Screw

Abstract

To provide a screw that can provide sufficient strength to join a plate material and durability after joining.SOLUTION: A screw includes a screw body part and a screw thread provided in the screw body part. The screw thread includes a first screw thread having a first height and a second screw thread having a second height, where the first height is higher than the second height.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a screw used for joining members, including wooden members. [Background technology]

[0002] There are many types of buildings in various places, such as houses, stores, commercial facilities, public facilities, and medical facilities. The materials used for these buildings are selected based on their characteristics, size, purpose, required specifications, and the like. In particular, concrete, new building materials, wood, or a combination of these materials are used for structural members such as pillars, beams, exterior walls, interior walls, roofs, and floors of buildings. Of course, concrete, new building materials, wood members, or a combination of these materials are also used for the foundations and frameworks of buildings.

[0003] Additionally, materials other than concrete, new building materials, and wood components may be used.

[0004] Recently, new building materials and wooden members are increasingly being used in structural components such as pillars, beams, exterior walls, interior walls, roofs, and floors, in addition to concrete. For example, exterior walls and floors are increasingly being constructed from wooden members. This is because buildings constructed from wooden members can reduce the environmental impact in homes, stores, public facilities, and the like.

[0005] Furthermore, residents and users can feel relaxed both physically and mentally in buildings made of wooden materials. Of course, there is also the benefit of increased livability. Buildings made of wooden materials have the advantage of being highly adaptable to outdoor temperatures (cool indoors in summer and warm indoors in winter) and to indoor humidity. This increases convenience for residents and users.

[0006] In addition, buildings made of wooden materials have a mentally refreshing effect on the residents and users. In Japan in particular, wooden buildings have been the norm for a long time, so wooden buildings have a great advantage on the Japanese mentality.

[0007] Alternatively, new building materials and special materials can often provide benefits and advantages to buildings that are different from those of concrete, even if they have the same or different effects as wooden components.

[0008] Thus, it is expected that buildings using not only concrete but also wooden members and new building materials (or similar materials) will become more common in the future. In other words, wooden members and new building materials (or similar materials) will be used for the structural parts of buildings, such as pillars, beams, exterior walls, interior walls, roofs, and floors. This will enable the construction of buildings such as homes, stores, and public facilities.

[0009] Here, when materials such as wooden members and new building materials are used in buildings, it is necessary to manufacture an integrated building material unit by combining multiple boards. For example, wooden boards are joined in the width direction to form a wooden member building material unit, or wooden boards are joined in the thickness direction to form a wooden member building material unit.

[0010] The same is true for building material units made from new building materials.

[0011] When joining such wood or new building material boards in the width direction or thickness direction, (1) they are joined with adhesive, (2) they are joined with connecting members such as screws, or (3) a combination of these or other means is used. This is because joining the boards produces building material units for use as wall materials for exterior and interior walls, or structural materials.

[0012] Here, when adhesive (1) is used, a certain level of strength can be achieved when bonding in the thickness direction, but when bonding in the width direction, the strength is undeniably insufficient. This is because bonding in the width direction only involves bonding on the sides of the boards, and the bonding area is too small. Furthermore, whether bonding in the thickness direction or width direction, problems arise in that the bonding strength of the adhesive itself is insufficient, and the adhesive strength of the adhesive decreases due to the influence of external environments such as heat (both high and low temperatures), deterioration over time, and wind and rain. There is a concern that buildings constructed with building material units bonded with such adhesives may be inferior in durability and weather resistance.

[0013] For this reason, connecting members such as screws are used to join wood or new building material boards in the width and thickness directions, as shown in (2). The screws join the boards together, and by joining them together, a building material unit is produced.

[0014] Several techniques have been proposed for such screws (see, for example, Patent Documents 1, 2, and 3). [Prior art documents] [Patent documents]

[0015] [Patent Document 1] JP 2018-189244 A [Patent Document 2] JP 2020-109321 A [Patent Document 3] Patent Publication No. 2020-133661 Summary of the Invention [Problem to be solved by the invention]

[0016] Patent Document 1 discloses a male threaded member having a head 10 and a shank 20, the shank 20 having a normal thread portion 22 on which a normal thread 21 is formed for fastening to a female thread member 110, a guide thread portion 265 provided on the shank tip side relative to the normal thread portion 22 and on which a guide thread 25 of a smaller diameter and the same pitch as the normal thread 21 is formed, and a cylindrical guide 24 provided further on the shank tip side of the guide thread portion 26, the male threaded member being characterized in that an unthreaded region 29 is provided between the guide thread 25 and the cylindrical guide 24, an axial gap g is provided between a tip 25e of the guide thread 25 and the cylindrical guide 24, and the outer circumferential surface of the root portion of the guide thread 25 is a cylindrical surface of the same diameter as the root diameter of the normal thread but smaller than the guide.

[0017] The screw disclosed in Patent Document 1 is intended to make it easier to insert into a screw hole by having the height of the threads at the tip of the screw lower than the height of the threads in other parts.

[0018] However, even if the screw hole is easily inserted, the joining strength of the plate material cannot be improved. This is the same as with conventional general screws. This means that the joining strength cannot be increased when joining plate materials in the thickness direction. Furthermore, the strength is even more insufficient when joining the sides of the plate materials in the width direction. Insufficient joining strength results in insufficient durability, weather resistance, environmental adaptability, and durability against aging deterioration after use in a building. In other words, the durability and strength of buildings using wooden members, etc. cannot be improved.

[0019] Patent Document 2 includes a start head 1 and a rod 2 integrally connected to the start head 1. The rod 2 has a main rod portion 21 and a terminal portion 22. The main rod portion 21 and the terminal portion 22 each have a first end and a second end, and the first end of the main rod portion 21 is provided on the start head 1 side. The second end of the main rod portion 21 and the first end of the terminal portion 22 are connected, and a pyramidal end 221 is formed at the second end of the terminal portion 22. The diameter of the terminal portion 22 is smaller than the diameter of the main rod portion 21. A first thread 23 is formed on the main rod portion 21, extending helically from the second end to the first end. A second thread 24 is formed on the terminal portion 22, extending helically from the second end to the first end. A thread structure is disclosed in which the second thread 24 and the first thread 23 are connected and a plurality of drill units 25 are formed on the terminal portion 22 .

[0020] Patent Document 2 has the same problems as Patent Document 1. In addition, when joining plate materials such as wooden members in the width direction, there is a problem that there is no ingenuity to increase the joining strength. The technology of Patent Document 2 may increase the joining strength when there is a nut to receive the screw, but if a nut is required, there is a problem that the plate materials cannot be joined continuously in the width direction.

[0021] Patent Document 3 discloses a screw having a recess 7 partially provided on a flank surface 131 of a thread provided on a screw shaft body, characterized in that the thread 13 in the portion where the recess 7 is formed is smaller than a regular thread 3, and the thread height H12 at the front end in the screwing direction is lower than the thread height at the rear end H11 in the screwing direction W.

[0022] Patent Document 3 has the same problem as Patent Document 1. That is, the problem is that the improvement of the joining strength of the plate materials is insufficient. Also, the insufficient joining strength leads to the problem that the building constructed with this building material unit is inferior in strength and durability.

[0023] As described above, the prior art had a problem in that it was not possible to exert sufficient strength to join board materials such as wooden members.

[0024] In view of these problems, the present invention has an object to provide a screw that can achieve sufficient strength for joining plate materials and durability after joining. [Means for solving the problem]

[0025] The screw of the present invention comprises a screw body and A screw thread is provided on the screw body portion, the threads include a first thread at a first height and a second thread at a second height; The first height is greater than the second height. Ku, The first thread and the second thread are provided in a random order in the thread body, and the thread further includes a third thread having a third height different from both the first height and the second height. A first wooden plank; A second wooden board having a second screw hole on a side into which the screw is inserted; a third wooden board having a third screw hole on a side surface thereof, the third screw hole being formed alternately with the second screw hole and into which the screw is inserted; is used in joined building material units, The building material unit is The side surfaces of the first wooden board and the second wooden board are joined together by the screw inserted through the second screw hole, The screw inserted through the third screw hole closes the second screw hole of the second wooden board with the third wooden board and joins the sides of the second wooden board and the third wooden board together, thereby joining the first wooden board, the second wooden board, and the third wooden board. . Effect of the Invention

[0026] The screw of the present invention has a thread of a first height and a thread of a second height, and therefore the joining strength of the plate members is increased. In particular, the joining strength is increased when joining plate members such as wooden members and new building materials. In addition, the joining strength can be achieved even when joining plate members in a direction connecting the side surfaces of the plate members.

[0027] Furthermore, the screws themselves and the joined state are highly durable, which improves the strength and durability of building material units that are joined together with the screws.

[0028] As a result, the strength and durability of buildings constructed using this building material unit are improved. In particular, it is now possible to apply the building material unit made of wooden members to locations where it has been difficult to use the building material unit made of wooden members in the past. [Brief description of the drawings]

[0029] [Figure 1] 6 is a photograph showing an operation of joining plate materials using the screw of the present invention. [Diagram 2] FIG. 2 is an explanatory diagram showing a state in which plate materials are joined together using the screw of the present invention. [Diagram 3] FIG. 1 is a side view of a screw according to a first embodiment of the present invention. [Figure 4] 1 shows comparative results of a pull-out test of the screw 1 according to the first embodiment of the present invention. [Diagram 5] FIG. 2 is a schematic diagram of two plate materials joined in the lateral direction by the screw of the present invention. [Figure 6] FIG. 2 is an enlarged view of a thread in the first embodiment of the present invention. [Figure 7] FIG. 11 is a schematic diagram of a construction material unit in accordance with a second embodiment of the present invention. [Figure 8] 1 is a photograph of a manufactured screw of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] The screw according to the first aspect of the present invention comprises a screw body and A screw thread is provided on the screw body portion, the threads include a first thread at a first height and a second thread at a second height; The first height is greater than the second height.

[0031] This configuration can increase the bonding strength.

[0032] A screw according to a second aspect of the present invention has the same features as those of the first aspect, and is used for joining plate materials in the side direction or in the thickness direction of the plate materials.

[0033] This configuration allows the plate materials to be joined together with high joining strength.

[0034] A third aspect of the present invention provides a screw according to the second aspect of the present invention, in which the plate material is made of wood.

[0035] This configuration makes it possible to create a building material unit in which wooden boards are joined together.

[0036] In a screw according to a fourth invention of the present invention, in addition to any one of the first to third inventions, the one or more first threads and the one or more second threads are provided alternately in the screw body portion.

[0037] This configuration increases the bonding strength.

[0038] In the screw according to a fifth aspect of the present invention, in addition to the features of the fourth aspect, the first threads and the second threads are provided alternately on the screw body.

[0039] This configuration not only makes manufacturing easier, but also increases the strength with which the plates are joined by the screws.

[0040] In a screw according to a sixth aspect of the present invention, in addition to any one of the first to third inventions, the first thread and the second thread are provided in a random order on the screw body.

[0041] This configuration allows for more complex mating and resistance forces to be exerted, increasing joint strength.

[0042] In a screw according to a seventh aspect of the present invention, in addition to any one of the first to sixth inventions, the thread further comprises a third thread of a third height different from both the first height and the second height.

[0043] This configuration can further increase the bonding strength.

[0044] In the screw according to the eighth invention of the present invention, in addition to any one of the first to seventh inventions, at least one of the first thread and the second thread has an inverted V-shaped ridgeline shape in the thread main body.

[0045] This configuration makes it easier to remove sawdust when inserting the screw, resulting in increased adhesion and joint strength.

[0046] A construction material unit according to a ninth aspect of the present invention comprises a screw according to any one of claims 1 to 8, a plurality of plate members each having a screw hole into which the screw is inserted; The plurality of plates are joined together by the screws.

[0047] This configuration makes it possible to realize a building material unit having high strength and durability.

[0048] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0049] (Embodiment 1)

[0050] (Manufacturing building material units using screws) The screw of the present invention is used to join two plates made of wood or other raw materials. Figure 1 is a photograph showing the process of joining two plates using the screw of the present invention. The wooden plates are joined side-to-side. At this time, the plate members are connected by inserting a screw from the side and rotating the screw. The screw fits into the wood by the threads and grooves inside the plate members. This fit gives the screw the power to connect the plate members together and join the plate members together.

[0051] In this case, as shown in Figure 1, it is possible to join the sides (smaller areas) of the plate materials together, rather than the surfaces (larger areas) of the plate materials together. In the latter case, there is a concern that the small joining area may result in insufficient strength and durability after joining. For this reason, when joining with screws, a stronger and more durable joint is required. In other words, screws that increase the joining strength are required.

[0052] 2 is an explanatory diagram showing a state in which plate materials are joined together using the screw of the present invention. Plate materials 100 need to be joined together. For example, this is the case when wooden plate materials are joined together to form a larger unit of building material 200. The larger unit of building material 200 is used for structural parts such as columns, beams, exterior walls, interior walls, roofs, and floors of various buildings such as houses and facilities. For example, the building material unit 200 is used as a wall material.

[0053] Furthermore, the boards 100 may be joined side-to-side as shown in Fig. 2, rather than joined together by surfaces with a larger surface area. This is because there are cases where it is desired to manufacture a building material unit 200 with a larger area. As described above, when used for the exterior or interior walls of a building, a building material unit 200 with a large area is required. This includes not only wooden boards 100, but also joining boards made of resin, new materials, and other materials.

[0054] The screw 1 is used to join such plate materials 100 together. That is, as shown in Fig. 2, the screw 1 is used to join the sides of the plate materials 100 together to manufacture a building material unit 200 with a larger area. Fig. 1 shows the operation of the device for manufacturing the building material unit 200.

[0055] Of course, the screw 1 may be used in other cases besides joining side surfaces together as shown in FIG. 2 (joining surfaces together or joining other parts together). The screw 1 joins multiple plate materials 100 together. In this way, a building material unit 200 is manufactured. This building material unit 200 can be used in various places in a building. For this reason, instead of joining only two plate materials 100 as shown in FIG. 2, three or more plate materials 100 may be joined together.

[0056] If the screw 1 is longer than the length of one of the plate materials 100 in the joining direction, two plate materials 100 can be joined as shown in Fig. 2. If the plate materials 100 are alternately joined using this screw 1, three or more plate materials 100 can be joined. Alternatively, if the screw 1 is longer than the length of two or more plate materials 100 in the joining direction, three plate materials 100 can be joined at once.

[0057] In this way, by using screws 1 of different lengths and by adjusting the order in which the plates 100 are joined and the arrangement of the screws 1, it is possible to join three or more plates 100 together to produce a larger building material unit 200.

[0058] Since the screws 1 are used to manufacture such building material units 200 from the plate materials 100, the screws 1 are required to have strong fitting and joining strength. In particular, when joining the plate materials 100, they may be joined only with the screws 1 without using adhesive. This is because using adhesive may cause deterioration of the plate materials 100. Alternatively, there may be a problem that the building material units 200 obtained by joining lose their flexibility.

[0059] For this reason, a building material unit 200 is manufactured from a plurality of plate materials 100 by mechanically and physically joining them with screws 1 .

[0060] (Screw 1) Fig. 3 is a side view of the screw in embodiment 1 of the present invention. It shows the state of the screw 1 described in Fig. 2 as seen from the side. The screw 1 has a screw body 2 and a thread 3 provided on the screw body 2. The thread 3 is a convex portion formed in a spiral shape on the outer periphery of the screw body 2.

[0061] This spirally formed convex portion becomes the screw thread 3, and the screw 1 can join the plate material 100 by being inserted into the plate material 100 from the tip 7. The portion other than the screw thread 3 becomes a groove. In addition, the head 6 of the screw 1 has a recess that is adapted to a tool. The tool is fitted into this recess and the screw 1 is inserted into the plate material 100.

[0062] Here, the thread 3 includes a first thread 4 having a first height and a second thread 5 having a second height. The first height is higher than the second height. That is, the first thread 4 is higher than the second thread 5. In this way, the screw 1 includes a mixture of first threads 4 and second threads 5 having different heights.

[0063] The mixture of the first thread 4 at the first height and the second thread 5 at the second height in this manner increases the joining strength of the screw 1. The different heights of the first thread 4 and the second thread 5 increase the degree of adhesion of the thread 3 inside the plate material 100. In particular, the physical position and physical volume of the adhesion inside the plate material 100 caused by the first thread 4 at the first height differs from that of the second thread 5 at the second height. The mixture of these different states enables the screw 1 to increase the joining strength of the plate material 100.

[0064] The strength of the connection between the plate materials 100 by the screw 1 is grasped by whether or not the connection by the screw 1 comes loose when the connected plate materials 100 are pulled in opposite directions. Alternatively, it is grasped by the durability when the screw 1 is pulled out of the plate materials 100.

[0065] The first screw thread 4 and the second screw thread 5, which have different heights, join the plate material 100. As a result, contacts of different heights are mixed inside the plate material 100. Therefore, even when a drawing pressure is applied, a high joining strength can be maintained.

[0066] The mixture of adhesions at different heights allows for a more complex resistance to pull-out. The first thread 4 and the second thread 5 create resistance to the pull-out pressure at different heights. This combination of different resistances creates a complex resistance. This complex resistance increases the joint strength and durability.

[0067] The screw 1 in the first embodiment of the present invention can increase the joint strength by mixing the first thread 4 and the second thread 5 of different heights in this way. The high joint strength also increases durability after joining.

[0068] Moreover, the first thread 4 and the second thread 5 form a helical shape on the screw body 2. Moreover, the first thread 4 and the second thread 5 have a V-shape. This makes it easier to expel sawdust when the screw 1 is screwed into wood. The ease of expelling sawdust means that wood fibers are less likely to be damaged. As a result, the degree of adhesion between the screw 1 and the wood increases. In other words, the screw 1 can increase the joining strength with the plate material 100.

[0069] Fig. 4 shows the comparative results of a pull-out test of the screw 1 in the first embodiment of the present invention. Fig. 4 shows the results of inserting the screw 1 of the present invention and another type of screw into a cedar plate material, and measuring the load when pulling each screw from the head. In the graph, the horizontal axis is the amount of displacement. The amount of displacement indicates the amount of pull-out from the plate material when a load to pull out the screw head is applied.

[0070] Since it is a screw, the threads are engaged with the inside of the plate material. In this state, a load is applied to pull the screw out from the head. This pull-out load weakens the internal fit (the tight fit between the threads and the screw groove is released), and the screw is pulled out of the plate material. Of course, this is different from the normal removal of the screw by turning it, as this load is applied to forcibly pull it out by pulling it.

[0071] The amount by which the screw is pulled out of the plate by this pull-out load is the displacement on the horizontal axis, and the pull-out load applied to the screw is the vertical axis of the graph in Figure 4.

[0072] That is, the value on the vertical axis is the pull-out load required to achieve a certain pull-out amount (displacement). In the graph of Fig. 4, the greater the load (vertical axis) required to produce the same amount of displacement, the higher the joining strength of the screw. Here, the graph of Fig. 4 shows the results of experiments conducted using screw 1 of the present invention and other types of screws as comparative examples 1 to 5.

[0073] Here, the screws of Comparative Examples 1 to 5 are different from screw 1 of the present invention in that they do not have a mixture of threads of different heights, but are general screws.

[0074] (Comparison at peak load) The applied load (test force in the graph (unit: Newton (N))) peaks at about 1.5 mm in displacement for both Screw 1 and the comparative example.

[0075] The load required for this peak (i.e., the load required to pull out the screw by about 1.5 mm) is the highest for screw 1, at about 1500 N. In the comparative examples, it is low, at about 1100 N to 1400 N. That is, comparative examples 1 to 5 can achieve a displacement of 1.5 mm with a smaller load than screw 1 of the present invention.

[0076] In other words, even at the peak of the pull-out load, screw 1 requires a larger pull-out load for pulling out compared to the screws of Comparative Examples 1 to 5. This shows that screw 1 has higher joining strength and durability after joining compared to the screws of the Comparative Examples.

[0077] (Comparison at maximum displacement) In the experiment, the maximum displacement was about 4 mm. The pull-out load (test force) required to produce this 4 mm displacement (pull-out amount) was about 1050 N for the screw 1 of the present invention. In contrast, in Comparative Examples 1 to 5, it was about 500 N to 800 N.

[0078] That is, screw 1 requires a larger pull-out load than comparative examples 1 to 5. As a result, it is found that the joint strength of screw 1 is higher than that of the comparative examples. Even when comparing the maximum displacement amounts, it is found that screw 1 has high joint strength and durability.

[0079] Of course, from the graph in Figure 4, it can be seen that the pull-out load of screw 1 is large regardless of the amount of displacement. In other words, it can be seen that screw 1 engaged with a plate material exhibits a higher joining strength than the screw of the comparative example. Furthermore, the fact that it is resistant to pull-out indicates that the durability of the joint, which may change over time, is also high. In other words, screw 1 shows high joining strength between plate materials and high durability against deterioration over time.

[0080] From the experimental results in Fig. 4, it was confirmed that the screw 1 having a mixture of the first thread 4 at the first height and the second thread 5 at the second height has a high joining strength. The experiment was conducted in a case where a wooden board made of cedar was engaged. In other words, the screw 1 having the first thread 4 and the second thread 5 can exhibit high joining strength and durability when joining wooden boards.

[0081] (Details and variations of each part) Next, details and variations of each part will be explained.

[0082] (Bonding plates with screws) Fig. 5 is a schematic diagram of two plate materials joined in the lateral direction by the screw of the present invention, showing the state after joining.

[0083] The screw 1 is used to join the plate materials 100 in the side direction (as shown in FIG. 5 ), or to join the plate materials 100 in the thickness direction. Note that joining is a fixed connection, and refers to connecting plate materials 100 together. A single unit can be composed of multiple plate materials 100.

[0084] The screw 1 has a length that allows it to join two plate materials 100 in the lateral direction as shown in Fig. 5. In this state, the screw 1 can be inserted from the side of one of the plate materials 100 to join the two plate materials 100. As explained in the experimental results of Fig. 4, the joining strength of the screw 1 is very high. Therefore, even when two plate materials 100 are joined in the lateral direction as shown in Fig. 5, the structural strength of the resulting building material unit 200 is also high.

[0085] Here, the board material 100 is often made of wood. Of course, materials other than wood may be used, but in recent years, there has been a trend toward wooden buildings being preferred due to their texture and weather resistance. Alternatively, wooden buildings may be used in construction due to their superiority.

[0086] Due to this trend, wooden building material units 200 may be required, but wooden boards 100 are limited in area and thickness because they are made from wood. For this reason, it is necessary to join multiple boards 100 together to form a building material unit 200 with a larger area and thickness. For this reason, as shown in FIG. 5, joining with screws 1 is required.

[0087] At this time, in joining the side of the plate material 100, since the area of ​​the joining surface is small, a high joining force is required from the screw 1. Since the screw 1 can exert a high joining force as described above, it is possible to reliably construct a building material unit 200 as shown in FIG.

[0088] (Thread) The thread 3 includes a first thread 4 of a first height and a second thread 5 of a second height. Here, as shown in Fig. 3, the first thread 4 and the second thread 5 may be provided alternately. A spiral convex portion forming the first thread 4 and a spiral convex portion forming the second thread 5 are formed on the screw body 2. This formation results in a state in which the first thread 4 and the second thread 5 are provided alternately.

[0089] By alternately arranging them, the joining strength is increased.

[0090] In this case, there may be a pattern in which a plurality of first threads 4 and a plurality of second threads 5 are alternately provided, a pattern in which a plurality of first threads 4 and a single second thread 5 are alternately provided, a pattern in which a single first thread 4 and a plurality of second threads 5 are alternately provided, or a pattern in which a single first thread 4 and a single second thread 5 are alternately provided.

[0091] By providing the first threads 4 and the second threads 5 with different heights in various patterns, the joining strength can be increased (the connecting strength and fitting strength are increased).

[0092] It is also preferable that the first thread 4 and the second thread 5 are provided in a random order on the screw body 2. By providing them randomly, it is possible to increase the joining strength and durability against irregular loads.

[0093] Of course, the first thread 4 and the second thread 5 may be provided in other arrangements.

[0094] It is also preferable that a third thread having a third height different from both the first height and the second height is further provided. Of course, a fourth thread may also be provided. In this way, it is also preferable that a plurality of threads having different heights are provided. A plurality of different resistance forces are generated during the engagement with the plate material. This is because it is possible to further increase the joining strength and durability.

[0095] Fig. 6 is an enlarged view of the threads in the first embodiment of the present invention, emphasizing the shape of the threads of the screw 1. As shown in Fig. 6, at least one of the first thread 4 and the second thread 5 has an inverted V-shaped ridgeline shape in the screw body 2.

[0096] The inverted V-shape of the ridge makes it easier to push sawdust out when the screw 1 is fitted into a wooden board. If the sawdust generated during fitting can be pushed out, the degree of adhesion between the threads and grooves of the screw 1 and the inside of the board 100 can be increased. Higher adhesion leads to increased joining strength of the screw 1 to the board 100.

[0097] Also, if the sawdust is removed, the area around the screw 1 inside the plate material 100 during joining is wooden, not crushed sawdust. Because of this, the area is in solid contact, and the interlocking force is strong. If sawdust is in powder form, the interlocking force is weak even when the area is in contact.

[0098] In this way, the inverted V-shaped ridgeline shape allows the screw 1 to produce sawdust as it fits. As a result, the degree of adhesion is increased, and since the contacting part is a solid part, the fitting force is also strong. This also increases the joining force and durability after joining.

[0099] As described above, the screw 1 in the first embodiment can join the plate materials 100 together with high joining force. In particular, it can increase the joining strength and durability between wooden plate materials 100. This makes it possible to manufacture a building material unit 200 that is large in area and thickness by joining a plurality of plate materials 100 together. The building material unit manufactured in this way has high strength and durability and can be used in buildings.

[0100] (Embodiment 2)

[0101] 7 is a schematic diagram of a construction material unit in embodiment 2 of the present invention. Three plate materials 100 are joined in the area direction (side to side) with screws 1. This joining results in a construction material unit 200 with a larger area. The three plate materials 100 are joined with multiple screws 1.

[0102] The plate material 100 also has a screw hole 110 into which a screw 1 is inserted. The screw 1 is inserted by turning through this screw hole 110. The screw hole 110 is provided on the side of the plate material 100. The screw 1 is inserted through the screw hole 110 on the side. The screw 1 joins the plate materials 100 that are connected in the lateral direction. In this way, a building material unit 200 as shown in FIG. 7 is manufactured.

[0103] The boards 100 may be made of wood. In this way, a wooden building material unit 200 is manufactured by joining wooden boards 100. Such a building material unit 200 is used as a wall material or floor material for a wooden building. As shown in FIG. 7, a building material unit 200 having an area larger than that of a single board 100 is manufactured, and thus can be suitably used in various places in a building. As a result, a wooden building can be easily constructed.

[0104] As described in the first embodiment, the joining strength and durability of the screw 1 are higher than those of other screws. This gives the manufactured building material unit 200 high strength and durability. In other words, the strength and durability of the building are also increased.

[0105] The use of the screw 1 for joining allows the construction material unit 200 manufactured by joining the boards 100 (especially wooden boards) to each other to have strength and durability. This construction material unit 200 improves the strength and durability of a building in which it is used as a wall material or floor material.

[0106] By using the building material unit 200 made of wood as a wall material or floor material, a building can be realized that enjoys the texture and gentleness of wood, as well as the unique benefits of wood, such as heat retention and moisture absorption. This also increases the benefits for residents and users.

[0107] The screw 1 described in the first and second embodiments is actually manufactured as shown in FIG. 8. FIG. 8 is a photograph of the manufactured screw of the present invention. As shown in the photograph in FIG. 8, the screw 1 has a first thread 4 and a second thread 5. The first thread 4 has a first height, and the second thread 5 has a second height. The first height is higher than the second height. Note that this height is the protruding height from the surface of the screw main body 2.

[0108] As described above, the building material unit 200 using the screw 1 is suitable for building materials due to its high strength and durability, and is particularly suitable for wooden buildings.

[0109] The screw 1 and the construction material unit described above in the first and second embodiments are merely examples for explaining the gist of the present invention, and include modifications and alterations that do not depart from the gist of the present invention. [Explanation of symbols]

[0110] 1 Screw 2 Screw body 3 Threads 4 First Thread 5 2nd thread 6 head 7 Tip 100 Board material 200 building material units

Claims

1. A screw comprising a screw body and a thread provided on the screw body, the thread including a first thread having a first height and a second thread having a second height, the first height being greater than the second height, the first thread and the second thread being provided in a random order on the screw body, and the thread further comprising a third thread having a third height different from both the first height and the second height, A first wooden plank; a second wooden board having a second screw hole on a side thereof into which the screw is inserted; a third wooden board having a third screw hole on a side surface thereof, the third screw hole being formed alternately with the second screw hole and into which the screw is inserted; is used in joined building material units, The building material unit is The side surfaces of the first wooden board and the second wooden board are joined together by the screw inserted through the second screw hole, The screw inserted through the third screw hole seals the second screw hole of the second wooden board with the third wooden board and joins the sides of the second wooden board and the third wooden board together, thereby joining the first wooden board, the second wooden board, and the third wooden board.

2. The screw according to claim 1 , wherein at least one of the first thread and the second thread has an inverted V-shaped ridgeline shape on a thread body portion.

3. A screw comprising: a screw body; and a thread provided on the screw body, the thread including a first thread of a first height and a second thread of a second height, the first height being higher than the second height, the first thread and the second thread being provided in a random order on the screw body, and the thread further comprising a third thread of a third height different in height from both the first height and the second height; A first wooden plank; a second wooden board having a second screw hole on a side thereof into which the screw is inserted; a third wooden board having a third screw hole on a side surface thereof, the third screw hole being formed alternately with the second screw hole and into which the screw is inserted; Prepare The screw is inserted through the second screw hole of the second wooden board to join the sides of the first wooden board and the second wooden board together; Next, the screw is inserted through the third screw hole of the third wooden board, the second screw hole of the second wooden board is blocked with the third wooden board, and the sides of the second wooden board and the third wooden board are joined together to produce a building material unit in which the first wooden board, the second wooden board, and the third wooden board are joined together, thereby producing a building material unit in which the first wooden board, the second wooden board, and the third wooden board are joined together.

4. A method for manufacturing a building material unit as described in claim 3, wherein at least one of the first thread and the second thread has an inverted V-shaped ridge shape in the screw body portion.

5. A building material unit manufactured using the building material unit manufacturing method described in claim 3 or 4.

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