Structure for preventing loosening of nut screwed onto bolt

Abstract

To reliably prevent loosening caused by vibration or the like when a headed bolt is screwed in, and to do so through a simple operation.SOLUTION: In a structure for preventing loosening of a nut screwed onto a bolt, 1 to 4 vertical rectangular grooves (8) are cut in advance in a female thread (7) of a tightening nut (6). After a bolt (1) is fixed to a lower member (3) by an embedding method, an upper member (4) is placed on the lower member through the bolt hole (5), and the tightening nut (6) is tightened onto the bolt. Then, a headed square nail (10) having an outer shape that fits tightly into the rectangular groove (8) of the tightening nut is driven or press-fitted from above. In an upper half (11) of the headed square nail that contacts a male thread (2) of the bolt, several heat-treated hardened longitudinal ridges (12) are provided. When the headed square nail is pressed downward, these ridges descend while crossing and biting into the male thread (2) of the bolt, thereby preventing rotation of the tightening nut holding the headed square nail with respect to the bolt.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention is a method for preventing loosening of a nut fastened to a bolt that requires a strong fastening force. [Background technology]

[0002] One method of securing a nut to a bolt to prevent it from loosening is to drill a hole through the nut and bolt and then push a cotter pin into it to secure it in place, but this drilling is often done on-site and is tedious; it also has the disadvantage that after being unscrewed once, the nut will not line up when tightened again; the nuts used to hold down rolling bearings are fine-threaded and cannot withstand heavy loads; and because the shaft requires groove machining, they are unsuitable for use on coarse-threaded bolts, which are used over a wide area; there are also double-nut type locking nuts that increase the frictional force on the thread surface, but their effectiveness is unknown. DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0003] The present invention prevents nuts tightened onto bolts from loosening and falling off due to strong vibrations. [Means for solving the problem]

[0004] One to four vertical square grooves (8) are cut into the female thread (7) of the clamping nut (6), and after the bolt (1) is fixed to the lower member (3) by a stud method, the upper member (4) is placed on top of the lower member through the bolt hole (5). After the clamping nut (6) is tightened onto the bolt, a headed square nail (10) with an outer shape that fits tightly into the square groove (8) of the clamping nut is struck or pressed in from above. The upper half (11) of the headed square nail that contacts the male thread (2) of the bolt has several vertical quench-hardened crests (12). When the headed square nail is pressed down, these crests descend and bite into the male thread (2) of the bolt, preventing the clamping nut, which holds the headed square nail, from rotating relative to the bolt. This is a locking nut structure.

[0005] One to four headed square nails (10) are fixed to the ring (14) and pressed down into the square grooves (8) of the clamping nut to be connected to the bolt (1). [Effects of the Invention]

[0006] By implementing the present invention, it is possible to reliably prevent loosening of the locking nut after it has been tightly fastened to the bolt, and it is possible to prevent the nut from falling off in vehicles subject to severe vibrations such as railway vehicles. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a longitudinal cross-sectional view of a state in which two square nails are driven into a nut as an example of an embodiment of the present invention. [Figure 2] Side view of Figure 1 [Figure 3] Plan view of Figure 1 [Figure 4] 1, 2 and 3. [Figure 5] Side view of Figure 4 [Figure 6] A front view of a square nail with sawtooth provided on the crest of the headed square nail as an example of an embodiment of the present invention. [Figure 7] FIG. 10 is a longitudinal cross-sectional view of a state in which a square nail fixed to a circular ring is driven into the circular ring as an example of an embodiment of the present invention. [Figure 8] Side view of Figure 7 [Figure 9] Plan view of Figure 7 [Figure 10] 7, 8 and 9 are front views of the square nails assembled in FIG. [Figure 11] Side view of Figure 10 DETAILED DESCRIPTION OF THE INVENTION

[0008] One to four vertical square grooves (8) are cut into the female thread (7) of the clamping nut (6), and after the bolt (1) is fixed to the lower member (3) by a stud method, the upper member (4) is placed on top of the lower member through the bolt hole (5). The clamping nut (6) is then tightened onto the bolt, and a headed square nail (10) with an outer shape that fits tightly into the square groove (8) of the clamping nut is struck or pressed in from above. The upper half (11) of the headed square nail that contacts the male thread (2) of the bolt has several vertical quench-hardened crests (12). When the headed square nail is pressed down, these crests descend and bite into the male thread (2) of the bolt, preventing the clamping nut, which holds the headed square nail, from rotating relative to the bolt. This is a locking nut structure.

[0009] A structure for preventing loosening of a clamping nut in which one to four headed square nails (10) are fixed to a ring (13) and pressed down into the square groove (8) of the clamping nut to connect with the bolt (1).

[0010] When the diameter of the clamping nut is large, sawtooth (13) is provided on several ridges (12) on the upper half of the headed square nail so that it can easily traverse the male thread of the bolt.

[0011] When removing the tightening nut from the male thread of the bolt, insert the tip of the L-shaped nail puller under the head of the headed square nail, and use the lever to easily pull out the headed square nail and release the tightening nut. [Explanation of symbols]

[0012] 1 Bolt 2 Bolt male thread 3 Lower member 4 Upper member 5····Bolt hole in upper member 6····Tightening nut 7····Internal thread of clamping nut 8····Angular groove of clamping nut 9 Bottom surface of square groove 10 Headed square nail 11···Upper half of headed square nail 12···Crown of headed square nail 13. Saw teeth on the crest of the square nail with a head 14. Ring

Claims

1. In this structure for preventing loosening of a nut tightened onto a bolt, one to four vertical square grooves (8) are cut into the female thread (7) of the clamping nut (6), and after the bolt (1) is fixed to the lower member (3) by a stud method, the upper member (4) is placed on top of the lower member through the bolt hole (5), the clamping nut is tightened onto the bolt, and then a headed square nail (10) with an outer shape that fits tightly into the square groove (8) of the clamping nut is struck or press-fitted from above. The upper half (11) of the headed square nail that contacts the male thread (2) of the bolt is provided with several vertical quench-hardened crests (12), and when the headed square nail is pressed down, these crests descend and bite into the male thread (2) of the bolt, preventing the clamping nut holding the headed square nail from rotating relative to the bolt.

2. A structure for preventing loosening of a clamping nut in which one to four headed square nails (10) as described in claim 1 are fixed to a circular ring (14) and coupled with a push-down bolt (1) in the square groove (8) of the clamping nut.

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