High strength bolted structure and method of securing nut and torque-shear type high strength bolt and joining method using same

Abstract

The present invention provides a join structure comprised of a box section column and split T-section joined by a high strength bolt and a method of securing a nut to an inside of the box section column. The present invention further provides a Torque-Shear type high strength bolt tightly tightened by a controlled tension and a joining method of a steel member using that bolt. The join structure is comprised of a box section column, a split T-section attached to its outer surface, and a high strength bolt inserted from the outside of the split T-section and fastened with the nut. The nut is secured to the box section column by joining a sleeve secured to a washer formed integrally with the nut and a sleeve of a nut holding part from the outside of the column. The Torque-Shear type high strength bolt has a pintail for controlling the torque at its top.

1 . A high strength bolted structure of a box section member and joining hardware characterized in that at least at a plurality of locations of high strength bolted locations of a box section member and joining hardware, a female thread end of a nut abutting against an inner side of the box section member is separately provided with a female thread of a larger diameter than the diameter of that female thread, a male thread of a sleeve of a nut holding part inserted into a bolt hole from an outer side is screwed into it, whereby the nut is secured to the inner side of the box section member, a high strength bolt is inserted into the bolt hole from the outer side of joining hardware abutting against the outside of the box section member, and a male thread is screwed with the nut secured to the inner side of the box section member.  
   
   
       2 - 20 . (canceled)  
   
   
       21 . In combination, a Torque Shear type high strength bolt assembly comprising: 
 a Torque-Shear type high strength bolt and a tightening tool for tightening said Torque-Shear type high strength bolt, wherein said Torque-Shear type high strength bolt comprises:    a male thread portion for engaging a female thread;    a head portion and a shaft portion located at an end of the male thread portion, said head portion comprising a head having a seat face facing the male thread portion and having a front end on a side of the head opposite to the seat face and said shaft portion is located between said head portion and said male thread portion;    a pintail for torque control formed with a breakneck disposed on the front end of said head, with said breakneck comprised of a groove located between the front end of said head and said pintail;    a washer having a polygonal shape and having an outer diameter larger than the diameter of the outer circumference of said head located and abutted between the seat face of said head and a steel member to be joined;    said washer having an inner surface defined by an inner diameter larger than an outer diameter of said shaft portion of said high strength bolt; and further comprising:    said tightening tool for tightening said bolt by the pintail, said tightening tool having an inner sleeve and an outer sleeve;    the inner sleeve of said tightening tool gripping the pintail and the outer sleeve of said tightening tool engaging said washer;    whereby friction force is generated between the washer and the steel member to be joined as a counter force of rotational torque for torque control of the bolt.    
   
   
       22 . A bolting method for a steel member using a Torque-Shear type high strength bolt; 
 wherein said Torque-Shear type high strength bolt is comprised of:    a male thread portion for engaging a female thread;    a head portion and a shaft portion located at an end of the male thread portion, said head portion comprising a head having a seat face facing the male thread portion and having a front end on a side of the head opposite to the seat face and said shaft portion is located between said head portion and said male thread portion;    a pintail for torque control formed with a breakneck disposed on the front end of said head, with said breakneck comprised of a groove located between the front end of said head and said pintail;    said bolting method comprising:    when screwing a male thread into a female thread of a screwing side to tighten the bolt, inserting and abutting a washer of a polygonal shape and an outer diameter larger than the diameter of the outer circumference of the head between the seat face of said head and the steel member to be joined, said washer having an inner surface defined by an inner diameter larger than an outer diameter of said shaft portion of said high strength bolt;    using a tightening tool comprised of an inner sleeve and an outer sleeve operating in association, and engaging the washer with the outer sleeve and gripping and rotating the pintail by the inner sleeve so as to control the tension introduced to the bolt by the breakneck made to break at a selected breaking torque by a rotational torque obtained as a reaction force of the washer through the outer sleeve.    
   
   
       23 . A Torque-Shear type high strength bolt as set forth in  claim 21 , characterized in that at least the head seat face and thread of the bolt are lubricated.  
   
   
       24 . A Torque-Shear type high strength bolt as set forth in  claim 21 , characterized in that a bolt head side seat face of the washer inserted and abutted between the head seat face of the bolt and a steel member to be joined is lubricated.  
   
   
       25 . A Torque-Shear type high strength bolt as set forth in  claim 21 , characterized in that at least the head seat face and thread of the bolt are lubricated and a bolt head side seat face of the washer inserted and abutted between a head seat face of the bolt and a steel member to be joined is lubricated.  
   
   
       26 . A bolting method for a steel member using a Torque-Shear type high strength bolt as set forth in  claim 22 , characterize in that the Torque-Shear type high strength bolt used is a through bolt and the object formed with a female thread for screwing with its male thread is a nut.  
   
   
       27 . A bolting method for a steel member using a Torque-Shear type high strength bolt as set forth in  claim 22 , characterized in that the Torque-Shear type high strength bolt used is a tap bolt and the object formed with a female thread for screwing with its male thread is a steel member to be joined.