JP3037654U - Loosening prevention bolt - Google Patents

Abstract

(57) [Summary] [Purpose] Not only can it be used to prevent loosening of nuts, but it can also be used to prevent loosening of bolts such as holding bolts and studs that do not use nuts, and the fastening work is easy.
(EN) Provided is a lock bolt which has a simple structure and can be manufactured at low cost. A loosening prevention spring 2 having a substantially L-shape when viewed from the side, a long side of which forms an arcuate spring body 2a bulging outward and a short side of which forms a mounting piece 2b is provided. In the axial groove 6, which is a bolt, an axial groove 6 is formed in the male screw portion 5 of the shaft body 3, and a diametrical groove 7 is formed on the tip end surface of the shaft body 3 so as to be continuous with the axial groove 6. The arcuate spring body 2a is inserted into the diametrical groove 7 so that the bow-shaped spring body 2a can be pressed into contact with the threads of a female threaded portion such as a nut 8 screwed with the male threaded portion 5. The groove 7 is fixed by caulking.

Description

[Detailed description of the invention]

[0001]

[Industrial applications]

 The present invention relates to a bolt with a lock.

[0002]

[Prior art]

 The tightening bolts and nuts have a pitch that prevents the screws from naturally loosening due to the friction generated on the contact surface of the screw thread when tightened, but the screws loosen when vibration or shock is applied repeatedly. There are many things. In order to prevent such loosening of the screw, conventionally, various loosening prevention means are provided in the nut screwed to the bolt, or two nuts are used to lock the nut closer to the material to be fastened. Some have adopted a double nut for nuts, or have holes for bolts and nuts and insert pins to stop them.

[0003]

[Problems to be solved by the device]

 Since the conventional screw loosening prevention means is always provided on the nut side as described above, there is a problem in that it cannot be applied to a retaining bolt that does not use a nut or a stud bolt. Further, there is a problem in that the loosening prevention means on the nut side is very difficult to process and is costly, and the double nut system and the pin insertion system are troublesome in fastening.

In view of the above problems, the present invention can be applied not only to prevent loosening of nuts, but also to prevent loosening of holding bolts and studs of studs that do not use nuts. It is an object of the present invention to provide a bolt with locking device that is easy to fasten, has a simple structure, and can be manufactured at low cost.

[0005]

[Means for Solving the Problems]

 According to a first aspect of the present invention, a flat rod-shaped spring material is formed into a substantially L-shape in a side view, and a long side portion thereof forms an arcuate spring main body 2a which bulges outward and a short side portion thereof is a mounting portion. A bolt having a locking spring (2) forming a piece (2b), which has an axial groove (6) formed in a male screw part (5) of a shaft body (3) and is connected to the axial groove (6) at a tip end surface of the shaft body (3). 7, the arcuate spring body 2a is inserted into the axial groove 6 so as to make elastic contact with the threads of the female screw portion such as the nut 8 screwed with the male screw portion 5, and the diametrical groove 7 The mounting portion 2b is fixed to the above by caulking.

According to a second aspect of the present invention, in the bolt with lock according to the first aspect, the outer surface of the arcuate spring main body 2 a is inside the thread of the female threaded portion such as the nut 8 screwed with the male threaded portion 5. It is formed into a curved surface having substantially the same curvature as the circumference.

According to a third aspect of the present invention, there is provided a bolt having a loosening bar 32 formed in a bow shape by a flat bar-shaped spring material, and an axial groove 36 is formed in a male screw portion 35 of a shaft body 33. Then, the loosening prevention spring 32 is inserted into the axial groove 36 so as to make elastic contact with the threads of the female thread portion such as the nut 8 screwed with the male thread portion 35, and the arcuate looseness prevention spring 32 is One end is fixed to the inner end in the axial groove 36 by caulking.

According to a fourth aspect of the present invention, in the bolt with lock according to the third aspect, the outer surface of the lock spring 32 is screwed to a female thread portion of a nut 8 or the like that is screwed with the male thread portion 35. It is formed in a curved surface shape having almost the same curvature as the inner circumference of the mountain.

[0009]

【Example】

 An embodiment will be described with reference to the drawings. FIGS. 1 to 5 show a bolt 1 with a locking spring 2 applied to a through bolt, the bolt 1 having a hexagonal shape at a base end of a shaft body 3. It has a head 4, a shaft body 3 is formed with a male screw portion 5 from the tip to a required length, and the shaft body 3 is formed with an axial groove 6 over the entire length of the male screw portion 5. A diametrical groove 7 continuous with the axial groove 6 is formed on the tip end surface of the shaft body 3. As can be seen from FIG. 2, the inner end of the axial groove 6 is formed slightly longer inward than the inner end of the male screw portion 5. As shown in FIGS. 2 and 5, the locking spring 2 is formed of a flat rod-shaped spring material into a substantially L-shape in a side view, and has a bow-shaped spring body 2a whose long sides bulge outward. And the short side portion forms the mounting portion piece 2b.

To attach the loosening prevention spring 2 to the shaft body 3, as shown in FIGS. 2 and 5, a bow-shaped spring body 2 a is screwed into the axial groove 6 and is screwed to the male screw portion 5. 8 is inserted so as to make elastic contact with the screw thread 9a of the female screw portion 9 of FIG. 8, the mounting piece 2b is inserted into the diametrical groove 7, and the mounting piece 2b inserted into the diametrical groove 7 is By caulking the directional groove 7, it is integrally fixed in this groove 7, so that the locking lug 2 extends from the axial groove 6 to the diametrical groove 7 as shown in particular in phantom in FIG. Be sure to attach it in the posture. At this time, the arcuate spring main body 2a is preferably attached in a state in which the maximum bulge portion thereof is at the tip position of the male screw portion 5 or slightly protruding therefrom, as shown by the phantom line in FIG. In FIG. 3, the caulking portion obtained by caulking the mounting piece 2b in the diametrical groove 7 is indicated by K.

As shown in FIG. 4, the outer surface 2ao of the arcuate spring main body 2a of the locking spring 2 has an inner circumference of the thread 9a of the female screw portion 9 of the nut 8 screwed to the male screw portion 5 described above. It is formed into a curved surface with almost the same curvature. Therefore, when the nut 8 is screwed onto the male screw portion 5 of the bolt 1, the outer surface 2ao of the arcuate spring body 2a is pressed in line contact with the screw thread 9a of the female screw portion 9 of the nut 8, whereby The pressure contact force of the arcuate spring body 2a with respect to the screw thread 9a effectively works, and a more effective anti-loosening action can be exerted.

When two bolts 1 to be fastened as shown in FIG. 1 are fastened by using the bolt 1 with the loosening prevention spring 2 and the nut 8 having the above-mentioned structure, both fastened members W1 and W2 are fastened. When the bolts 10 and the bolts 1 of the fastening members W1 and W2 are passed through and the nut 8 is screwed into the male thread portion 5 of the bolt 1 from the position shown by the phantom line on the right end side in FIG. The fastened members W1 and W2 are fastened, and the screw thread 9a of the female screw portion 9 of the nut 8 is spring-biased to the arcuate spring body 2a inserted into the axial groove 6 of the male screw portion 5. The nut 8 is prevented from being loosened by being pressed.

The tightening operation of the nut 8 with respect to the male screw portion 5 of the bolt 1 can be easily and easily performed by using a common nut rotating tool such as a wrench and does not require a special tool.

In manufacturing the bolt 1 with the locking spring 2 as described above, in order to manufacture the bolt 1, for example, a bolt material including the shaft body 3 and the head portion 4 on which the male screw portion 5 is not formed is used. The bolt material is prepared, and the axial direction groove 6 and the diametrical groove 7 are formed at predetermined positions of the shaft body 3 of the bolt material by cold forging, and then the shaft body 3 is extended inward from the tip to the required length. The external thread portion 5 may be formed by rolling. At the time of this thread rolling, so-called burr may occur at the opening edge of each groove 6, 7, so the burr is removed after rolling. The method of manufacturing the bolt 1 is an example, and the bolt 1 can be manufactured by any other suitable method. Further, the loosening prevention spring 2 can be easily formed by press molding flat bar-shaped spring steel. Further, as the material of the bolt 1, a desired metal material such as steel, stainless steel, brass and aluminum can be used.

In the bolt 1 described above, the head portion 4 is formed in a hexagonal shape, but the bolt of the present invention has a cylindrical head portion 14 at the base end of the shaft body 13 as shown in FIG. The bolt 11 may be provided with a square or hexagonal hole 14a for screwing into the head 14. In the bolt 11, the male screw portion 5, the axial groove 6 and the diametrical groove 7 are the same in other structures as those shown in FIGS. 1 to 5, and the same symbols are given.

FIG. 7A shows a usage example in which the bolt 1 with the locking spring 2 shown in FIGS. 1 to 5 is used as a holding bolt. This is the case, for example, where the member W to be fastened is fastened to the fixed base S with the bolts 1, and the fixed base S is formed with a screw hole H having a female screw portion 19 and the bolt W of the member W to be fastened is inserted. The bolt 1 with the locking spring 2 is screwed from the hole 20 into the female screw portion 19 of the screw hole H of the fixing base S, and when tightened, the locking spring 2 attached to the bolt 1 prevents the bolt 1 from loosening. be able to. That is, when the bolt 1 is screwed into the female screw portion 19 of the fixing base S and tightened, the arcuate spring body 2a of the loosening prevention spring 2 inserted in the axial groove 6 of the male screw portion 5 has its spring urging force. As a result, the bolt 1 is pressed against the thread of the female screw portion 19 of the fixing base S to prevent the bolt 1 from loosening.

FIG. 7B shows a usage example in which the bolt 21 provided with the two locking springs 2 and 12 is used as an implantation bolt. The bolt 21 has male screw portions 15 and 25 at both upper and lower ends of a shaft body 23, and loosening prevention springs 12 and 2 are attached to the male screw portions 15 and 25 side in the same manner as in the above-mentioned embodiments. Therefore, when the member to be fastened W is fastened to the fixed base S by using the bolt 21 and the nut 8, first, the female screw of the screw hole H of the fixed base S is inserted from the bolt insertion hole 20 of the fastened member W. The bolt 21 is fixed to the screw hole H of the fixing base S by screwing it into the portion 19 and tightening it, and the bolt 21 is fixed by the locking spring 2 attached to the lower end side of the shaft body 3. Loosening is prevented in the same manner as in the example 7 (A). Next, the nut 8 is screwed into the male screw portion 15 of the bolt 21 and tightened to fasten the member W to be fastened to the fixed base S, and the thread (not shown) of the female screw portion of the nut 8 is tightened. The loosening prevention spring 12 attached to the upper end side of the shaft body 3 prevents the nut 8 from loosening in the same manner as in the embodiment of FIGS.

As described above, the loosening prevention springs in the bolts 1, 11 and 21 with the loosening prevention springs of the embodiment shown in FIGS. 1 to 7 are formed in a generally L-shape in side view, and their long side portions are formed. Although the spring body is formed in an arc shape and the short side portion is formed as a mounting piece, the loosening prevention spring has an arc shape like the loosening prevention spring 32 shown in FIGS. 8A and 8B. It can be formed only by parts. That is, the bolt 31 with the loosening prevention spring 32 is a bolt provided with the loosening prevention spring 32 formed in a bow shape by a flat rod-shaped spring material, and the male thread portion 35 of the shaft body 33 has only the axial groove 36. The arcuate lock spring 32 is inserted into the axial groove 36 so as to make elastic contact with the thread of the female thread 9 of the nut 8, and one end of the arc lock spring 32 is formed. The portion is fixed to the inner end of the axial groove 36 by caulking the groove 36, and the caulked portion is shown by K in FIG. 8B. The cross-sectional shape of the arcuate lock spring 32 is exactly the same as the spring body 2a of the lock spring 2 of the embodiment shown in FIGS. 1 to 5, and the outer side surface of the lock spring 32 has a nut 8a. Is formed into a curved surface having substantially the same curvature as the inner circumference of the screw thread 9a of the female screw portion 9.

When fastening the two members to be fastened W1 and W2 as shown in FIG. 8B by using the bolt 31 with the loosening prevention spring 32 as described above, it is similar to the embodiment shown in FIG. When the nut 8 is screwed into the male screw portion 35 of the shaft body 33 and tightened, the screw thread 9a of the female screw portion 9 of the nut 8 is inserted into the axial groove 36 of the male screw portion 35. The nut 8 is prevented from being loosened by being pressed against the bow-shaped loosening prevention spring 32. According to this embodiment, since the locking spring 32 can be formed only by the arcuate portion and only the axial groove 36 is formed in the shaft body 33, the structure is extremely simple and the manufacturing is easy, and the cost is low. The cost can be reduced.

[0020]

[Effect of the invention]

 According to another aspect of the present invention, there is provided a locking bolt, wherein an axial groove is formed on a male thread portion of a shaft body and a diametrical groove is formed on a tip end surface of the shaft body, and an arcuate spring main body and a nut are provided in the axial groove. It is inserted so as to make elastic contact with the threads of the female threaded part, etc., and the mounting part is fixed by caulking in the diametrical groove. Since it is provided on the shaft body, it can be applied not only to prevent the nuts from loosening, but also to prevent the bolts themselves that do not use nuts or the bolts of the studs from loosening. In particular, this loosening prevention uses a spring, and the bow-shaped spring body presses against the threads of the female threaded portion by its urging force to prevent the loosening of the screw, which prevents vibration and vibration. Even if it is used in a place with a strong impact, it is possible to reliably prevent the screws from loosening.

Further, since the arcuate spring body is inserted into the axial groove and the mounting piece is inserted into the diametrical groove to be caulked, the entire arcuate spring body can be effectively used and its spring action is sufficiently achieved. The attachment piece can be fixed easily and easily. Furthermore, the structure is simple and can be manufactured at low cost, and the fastening work during use is easy and easy, and no special tool is required.

According to the second aspect, the outer surface of the arcuate spring body is formed into a curved surface having substantially the same curvature as the inner circumference of the screw thread of the female threaded portion, so that the outer surface of the arcuate spring body has a female threaded portion. It is pressed against the ridge in a line contact state, whereby the pressure contact force of the main body of the arcuate spring against the screw ridge of the female thread portion effectively works, and a more effective anti-loosening action can be exerted.

According to the lock bolt of the third aspect, almost the same effect as that of the first aspect can be obtained, and in particular, the lock spring can be formed only by the arcuate body, and the shaft body can be formed. Since only the axial groove needs to be formed in the groove, the structure is extremely simple, the manufacturing is easy, and the cost can be significantly reduced.

According to the fourth aspect, the outer surface of the arcuate locking spring is formed into a curved surface having substantially the same curvature as the inner circumference of the screw thread of the female threaded portion. It makes pressure contact with the thread of the part in a line contact state, whereby the pressure contact force of the arcuate locking spring against the thread of the female thread works effectively, and a more effective locking effect can be exerted. .

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a lock bolt according to the present invention.

FIG. 2 is an enlarged sectional view taken along line XX of FIG.

FIG. 3 is an end view of the lock bolt of FIG. 1 viewed from the nut side.

FIG. 4 is an enlarged sectional view taken along line YY of FIG.

FIG. 5 is a perspective view showing how to attach a locking spring to the shaft body.

FIG. 6 is a side view of a bolt according to another embodiment of the present invention.

FIG. 7A is a sectional view showing an example of using the locking bolt of the present invention as a holding bolt, and FIG. 7B is a sectional view showing an example of using the locking bolt of the present invention as a stud bolt. Is.

FIG. 8A is a perspective view showing still another embodiment of the present invention, and FIG. 8B is a sectional view of the same embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bolt 2 Locking spring 2a Bow spring body 2b Mounting piece 3 Shaft body 4 Hexagonal head 5 Male screw portion 6 Axial groove 7 Diameter groove 8 Nut 9 Female screw portion 9a Screw thread 11 Bolt 12 Locking spring 13 Shaft Body 14 Cylindrical head 19 Female screw portion 21 Bolt 31 Bolt 32 Bow-shaped loosening prevention spring 33 Shaft body 35 Male screw portion 36 Axial groove K Caulking portion

Claims (4)

[Utility model registration claims] 1. A slack that is formed by a flat rod-shaped spring material into a substantially L-shape in a side view and has a long side portion forming an arcuate spring body bulging outward and a short side portion forming a mounting piece. A bolt having a retaining spring, wherein an axial groove is formed in the male thread portion of the shaft body, and a diametrical groove continuous with the axial groove is formed on the tip end surface of the shaft body, and an arcuate shape is formed in the axial groove. A loosening prevention bolt in which the spring body is inserted so as to make elastic contact with the threads of a female threaded portion such as a nut screwed with the male threaded portion, and the mounting portion is fixed by caulking in the diametrical groove. 2. The looseness according to claim 1, wherein an outer surface of the arcuate spring body is formed into a curved surface having substantially the same curvature as an inner circumference of a thread of a female thread portion such as a nut screwed with the male thread portion. Stop bolt. 3. A bolt provided with a locking spring formed in a bow shape by a flat rod-shaped spring material, wherein an axial groove is formed in a male screw portion of a shaft body, and the locking is secured in the axial groove. Insert the spring so as to make elastic contact with the threads of the female screw part such as the nut that is screwed with the male screw part, and fix one end of this arcuate locking spring to the inner end of the axial groove by caulking. Loosening prevention bolt. 4. The locking device according to claim 3, wherein an outer surface of the locking spring is formed into a curved surface having substantially the same curvature as an inner circumference of a screw thread of a female thread portion such as a nut screwed with the male thread portion. bolt.