,   wherein   the heat sink further comprises a plate-shaped holding member that has an insertion hole formed at the center thereof and a plurality of grooves formed to extend from the insertion hole outward,   a longitudinal end portion of the pillar member is inserted in the insertion hole of the holding member,   the holding member has each of the heat-dissipating fins inserted in a corresponding one of the grooves of the holding member, thereby holding the heat-dissipating fins to the pillar member, and   each of the heat-dissipating fins has a detachment prevention portion that prevents the heat-dissipating fin from being detached from the pillar member in a direction perpendicular to the longitudinal direction of the pillar member.   
     
     
         7 . The heat sink as set forth in  claim 6 , wherein the heat-dissipating fins are joined to the pillar member by brazing. 
     
     
         8 . The heat sink as set forth in  claim 6 , wherein the holding member is bent on the insertion hole side so that the grooves of the holding member are inclined with respect to the longitudinal direction of the pillar member, thereby allowing the heat-dissipating fins to be respectively inserted into the grooves. 
     
     
         9 . The heat sink as set forth in  claim 6 , wherein for each of the heat-dissipating fins, the detachment prevention portion is formed by bending the heat-dissipating fin on the pillar member side and along the longitudinal direction of the pillar member, and
 the detachment prevention portion is sandwiched between the side surface of the pillar member and an inner surface of the holding member which defines the insertion hole.   
     
     
         10 . The heat sink as set forth in  claim 6 , wherein each of the heat-dissipating fins is stepped at a longitudinal end thereof to form the detachment prevention portion that protrudes in the longitudinal direction of the pillar member, and
 the detachment prevention portion is inserted in the corresponding groove of the holding member.   
     
     
         11 . The heat sink as set forth in  claim 6 , wherein the plate-shaped holding member is a first holding member, and the longitudinal end portion of the pillar member is a first longitudinal end portion of the pillar member,
 the heat sink further comprises a second plate-shaped holding member that has an insertion hole formed at the center thereof and a plurality of grooves formed to extend from the insertion hole outward,   a second longitudinal end portion of the pillar member, which is opposite to the first longitudinal end portion in the longitudinal direction of the pillar member, is inserted in the insertion hole of the second holding member, and   the second holding member has each of the heat-dissipating fins inserted in a corresponding one of the grooves of the second holding member, thereby holding the heat-dissipating fins to the pillar member.   
     
     
         12 . The heat sink as set forth in  claim 6 , wherein the heat sink further comprises a ring-shaped holding member that has a plurality of grooves formed therein,
 the ring-shaped holding member is mounted to a longitudinal end of the pillar member, the longitudinal end being opposite, in the longitudinal direction of the pillar member, to the longitudinal end portion of the pillar member which is inserted in the insertion hole of the plate-shaped holding member, and   the ring-shaped holding member has each of the heat-dissipating fins inserted in a corresponding one of the grooves of the ring-shaped holding member, thereby holding the heat-dissipating fins to the pillar member,   
     
     
         13 . A heat sink comprising:
 a pillar member to which a device that generates heat is to be mounted; and   a plurality of heat-dissipating fins arranged on a side surface of the pillar member to dissipate the heat generated by the device,   wherein   the heat sink further comprises a pair of plate-shaped holding members and a plurality of bar members,   the holding members are respectively provided at opposite longitudinal ends of the pillar member,   each of the bar members extends in the longitudinal direction of the pillar member with its longitudinal ends respectively engaging with the holding members,   each of the heat-dissipating fins is bent, on the pillar member side and along the longitudinal direction of the pillar member, to form a detachment prevention portion thereof,   for each of the heat-dissipating fins, the detachment prevention portion of the heat-dissipating fin is sandwiched between the side surface of the pillar member and a corresponding one of the bar members, thereby preventing the heat-dissipating fin from being detached from the pillar member in a direction perpendicular to the longitudinal direction of the pillar member.   
     
     
         14 . The heat sink as set forth in  claim 13 , wherein the heat-dissipating fins are joined to the pillar member by brazing. 
     
     
         15 . The heat sink as set forth in  claim 13 , wherein each of the holding members has a plurality of recesses formed in an end face thereof facing the pillar member,
 for each of the bar members, the longitudinal ends of the bar member are respectively inserted in a corresponding pair of the recesses of the holding members, thereby respectively engaging with the holding members, and   for each of the heat-dissipating fins, the detachment prevention portion of the heat-dissipating fin has formed therein a groove which extends in the longitudinal direction of the pillar member and in which the corresponding bar member is inserted.   
     
     
         16 . A heat sink comprising:
 a pillar member to which a device that generates heat is to be mounted; and   a plurality of heat-dissipating fins arranged on a side surface of the pillar member to dissipate the heat generated by the device,   wherein   each of the heat-dissipating fins is bent, on the pillar member side and along the longitudinal direction of the pillar member, twice to form an overlapping portion and a detachment prevention portion thereof, the overlapping portion extending along the side surface of the pillar member and having a hole formed therein, the detachment prevention portion being formed at a distal end of the overlapping portion so as to protrude from the detachment prevention portion in a direction away from the pillar member, and   for each adjacent pair of the heat-dissipating fins, the overlapping portions of the pair of the heat-dissipating fins partially overlap each other and the detachment prevention portion of one of the pair of the heat-dissipating fins is inserted in the hole of the other heat-dissipating fin, thereby preventing the heat-dissipating fins from being detached from the pillar member.   
     
     
         17 . The heat sink as set forth in  claim 16 , wherein the heat-dissipating fins are joined to the pillar member by brazing. 
     
     
         18 . The heat sink as set forth in  claim 16 , wherein the heat-dissipating fins are arranged within only part of the outer circumference of the pillar member,
 the heat sink further comprises a holding member that is arranged to cover that part of the outer circumference of the pillar member in which no heat-dissipating fin is arranged,   the holding member has a hole formed close to one circumferential end of the holding member and a detachment prevention portion formed at the other circumferential end of the holding member,   in the hole of the holding member, there is inserted the detachment prevention portion of that one of the heat-dissipating fins which adjoins the holding member from the one circumferential end of the holding member, and   the detachment prevention portion of the holding member is inserted in the hole of that one of the heat-dissipating fins which adjoins the holding member from the other circumferential end of the holding member.