nail

Abstract

To provide a nail having sufficient fastening power even for cedar. [Solution] The base portions R1ba, R2ba of the slopes R1b and R2b on the body shaft side are formed in an R shape. Furthermore, the second ring group is provided at a position 52 mm or more away from the bottom of the nail head of the body shaft. Furthermore, the crest heights (H1, H2) of the first ring portion R1 and the second ring portion R2 are 0.2 mm or more. This makes it possible to provide a nail with sufficient fastening power even for cedar.

Description

[Technical field]

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

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

[0003] [Patent Document 1] JP 2007-182933 A 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 a wooden house, and have a strong binding force, making them particularly useful for SPF (Spruce Pine Fir) lumber, a type of wood used as a building material in two-by-four construction methods and the like.

[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 there has been a problem in that the above nails do not have sufficient fastening power for this cedar.

[0006] To explain this in more detail, the Ministry of Land, Infrastructure, Transport and Tourism Notifications No. 1540 and 1541 of 2001 for frame wall construction 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 nails is less than 800N for cedar. Therefore, there was a problem that the fastening strength of the above nails is insufficient for cedar.

[0008] In view of the above problems, the present invention has an object to provide a nail that has sufficient fastening strength 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 the embodiments described below, but the present invention is not limited thereto.

[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) having a triangular mountain-shaped cross section, The first ring portion (R1) is composed of a first inclined surface (inclined surface R1a) having a gentle downward slope toward the nail head portion (2a) side, and a second inclined surface (inclined surface R1b) having a steep downward slope toward the nail tip portion (2b) side, The second ring portion group (4) includes a second ring portion (R2) having a triangular mountain-shaped cross section, The second ring portion (R2) is composed of a third inclined surface (slope R2a) having a gentle downward slope toward the nail tip portion (2b) side, and a fourth inclined surface (slope R2b) having a steep downward slope toward the nail head portion (2a) side, The base portions of the first inclined surface (inclined surface R1a) and the third inclined surface (inclined surface R2a) on the side of the main body shaft portion (2) are not formed in an R shape, but the base portions (R1ba, R2ba) of the second inclined surface (inclined surface R1b) and the fourth inclined surface (inclined surface R2b) on the side of the main body shaft portion (2) are formed in an R shape, and further, The second ring group (4) is formed from below the nail head (2a) of the main body shaft portion (2). Not located closer than 52 mm apart, The sensors are located at least 52 mm apart, and The first ring portion (R1) and the second ring portion (R2) have respective peak heights (H1, H2) of 0.2 mm or more. Effect of the Invention

[0011] According to the present invention, it is possible to provide nails that have sufficient fastening strength even when made of cedar. [Brief description of the drawings]

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

[0013] Hereinafter, an embodiment of the nail according to the present invention will be described in detail 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 figure.

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

[0015] <Description of the main body shaft> As shown in Fig. 1(a), the main body shaft 2 is formed in a generally cylindrical shape extending in the left-right direction, and a nail head 2a having a rectangular shape in side view is integrally provided on the left side surface of the main body shaft 2. Furthermore, as shown in Fig. 1(a), a nail tip 2b having an acute angled mountain shape is integrally provided on the right side surface of the main body shaft 2.

[0016] Thus, the main body shaft portion 2 formed in this manner is provided with 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 a constant pitch in the axial direction (left-right direction in the figure), and is formed into a triangular mountain shape in cross section as shown in Figure 2(a). As shown in Figures 1(b) and 2(a), a first valley bottom V1 is formed between the first ring portions R1, the first valley bottom V1 being parallel to the axial direction (left-right direction in the figure) and having a smaller diameter than the diameter of the main body shaft portion 2.

[0018] Incidentally, the first ring portion R1, as shown in Fig. 2(a), is composed of a slope R1a with a gentle downward slope toward the nail head portion 2a (see Fig. 1(a)) side (to the left in the figure), and a slope R1b with a steep downward slope toward the nail tip portion 2b (see Fig. 1(a)) side (to the right in the figure). And, as shown in Fig. 2(a), the side of the body shaft portion 2 (see Fig. 1) of this slope R1b, i.e., the base portion R1ba on the side of the first valley bottom V1, 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 shape in 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 a constant pitch in the axial direction (left-right direction in the figure), and is formed into a triangular mountain shape in cross section as shown in Figure 2(b). As shown in Figures 1(c) and 2(b), a second valley bottom V2 is formed between the second ring portions R2, the diameter of which is smaller than the diameter of the main body shaft portion 2 and which 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 gentle downwardly sloping surface R2a toward the nail tip portion 2b (see Fig. 1(a)) (to the right in the figure) and a steep downwardly sloping surface R2b toward the nail head portion 2a (see Fig. 1(a)) (to the left in the figure). As shown in Fig. 2(b), the side of the body shaft portion 2 (see Fig. 1) of this slope R2b, 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 mountain height H2 of the second ring portion R2 (the distance from the second valley bottom V2 to the apex R2c of the triangular mountain shape in cross section) is set to 0.2 mm or more.

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

[0024] Therefore, the nail 1 described above has the above-mentioned configuration, but by satisfying the following conditions (1) to (3), this nail 1 has sufficient fastening power even for cedar. (1) The base portion R1ba of the slope R1b on the side of the main body shaft portion 2 (see FIG. 1), i.e., on the side of the first valley bottom V1, is formed in an R shape. Furthermore, the base portion R2ba of the slope R2b on the side of the main body shaft portion 2 (see FIG. 1), i.e., on the side of the second valley bottom V2, is formed in an R shape. (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 shaft 2 (to the right in the figure). (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 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 0.2 mm or more. EXAMPLES

[0025] Here, in order to prove this, the present inventors carried out 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) are formed into an R shape, the distance L shown in FIG. 1(a) is set to 52 mm, and the crest height H1 shown in FIG. 2(a) and the crest height H2 shown in FIG. 2(b) are 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) are not formed into an R shape, the distance L shown in FIG. 1(a) is set to 52 mm, and the crest height H1 shown in FIG. 2(a) and the crest height H2 shown in FIG. 2(b) are set to 0.2 mm.

[0030] For the nail of test C, the root portion R1ba shown in FIG. 2(a) and the root portion R2ba shown in FIG. 2(b) are formed into an R shape, the distance L shown in FIG. 1(a) is set to 51 mm, and the crest height H1 shown in FIG. 2(a) and the crest height H2 shown in FIG. 2(b) are 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) are formed into an R shape, the distance L shown in FIG. 1(a) is set to 52 mm, and the crest height H1 shown in FIG. 2(a) and the crest height H2 shown in FIG. 2(b) are set to 0.18 mm.

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

[0033] The test specimen was prepared as follows. That is, as shown in Fig. 3(a), the main material S1 and the side material S2 were overlapped 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, 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 head 2a and the nail tip 2b were inverted, 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 performed 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 Fig. 3(a). Specifically, the test was performed according to the following procedure. The relative displacement of the main material S1 and the side material S2 of the test specimen was measured with a displacement meter (capacity 100mm, 200μ / mm).

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

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

[0037] Next, after reaching the maximum load, the load was applied until the load decreased to 80% of the maximum load or the displacement was 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 by 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 start of the test, and the moisture content was measured using a wood moisture meter (Kett Electric Laboratory). The standard allowable stress of the joint was calculated according to Chapter 2 (5) "Evaluation of standard allowable stress and standard ultimate strength of joints" in Part V of the document "2018 Guideline for structural calculation of wood frame construction buildings" (published by Japan 2x4 Building Association), and the test allowable stress Py was obtained from the load deformation curve, and the short-term allowable shear strength per nail was calculated using the following formula 1.

[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, the Ministry of Land, Infrastructure, Transport and Tourism Notifications No. 1540 and 1541 of 2001 for the frame wall construction method stipulate that CN90 nails must be used in some fastening parts. However, this does not apply to these parts 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 of test A had an allowable shear strength of 800 N or more. In other words, it was found that only the nail in which the base portion R1ba shown in Fig. 2(a) and the base portion R2ba shown in Fig. 2(b) were 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 had an allowable shear strength of 800 N or more.

[0053] Therefore, the above results prove 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 portion 2 (see FIG. 1), i.e., on the side of the first valley bottom V1, is formed in an R shape. Furthermore, the base portion R2ba of the slope R2b on the side of the main body shaft portion 2 (see FIG. 1), i.e., on the side of the second valley bottom V2, is formed in an R shape. (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 shaft 2 (to the right in the figure). (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 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 0.2 mm or more.

[0054] On the other hand, the failure modes of each specimen after testing are as follows:

[0055] [Table 11]

[0056] From the above, it was found that the nail of test A was less prone to breakage 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 satisfying the above conditions (1) to (3) has sufficient fastening strength and is also resistant to bending.

[0058] <Description of Modifications> 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 described 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 1st 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 shaft portion; A second ring group is provided on the nail tip side of the main body shaft portion, The first ring portion group includes a first ring portion having a triangular mountain shape in cross section, The first ring portion is composed of a first inclined surface having a gentle downward slope toward the nail head side and a second inclined surface having a steep downward slope toward the nail tip side, The second ring portion group includes a second ring portion having a triangular mountain shape in 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 first inclined surface and the third inclined surface have root portions on the main body shaft portion side that are not formed in an R shape, but the second inclined surface and the fourth inclined surface have root portions on the main body shaft portion side that are formed in an R shape, and further The second ring group is not provided at a position less than 52 mm away from the bottom of the nail head of the main body shaft, but is provided at a position 52 mm or more away from the bottom of the nail head of the main body shaft, The nail has a crest height of 0.2 mm or more for the first ring portion and the second ring portion.

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