JP2010036277A - Method for forming screw on timber, timber with screw, and joining structure of timbers - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To directly join timbers with each other without using a metal joining tool. <P>SOLUTION: A screw is formed on an outer peripheral surface of a shaft of the timber or an inner peripheral surface of a hole of the timber by applying a blade of a screw-machined cutter operated on a machining condition set in a NC machining machine to the outer peripheral surface or the inner peripheral surface. As the screw-machined cutter, the same screw-machined cutter can be used for screw-machining on the outer peripheral surface of the shaft and screw-machining on the inner peripheral surface of the hole. The screw can be formed on the outer peripheral surface of the shaft or the inner peripheral surface of the hole, a fitting part without a screw can be provided at a root part of the outer peripheral surface of the shaft, and a fitting recess without a screw can be provided on an entrance side of the hole. The timbers can be joined by screwing a male screw shaft of the timber into a female screw hole of the timber, and the fitting part without the screw at the root part of the outer peripheral surface of the shaft is fitted up to the fitting recess without the screw on the entrance side of the hole. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for forming a screw on the outer peripheral surface of a wood shaft or navel (hereinafter collectively referred to as “shaft”) or the inner peripheral surface of a hole in the wood, and a male screw or an inner peripheral surface of the hole on the outer peripheral surface of the wood shaft. The present invention relates to a threaded wood having a female screw formed thereon, a wood provided with a male screw shaft, and a wood having a female screw hole.

  Conventionally, joining two pieces of wood is generally performed using a metal screw jig or a dowel (a shaft inserted into a hole in the wood and fixed with an adhesive). There exists invention of patent document 1 as an example of this kind of screw jig.

  In the screw jig of Patent Document 1, a metal female screw hole jig is embedded in one piece of wood to be joined, a metal male screw shaft is inserted into the other piece of wood, and the male screw shaft is inserted into the female screw hole jig. It is screwed to join both woods (Patent Document 1).

JP 2007-71339 A

The conventional techniques have the following problems.
(1) In Patent Document 1, it is necessary to embed a metal female screw hole jig in one piece of wood and insert a metal male screw shaft into the other piece of wood, which is cumbersome and costly. It was.
(2) It was easy for rattling to occur due to aging between the wood and the metal female screw hole jig embedded in it and between the wood and the metal male screw shaft embedded in it. .
(3) When a dowel is used, since an adhesive is required, the joining is troublesome, and the joining strength is weak as compared with the screw-in joining.

  The subject of this invention is enabling it to join wood directly, without using the above metal screw jigs.

  The screw forming method for wood according to the present invention operates on the outer peripheral surface of the wood shaft or the inner peripheral surface of the hole of the wood under the processing conditions set in the NC processing machine (rotation, revolution). This is a method of forming a male screw on the outer peripheral surface of the shaft and a female screw on the inner peripheral surface of the hole by applying a blade of a threaded cutting tool that moves up and down, laterally, etc. According to the second aspect of the present invention, the same threaded cutting tool can be used for the threaded cutting tool for threading the shaft outer peripheral surface and the screw inner peripheral surface. The wood shaft and hole may be formed in a step before screw formation, or may be formed in advance.

  The threaded wood according to the present invention includes a screw shaft or a screw hole in which a screw is formed by the screw forming method on an outer peripheral surface of a wood shaft or an inner peripheral surface of a hole of a wood as described in claim 3. It is. In this case, the screw shaft may be provided with a fitting portion on which the screw is not formed on the base side of the screw shaft as described in claim 4, and the screw is formed on the inlet side of the screw hole as described in claim 5. However, it can also be provided with a fitting recess into which the fitting portion of the screw shaft can be fitted.

  According to a sixth aspect of the present invention, there is provided a wood joining structure in which a male screw shaft of the wood is screwed into a female screw hole of the wood to join both pieces of wood. In this case, as described in claim 7, both the wood pieces can be joined by fitting the fitting portion of the male screw shaft into the fitting concave portion of the female screw hole.

The screw forming method for wood according to the present invention has the following effects.
(1) Since the screw cutting tool is operated under the processing conditions set in the NC processing machine to form screws, if the wood shaft and hole are set at predetermined positions, the shaft outer periphery and the hole inner peripheral surface Screws are automatically formed.
(2) Since the thread cutting tool operates according to the processing conditions set in the NC processing machine, it is possible to form a screw with high dimensional accuracy.
(3) Since the male screw and the female screw can be formed with the same threaded cutting tool, it is not necessary to separately prepare the threaded cutting tool for forming the male screw and the female screw, and the cost can be reduced. Further, the screw shaft is tightly screwed into the screw hole, and rattling is unlikely to occur.
(4) By changing the machining conditions of the NC program set in the NC machine or the machining conditions (numerical values) input to the NC machine, the desired thread height, thread groove depth, number of screws, Screws with a screw pitch can be freely formed.
(5) Since the threading tool is rotated by an NC machine in the present invention, a threading tool having a uniform depth of the groove from the tip side to the root side can be used. Screws with a uniform depth can be formed. If the screw processing blade is manually rotated to form a screw, there is a limit to the rotational force, so the blade groove on the tip side is shallow and the blade groove gradually becomes deeper toward the root side. The thread must be deepened using a type of threaded cutting tool, and it is difficult to form a screw of uniform depth to the immediate vicinity of the hole bottom.

The threaded wood of the present invention has the following effects.
(1) Since the wood shaft and the hole itself are provided with screws, there is no trouble in inserting and fixing a metal screw shaft or a metal screw hole pipe into the wood as in the past. Further, since there is no metal screw shaft or metal screw hole pipe, the cost can be reduced.
(2) There is rattling between wood and these female screw hole pipes and male screw shafts, such as when embedding metal female screw hole pipes in wood or inserting metal male screw shafts. Does not occur.
(3) Since a fitting portion not formed with a screw is formed in the base portion of the outer peripheral surface of the wood shaft, and a fitting recess is formed on the inlet side of the screw hole, the fitting portion and the fitting recess are fitted. By doing so, the joining of the woods becomes stable.
(4) Since there is an insertion part without screws on the base side of the screw shaft, and there is a fitting recess without screws on the inlet side of the screw hole, if both screws are inserted into the screw hole to the base side of the screw shaft, The match is certain and stable.

The screwed wood joining structure of the present invention has the following effects.
(1) Since wood is provided with wood screws, the screws are easily compatible and the joining is stable.
(2) Since the metal material is not embedded in the wood, rust and corrosion do not occur due to secular change, and the wood does not corrode due to them.
(3) Since the screwless insertion portion on the root side of the screw shaft is screwed into the screwless fitting recess on the inlet side of the screw hole, the fitting of both pieces of wood is stabilized.

(Embodiment 1 of screw forming method)
An example of an embodiment of the screw forming method of the present invention will be described with reference to FIGS. In this embodiment, a round bar-shaped shaft 3 is pre-processed on one end side of a square-bar-shaped wood 1 with a shaft machining tool 2 (FIGS. 1B and 1C), and the shaft 3 is shown in FIG. 4 or FIG. This is an example in which a male screw 5 (FIG. 2) is formed using such a bit (threaded cutting tool) 4.

  In this invention, a general purpose thing or a novel thing can be used for the said NC processing machine. Any NC processing machine can be equipped with trimmers, router bits, etc. (collectively these are called “processing tools”), and the processing tools can be automatically replaced according to the processing application. . In addition, the cutting tool rotates (spins) based on the input NC program and the input (set) numerical values, and the X axis (lateral direction), Y axis (front-rear direction), Z axis (vertical direction), diagonal direction And revolve along the outer peripheral surface of the shaft forming the screw and the inner peripheral surface of the hole forming the screw. Further, numerical control of various operations such as increase / decrease adjustment of the rotational speed of the processing blade, position confirmation of the blade, feed amount, and feed speed is possible.

  In the present invention, it is possible to use processing blades having various shapes and structures according to the application. In order to form the round rod-shaped shaft 3 (FIG. 1 (c)) at the tip end portion 14 of the square-shaped wood 1, the shaft machining tool 2 as shown in FIG. 1 (a) is used. In order to form the external thread 5 (FIGS. 2B and 2C) on the outer peripheral surface, a single-stage threaded cutting tool 6 as shown in FIGS. 4A and 4B, or FIGS. A multi-stage threaded cutting tool 7 as shown can be used. 1A is a straight type in which a vertically long blade 22 is formed on the outer peripheral surface of a blade base 21 at the tip of the blade shaft 20. 4 (a) and 4 (b), the single-stage threaded cutting tool 6 has two blades 26 formed on the outer periphery of the blade base 25 at the tip of the blade shaft 24. The multi-stage shown in FIGS. 5 (a) and 5 (b). In the threaded cutting tool 7, the blade 29 is formed in multiple stages on the outer periphery of the blade base 28 at the tip of the blade shaft 27. The multistage threaded cutting tool 7 can set the pitch P between the blades (FIG. 5A) according to the application. In any case, it is desirable to use a blade having a substantially trapezoidal cross-sectional shape as shown in FIG. By forming the trapezoidal shape, the bottom (valley) of the screw groove formed in the square bar-shaped wood 1 formed thereby becomes trapezoidal, and the strength is improved, so that the screw can be prevented from being broken or damaged.

(Screw forming method 1 on the outer peripheral surface of the shaft)
A round bar-shaped shaft 3 (FIG. 1 (c)) is formed on a square bar-shaped wood 1 shown in FIGS. 1 (a) and 1 (b) using an NC processing machine, and a male screw 5 (FIG. 2 (b) is formed on the outer periphery thereof. ) (C)) is formed as follows.
1. As shown in FIG. 1A, a square bar-like wood 1 is fixed to a table (pedestal) 10. Fixing can be performed with a general-purpose clamp of an NC processing machine. The tip 14 of the wood 1 is projected upward from the upper surface of the base 10.
2. A straight type shaft machining tool 2 shown in FIG. 1 (a) is mounted on an NC processing machine, and the shaft 1 is rotated (spinned) in the direction of arrow X (clockwise direction) in FIG. The tip portion 14 is cut by rotating it in the direction of the arrow Y in FIG. 1B along with the outer peripheral surface of the tip portion 14 and rotating (revolving) along the outer peripheral surface of the tip portion 14. (FIG. 1C) is formed. The rotation and revolution of the shaft machining tool 2 rotate under the machining conditions set by the NC program. The thickness and length of the shaft 3 can be selected according to the application.
3. When the formation of the shaft 3 is completed, the shaft machining tool 2 mounted on the NC machine is automatically replaced with a one-stage thread machining tool 6 shown in FIGS.
4). The one-stage threaded cutting tool 6 is an outer peripheral surface with the cutting edge contacting the outer peripheral surface of the shaft 3 while rotating (spinning) in the direction of arrow X in FIG. 2 (revolution) in the direction of arrow Y in FIG. 2 (a), and during one revolution, one pitch at a root of the shaft 3 (the connecting portion between the square bar-shaped wood 1 and the round bar-shaped shaft 3). The right-handed male screw 5 (FIG. 2B) is formed on the outer peripheral surface of the shaft 3 by lowering. In this case, as shown in FIG. 2C, a screwless insertion portion 11 can be left without forming a screw in the portion near the base of the shaft 3.
5). When the formation of the male screw 5 is finished, the one-step threaded cutting tool 6 moves laterally and leaves the outer peripheral surface of the shaft 3, and then is pulled up to return to the original position before starting the processing.

(Screw forming method 2 on the outer peripheral surface of the shaft)
In the present invention, a multistage threaded cutting tool 7 shown in FIGS. 5A and 5B can be used for forming the male screw 5 on the outer peripheral surface of the shaft 3. In this case, the multi-stage threaded cutting tool 7 is rotated (rotated) in the direction of the arrow X in FIG. 2A under the machining conditions set in the NC machine, and contacts the outer peripheral surface of the shaft 3 in FIG. While rotating (revolving) along the outer peripheral surface in the direction of arrow Y in FIG. 2A, a multi-stage (number of blades) right-hand thread is formed on the outer peripheral surface of the shaft 3 at a time. In this case, the right male screw 5 is formed by lowering by one pitch while the multistage threaded cutting tool 7 revolves once. Also in this case, it is possible to leave the screwless insertion portion 11 (FIGS. 2B and 2C) without forming a screw in the portion near the base of the shaft 3. When the formation of the right male screw 5 is completed, the multi-stage screw machining blade 7 moves laterally and leaves the outer peripheral surface of the shaft 3, and then is pulled up to return to the original position before the machining is started.

(Screw forming method 3 on shaft outer peripheral surface)
The screw forming methods 1 and 2 on the outer peripheral surface of the shaft are cases where a right screw is formed on the shaft 3, but in the present invention, the threaded cutting tool 4 is rotated in the right direction along the outer peripheral surface of the shaft 3 (right revolution: It is also possible to form a left-hand thread by raising the shaft 3 from the base side to the tip side while rotating in the direction of arrow Y in FIG. When the one-stage threaded cutting tool 6 is used, it is raised from the root side to the tip side of the shaft 3 while revolving right along the outer peripheral surface of the shaft 3. In this case, a left-hand thread can be formed by raising the thread-forming blade 6 one pitch at a time during a single right revolution. When using a multi-stage threaded cutting tool 7, it is possible to form a left-hand thread by raising it by one pitch from the base side to the tip side while revolving right along the outer peripheral surface of the shaft 3. it can.

  In any of the above screw forming methods, the pitch interval of the threads of the male screw 5, the angle of the thread, the height of the thread, the depth of the groove, etc. are the NC program design values and set numerical values input to the NC processing machine. Determined by. The shaft 3 of the wood 1 can be formed in advance in a pre-process separately from the screw formation.

(Embodiment 2 of screw forming method)
An example of the embodiment of the screw forming method of the present invention will be described with reference to FIGS. In this embodiment, a substantially cylindrical hole 8 is formed in a flat wood 1 with a hole-cutting blade 12, and a female screw 9 is used on the inner peripheral surface of the hole 8 by using a screw-cutting blade 4 (FIG. 4 or FIG. 5). It is an example in the case of forming. In the present embodiment, the same NC processing machine and threaded cutting tool 4 (FIG. 4 or FIG. 5) as in the first embodiment can be used. Also in this case, if the cross-sectional shape of the cutting edge is substantially trapezoidal as shown in FIG. 5A, the strength of the bottom (valley) of the thread groove of the female screw 9 formed on the inner peripheral surface of the hole 8 is ensured. This prevents the screw from being lost or damaged.

(Method 1 of forming screw on the inner peripheral surface of the hole)
In order to form a round hole (hole 8) in the flat wood 1 shown in FIG.
1. The wood 1 to be processed is fixed to the pedestal 10 as shown in FIG.
2. A drilling cutter 12 that rotates under the processing conditions set in the NC processing machine is lowered on the wood 1 to form an unthreaded fitting recess 13 on the inlet side as shown in FIG. A hole 8 having a smaller diameter than the fitting recess 13 is formed inside the fitting recess 13. The screw-less fitting recess 13 can also be formed after the hole 8 is made. As the hole machining blade 12, the same or different one as the shaft machining blade 2 of FIG. 1 can be used. The diameter and depth of the hole 8 are selected according to the application. The fitting recess 13 has an inner diameter that allows the fitting portion 11 formed on the outer peripheral surface of the shaft 3 to be fitted.
3. When the drilling is completed, the drilling tool 12 mounted on the NC machine is automatically replaced with the threading tool 4. As the threading cutter 4, for example, a one-stage threading cutter 6 shown in FIGS. 4A and 4B or a multi-stage threading cutter 7 shown in FIGS. 5A and 5B can be used. When using a single-stage threaded cutting tool 6, it rotates on the inner peripheral surface of the hole 8 while rotating (spinning) in the direction of arrow X (clockwise) in FIG. While rotating in the direction of arrow Y in FIG. 3C along the inner peripheral surface (right revolving), during one revolution, the pitch is lowered to the bottom side of the hole 8 by one pitch and moved to the inner peripheral surface of the hole 8. A female screw (right screw) 9 is formed as shown in FIG.
4). When the internal thread 9 is formed, the threaded cutting tool 6 moves laterally toward the center of the hole 8 and moves away from the inner peripheral surface of the hole 8 to the center, and is then lifted back to the original position before starting the threading. .

(Method 2 for forming screws on the inner peripheral surface of the hole)
In the present invention, a multistage threaded cutting tool 7 shown in FIGS. 5A and 5B can also be used. In this case, do as follows.
1. In the same manner as the screw forming method 1 on the inner peripheral surface of the hole, the screw-less fitting recess 13 and the hole 8 are formed.
2. While rotating (spinning) the multi-stage threaded cutting tool 7 in the direction of the arrow X (clockwise) in FIG. 3 (c) under the processing conditions set in the NC processing machine, while touching the inner peripheral surface of the hole 8 in FIG. A six-step right screw is formed on the inner peripheral surface by making one rotation (right revolving) along the inner peripheral surface in the direction of arrow Y in FIG. Also in this case, the multi-stage threaded cutting tool 7 is lowered by one pitch during the right revolution.
3. When the female screw 9 is formed, the multi-stage threaded cutting tool 7 moves sideways and moves to the center of the hole 8 to move away from the inner peripheral surface of the hole 8, and then is pulled up to the original position before starting the machining. Return. The pitch interval, screw angle, screw groove depth, and the like of the female screw 9 are formed in accordance with the screw of the male screw shaft 15 to be screwed. These are also determined by the machining conditions of the NC program and the numerical values input to the NC machine.

(Method 3 for forming screws on the inner peripheral surface of the hole)
The screw forming methods 1 and 2 on the inner peripheral surface are cases in which a right screw is formed in the hole 8, but in the present invention, the threaded cutting tool 6 is rotated once in the right direction along the inner peripheral surface of the hole 8 (rightward). Revolution: Rotation in the direction of arrow Y in FIG. 3C (the same applies in this paragraph), and a left screw can be formed by raising from the bottom side of the hole 8 to the inlet side. When the one-stage threaded cutting tool 6 is used, it is raised from the bottom side of the hole 8 to the inlet side while revolving right along the inner peripheral surface of the hole 8. In this case as well, one step of the threaded cutting tool 6 is raised by one pitch during the right revolution. When the multi-stage threaded cutting tool 7 of FIG. 5 is used, it is raised by one pitch from the bottom side of the hole 8 to the entrance side while revolving right along the inner peripheral surface of the hole 8.

  In any of the above screw forming methods, the pitch interval of the thread of the male screw 5, the screw angle, the depth of the thread groove, etc. are the numerical values input to the NC program or the NC processing machine and the cutter pitch (using a multi-stage screw processing cutter) Determined). The screw forming method is the case where the screw is formed after the hole 8 is formed. In the present invention, a large number of woods 1 in which the hole 8 is formed in advance are prepared, and the female screw 9 is formed on the inner peripheral surface of the hole 8. Can also be cut.

(Embodiment 1 of threaded wood)
An embodiment of the wood with a screw according to the present invention will be described with reference to FIGS. 6A is provided with a male screw shaft 15, and a screwless insertion portion 11 is formed at the root of the male screw shaft 15. 6A is provided with a female screw hole 19, and a fitting recess 13 without a screw is provided on the inlet side of the female screw hole 19 as shown in FIG. 6A. Is formed. The shape, length, thickness and dimensions of the wood, the outer diameter and length of the male screw shaft 15, the inner diameter and depth of the female screw hole 19, etc. can be arbitrarily selected.

(Other threaded wood embodiments)
The male screw shaft 15 can be formed not only at one end of the wood 1 but also at the other end, or can be formed on the entire outer circumferential surface of the wood 1. When the male screw 5 is provided on the outer circumferential surface of the entire length of the wood 1, it can be used instead of the dowel.

(Embodiment of joining structure of wood with male thread and wood with female thread)
A wood (wood with a male thread) 16 formed with the male screw shaft 15 shown in FIG. 2C and a wood (wood with a female screw) 18 with a female screw hole 19 shown in FIG. As shown in FIG. 7, the male screw shaft 15 can be joined by screwing into the female screw hole 19. In this case, the surface 30 on the root side of the male screw shaft 15 of the male threaded wood 16 is in close contact with the surface 31 of the female threaded wood 18 by screwing into the fitting recess 13 until the fitting portion 11 is fitted. Thus, both the woods 1 are securely screwed together.

  The present invention can be used for joining in various fields such as joining of furniture and joinery such as tables, fences, chairs, joining of pillars and beams of wooden houses, joining of buildings such as pillars and foundations, etc. is there.

An example of the screw formation method of this invention is shown, (a) is a side view of the state which set the square-bar-shaped wood to the base, (b) is a top view of a square-bar-shaped wood, (c) is a square-bar shape The top view of the state which formed the rod-shaped axis | shaft in the end of wood. An example of the male screw formation method of this invention is shown, (a) is a side view at the time of the start of male screw formation to the outer peripheral surface of a rod-shaped shaft, (b) is a side view after male screw formation, (c ) Is a perspective view after male screw formation. It shows an example of the female screw forming method of the present invention, (a) is a vertical cross-sectional view of a state in which a flat plate-like wood is set on a pedestal, (b) is a vertical cross-sectional view of a state in which a round hole is formed in the wood, (C) is a longitudinal cross-sectional view at the start of female screw formation on the inner peripheral surface of the round hole, and (d) is a vertical cross-sectional view of the wood after the female screw hole is formed. It shows an example of a one-stage threaded cutting tool used for screw formation of the present invention, (a) is a side view, (b) is a bottom view. It shows an example of a multi-stage threaded cutting tool used for screw formation of the present invention, (a) is a side view, (b) is a bottom view. (A) is a perspective view before screwing the wood with an external thread of this invention into the wood with an internal thread, (b) is a longitudinal cross-sectional view of the wood with an internal thread. The joint structure of the wood with an external thread and the wood with an internal thread of this invention is shown, (a) is the longitudinal cross-sectional view of the state which screwed the wood with an external thread to the middle, (b) is the state of joining both wood FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wood 2 axis | shaft processing blade 3 axis | shaft 4 Thread processing blade 5 Male screw 6 One-step screw processing blade 7 Multi-step thread processing blade 8 Hole 9 Female screw 10 Base 11 Insertion part 12 Hole processing blade 13 Fitting recessed part 14 Wood tip DESCRIPTION OF SYMBOLS 15 Male threaded shaft 16 Wood with male thread 18 Wood with female thread 19 Female threaded hole 20 Axle blade of a 21-axis machining tool 21 Axis of a knife with a machining tool 22 Abrasion blade of a machining tool 24 A knife axis of one-stage machining tool 25 Thread base of screw cutting tool 26 Blade of one stage thread cutting tool 27 Blade axis of multi stage screw processing tool blade 28 Blade stage of multi stage screw processing tool blade 29 Blade of multi stage screw processing tool blade 30 (on the male screw shaft) Surface 31 (surface of female threaded wood) P Pitch between blades

Claims (7)

  In the screw forming method for wood, the outer peripheral surface of the shaft is applied by applying a blade of a threaded cutting tool that operates under the processing conditions set in the NC processing machine to the outer peripheral surface of the wood shaft or the inner peripheral surface of the wood hole. Or the screw formation method to the wood characterized by forming a screw in the internal peripheral surface of a hole.   The screw forming method for wood according to claim 1, wherein the same threading blade is used for screwing the outer peripheral surface of the shaft and screwing the inner peripheral surface of the hole. Forming method.   A screw shaft or a screw hole in which a screw is formed by the screw forming method for a wood according to claim 1 or 2 is provided on an outer peripheral surface of the wood shaft or an inner peripheral surface of a wood hole. Threaded wood.   4. The threaded wood according to claim 3, further comprising a fitting portion on which a screw is not formed on the root side of the screw shaft.   The threaded wood according to claim 3, wherein the threaded wood is provided with a fitting recess in which the threaded shaft fitting part according to claim 4 is not threaded on the screw hole inlet side. .   4. A wood joining structure characterized in that, in a wood-to-wood joining structure, both woods are joined by screwing the male threaded shaft of wood according to claim 3 into the female threaded hole of wood according to claim 3.   In the joining structure of wood, the male screw shaft of the wood according to claim 4 is screwed into the female screw hole of the wood according to claim 5, and the fitting portion of the male screw shaft is fitted into the fitting recess of the female screw hole. A joint structure of wood characterized by joining both pieces of wood.

Images