Nail

Abstract

To provide a nail having sufficient fastening strength even when used with cedar wood.SOLUTION: Root portions R1ba, R2ba on the main shaft side of inclined surfaces R1b, R2b are formed in an R shape. Furthermore, a second ring portion group is provided at a position 52 mm or more away from the underside of the nail head portion of the main shaft portion. In addition, the crest heights (H1, H2) of a first ring portion R1 and a second ring portion R2 are 0.2 mm or more. Thus, even when used with cedar wood, a nail having sufficient fastening strength can be provided.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a nail. [Background technology]

[0002] A known conventional nail is that described in Patent Document 1. The nail described in Patent Document 1 has a group of ring portions formed at a constant axial pitch and triangular in cross section on at least the nail tip side of the shank, with a valley bottom formed between adjacent triangular ring portions that is smaller in diameter than the diameter of the nail blank and parallel to the axial direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-182933 Summary of the Invention [Problem to be solved by the invention]

[0004] The above nails do not cause board cracks even when nailed into structurally important parts of the body of a wooden house, and have a strong binding force, making them particularly useful for SPF (Spruce Pine Fir), a type of wood used as a building material in two-by-four construction methods.

[0005] However, in recent years, there has been an increase in demand for cedar, which is a wood that is softer and harder than SPF lumber, and the above nails have the problem of not having sufficient fastening power for this cedar.

[0006] To explain this in more detail, Ministry of Land, Infrastructure, Transport and Tourism Notifications No. 1540 and No. 1541 of 2001 for the framework wall construction method stipulate that CN90 nails must be used in some fastening sections. However, this does not apply to these sections if it is confirmed that the allowable shear strength is 800N or more.

[0007] However, the above nails do not meet the standard of the notification because the allowable shear strength of the above nails is less than 800N when used with cedar. Therefore, there was a problem that the above nails did not have sufficient fastening power when used with cedar.

[0008] In view of the above problems, the present invention aims to provide a nail that has sufficient fastening power even when used with cedar. [Means for solving the problem]

[0009] The above object of the present invention can be achieved by the following means: Note that the parentheses indicate reference symbols of embodiments to be described later, but the present invention is not limited to these.

[0010] The nail according to claim 1 comprises a main body shaft portion (2), a first ring group (3) provided on the nail head (2a) side of the main body shaft portion (2); a second ring group (4) provided on the nail tip portion (2b) side of the main body shaft portion (2), The first ring portion group (3) includes a first ring portion (R1) formed in a triangular mountain shape in cross section, The first ring portion (R1) is composed of a first inclined surface (inclined surface R1a) that has a gentle downward slope toward the nail head portion (2a) side, and a second inclined surface (inclined surface R1b) that has a steep downward slope toward the nail tip portion (2b) side, The second ring portion group (4) includes a second ring portion (R2) formed in a triangular mountain shape in cross section, The second ring portion (R2) is composed of a third inclined surface (inclined surface R2a) that has a gentle downward slope toward the nail tip portion (2b) side, and a fourth inclined surface (inclined surface R2b) that has a steep downward slope toward the nail head portion (2a) side, The base portions (R1ba, R2ba) of the second inclined surface (inclined surface R1b) and the fourth inclined surface (inclined surface R2b) on the main body shaft portion (2) side are formed in an R shape, and The second ring group (4) is provided at a position 52 mm or more away from the nail head portion (2a) of the main body shaft portion (2), and further The first ring portion (R1) and the second ring portion (R2) have a height (H1, H2) of 0.2 mm or more. [Effects of the Invention]

[0011] According to the present invention, nails having sufficient fastening strength can be provided even for cedar. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1(a) is a side view showing one embodiment of the nail according to the present invention, (b) is an enlarged view of the X1 portion of (a), and (c) is an enlarged view of the X2 portion of (a). [Figure 2] 1(a) is an enlarged cross-sectional view of the part shown in FIG. 1(b), and FIG. 1(b) is an enlarged cross-sectional view of the part shown in FIG. 1(c). [Figure 3] The test specimen is shown, (a) being a side view and (b) being a front view. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, one embodiment of the nail according to the present invention will be specifically described with reference to the drawings. In the following description, when directions such as up, down, left, and right are indicated, they refer to up, down, left, and right when viewed from the front of the illustration.

[0014] <Outline of nails> The nail according to this embodiment has sufficient fastening power even for cedar. Specifically, as shown in Figure 1, the nail 1 is mainly composed of a main body shank 2, a first ring group 3, and a second ring group 4. Each component will be described in detail below.

[0015] <Explanation of the main body shaft> As shown in Fig. 1(a), the main body shank 2 is formed in a substantially cylindrical shape extending in the left-right direction, and a nail head portion 2a that is rectangular in side view is integrally formed on the left side surface in the figure. Furthermore, as shown in Fig. 1(a), a nail tip portion 2b that is shaped like an acute mountain is integrally formed on the right side surface in the figure of the main body shank 2.

[0016] Thus, the main body shaft portion 2 formed in this manner has a first ring group 3 on the nail head portion 2a side and a second ring group 4 on the nail tip portion 2b side, as shown in Figure 1(a).

[0017] <Explanation of the first ring group> As shown in Figures 1(b) and 2(a), the first ring group 3 includes a plurality of first ring portions R1 arranged at regular intervals in the axial direction (left-right direction in the figure), and as shown in Figure 2(a), each of the first ring portions R1 has a triangular mountain-shaped cross section. As shown in Figures 1(b) and 2(a), a first valley bottom V1 is formed between the first ring portions R1, and has a diameter smaller than that of the main body shaft portion 2 and is parallel to the axial direction (left-right direction in the figure).

[0018] As shown in Fig. 2(a), the first ring portion R1 is composed of a slope R1a that slopes gently downward toward the nail head portion 2a (see Fig. 1(a)) side (to the left in the figure), and a slope R1b that slopes steeply downward toward the nail tip portion 2b (see Fig. 1(a)) side (to the right in the figure). As shown in Fig. 2(a), the side of this slope R1b on the main body shank portion 2 (see Fig. 1), i.e., the base portion R1ba on the first valley bottom V1 side, is formed in an R shape.

[0019] Furthermore, as shown in FIG. 2(a), the height H1 of the first ring portion R1 (the distance from the first valley bottom V1 to the apex R1c of the triangular mountain cross section) is set to 0.2 mm or more.

[0020] <Explanation of the second ring group> As shown in Figures 1(c) and 2(b), the second ring group 4 includes a plurality of second ring portions R2 arranged at regular intervals in the axial direction (left-right direction in the figure), and as shown in Figure 2(b), each second ring portion R2 has a triangular mountain-shaped cross section. As shown in Figures 1(c) and 2(b), a second valley bottom V2 is formed between the second ring portions R2, and the second valley bottom V2 has a diameter smaller than that of the main body shaft portion 2 and is parallel to the axial direction (left-right direction in the figure).

[0021] As shown in Fig. 2(b), the second ring portion R2 is composed of a slope R2a that slopes gently downward toward the nail tip portion 2b (see Fig. 1(a)) side (to the right in the figure), and a slope R2b that slopes steeply downward toward the nail head portion 2a (see Fig. 1(a)) side (to the left in the figure). As shown in Fig. 2(b), the side of this slope R2b on the main body shank portion 2 (see Fig. 1), i.e., the base portion R2ba on the second valley bottom V2 side, is formed in an R shape.

[0022] Furthermore, as shown in FIG. 2(b), the height H2 of the second ring portion R2 (the distance from the second valley bottom V2 to the apex R2c of the triangular mountain cross section) is set to 0.2 mm or more.

[0023] As shown in Figure 1(a), the second ring group 4 thus formed is provided at a distance L from below (to the right in the figure) the nail head 2a of the main body shank 2. This distance L is set to 52 mm or more.

[0024] Therefore, the nail 1 described above has the above-mentioned configuration, but by meeting the following conditions (1) to (3), this nail 1 becomes a nail 1 with sufficient fastening power even for cedar. (1) The base portion R1ba of the slope R1b on the side of the main body shaft 2 (see FIG. 1), i.e., on the side of the first valley bottom V1, is rounded. Furthermore, the base portion R2ba of the slope R2b on the side of the main body shaft 2 (see FIG. 1), i.e., on the side of the second valley bottom V2, is rounded. (2) The second ring group 4 is provided at a position 52 mm or more away from the nail head 2a of the main body shank 2 (to the right in the drawing). (3) The height H1 of the first ring portion R1 (the distance from the first valley bottom V1 to the apex R1c of the triangular mountain cross section) is set to 0.2 mm or more. Furthermore, the height H2 of the second ring portion R2 (the distance from the second valley bottom V2 to the apex R2c of the triangular mountain cross section) is set to 0.2 mm or more. [Example]

[0025] To prove this, the present inventors conducted the following experiment.

[0026] <Test specimen description> The types of test specimens and their constituent materials are shown in Table 1 below.

[0027] [Table 1]

[0028] For the nail of test A, the root portion R1ba shown in FIG. 2(a) and the root portion R2ba shown in FIG. 2(b) were formed in an R shape, the distance L shown in FIG. 1(a) was set to 52 mm, and the crest height H1 shown in FIG. 2(a) and the crest height H2 shown in FIG. 2(b) were set to 0.2 mm.

[0029] For the nail of test B, the root portion R1ba shown in FIG. 2(a) and the root portion R2ba shown in FIG. 2(b) were not formed into an R shape, the distance L shown in FIG. 1(a) was set to 52 mm, and the crest height H1 shown in FIG. 2(a) and the crest height H2 shown in FIG. 2(b) were set to 0.2 mm.

[0030] For the nail of test C, the root portion R1ba shown in Figure 2(a) and the root portion R2ba shown in Figure 2(b) were formed in an R shape, the distance L shown in Figure 1(a) was set to 51 mm, and the crest height H1 shown in Figure 2(a) and the crest height H2 shown in Figure 2(b) were set to 0.2 mm.

[0031] For the nail of test D, the root portion R1ba shown in FIG. 2(a) and the root portion R2ba shown in FIG. 2(b) were formed in an R shape, the distance L shown in FIG. 1(a) was set to 52 mm, and the crest height H1 shown in FIG. 2(a) and the crest height H2 shown in FIG. 2(b) were set to 0.18 mm.

[0032] <Test method explanation> Next, the test method will be described.

[0033] The test specimens were prepared as follows. That is, as shown in Fig. 3(a), the main material S1 and the side material S2 were stacked in a shifted state so that the upper surface S1a of the main material S1 and the upper surface S2a of the side material S2 were not flush with each other, and further so that the lower surface S1b of the main material S1 and the lower surface S2b of the side material S2 were not flush with each other. Then, as shown in Fig. 3(a), nails 1 were driven into the upper surface S1a of the main material S1 and the upper surface S2a of the side material S2, and nails 1 were driven into the lower surface S1b of the main material S1 and the lower surface S2b of the side material S2. At this time, as shown in Fig. 3(b), a pair of nails 1 were driven side by side so that the positions of the nail heads 2a and nail tips 2b were reversed, into the upper surface S1a of the main material S1 and the upper surface S2a of the side material S2, and into the lower surface S1b of the main material S1 and the lower surface S2b of the side material S2, respectively. The nail 1 was driven in so that the nail head 2a was flush with the surface of the side material S2, and one test specimen was created.

[0034] After preparing such a test specimen, a shear test of the nail 1 was carried out by applying a load P to the upper surface S1a of the main material S1 using a hydraulic material testing machine (Shimadzu Corporation, UH-50A model, capacity: 500KN) as shown in Figure 3(a). Specifically, the test was carried out according to the following procedure. The relative displacement between the main material S1 and the side material S2 of the test specimen was measured using a displacement meter (capacity 100mm, 200μ / mm).

[0035] First, a preliminary test using a monotonic load joint test was conducted on specimen No. 00, and the yield point displacement δy corresponding to the allowable test stress was determined.

[0036] Next, for the main test, a load schedule for a positive-negative alternating cyclic test was determined based on the yield point displacement δy obtained in the preliminary test, and cyclic tests were conducted on specimens No. 01 to 06. The load schedule involved applying load once in both the positive and negative directions to displacements of 25% and 50% of the yield point displacement δy, and then applying load three times in both the positive and negative directions to displacements of 75%, 100%, 400%, 600%, and 800%.

[0037] Next, after reaching the maximum load, the force was applied until the load decreased to 80% of the maximum load or the displacement became 30 mm or more. If the maximum load exceeded 30 mm of displacement, the maximum value within 30 mm of displacement was taken as the maximum load.

[0038] <Test Results> The test results obtained using the above test method are shown in Tables 2 to 9. The density and moisture content of the main material S1 and side material S2 of the test specimen were measured before the test began, and the moisture content was measured using a wood moisture meter (manufactured by Kett Electric Research Institute). The allowable test stress Py was calculated from the load-deformation curve in accordance with Section V, Chapter 2 (5), "Evaluation of the allowable test stress and ultimate strength of joints" in the "2018 Guidelines for Structural Calculation of Wood-Framed Construction Buildings" (published by the Japan Two-by-Four Building Association). The short-term allowable shear strength per nail was calculated using Equation 1 below.

[0039]

number

[0040] [Table 2]

[0041] [Table 3]

[0042] [Table 4]

[0043] [Table 5]

[0044] [Table 6]

[0045] [Table 7]

[0046] [Table 8]

[0047] [Table 9]

[0048] The above test results can be summarized as follows:

[0049] The calculation results for the short-term allowable shear force of each nail in each test specimen are as follows:

[0050] [Table 10]

[0051] As explained above, in the framework wall construction method, Ministry of Land, Infrastructure, Transport and Tourism Notifications No. 1540 and No. 1541 of 2001 stipulate that CN90 nails must be used in some fastening sections. However, this does not apply in these sections if it is confirmed that the allowable shear strength is 800N or more.

[0052] Therefore, in light of this standard, it was found that only the nail in test A had an allowable shear strength of 800 N or more. In other words, it was found that only the nails in which the base portion R1ba shown in Figure 2(a) and the base portion R2ba shown in Figure 2(b) were formed into an R shape, the distance L shown in Figure 1(a) was set to 52 mm, and the crest height H1 shown in Figure 2(a) and the crest height H2 shown in Figure 2(b) were set to 0.2 mm had an allowable shear strength of 800 N or more.

[0053] Therefore, from the above results, it was proven that if nail 1 satisfies the following conditions (1) to (3), the fastening force is sufficient, even for cedar, since the allowable shear strength is 800 N or more. (1) The base portion R1ba of the slope R1b on the side of the main body shaft 2 (see FIG. 1), i.e., on the side of the first valley bottom V1, is rounded. Furthermore, the base portion R2ba of the slope R2b on the side of the main body shaft 2 (see FIG. 1), i.e., on the side of the second valley bottom V2, is rounded. (2) The second ring group 4 is provided at a position 52 mm or more away from the nail head 2a of the main body shank 2 (to the right in the drawing). (3) The height H1 of the first ring portion R1 (the distance from the first valley bottom V1 to the apex R1c of the triangular mountain cross section) is set to 0.2 mm or more. Furthermore, the height H2 of the second ring portion R2 (the distance from the second valley bottom V2 to the apex R2c of the triangular mountain cross section) is set to 0.2 mm or more.

[0054] On the other hand, the failure modes of each test specimen after testing are shown below.

[0055] [Table 11]

[0056] From the above, it was found that the nail of test A was less likely to break than the nails of tests B to D. Therefore, it was also found that nail 1, which satisfies the above conditions (1) to (3), was resistant to bending.

[0057] Therefore, from the above test results, it was found that the nail 1 that satisfies the above conditions (1) to (3) has sufficient fastening power and is also resistant to bending.

[0058] <Description of Modifications> It should be noted that the shapes and the like shown in this embodiment are merely examples, and various modifications and changes are possible within the scope of the gist of the present invention as set forth in the claims. [Explanation of symbols]

[0059] 1 nail 2 Main body shaft 2a Nail head 2b Nail tip 3. First Ring Group 4 Second Ring Group R1 First ring section R1a slope (first slope) R1b slope (second slope) R1ba base part R2 Second ring section R2a slope (third slope) R2b slope (fourth slope) R1ba base part H1 Height of the first ring H2 Height of the second ring

Claims

[Claim 1] A main body shaft portion, A first ring group provided on the nail head side of the main body shank; a second ring group provided on the nail tip side of the main body shank, The first ring portion group includes first ring portions each having a triangular mountain-shaped cross section, The first ring portion is composed of a first inclined surface that has a gentle downward slope toward the nail head side and a second inclined surface that has a steep downward slope toward the nail tip side, The second ring portion group includes second ring portions each having a triangular mountain-shaped cross section, The second ring portion is composed of a third inclined surface having a gentle downward slope toward the nail tip portion side and a fourth inclined surface having a steep downward slope toward the nail head portion side, The second inclined surface and the fourth inclined surface have a base portion on the main body shaft side formed in an R shape, The second ring group is provided at a position 52 mm or more away from the nail head of the main body shank, and further The nail has a crest height of 0.2 mm or more in the first ring portion and the second ring portion.

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