JP2000314414A - Embedded nut for architecture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an embedded nut for architecture, capable of maintaining an exact fixing against wood materials even for a long time used. SOLUTION: This embedded nut A thread-inserted to wood materials has a cylindrical shaft portion 2 and a flange 4 provided on a tip end thereof. The embedded nut A has a female screw 1 on the inner periphery of the shaft portion 2 and has a male screw 2 cutting into the wood materials on an outer periphery surface with a portion left around a tip end being a guide portion 3a. Screw ridges 2a, 2b, 2c of the male screws 2 have a gradually enlarging diameter around the tip end in a longitudinal direction, intermediate portions have the same diameters and a base end has a small diameter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a building embedded nut. More particularly, the present invention relates to a screw-in type building embedded nut used for connecting timber to each other.

[0002]

2. Description of the Related Art A conventional embedded nut for construction is shown in FIG.
The height and size of the screw thread 101 are uniform as shown in FIG. The thread 101 is not continuous, and a notch 102 is formed in the middle. The buried nut is buried in the wood while shaving the wood at the notch 102 and setting up a screw like a tap for machining. Therefore, the thread at the intermediate portion is located at substantially the same place as the place where the thread at the tip has passed. That is, since the screw thread at the intermediate portion fits into the existing hole, it becomes loosely fixed after embedding. Therefore, there is a problem in that the embedded nut is loosened and the connection between the woods is loosened in long-term use.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the embedded nut for building and to provide an embedded nut for building which can be reliably fixed to wood even after long use. Things.

[0004]

An embedding nut according to the present invention is an embedding nut having a female screw on an inner periphery and a male screw cut into wood on an outer peripheral surface, wherein a cross-sectional shape of a thread of the male screw is provided. However, it is characterized in that it gradually becomes larger from the longitudinal end toward the middle part. “The cross-sectional shape increases” includes the case where only the diameter, only the thickness, or both increase.

[0005] In such an embedded nut, it is preferable that the cross section of the peripheral portion of the thread is sharp at the tip end and becomes dull at the intermediate portion. Also, it is preferable that the cross section of the thread on the tip side is triangular and the height increases from the tip toward the middle. Furthermore, a shaft portion, a flange provided at one end of the shaft portion, and a male screw provided around the shaft portion while leaving the vicinity of the tip, and the female screw is formed from the flange portion to the shaft portion. Are preferred. A shaft portion, a flange provided at one end of the shaft portion, and a male screw provided around the shaft portion, wherein the female screw is formed from the flange portion to the shaft portion; and May be provided with a cutting blade at the tip of.

[0006]

[Operation and Effect of the Invention]
Prepare a prepared hole in the wood and screw it into the wood using a predetermined tool. At this time, since the thread has a gradually increasing cross-sectional shape from the tip toward the middle, the biting force into the wood is very strong. In addition, since it is fixed to the wood in a crimped state, the fixed state is extremely robust, and the fixed state can be maintained against external pressure from any direction.

[0007] In the case of an embedded nut in which the cross-sectional shape of the peripheral portion of the screw thread is sharp at the tip end in the longitudinal direction and dull at the middle portion, the first passage hole formed at the time of cutting into wood has the tip end. It is formed by sharp parts, and the amount of bite into the wood increases as the screw thread advances. Thus, the first penetration of the thread is easy and the final fixing to the wood is very strong.

When the cross-sectional shape of the peripheral portion of the screw thread is triangular on the distal end side and the diameter increases toward the middle portion, the first through hole formed in the wood has the inner peripheral edge portion. The cross section is triangular. Since the intermediate portion of the screw thread to be inserted into the through hole later is larger than the through hole, the screw thread at the intermediate portion presses and spreads the through hole and bites into the wood. Therefore, the power to bite into the wood is strong,
The state of pressure bonding to wood is reliably obtained.

[0009] In the case of an implanted nut provided with a male screw around the shaft portion except for the vicinity of the tip, when the embedded nut is screwed into the prepared hole, the tip portion of the shaft portion is guided to the prepared hole. Therefore, the embedded nut is easy to go straight. Therefore, there is little possibility that the embedded nut enters the wood obliquely and thereby causes the wood to crack.

[0010] In the case of an embedded nut having a cutting edge at the tip of the shaft portion, the embedded nut is to be embedded in wood even if the inner diameter of the prepared hole is insufficient or even if the prepared hole is not formed in some cases. Can be.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an embedding nut for a building according to the present invention. FIG.
Is a partially cutaway side view showing an embodiment of the embedding nut of the present invention, FIG. 2 is a sectional view thereof, FIGS. 3, 4 and 5 are explanatory views showing the embedding procedure of the embedding nut, FIGS. 6b is a sectional view showing still another embodiment of the embedded nut of the present invention, FIG. 7 is a partially cutaway side view showing another embodiment of the embedded nut of the present invention, and FIG. 8 is an embedded nut of the present invention 9 to 13 are explanatory views showing examples of use of the embedded nut of the present invention.

An embedded nut A shown in FIGS. 1 and 2
Comprises a shaft portion 2 having a female screw 1 on the inner periphery thereof and a male screw 2 on the outer peripheral surface thereof, and a flange 4 formed at one end of the shaft portion 2. The male screw 2 is not provided in the vicinity of the tip of the shaft portion 2, and its range is a cylindrical guide portion 3a. The shaft portion 2 is cylindrical in this embodiment, and has a through hole 1a at the center thereof.
The female screw 1 is formed on the inner surface on the base end side of the through hole 1a. In the present embodiment, the inner diameter of the through hole 1 a is larger than the root diameter of the female screw 1. Thus, a long bolt or the like can be screwed into the female screw 1. The female screw 1 is a normal inch screw or metric screw screwed with a bolt or the like. The male screw 2 has basically the same shape as a wood screw, but has a specific form as described below.

In other words, the male screw 2 is a triangular shape having a sharp edge at the tip end side (for example, one or two turns) of the shaft portion 2 at the peripheral edge portion of the screw thread 2a, and its outer diameter gradually increases. I have. In the middle part (for example, two or three rounds), the tip of the screw thread 2b is slightly slackened, has a flat trapezoidal triangular shape, and has the same outer diameter. These screws 2a and 2b have the same thickness at the root of the screw. The thread of the male screw 2 is continuous 1
It is a thread screw. Also, the cross-sectional shape changes continuously.

Further, in this embodiment, the height of the thread 2c is gradually reduced on the base end side (left side in FIG. 1, for example, one or two turns). Therefore, the outer diameter of the thread gradually increases from the distal end toward the intermediate portion, continues at the same diameter at the intermediate portion, and gradually decreases toward the proximal end. In addition, even if it gradually increases toward the middle portion and gradually decreases from the middle portion toward the base end side, the virtual line L connecting the top portion may form a gentle curve and form a drum shape. Good.

It is difficult to machine a screw whose thread form changes in the longitudinal direction by using an ordinary machine such as a lathe. Therefore, the above embedded nut A is preferably manufactured by casting, particularly by precision casting such as a lost wax method. However, it can also be manufactured by forging using a press or the like. The material is preferably stainless steel from the viewpoint of rust prevention. However, other materials such as ordinary cast steel, malleable cast iron, and hard steel may be used. When steel or cast steel is used, it is preferable to perform a chemical rust preventive treatment such as a dacro treatment or a black dyeing.

Next, a procedure for embedding the embedding nut A of the above embodiment in wood will be described. As shown in FIG. 3, the embedded nut A is embedded in the wood 10 using a hexagonal head bolt B screwed into the female screw 2 and an impact wrench C fitted to the head of the bolt. The bolt B is formed by integrally forming a flange portion 9 between the shaft portion 7 and the head portion 8, and is hardened by carburizing and quenching the whole.

When the embedding nut A is embedded in the wood 10, as shown in the first step S1 of FIG.
, A pilot hole 11 is formed. The inner diameter of the pilot hole 11 is slightly smaller than or the same as the shaft portion 2 of the embedded nut A. The depth is slightly longer than the length of the embedded nut A. Next, as shown in the second step S2, the guide portion 3a at the tip of the embedding nut A is fitted into the prepared hole 11, and the screw 2a is turned into the wood 10 by turning it somewhat with a finger. Next, as shown in the third step S3, the bolt B is screwed into the female screw 1 of the embedded nut A, and the flange 9 of the bolt is firmly brought into contact with the flange 4 of the embedded nut A. The bolt B may be attached to the embedded nut A before the second step S2.

Then, as shown in FIG. 3, the impact wrench C is fitted to the head 8 of the bolt B, and the embedded nut A
Is applied to the wood 10 by screwing. Thereby, via the state of the fourth step S4, finally, as shown in the fifth step S5, the shaft portion 2 of the embedded nut A is fitted into the prepared hole 11, and the flange 4 is Abut Thereafter, by removing the bolt B from the embedded nut A, the wood 10 in which the embedded nut A is embedded as shown in FIG. 5 is obtained. A counterbore may be formed on the surface of the wood 10 and the flange 4 may be fitted into the counterbore.

At the beginning of the embedding operation, the thread 2a on the tip side having a small outer diameter bites into the wood 10, so that it can be relatively easily screwed. And the fourth step S4
After the triangular thread 2a on the tip side has passed as shown in the above, the trapezoidal thread 2b at the intermediate portion is pushed in. Therefore, the screw thread 2b at the intermediate portion is in close contact with the wood 10 and does not come off even when a large pulling force is applied to the embedded nut A. As shown in FIG. 5, the small diameter triangular cross section thread 2c at the base end passes after the trapezoidal thread 2b at the middle section passes. Therefore, the thread 2c is not cut into the wood 10 and tightened, and the thread 2c is simply inserted into the hole on the base end side.

That is, in the embedded nut A, the thread from the distal end thread 2a to the intermediate thread 2b is tightly fixed to the wood, whereas the proximal end 2c is only loosely inserted into the wood. Therefore, the load on the shaft portion 2 is applied only to the intermediate thread 2a to 2b, and no load is applied to the proximal thread 2c. Therefore, even if the screw thread 2c pushes the insertion opening, since there is a margin between the screw thread 2c and the hole, it is prevented that the periphery of the hole of the wood 10 is broken by the screw thread 2c. Is done. Thus, even if the embedded nut A is attached to the dry hard wood 10, the wood does not crack.

According to the results of experiments conducted by the present applicant, the embedding nut A is embedded in wood, and approximately 1
Even when a load of tons was applied, the embedded nut A did not come off the wood. The embedded nut A used in the experiment had a total length of 35 mm, a diameter of the flange 4 of 22 mm, a diameter of the body of 13.8 mm, an inner diameter of the through hole of 12 mm, a thickness of the external thread of 2 mm, and a height of 2 mm. 4mm, cross section is triangular,
The thread pitch was 6 mm. In addition, the length of each part can be changed according to the total length of the embedded nut.

The embedding nut D in FIG. 6A is the same as the embedding nut A in FIG. 1 from the front end to the middle, but the shape of the thread 2c at the rear end is the same as the middle. Since the thread is formed up to the base end, the fixing force to the wood is higher than that of FIG. However, when it is used for dry hard wood, it is liable to crack. Therefore, it is preferable to use it for relatively soft wood. The embedded nut D in FIG. 6A does not have a through hole in the shaft portion 2 but forms a bottomed hole 1b that opens to the flange 4 side. This increases the strength of the tip.

The embedded nut E in FIG.
The outer diameters of a, 2b, and 2c are the same, but the thickness W is thinner at the distal end, thicker at the middle, and thinner again at the proximal end. The cross-sectional shape is triangular at the distal end, trapezoidal at the middle, and triangular again at the proximal end. These embedded nuts D and E also have substantially the same operation and effect as the above-described embedded nut A, in that the first embedded nuts D and E are easy to bite into the wood and are firmly fixed after being tightened.

In the embedding nut E of FIG. 6B, the thread from the tip 2a to the middle thread 2b is tightly fixed to the wood when embedded in the wood, whereas the thread at the proximal end is fixed. Since 2c is only loosely inserted into the wood, the load of the shaft 2 is applied to the threads 2a to 2b, and no load is applied to the proximal thread 2c. Therefore, even if the screw thread 2c pushes the insertion opening, there is a margin between the screw thread 2c and the hole.
Breaking of the periphery of the hole by the screw thread 2c is prevented.

The embedded nut F shown in FIG. 7 has a hexagonal column-shaped head 8 integrally provided outside the flange 4. And female screw 1
Is formed from the head 8 to the shaft 2. This screw does not require the bolt B of FIG. 3 to be attached when screwing into wood, and a tool such as an impact wrench can be directly engaged with the head. Therefore, there is no need to attach or remove the bolt B. However, with this embedded nut F, even if the shaft portion 2 is embedded in wood,
The head 8 protrudes. Therefore, when it is desired to flatten the surface of the wood, counterbores are formed in advance as shown by the imaginary line 10a.

The embedding nut G shown in FIG. The cutting blade K is formed from a triangular plate made of metal, and an edge is formed at an inclined edge. The cutting blade K can be formed integrally with the shaft 2, but may be manufactured separately and fixed to the shaft. Shaft 2
Is preferably closed as shown in FIG. 6a. The cutting blade K is used for removing a prepared hole of wood to be screwed in so that a screw thread can be easily formed. Further, in the case of soft wood, it is also possible to screw in while forming a pilot hole directly with the cutting blade K without providing a pilot hole.

The embedded nut of the present invention is, for example, shown in FIG.
As shown in FIG. 2, in order to directly connect the woods 10 and 11 by embedding the embedded nut A in one wood 10 and passing the bolt 12 through the other wood 11 and fastening the bolt 12 to the embedded nut A. use. Conventionally, in such a case, there is a problem that the strength of the wood is reduced because the through holes are formed in both the woods 10 and 11. However, when the embedded nut A of the present invention is used, at least the embedded nut A There is no need to provide a through-hole in the wood 10 in which is embedded, so that the strength can be improved.

Further, as shown in FIG.
A variety of usages can be adopted, such as attaching the feather plate metal fitting 13 to the other piece of wood, embedding the embedding nut A in the other piece of wood 10, and connecting the wood pieces 10 and 11 via the feather sheet metal fitting 13 and the embedding nut A.

FIG. 11 shows a state in which a brace 16 is attached to a gate 14 (and a beam) and a stud 15 supporting the same. For the brace 16, a metal rod connected by a turnbuckle 17 is used. After embedding the embedding nut A into the gate 14 or the stud 15, the end of the brace 16 is screwed into the female screw of the embedding nut A, and the dumbbell 14 and the brace 16 or the stud 15 and the brace 16 are connected. ing.

In the embedded nut A in this state, the screw threads 2a to 2b from the tip to the middle of the shaft portion 2 are tightly fixed in the middle of the gate 14 or the stud 15. The base end side of the embedding nut A is a portion to which a load is extremely applied, but it is not necessary to provide a through hole in the wood in which the embedding nut A is embedded. Therefore, the strength of the wood is improved. In addition, since the embedded nut A is gently inserted into the insertion port of the headgate or stud 15 at the base end side of the wood and the middle part is firmly fixed from the front end, the load is applied from the front end to the middle part. become. Therefore Kamoi 1
Cracking due to a load on the insertion opening of the stud 4 or the stud 15 is prevented.

FIG. 12 shows a case in which a connecting fitting 18 for connecting wooden pieces at right angles to each other is fixed to the wooden piece, like the stud 15 and the Kamoi 14. The connecting bracket 18 is made of a thin metal plate,
A rectangular rising portion 18b rises from two sides of the right triangle base 18a.
A bolt hole 18c is formed in each rising portion 18b. The embedding nut A is embedded in each piece of wood 10, and a bolt is screwed into the embedding nut A from the inside of the rising portion 18 b, so that the connection fitting 18 and the wood 10 are
Can be fixed, so that the woods 10 can be connected to each other at a right angle without providing a through hole in the woods 10.

FIG. 13 shows a case where a fire (wood) 20 is fixed to a concrete foundation 19. A recess 21 for inserting the bolt 12 to rotate the head and a bolt hole 22 are provided in the foundation 19, and an embedded nut A is screwed into the bottom of the fire 20. In this case also the recess 21
By inserting the bolt 12 into the bolt hole 22 and screwing it into the embedded nut A, the fire strike 20 can be fixed to the foundation 19. Conventionally, anchor bolts are buried before the concrete of the foundation 19 is cast, a through hole of wood is passed through the anchor bolt, and a normal nut is fastened and fixed to the tip of the anchor bolt coming out of the wood. ing. Therefore, the use of the embedded nut A eliminates the need for a through hole for wood, improves the strength of the wood, and eliminates the labor for embedding anchor bolts.

In the above embodiment, the external thread of the embedded nut is a single thread, but may be a multiple thread such as a double thread. Also, the direction of the screw is usually the right screw,
A left-hand thread may be used.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing an embodiment of an embedded nut of the present invention.

FIG. 2 is a longitudinal sectional view of the embedded nut of FIG. 1;

FIG. 3 is a sectional view showing a method of embedding the embedding nut.

FIG. 4 is a process diagram showing a method of embedding the embedding nut.

FIG. 5 is a sectional view showing a state in which the embedding nut is embedded.

6a and 6b are cross-sectional views showing still another embodiment of the embedded nut of the present invention.

FIG. 7 is a partially cutaway side view showing another embodiment of the embedding nut of the present invention.

FIG. 8 is a perspective view showing still another embodiment of the embedded nut of the present invention.

FIG. 9 is an explanatory view showing an example of use of the embedded nut of the present invention.

FIG. 10 is an explanatory view showing another usage example of the embedding nut of the present invention.

FIG. 11 is an explanatory view showing another usage example of the embedding nut of the present invention.

FIG. 12 is an explanatory view showing another example of use of the embedded nut of the present invention.

FIG. 13 is an explanatory view showing another usage example of the embedding nut of the present invention.

FIG. 14 is a perspective view showing an example of a conventional embedded nut.

[Explanation of symbols]

 A Embedded nut 1 Female screw 1a Through hole 2 Male screw 2a, 2b, 2c Thread 3 Shaft 4 Flange B Bolt C Impact wrench 10 Wood 11 Wood D Embedded nut E Embedded nut F Embedded nut G Embedded nut 18 Connection fitting

Claims (5)

[Claims] 1. An embedded nut having a female screw on an inner periphery and a male screw cut into wood on an outer peripheral surface, wherein a cross-sectional shape of a thread of the male screw is changed from near a front end in a longitudinal direction to an intermediate portion. Embedded nuts for construction that are getting bigger and bigger. 2. The embedded nut according to claim 1, wherein a cross section of a peripheral edge portion of said thread is sharp at a tip end side and becomes dull at an intermediate portion. 3. The cross section of the thread on the tip side is triangular,
The embedded nut according to claim 1, wherein the height of the embedded nut increases from the tip toward the middle. 4. A shaft, and a flange provided at one end of the shaft,
The embedded nut according to claim 1, further comprising: a male screw provided around the shaft portion except for the vicinity of the tip, wherein the female screw is formed from the flange portion to the shaft portion. 5. A shaft, and a flange provided at one end of the shaft,
The embedded nut according to claim 1, further comprising a male screw provided around the shaft, wherein the female screw is formed from the flange to the shaft, and a cutting blade is provided at a tip of the shaft. .