JPH0623601Y2 - Wooden space truss member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This utility model relates to a wooden space truss member in which a shaft bolt is fixed by a large nut embedded in a longitudinal fiber of a tree.

In a conventional wooden three-dimensional truss, an axial bolt attached to the tip of a member is screwed into a ball-shaped nut, which is the same as a steel frame, to be assembled, so that various metal objects are used as a means for fixing the axial bolt to the wooden member.

Conventional hardware is a steel part at the tip of a member welded with a shaft bolt and a steel plate. After inserting the steel plate into a wooden member or sandwiching the member with two steel plates, a steel frame structure is made. Since the shaft bolts are fixed to the member by a method of attaching a steel plate using two or more shear bolts having the same structure as the above, there is a problem that the hardware becomes complicated and heavy, and the labor and cost increase.

Conventional hardware using shear bolts can be expected to have bonding strength due to friction and bearing pressure in the case of steel frame construction in which hard steel sheets are stacked together, but in the case of wooden construction, since hard steel sheets are applied to soft wood, friction and The bearing joint was not established and even if the number of bolts was increased, the strength could not be achieved. Also, since the shear bolt is used in the direction perpendicular to the axis of the member, when the shear bolt is tightened, the steel plate is compressed, and the straw-shaped longitudinal fibers packed in the axial direction are compressed from the lateral direction. There was a problem that it was dented and deformed. Moreover, when the axial bolt is strongly pulled, this shear bolt is laterally pulled and bent by the hard steel plate that tries to move in the axial direction, and at the same time becomes a thin and hard sword tool, and the longitudinal fibers of soft wood are axially moved. As a result of being cut into pieces, there was a drawback that strength could not be obtained.

In addition, since the wooden member shrinks when dried, not only is there a gap between the steel plate and the wooden member, but it is difficult to align the hole of the wooden member with the hole of the metal piece during construction, making it difficult to perform highly accurate construction. There was a drawback that it took a long time.

For the above reason, in the conventional example, as a means for eliminating the backlash at the joint and increasing the strength, a method of injecting an adhesive such as an epoxy resin into the hole of the bolt was used, so that the labor and cost are further increased. It had the drawback of being more expensive than steel frame construction.

The present invention was devised in order to eliminate this drawback, and it will be explained with reference to the drawings. (A) A wood made by processing logs such as logs and laminated wood in which longitudinal fibers of solid wood are lined up in the axial direction. The member 6 is made.

(B) A hole 8 for a shaft bolt is formed in the shaft core of the member from both ends.

C) Drill a hole 9 for a round or square nut in the direction perpendicular to the axis of the member d) The hole 9 for a nut is as long as the length of the longitudinal fiber required for strength (about 20 times the bolt diameter). Place it in a position where you can take it.

E) The nut shall be a large nut having a side surface close to the diameter of the member, and shall have the same shape and the same diameter cross section as the hole for the nut.

F) The nut should be wide and thick enough to compress the longitudinal fibers of the required cross-sectional area for strength.

G) The nut is tapped into the hole for the nut to be embedded in the member and brought into close contact with the cross section of the longitudinal fiber.

H) Insert a shaft bolt from the small end of the member and screw it into the nut that was embedded in advance to fix it.

Re) Install a washer to prevent cracking on the small edge with screws.

(N) A fastener is attached to the axial bolt protruding from the tip of the member, and a pin is set to complete the member product.

B) The finished products will be sent directly from the factory to the construction site.

E) At the time of erection, screw the shaft bolt into the same ball-type nut as the steel frame structure and tighten with the fasteners to assemble a three-dimensional truss.

Since the present invention is configured as described above, a wooden space truss having a strong tensile strength, which has been impossible in the past, can be obtained at a lower cost with a simple metal object having only one shaft bolt and one nut. And can be assembled in a short construction period.

According to the present invention, when the shaft bolt is screwed into the ball and tightened, the shaft bolt having no eccentricity pulls the large nut embedded in the wooden member by the shaft core, and this large nut is necessary to obtain a predetermined strength. Longitudinal fibers of length and cross-section are axially compressed to accommodate the tensioning of bolts and resist the tautness of the longitudinal fibers, which wood is best at, resulting in strong tensile joints.

The present invention is based on a tensile test conducted by the Ministry of Construction Architectural Research Institute and the Ministry of Agriculture, Forestry and Fisheries Forestry Research Institute (currently Forestry Research Institute). The above-mentioned effects have been proved, such as producing a tensile strength of 10 tons or more, which was impossible with a wooden member.

Further, as a result of the above-mentioned experiment, it was also found that the embedded nut is more effective in terms of strength in the square cross section than in the round cross section. The washer makes the edge of the wood less prone to cracking and helps to further increase the strength of the joint, and the bowl type is more effective than the flat type.

Due to the construction, when tightening the axial bolt into the ball,
Although there are various methods, the pin fastener used in the present invention is one example thereof.

According to the present invention, a wooden member which can be used only with a square member in the conventional embodiment can be used as a member having various designs such as a log or a polygon.

Also, unlike conventional hardware, several bolts and steel plates do not travel from members, and the hardware is hidden, so a beautiful skeleton that makes the most of the wood surface can be created.

According to the present invention, the strength of the joint portion can be changed by the diameter of the bolt and the size of the nut even with a standard member having a uniform length and thickness, and can be set to an appropriate strength according to the purpose.

According to the present invention, the strength of the joint can be further increased by using two nuts for one shaft bolt. In this case, it is more effective if the distance between the nuts is increased and the directions of the nuts are changed so that the longitudinal fibers are not cut into short pieces. High strength members can be used for large span frames.

The present invention economically builds a large-span spatial structure that can accommodate various shapes, and is much lighter than a steel structure, so it is suitable for large-scale water stages and high-floor structures of cliff buildings. It can be conveniently used for skeletons.

[Brief description of drawings]

FIG. 1 is a perspective view of a metal article of one embodiment used in the present invention. FIG. 2 is a perspective view of a member of the present invention (represented by hollowing out a part) in a ball. The figure is a sectional view of the member of the present invention. 1 is an axial bolt 2 is a large-sized embedded nut 3 is a washer 4 is a fastener 5 is a pin 6 is a wood member filled with longitudinal fibers 7 is a ball nut 8 is a hole for an axial bolt 9 is a hole for nuts

Claims (1)

[Scope of utility model registration request] 1. An axial bolt hole 8 is formed in an axial center of an end portion of a wooden member 6 in which straw-like solid wood longitudinal fibers are lined up in the axial direction, and further in a direction perpendicular to the axis. A member having a round or square nut hole 9 and having a side surface having a length close to the diameter of the member and having a large nut 2 having the same diameter as the hole 9 provided in the hole 9 to provide a predetermined length. A wooden three-dimensional truss member in which an axial bolt 1 is screwed and fixed to the center of a nut 2 that closely adheres to the cross section of the longitudinal fiber.