JP7480108B2 - How to reuse wood using drift pins - Google Patents

Description

The present invention relates to a method for recycling wood using a drift pin that can connect a first member and a metal fitting by inserting a part of the metal fitting that connects to the first member into a slit of a predetermined depth formed on the end surface of the first member and driving the drift pin into a pin insertion hole formed on the side of the first member and on a part of the metal fitting within the slit.

Conventionally, for example in wooden buildings, drift pins have been used at the joints between columns and beams or between beams, and the base end of the drift pin, which is opposite the tip end, is generally driven into the pin insertion hole with a hammer or the like to connect one of the components to the connecting fitting (see, for example, Patent Document 1).

JP 2017-119962 A

In the case where the first member in the conventional method described above is made of wood, in particular, it was not considered that the building would be dismantled and rebuilt in order to move the building to another location after assembly, or to be converted into a building for a different purpose than the original building, and that the building members such as wood would be reused.
For this reason, no special improvements have been made to the drift pins.
However, when a building is used for a short period of time and then an equivalent building is moved to another location or converted into a different use, the connections between the components are often destroyed when the old building is demolished, making it difficult and uneconomical to reuse the components.

The object of the present invention is therefore to solve the above problems and make it easier to reuse building materials such as wood, making it easier to relocate them or repurpose them into buildings for different uses, thus improving economic efficiency.

The first characteristic feature of the method for recycling wood using drift pins of the present invention is to form the driving tip so that the diameter becomes smaller toward the tip, and to form the driving base end, which is opposite to the driving tip and for directly striking the wood with a hammer, to have a diameter equal to or larger than that of the main body between the driving tip and the driving base end, to provide a recess for engaging with a pin extraction metal fitting at the driving base end, and to prepare at least two types of drift pins in which the main body has an uneven surface portion formed with a large number of protrusions that protrude in the radial direction on a part of the outer circumferential surface in the longitudinal direction, and to form the uneven surface portion of the first drift pin among the plurality of drift pins. Rather, the position of the uneven surface portion of the second drift pin is formed close to the driving tip, and the first drift pin is driven into the pin insertion hole of the first member made of wood and the connecting fitting to connect the first member and the connecting fitting in a first connected state in which the first member and the connecting fitting are connected, and the tip of the pin removal fitting and the locking recess are engaged and connected to pull the first drift pin out of the first member, separating the first member and the connecting fitting to a disassembled state, and then a second drift pin is driven into the pin insertion hole of the first member and the connecting fitting that was used in the first connected state to connect the first member and the connecting fitting to a second connected state in which the first member and the connecting fitting are connected.

According to the first characteristic configuration of the present invention, a locking recess for the pin extraction hardware is provided at the base end of the drift pin opposite the tip end. This makes it possible to easily pull out the drift pin that has been driven into the first member by engaging and connecting the pin extraction hardware with the locking recess, and allows the first member to be dismantled without damaging the connection as much as possible, making it easier to reuse the building member.

The uneven surface portion of the second drift pin is formed closer to the driving tip than the uneven surface portion of the first drift pin among the plurality of drift pins, so that the first drift pin and the second drift pin can be used differently depending on the material of the first member, for example. In addition, when the first member is reused several times, the uneven surface portion formed closer to the driving tip can be pressed into a pin insertion hole that has not been enlarged by using the second drift pin after removing the first drift pin, thereby maintaining the holding force of the drift pin when the member is reused.
The pin extraction fittings allow the drift pin to be easily extracted from the first component while preventing damage to the structural connection of the building, making it easier to reuse each component of the structure to reach the second connection state, thereby improving cost-effectiveness.
Then, when the wood used in the first connection state is reused to create the second connection state by driving in the drift pin, even if the inner surface of the pin insertion hole after the disassembled state is slightly roughened by the uneven surface of the drift pin when it is pulled out from the drift pin that was driven in the first connection state, the engagement force between the uneven surface of the drift pin and the pin insertion hole in the second connection state is ensured to be strong, and the connection state with the first member can be again stably ensured.
In other words, when the first connected state is used, and when the second connected state is achieved after subsequent separation and disassembly, even if the pin insertion hole of the first member is enlarged in diameter by driving in the first drift pin, the use of the second drift pin ensures a high frictional engagement force between the second drift pin and the pin insertion hole, thereby making it easier to reuse the first member.
Therefore, it is possible to improve the economic efficiency by reusing building materials.

The second characteristic configuration of the present invention is to form the driving tip end so that the diameter becomes smaller toward the tip end, and to form the driving base end, which is for providing a direct impact with a hammer on the opposite side of the driving tip end, so that the diameter is the same as or larger than the main body between the driving tip end and the driving base end, and to provide a recess for engagement with a pin extraction fitting on the driving base end, and to provide at least two types of drift pins in which the main body has an uneven surface portion formed with a large number of protrusions that protrude in the radial direction on a part of the outer circumferential surface in the longitudinal direction, and to provide a second drift pin having a larger diameter than the uneven surface portion of the first drift pin among the plurality of drift pins. The area in which the uneven surface portion is formed in the axial direction of the drift pin is made large, and the first drift pin is driven into the pin insertion hole of the first member made of wood and the connecting fitting to connect the first member and the connecting fitting in a first connected state, and the tip of the pin removal fitting is engaged with the locking recess to pull the first drift pin out of the first member, separating the first member and the connecting fitting to a disassembled state, and then a second drift pin is driven into the pin insertion hole of the first member and the connecting fitting that was used in the first connected state to connect the first member and the connecting fitting to a second connected state.

According to the second characteristic configuration of the present invention, for example, the first drift pin and the second drift pin can be used selectively depending on the material of the first member.
In other words, when the material of the first component is hard, using the first drift pin makes it easier to hammer the component into the pin insertion hole, and when the material is soft, using the second drift pin increases the frictional resistance, making it easier to prevent the drift pin from falling out after being driven in.
Furthermore, when the first member is reused several times, the first and second drift pins can be replaced in sequence, thereby making it possible to maintain the holding force of the drift pins when the member is reused.

The third characteristic configuration of the present invention is to form the driving tip end so that the diameter becomes smaller toward the tip end, and to form the driving base end, which is for providing a direct impact with a hammer on the opposite side of the driving tip end, so that the diameter is the same as or larger than the main body between the driving tip end and the driving base end, and to provide a recess for engaging with a pin extraction fitting on the driving base end, and to provide at least two types of drift pins in which the main body has an uneven surface portion formed with a large number of protrusions that protrude in the radial direction on a part of the outer circumferential surface in the longitudinal direction, and to provide a first drift pin of the plurality of drift pins with a larger diameter than the uneven surface portion of the first drift pin. The degree of protrusion of the convex portion of the uneven surface of the second drift pin is increased, and the first drift pin is driven into the pin insertion hole of the first member made of wood and the connecting fitting to connect the first member and the connecting fitting in a first connected state, and the tip of the pin removal fitting is engaged and connected to the locking recess to pull the first drift pin out of the first member, separating the first member and the connecting fitting to a disassembled state, and then a second drift pin is driven into the pin insertion hole of the first member and the connecting fitting that was used in the first connected state to connect the first member and the connecting fitting to a second connected state.

According to the third characteristic configuration of the present invention, for example, the first drift pin and the second drift pin can be used selectively depending on the material of the first member.
In other words, if the material of the first member is hard, using the first drift pin makes it easier to hammer it into the pin insertion hole, and if it is soft, using the second drift pin increases the degree of protrusion of the convex portion (i.e., the maximum outer diameter of the convex portion of the second drift pin is larger than that of the first drift pin), which increases the frictional resistance and makes it easier to prevent the drift pin from falling out after being driven in.
Furthermore, when the first member is reused several times, the first and second drift pins can be replaced in sequence, thereby making it possible to maintain the holding force of the drift pins when the member is reused.

The fourth characteristic feature of the present invention is that the pin insertion hole is a through hole whose orientation has a vertical component, the base end of the drift pin has a flange portion with a diameter larger than the outer diameter of the main body, and the drift pin is driven in so that the flange portion is positioned on the higher of the two openings of the pin insertion hole.

According to the fourth characteristic configuration of the present invention, by driving the drift pin into the pin insertion hole so that the flange portion is positioned on the higher of the two openings, the drift pin can be prevented from falling downward inside the pin insertion hole even if the building is subjected to vibrations or the like.
Therefore, the connection structure by the drift pin can be stably maintained.
When a drift pin is driven into a pin insertion hole drilled in the first member, for example, vertically or diagonally, there is a risk that the frictional holding force with the pin insertion hole will weaken and the pin will slip out, especially if the first member is made of wood, due to prolonged drying or external forces such as vibrations applied to the building.In such a case, the flange portion can prevent the pin from slipping out of the pin insertion hole, making it easier to ensure the stability of the building's structure over the long term.

FIG. 2 is an overall perspective view of the disassembled state before the drift pin is assembled. FIG. 2 is a perspective view showing a state in which the drift pin is assembled and in use. 1A is a partial cross-sectional front view of a drift pin, and FIG. 1B is a partial cross-sectional front view of a driving base end portion (part AA in FIG. 1A) of the drift pin. 1A is a front view of the drift pins, (b) is a front view of the drift pins in a first connection state, (c) is a front view of the drift pins in a first connection state of another embodiment, and (d) is a front view of the drift pins in a second connection state of another embodiment. FIG. 1 is an operational diagram showing the procedure for using a pin extraction fitting to extract a drift pin, where (a) shows the state before being connected to the drift pin, (b) shows the state after being connected to the drift pin, (c) shows the state in the middle of being extracted by sliding the weight member of the pin extraction fitting, and (d) shows the state after the drift pin has been extracted. 1A is a plan view showing a pin connection state of a comparative example, and FIG. 1B is a longitudinal sectional front view taken along line BB of FIG. 1A is a partial cross-sectional front view of a drift pin of another embodiment, and FIG. 1B is a partial cross-sectional front view of a driving base end portion (the CC portion in FIG. 1A) of the drift pin of another embodiment. 1A is a plan view showing another embodiment of a drift pin in use, and FIG. 1B is a vertical sectional front view taken along line DD of FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in Figures 1 and 2, in a wooden building, for example, when connecting a wooden beam 2 to a wooden pillar 1, a pair of left and right side plates 3A that are part of a metal connecting fitting 3 to be attached to the pillar 1 protrude from the base end 3B of the connecting fitting 3 and are inserted into a pair of slits 4 of a predetermined depth formed in the end face of the beam 2. Drift pins 6 are provided that can be driven into pin insertion holes 5 formed in each of the pair of side plates 3A of the connecting fitting 3 in the slits 4 and on the side of the beam 2, thereby connecting the beam 2 and the connecting fitting 3.

The connection between the connecting fitting 3 and the pillar 1 is achieved by forming bolt insertion holes 7 in the base end 3B of the connecting fitting 3 and in the pillar 1, and fixing the base end 3B of the connecting fitting 3 to the pillar 1 with a bolt 9 inserted into the bolt insertion hole 7 via a washer (not shown).
The base end 3B of the connecting fitting 3 is accommodated within a first countersink portion 10 formed in the pillar 1 and has a larger diameter than the bolt insertion hole 7, and a second countersink portion 11 for internally accommodating a bolt head 9A or a nut 12 is also formed in the pillar 1 on the side opposite the first countersink portion 10.
In addition, a pair of left and right side plates 3A of the connecting fitting 3 are formed with pin grooves 13 that enable the drift pin 6 to be engaged to temporarily fix the beam 2 to the column 1. Therefore, when the drift pin 6 is driven into the beam 2 in advance and the drift pin 6 is engaged into the pin groove 13, the beam 2 is temporarily fixed to the column 1, and then the drift pin 6 is driven into another pin insertion hole 5, whereby the beam 2 is fixed to the column 1.

[First embodiment]
As shown in Figures 3(a) and (b), the drift pin 6 is formed from a metal rod-shaped body with a rounded tip, and a base end 15 opposite the driving tip 14 is provided with a locking recess 17 for engagement with a pin extraction fitting 16.
In other words, the driving tip 14 is formed so that the diameter becomes smaller toward the tip, and the driving base end 15, which is for delivering a direct strike with the hammer on the opposite side to the driving tip 14, is formed to be the same diameter as or larger than the main body portion 25 between the driving tip 14 and the driving base end 15.

As shown in Figures 1, 2, 3(a) and 3(b), in order to reuse wood, a locking recess 17 for a pin extraction fitting 16 is provided at the driving base end 15 opposite to the driving tip 14 of the drift pin 6. The drift pin 6 is driven into the pin insertion hole 5 to connect one member, the beam 2, and the connecting fitting 3, in the first connection state, the tip of the pin extraction fitting 16 is engaged and connected to the locking recess 17 to pull the drift pin 6 out of the beam 2 (Figures 5(a) to (d)), and the column 1 and beam 2 are separated to a dismantled state. After that, a part of the connecting fitting 3 is inserted into a slit 4 of a specified depth formed on the end surface of the beam 2 that was used in the first connection state, and then the drift pin 6 is driven into the pin insertion hole 5 formed on the side of the beam 2 and on a part of the connecting fitting 3 in the slit 4 to connect the beam 2 and the connecting fitting 3 to the second connection state.

As shown in Figures 3(a) and (b), the locking recess 17 has a female threaded portion 18, and at its outer end closer to the entrance of the recess than the female threaded portion 18, an enlarged diameter hole portion 19 larger than the diameter of the valley portion of the female threaded portion 18 is provided.When the drift pin 6 is driven into the pin insertion hole 5 of the wood with a hammer, even if the impact of the hammer is so great that the driving base end 15 is plastically deformed, deformation of the female threaded portion 18 can be prevented.Therefore, when a building is demolished, the drift pin 6 can be smoothly pulled out without interfering with the screw-threaded connection work between the male threaded portion 20 formed at the tip of the pin removal fitting 16 and the female threaded portion 18 provided at the driving base end 15 of the drift pin 6.
As shown in FIG. 5, the pin removal fitting 16 is configured from what is generally referred to as a slide hammer, which has a rod-shaped main body 22 with a male threaded portion 20 at its tip, and a slidable weight member 21 attached to the rod-shaped main body 22. The weight member 21 is slid between a pair of stopper portions 23 provided at two locations, one end of the main body 22 on the base end side and the other end forward of the male threaded portion 20, and an impact force is applied to the stopper portion on the opposite side to the male threaded portion 20, thereby applying a removal force to the male threaded portion 20.

As shown in Figures 3(a) and (b), the outer peripheral edge of the driving base end 15 of the drift pin 6 is chamfered to prevent the outer diameter from becoming larger than the main body 25 due to plastic deformation caused by the impact of the hammer.

In order to increase the connecting strength with the pin insertion hole in the wood, the outer peripheral surface of the drift pin 6 is formed with an uneven surface portion 26, for example by knurling, along part of the longitudinal direction of the outer peripheral surface (Figures 4(a) and (c)).
After the drift pins 6 driven in during the first connection state are pulled out and disassembled, the drift pins 6 are driven in again to return to the second connection state, so that the building materials can be reused. In order to do this, the drift pins 6 used in the second connection state have knurled parts that are different from those used in the first connection state (Figures 4(b) and (d)).
In other words, among the drift pins 6, the position of the uneven surface portion 26 of the second drift pin 6B used in the second connected state is located closer to the driving tip 14 (Figure 4(b)) than the position of the uneven surface portion 26 of the first drift pin 6A used in the first connected state (Figure 4(a)).
Therefore, by positioning the uneven surface portion 26 of the second drift pin 6B used in the second connection state closer to the driving tip 14 than the position of the uneven surface portion 26 of the first drift pin 6A used in the first connection state, after the first drift pin 6A used in the first connection state is pulled out, the uneven surface portion 26 of the second drift pin 6B forming the second connection state will be driven into the pin insertion hole portion that is not damaged by the uneven surface portion 26, unlike the rough surface portion of the inner surface of the pin insertion hole 5 formed by the uneven surface portion 26 of the first drift pin 6A, making the connection state stronger when the building components are reused.

[Another embodiment]
Other embodiments will be described below.
In the following other embodiments, the same components as those in the above embodiment are denoted by the same reference numerals.
<1> The objects to be connected may be drift pins 6 used in connecting structures of materials other than wood.
<2> The locking recess 17 is provided with a female thread portion 18 for connection to the pin-removal fitting 16. However, a locking mechanism having a different structure other than the female thread portion 18 may be used as long as it is capable of connecting to the pin-removal fitting 16. The locking mechanism may have a simple structure.
<3> Of the plurality of drift pins 6, the uneven surface portion 26 of the second drift pin 6B may have a greater protrusion than the uneven surface portion 26 of the first drift pin 6A.
4(c) and 4(d), the uneven surface portion 26 may be formed so that the length of the uneven surface portion 26 on the first drift pin 6A to be driven in the first connected state (FIG. 4(c)) is longer than the length of the uneven surface portion 26 on the second drift pin 6B to be driven in the second connected state (FIG. 4(d)).
<5> The uneven surface portion 26 may be formed in the form of a spiral groove, a number of wart-like protrusions, a plurality of ring grooves, or a ring-like protrusion, other than the knurling.
<6> In the embodiment described above, the connecting fitting 3 is attached to the column 1, and the side panel 3A of the connecting fitting 3 is inserted into the slit 4 formed on the end surface of the beam 2, and the column 1 and the beam 2 are connected by the drift pin 6. However, the drift pin 6 may be used in a structure for connecting beams 2 that have different extension directions.

[Second embodiment]
As shown in Figures 6(a) and 6(b), when drift pins 6 are used in structures such as connecting beams 2 that support a floor surface, the drift pins 6 may be driven into pin insertion holes 5 that have a vertical component or a top-bottom direction, and in this case, if a normal rod-shaped drift pin 6 has a pin insertion hole 5 that is a vertical through hole, it may slip out downward due to external factors such as vibrations acting on the building. In contrast, as shown in Figures 7(a) and 7(b) and Figures 8(a) and 8(b), a drift pin 6 having a flange 27 with a diameter larger than the outer diameter of the main body 25 at its driving base end 15 is used, and the drift pin 6 is driven in so that the flange 27 is located on the higher of the two openings of the pin insertion hole 5.

In addition, as shown in Figures 7(a) and (b), the engagement recess 17 of the drift pin 6 is provided with a female thread 18, as described above, and an enlarged diameter hole 19 larger than the diameter of the valley of the female thread 18 is provided at the outer end of the recess entrance side of the female thread 18. When the drift pin 6 is hammered into the pin insertion hole 5 of the wood, even if the impact of the hammer is large and the driving base end 15 is plastically deformed, the deformation of the female thread 18 can be prevented. Therefore, when the building is demolished (Figures 5(a) to (d)), the male thread 20 formed at the tip of the pin extraction fitting 16 and the female thread 18 provided at the driving base end 15 of the drift pin 6 are not hindered, and the drift pin 6 can be smoothly pulled out.

[Another use for drift pins]
The drift pins 6 are driven into the pin insertion holes 5 from different openings in the first and second connection states.
In other words, in the pin insertion hole 5, in the first connection state, the drift pin insertion portion at the back from the opening of the pin insertion hole is expanded in diameter by the drift pin 6 and its inner surface is deformed, so that when the drift pin 6 is driven in again, the frictional holding force of the pin insertion hole 5 against the drift pin 6 may be lower than in the first connection state. However, if the drift pin 6 is driven in from different openings of the pin insertion hole 5 in the first and second connection states, it is possible to achieve the same thing as driving the drift pin 6 into a new pin insertion hole portion, and the frictional holding force of the pin insertion hole 5 against the drift pin 6 can be ensured to be high.
Therefore, when reusing a building component, for example, if the pin insertion hole 5 is a through hole, the drift pin 6 can be driven in from the opening on one side and the drift pin 6 can be driven in from the opening on the other side twice in the first connection state and the second connection state, respectively, so that the building component can be reused a total of at least four times.

As mentioned above, the reference numerals are used for ease of comparison with the drawings, but the present invention is not limited to the configurations shown in the attached drawings. Furthermore, it goes without saying that the present invention can be embodied in various forms without departing from the spirit of the invention.

3 Connecting metal fitting 4 Slit 5 Pin insertion hole 6 Drift pin 6A First drift pin 6B Second drift pin 14 Driving tip portion 15 Driving base portion 16 Pin removal metal fitting 17 Retaining recess 25 Main body portion 26 Uneven surface portion 27 Flange portion

Claims (4)

The driving tip is formed so that the diameter becomes smaller toward the tip side,
A driving base end portion for directly striking the driving tip end portion with a hammer is formed to have the same diameter as or a larger diameter than a main body portion between the driving tip end portion and the driving base end portion,
A recess for engaging with a pin-removing metal fitting is provided at the driving base end,
At least two types of drift pins are prepared, each having an outer circumferential surface portion formed with a large number of protrusions protruding in a radially expanding direction on a part of the longitudinal direction of the outer circumferential surface of the main body,
the uneven surface portion of the second drift pin is formed closer to a driving tip portion than the uneven surface portion of the first drift pin among the plurality of drift pins;
From a first connected state in which a first drift pin is driven into a pin insertion hole of a first member made of wood and a connecting fitting, the first member and the connecting fitting are connected to each other,
a tip end of the pin-removal fitting and the locking recess are engaged to pull out the first drift pin from the first member, and the first member and the connecting fitting are separated to a disassembled state;
A method of recycling wood using drift pins, in which a second drift pin is then driven into the pin insertion hole of the first member and the connecting fitting that were used in the first connected state to create a second connected state in which the first member and the connecting fitting are connected. The driving tip is formed so that the diameter becomes smaller toward the tip,
A driving base end portion for directly striking the driving tip end portion with a hammer is formed to have the same diameter as or a larger diameter than a main body portion between the driving tip end portion and the driving base end portion,
A recess for engaging with a pin-removing metal fitting is provided at the driving base end,
At least two types of drift pins are prepared, each having an outer circumferential surface portion formed with a large number of protrusions protruding in a radially expanding direction on a part of the longitudinal direction of the outer circumferential surface of the main body,
a forming area of the uneven surface portion of a second drift pin in an axial direction of the second drift pin is made larger than a forming area of the uneven surface portion of a first drift pin among the plurality of drift pins,
From a first connected state in which a first drift pin is driven into a pin insertion hole of a first member made of wood and a connecting fitting, the first member and the connecting fitting are connected to each other,
a tip end of the pin-removal fitting and the locking recess are engaged to pull out the first drift pin from the first member, and the first member and the connecting fitting are separated to a disassembled state;
A method of recycling wood using drift pins, in which a second drift pin is then driven into the pin insertion hole of the first member and the connecting fitting that were used in the first connected state to create a second connected state in which the first member and the connecting fitting are connected. The driving tip is formed so that the diameter becomes smaller toward the tip,
A driving base end portion for directly striking the driving tip end portion with a hammer is formed to have the same diameter as or a larger diameter than a main body portion between the driving tip end portion and the driving base end portion,
A recess for engaging with a pin-removing metal fitting is provided at the driving base end,
At least two types of drift pins are prepared, each having an outer circumferential surface portion formed with a large number of protrusions protruding in a radially expanding direction on a part of the longitudinal direction of the outer circumferential surface of the main body,
a protruding degree of the convex portion on the uneven surface portion of a second drift pin is set to be larger than a protruding degree of the convex portion on the uneven surface portion of a first drift pin among the plurality of drift pins,
From a first connected state in which a first drift pin is driven into a pin insertion hole of a first member made of wood and a connecting fitting, the first member and the connecting fitting are connected to each other,
a tip end of the pin-removal fitting and the locking recess are engaged to pull out the first drift pin from the first member, and the first member and the connecting fitting are separated to a disassembled state;
A method of recycling wood using drift pins, in which a second drift pin is then driven into the pin insertion hole of the first member and the connecting fitting that were used in the first connected state to create a second connected state in which the first member and the connecting fitting are connected. The pin insertion hole is a through hole oriented in a vertical direction, and the base end of the drift pin has a flange portion with a diameter larger than the outer diameter of the main body. The drift pin is driven into the pin insertion hole so that the flange portion is positioned on the higher of the two openings. A method for recycling wood using drift pins according to any one of claims 1 to 3.

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