CN116517940A - Pretightening force locknut - Google Patents

Abstract

The invention belongs to the field of thread looseness prevention, and relates to a pretightening force locknut. The locknut thread comprises two continuous sections of internal threads, the length of the front section of thread is larger than that of the rear section of thread, the front section of thread is used for fastening the nut, the rear section of thread is used for locking, and the pitches of the two sections of threads are identical and the starting points are different. According to the locknut disclosed by the invention, when the bolt threads are screwed into the rear-section thread part, due to the fact that a certain amount of difference exists between the front thread starting point and the rear thread starting point, the gap between the bolt threads and the meshing part of the two sections of threads of the nut is eliminated after the bolt is screwed, the extrusion deformation and the friction resistance which are effectively formed exist together, the pretightening force is generated, and the expected force exists all the time after the nut is screwed, so that the locknut is capable of realizing the lockeffect.

Description

A kind of pretightening locknut

technical field

The invention belongs to the field of thread anti-loosening, and relates to a pretightening force anti-loosening nut.

Background technique

Commonly used nut loosening methods include: riveting anti-loosening, mechanical anti-loosening, frictional anti-loosening, etc. The disadvantage of the riveting anti-loosening method is that the bolt can only be used once, and the disassembly is very difficult, and the bolt pair must be destroyed before disassembly.

Mechanical anti-loosening Since the lock nut stopper has no pre-tightening force, the anti-loosen stopper will only work when the locknut nut is loose and retreats to the stop position. Therefore, the locknut is not actually loose but Avoid shedding.

Friction anti-loosening is the most widely used anti-loosening method. This method generates a positive pressure that does not change with the external force between the lock nut pairs to generate a frictional force that can prevent the relative rotation of the lock nut pairs. This positive pressure can be achieved by compressing the lock nut pair axially or simultaneously. For example, elastic washers, double nuts, self-locking nuts and insert lock nuts are used, but they need to be combined and used by multiple parts, and it is inconvenient to assemble and disassemble.

Contents of the invention

The object of the present invention is: based on the frictional anti-loosening principle, to provide a pre-tightening force anti-loosening nut with simple structure, reliable anti-loosening, reusability and wide application range.

Technical solutions

The technical solution of the present invention: a pre-tightening force locknut, characterized in that the internal thread of the locknut is composed of two consecutive sections of internal thread before and after, the length of the internal thread 11 of the front section is greater than the length of the internal thread 12 of the rear section, The pitches of the two sections of internal threads are the same, but the starting points of the threads are different.

Further, the lengths of the internal threads of the front and rear sections are adapted according to the specification of the locknut.

Further, the thread start angle variables of the two sections of the front and rear internal threads are in the range of 10°-120°.

Further, the difference between the pitch diameters of the front and rear internal threads is adapted according to the anti-loosening performance requirements.

Further, the said is made of metal and non-metal materials with certain strength.

Further, the metal material is preferably 40Cr steel.

Further, the shape of the locknut is optional, preferably hexagonal.

technical effect

In the anti-loosening nut of the present invention, when the bolt thread is screwed into the internal thread 12 of the rear section of the nut, since there is a certain amount of difference in the starting point of the internal thread before and after the nut, after the bolt is screwed into the nut, the external thread 2 of the bolt and the internal thread teeth of the two sections of the nut The gap at joint 3 is eliminated, and the effectively formed extrusion deformation and frictional resistance exist together, resulting in a certain pre-tightening force. After the nut is tightened, the pre-tightening force of the clamped workpiece also exists all the time, so as to achieve the purpose of preventing loosening.

Description of drawings

Fig. 1 is a schematic diagram of a locknut;

Fig. 2 is a schematic diagram of the connection thread between the locknut and the bolt;

The marks in the figure are: 1. Locknut body; 2. Bolt external thread; 3. Thread engagement surface; 4. Workpiece to be clamped; 11. Front internal thread; 12. Rear internal thread.

Detailed ways

The present invention will be further described below in conjunction with embodiment. The following descriptions are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

The present invention is an integrated pre-tightening force lock nut. When the nut blank is used to process the inner hole thread, according to the nut specification or the anti-loosening performance requirements, two sections of internal threads with the same pitch are formed in the inner hole of the nut. The front section The length of the internal thread 11 accounts for 2/3 of the total length of the internal thread, the pitch diameter of the rear internal thread 12 is the same as that of the preceding internal thread 11, and the starting position of the thread differs by 30° from the preceding internal thread 11.

Screw the bolt from the internal thread 11 of the front section of the nut, and when the internal thread 12 of the rear section is screwed into the external thread 2 of the bolt, due to the 30° difference in the starting point of the internal thread of the front and rear sections, the external thread 2 of the bolt and the two sections of the nut before and after The gap between the thread teeth 3 is eliminated, and the effectively formed extrusion deformation and frictional resistance exist together, resulting in a certain pre-tightening force. After the nut is tightened, the pre-tightening force still exists to compress the workpiece, so as to achieve the purpose of loosening.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (7)

1. A pre-tightening locknut, characterized in that the internal thread of the locknut is composed of two consecutive internal threads, the front section internal thread (11) is longer than the rear section internal thread (12), and the two The pitches of internal threads are the same, but the starting points of the threads are different. 2 . The pretightening locknut according to claim 1 , wherein the lengths of the front and rear internal threads are adapted according to the specifications of the locknut. 3 . 3. A pre-tightening locknut according to claim 1, characterized in that, the thread starting angle variables of the front and rear two sections of internal threads are within the range of 10°-120°. 4. A pre-tightening locknut according to claim 1, characterized in that the difference in pitch diameter of the internal threads of the front and rear sections is adapted according to the anti-loosening performance requirements. 5. A pre-tightening force locknut according to claim 1, characterized in that, the locknut is made of metal or non-metal materials with certain strength. 6. A pre-tightening locknut according to claim 5, wherein the metal material is preferably 40Cr steel. 7. A pre-tightening locknut according to claim 1, characterized in that, the shape of the locknut is optional, preferably hexagonal.