Detachment prevention tool and detachment prevention system

Abstract

[Problem] To achieve all of reduction in manufacturing cost, easy disengagement from bolts and nuts, and prevention of loosening of bolts and nuts. [Solution] The present invention comprises: a tool coil spring part 100 having a shape corresponding to the inner wall shape of a socket of an attachment / detachment tool; a circular bolt coil spring part 200 that is brought into contact with a threaded groove of a bolt 1000; a polygonal nut coil spring part 300 that is brought into contact with a side surface of a nut 2000; and a linking part 400 that links the bolt coil spring part and the nut coil spring part together. The nut coil spring part 300 has a tip section 310 from the tip to the boundary with respect to the linking part. The tip section is positioned across adjacent side-surface edges 2100, 2200 of the nut 2000.

Description

Fall prevention device and fall prevention system

[0001] The present invention relates to a fall-off prevention device and a fall-off prevention system, and more particularly to a fall-off prevention device and a fall-off prevention system that prevent a nut from falling off a bolt.

[0002] Patent Document 1 discloses a fall-off prevention device 1 having the following configuration: That is, the fall-off prevention device 1 is configured, from top to bottom with reference to Fig. 1, to include a second coil spring portion 3 having a second coil wire 3A in a substantially triangular shape, a first coil spring portion 2 having a first coil wire 2A in a substantially circular shape, a third coil spring portion 4 having a third coil wire 4A in a substantially triangular shape, an extension portion 5 in which an extension coil wire extends vertically, and a fourth coil spring portion 6 having a fourth coil wire 6A in a substantially hexagonal shape.

[0003] Here, the fall prevention device 1 prevents the nut 22 fastened to the bolt 21 from falling off (paragraph 0001), and as shown in Figure 3 of Patent Document 1, the third coil spring portion 4 abuts against the upper surface of the nut 22 to prevent it from loosening (paragraph 0050).

[0004] In addition, in the fall prevention device 1 of Patent Document 1, it is explained that the fall prevention device 1 can be attached to the bolt 21 to which the nut 22 is fastened using a general socket tool such as a socket wrench (paragraphs 0013, 0021, 0043, 0047 to 0049).

[0005] Furthermore, looking at Figure 1 of Patent Document 1, it can be seen that the three apexes 3B of the second coil spring portion 3, the three apexes 4B, 4C, 4D of the third coil spring portion 4, and the corresponding three apexes 6B of the fourth coil spring portion 6 are designed to be aligned along the axial direction of the fall-off prevention device 1.

[0006] If this assessment is correct, the reason for such a design is understood to be that the inner wall of the socket is formed with 12 grooves corresponding to common nuts (e.g., hexagonal nuts or dodecagonal nuts), and a set of corresponding tops 3B, 4B, etc., 6B can be fitted into the same groove.

[0007] Japanese Patent Application Laid-Open No. 2020-012545

[0008] However, when manufacturing the fall prevention device 1, the bending work required to align the three points, i.e., the tops 3B, 4B, etc., and 6B, is difficult and takes a long time, so it is undeniable that the manufacturing costs are high.

[0009] Furthermore, when the fall-off prevention device 1 is in use, it is deformed to a certain extent when attached to the bolt 21 to which the nut 22 is fastened, and a misalignment occurs in the set of corresponding peaks 3B, 4B, etc., 6B. Therefore, when attempting to detach the fall-off prevention device 1 attached to the bolt 21 from the bolt 21 using a socket tool, it is undeniable that it is difficult to attach it so that all of the set of corresponding peaks 3B, 4B, etc., 6B fit into the same groove in the socket.

[0010] Due to these circumstances, the inventor of Patent Document 1 considered whether any of the second coil spring portion 3 to the fourth coil spring portion 6 could be eliminated by making alternative changes to the configuration, and it appears that this led to the creation of the fall-off prevention device 1 that adopts the approach of excluding the fourth coil spring portion 6 as shown in FIG. 4.

[0011] However, the invention described in Patent Document 1 solves the problem that simply pressing the top surface of the nut 22 may not be effective enough to prevent loosening (paragraph 0009). Therefore, the approach of excluding the fourth coil spring portion 6 (paragraph 0048), which directly prevents rotation of the nut 22 by abutting against its side, is a change that impairs the anti-rotation effect, and is therefore considered to be a backward-looking response.

[0012] In actual consideration, if a rotational force is applied to the nut 22 without excluding the fourth coil spring portion 6, the force will be applied globally and dispersedly, from the fourth coil spring portion 6 through the extension portion 5 toward the third coil spring portion 4, making the anti-slip device 1 less likely to deform plastically. Furthermore, it can be said that the anti-slip device 1 will tend to return to its original state from its deformed state, and therefore it is believed that rotation of the nut 22 can be effectively prevented.

[0013] In contrast, if a rotational force is applied to the nut 22 when the fourth coil spring portion 6 is excluded, the force is applied locally and concentratedly to the boundary between the extension portion 5 and the third coil spring portion 4, making the anti-slip device 1 prone to plastic deformation.Furthermore, it can be said that the anti-slip device 1 is unlikely to return to its original state from its deformed state, and therefore it is thought that rotation of the nut 22 cannot be effectively prevented.

[0014] If this is the case, it seems more reasonable to adopt the approach of excluding the third coil spring portion 4 rather than the approach of excluding the fourth coil spring portion 6. The approach of excluding the second coil spring portion 3 was also considered, but the inventors have not yet come up with a clever idea to replace its function of allowing the fall-off prevention device 1 to be attached and detached using a general socket tool (paragraph 0021, etc.) by changing other components.

[0015] Therefore, the present invention aims to provide a fall prevention device that adopts an approach of excluding the third coil spring portion 4, while maintaining the same effect as when the third coil spring portion 4 abuts against the upper surface of the nut 22, thereby preventing it from rotating in the direction of loosening.

[0016] In order to solve the above problems, the fall-off prevention device of the present invention has a tool coil spring portion shaped to correspond to the inner wall shape of the socket of the attachment / detachment tool, a circular bolt coil spring portion that abuts against the thread groove of the bolt, a polygonal nut coil spring portion that abuts against the side of the nut, and a connecting portion that connects the bolt coil spring portion and the nut coil spring portion, and the tip of the nut coil spring portion from its tip to the boundary with the connecting portion is positioned across the adjacent side edge of the nut.

[0017] The tool coil spring portion may be triangular in shape, and the nut coil spring portion may be hexagonal in shape.

[0018] The length of the tip portion may be 1.5 times or more the width of the side edge of the nut.

[0019] The anti-fall-off system of the present invention comprises the above-mentioned anti-fall-off device, and a bolt and a nut to which the anti-fall-off device is attached.

[0020] FIG. 1 is a front view of a fall-off prevention device according to an embodiment of the present invention. FIG. 2 is a back view of a fall-off prevention device according to an embodiment of the present invention. FIG. 3 is a right side view of a fall-off prevention device according to an embodiment of the present invention. FIG. 4 is a left side view of a fall-off prevention device according to an embodiment of the present invention. FIG. 5 is a plan view of a fall-off prevention device according to an embodiment of the present invention. FIG. 6 is a bottom view of a fall-off prevention device according to an embodiment of the present invention. FIG. 7 is a perspective view of a fall-off prevention device according to an embodiment of the present invention. FIG. 8 is an explanatory view of example dimensions of each part of a fall-off prevention device according to an embodiment of the present invention. FIG. 9 is a view showing a state in which the fall-off prevention device shown in FIG. 1 etc. is attached to a bolt 1000 and a nut 2000.

[0021] 100 Coil spring portion for tool 200 Coil spring portion for bolt 300 Coil spring portion for nut 310 Tip portion 400 Connecting portion 1000 Bolt 2000 Nut 2100, 2200 Adjacent side edges MODE FOR CARRYING OUT THE INVENTION

[0022] Hereinafter, a fall-off prevention device according to an embodiment of the present invention will be described with reference to the drawings.

[0023] 1 to 7 are views showing the appearance of the fall-off prevention device, with FIG. 1 being a front view, FIG. 2 being a rear view, FIG. 3 being a right side view, FIG. 4 being a left side view, FIG. 5 being a plan view, FIG. 6 being a bottom view, and FIG. 7 being a perspective view.

[0024] The fall-off prevention device is broadly divided into a tool coil spring portion 100, a bolt coil spring portion 200, a nut coil spring portion 300, and a connecting portion 400, which will be described below. This fall-off prevention device is manufactured by winding a coil wire of approximately the same diameter and a predetermined length made of, for example, stainless steel (SUS304, etc.).

[0025] As shown in FIG. 5, the tool coil spring portion 100 is a portion in which the coil wire is wound, for example, once, in a regular triangular shape in plan view (strictly speaking, the midpoints of each side are convex outward).

[0026] The tool coil spring portion 100 is housed in the socket of an attachment / detachment tool such as a socket wrench (not shown) when attaching or detaching the fall prevention device to or from a bolt 1000 (see Figure 9) that has been tightened with a nut 2000 (see Figure 9).

[0027] The shape of the tool coil spring portion 100 does not necessarily have to be triangular, but may be, for example, rectangular or octagonal, as long as it corresponds to the shape of the inner wall of the socket. Also, the number of turns of the tool coil spring portion 100 does not necessarily have to be one, but may be, for example, two turns.

[0028] As shown in FIG. 5, the bolt coil spring portion 200 is a portion that is continuous with the tool coil spring portion 100 and is formed by winding a coil wire around the bolt coil spring portion 200 in a perfect circular shape in a plan view, for example, approximately four times.

[0029] In this example, the bolt coil spring portion 200 includes a small circular portion with approximately 2 turns and a large circular portion with just under 1 turn. However, the number of turns of the bolt coil spring portion 200 is merely an example, and the bolt coil spring portion 200 may have more or fewer turns.

[0030] In addition, the diameter of the bolt coil spring portion 200 is slightly smaller than the outer diameter of the threaded portion of the bolt 1000, so that the nut 2000 is brought into contact with the thread groove of the bolt 1000 under pressure when the nut 2000 is fastened.

[0031] As shown in FIG. 5, the nut coil spring portion 300 is a portion in which the coil wire is wound, for example, by approximately 1.25 turns in a hexagonal shape in plan view, and its total length corresponds to approximately 7.5 sides of the hexagon, including a tip portion 310 having a length of approximately 0.25 turns, with the tip at one end and a position perpendicular to the connecting portion 400 at the other end.

[0032] The nut coil spring portion 300 abuts against the side surface of the nut 2000 fastened to the bolt 1000 , and the tip portion 310 of the nut coil spring portion 300 abuts across the adjacent side surface edges 2100 and 2200 of the nut 2000 .

[0033] The length of the tip portion 310 depends on the thickness and strength of the wire that constitutes the fall prevention device, but in order to ensure that it does not loosen from the bolt 1000 and nut 2000, it is preferable that the length be at least 1.5 times the circumferential edge length (width) of the adjacent side edges 2100, 2200.

[0034] Furthermore, a gripping portion for gripping the fall-off prevention device may be provided continuous with the tip of the tip portion 310. The gripping portion is not limited to this, but may be a circular portion with a diameter of about 1 cm.

[0035] The shape of the nut coil spring portion 300 does not necessarily have to be hexagonal, and may be, for example, a dodecagonal shape, as long as it corresponds to the shape of the nut 2000.

[0036] Here, in this embodiment, the reason for providing the tip portion 310 is to provide the nut coil spring portion 300 with strength that makes it difficult for it to deform even when force is applied to the nut coil spring portion 300, thereby preventing the nut 2000 from loosening.

[0037] It should be noted that, as can be intuitively understood by a person skilled in the art by looking at FIG. 1 of Patent Document 1, the length of the coil wire of the fourth coil spring portion 6, which corresponds to the "nut coil spring portion 300", is only slightly less than half the length of the six sides of the fourth coil spring portion 6, and therefore the fourth coil spring portion 6 is configured to be able to deform appropriately even when the third coil spring portion 4 is not present.

[0038] As shown in FIG. 1 , the connecting portion 400 extends, for example, perpendicular to the planar direction of the bolt coil spring portion 200 and the nut coil spring portion 300, and is a portion that connects the bolt coil spring portion 200 and the nut coil spring portion 300.

[0039] Examples of precise dimensions of each part of the fall-off prevention device will be explained later, but for example, as shown in FIG. 1, the thickness of the connecting part 400 is approximately the same as the thickness of the tool coil spring part 100 and the bolt coil spring part 200, but it may or may not be thicker than this.

[0040] However, if the thickness of the connecting portion 400 is approximately as shown in Figure 1, the nut coil spring portion 300 will be positioned at about half the height of the nut 2000, making it possible to stably attach the anti-fall-off device to the bolt 1000 and the nut 2000.

[0041] 5, the axes of the tool coil spring portion 100, the bolt coil spring portion 200, and the nut coil spring portion 300 are substantially aligned. Therefore, it can be seen that the ratio of the diameter of the tool coil spring portion 100: the side length of the bolt coil spring portion 200: the side length of the nut coil spring portion 300 is geometrically approximately 1:2√3 (≈3.46):2.

[0042] 8 is an explanatory diagram of example dimensions of each part of the fall-off prevention device. When the nut 2000 is an M22 fine-thread nut, example dimensions of each part of the fall-off prevention device can be as follows:

[0043] <Coil wire> Wire diameter (d): φ1.80±0.02 mm, <Tool coil spring portion 100> Inner diameter (ID): φ18.90-0.2 mm to φ18.90+0 mm, <Bolt coil spring portion 200> Number of coil turns: 3.289 <Nut coil spring portion 300> Opposite side length (S): 32.00 mm <Connecting portion 400> Thickness (mm) (length from the bottom surface of the bolt coil spring portion 200 to the bottom surface of the nut coil spring portion 300): 18.00 mm

[0044] For reference, examples of dimensions of each part of the fall-off prevention device for sizes other than M22 fine thread are summarized in Table 1. Note that the values ​​shown in Table 1 are just an example, and if a large nut is used, for example, the face length (S) and thickness (m) should be increased accordingly, and the number of coil turns should be reduced.

[0045] For example, in the case of a so-called M12 special nut, it is possible to change the face length (S) to 24.00 mm, the thickness (m) to 11.00 mm, and the number of coil turns to 3.210.

[0046]

[0047] 1 etc. is attached to the bolt 1000 and the nut 2000. This fall-off prevention tool is attached to the bolt 1000 and the nut 2000 via the tool coil spring part 100 using a socket (not shown).

[0048] Specifically, as shown in FIG. 9 , in this fall prevention device, the bolt coil spring part 200 abuts against the thread groove of the bolt 1000, the nut coil spring part 300 abuts against the side surface of the nut 2000, and further, the tip part 310 abuts across the adjacent side edges 2100 and 2200 of the nut 2000, but after attachment, no misalignment occurs between the tops of the tool coil spring part 100 and the nut coil spring part 300.

[0049] Therefore, the fall prevention device of this embodiment can be easily bent, which reduces manufacturing costs, and can be easily detached from the bolt and nut, thereby preventing the bolt and nut from loosening.

Claims

1. A device for preventing falling off, comprising: a tool coil spring part having a shape corresponding to the shape of the inner wall of the socket of an attachment / detachment tool; a circular bolt coil spring part that abuts against the thread groove of the bolt; a polygonal nut coil spring part that abuts against the side of the nut; and a connecting part that connects the bolt coil spring part and the nut coil spring part, wherein the tip of the nut coil spring part from its tip to the boundary with the connecting part is positioned across the adjacent side edge of the nut.

2. The fall-off prevention device according to claim 1, wherein the tool coil spring portion is triangular in shape, and the nut coil spring portion is hexagonal in shape.

3. The fall prevention device according to claim 1, wherein the length of the tip is at least 1.5 times the width of the side edge of the nut.

4. A fall prevention system comprising: the fall prevention device according to claim 1; and a bolt and a nut to which the fall prevention device is attached.

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