Press-fit nut for assembly, press-fit nut-bolt assembly, and method of constructing steel-concrete composite structure using same

A press-fit nut-bolt assembly having a press-fit nut, a stud bolt, a counter nut, and a washer, wherein the press-fit nut comprises:

• a head part formed in a normal nut shape;
• and
• a press-fit part formed to extend from one of both sides of the head part and having an outer diameter of the head part reduced as it extends, and is inserted by press-fitting into a base material M which requires fastening,
• wherein the head part and the press-fit part have a hollow with ridges continuously formed therein,
• wherein the stud bolt includes:
• a body part penetrating the press-fit nut so as to be coupled with the press-fit nut;
• and
• a pin tail formed to extend from the end of the body part and coupled with a mechanism for rotating the body part,
• wherein the body part includes a first ridge part and a second ridge part which are formed on an outer surface of the body part along the length direction of the body part and formed to be spaced apart from each other,
• wherein the counter nut is disposed on the opposite side of the press-fit nut with the base material therebetween which the stud bolt penetrates so that the stud bolt penetrates the counter nut so as to be coupled with the counter nut,
• wherein the washer is disposed between the base material and the counter nut, and the stud bolt penetrate its center,
• wherein the pin tail is formed at an end of the second ridge part which is one of both ends of the body part, so that the press-fit nut is coupled with the first ridge part and the counter nut is coupled to the second ridge part, and the first ridge part and the second ridge part are opposite to each other in directions of their ridges, and
• wherein the pin tail has a polygonal protruding pin formed at its center, and is further provided with a connector having an assembly groove formed thereon that is matching the protruding pin, so that the connector coupled with the protruding pin can be rotated so as to install the stud bolt stably.

A press-fit nut-bolt assembly having a press-fit nut, a stud bolt, a counter nut, and a washer, wherein the press-fit nut comprises:

• a head part formed in a normal nut shape;
• and
• a press-fit part formed to extend from one of both sides of the head part and having an outer diameter of the head part reduced as it extends, and is inserted by press-fitting into a base material M which requires fastening,
• wherein the head part and the press-fit part have a hollow with ridges continuously formed therein,
• wherein the stud bolt includes:
• a body part penetrating the press-fit nut so as to be coupled with the press-fit nut;
• and
• a pin tail formed to extend from the end of the body part and coupled with a mechanism for rotating the body part,
• wherein the body part includes a first ridge part and a second ridge part which are formed on an outer surface of the body part along the length direction of the body part and formed to be spaced apart from each other,
• wherein the counter nut is disposed on the opposite side of the press-fit nut with the base material therebetween which the stud bolt penetrates so that the stud bolt penetrates the counter nut so as to be coupled with the counter nut,
• wherein the washer is disposed between the base material and the counter nut, and the stud bolt penetrate its center,
• wherein the pin tail is formed at an end of the second ridge part which is one of both ends of the body part, so that the press-fit nut is coupled with the first ridge part and the counter nut is coupled to the second ridge part, and the first ridge part and the second ridge part are opposite to each other in directions of their ridges,
• wherein the press-fit nut-bolt assembly further comprises a press-fit ring that is a ring-shaped member and press-fitted to a surface of the base material, the other surface of which the press-fit part is inserted into, and
• wherein the press-fit ring deforms the surface of the base material as much as the other surface of the base material which the press-fit part is press-fitted into to deform lest the base material should be twisted and bent due to an excessive deformation of the other surface of the base material.

A method for constructing a steel-concrete composite structure using a press-fit nut-bolt assembly having a press-fit nut, a stud bolt, a counter nut, and a washer, wherein the press-fit nut comprises:

• a head part formed in a normal nut shape;
• and
• a press-fit part formed to extend from one of both sides of the head part and having an outer diameter of the head part reduced as it extends, and is inserted by press-fitting into a base material M which requires fastening,
• wherein the head part and the press-fit part have a hollow with ridges continuously formed therein,
• wherein the stud bolt includes:
• a body part penetrating the press-fit nut so as to be coupled with the press-fit nut;
• and
• a pin tail formed to extend from the end of the body part and coupled with a mechanism for rotating the body part,
• wherein the body part includes a first ridge part and a second ridge part which are formed on an outer surface of the body part along the length direction of the body part and formed to be spaced apart from each other,
• wherein the counter nut is disposed on the opposite side of the press-fit nut with the base material therebetween which the stud bolt penetrates so that the stud bolt penetrates the counter nut so as to be coupled with the counter nut,
• wherein the washer is disposed between the base material and the counter nut, and the stud bolt penetrate its center,
• wherein the pin tail is formed at an end of the second ridge part which is one of both ends of the body part, so that the press-fit nut is coupled with the first ridge part and the counter nut is coupled to the second ridge part, and the first ridge part and the second ridge part are opposite to each other in directions of their ridges,
• wherein the stud bolt is as long as a sum of a grip area that is an entire thickness of the base material to be combined with the stud bolt, a press-fit nut thickness, a counter nut thickness, and a washer thickness, and additionally a sum of the first surplus section and the second surplus section of predetermined lengths,
• wherein the first surplus section and the second surplus section are formed at one end and the other end of the stud bolt respectively, and
• wherein the method includes steps of:
• perforating so as to insert the stud bolt into the steel material;
• press-fitting the press-fit nut so as to form a concentric circle with a hole formed by the perforation in the area where the perforation is made on a surface of the steel material to be bonded to concrete;
• installing the stud bolt, the counter nut, and the washer to the press-fit nut;
• pouring the concrete on the surface to be bonded;
• and
• adjusting the installation position of the stud bolt before curing the concrete so as to maximize the length of one of the first surplus section and the second surplus section, which is buried in the concrete, wherein there is no temporal precedence between the step of pouring concrete and the step of adjusting to maximize the length.

A press-fit nut comprises:

• a head part formed in a normal nut shape such as a polygonal column or a circular column, and having ridges on an inner surface of a hollow that penetrates between both sides thereof;
• and
• a press-fit part extending from one of both sides of the head part with decreasing in diameter,
• wherein the press-fit part has:
• a hollow at a center of the press-fit part, which continues to the hollow of the head part;
• and
• plate-shaped splines on a circumferential side of the press-fit part, which are aligned parallel in the protruding direction and closely to each other with predetermined interval,
• wherein the press-fit part includes:
• a front sector which is a portion between an end and a certain point;
• and
• a rear sector which is a portion between the certain point and a point in contact with the head part,
• wherein the splines are formed continuously in length direction from the front sector to the rear sector,
• wherein the front sector decreases in its diameter as it goes from a boundary with the front sector and the rear sector to an end of the front sector, and converges toward its center.