CN209278317U - A kind of pairs of anti-loose nut bolt group with elastic bumps nut and rotary table hex nut composition - Google Patents

Abstract

A kind of pairs of anti-loose nut bolt group with elastic bumps nut and rotary table hex nut composition, it is interacted using the upstanding elastomeric protrusion of raised nut and the frustum cone side of rotary table hex nut, when screw thread pair pre-tightens, other than axial pre tightening force, it increases a radial forces more, forms pressure and frictional force bigger between screw thread pair.Simultaneously also as elastic bumps and wedge shaped side interact, an additional rubbing action point is increased again, increase additional pressure and frictional force, improve total frictional force limiting value, total frictional force limiting value is much larger than frictional force limiting value caused by common pretension bolt, its anti-loosing effect is more preferable, can prevent screw thread pair from relatively rotating.Reliability, practicability are good, can be used in severe impact, vibration, alternating load or the big occasion of temperature change, effectively reduce maintenance, maintenance to thread connection, improve safety, the utilization rate of equipment utilization.

Description

A double-nut anti-loosening screw with elastic protruding nuts and round table hexagonal nuts Throat group

technical field

The utility model belongs to the field of thread connection anti-loosening in mechanical engineering, and relates to a hexagonal nut with elastic protrusions and a round table hexagonal nut which can make full use of friction and anti-loosening to prevent thread connection from loosening, improve the connection effect, and reduce the maintenance and repair of the thread connection. Composed of double nut anti-loosening bolt group.

Background technique

Various machines and components are inseparable from couplings in connection assembly. The number of connectors accounts for about 60% of the total number of mechanical parts. Among them, threaded connection is the most common form used in mechanical connection. It has the advantages of simple structure, reliable connection, convenient assembly and disassembly, etc., which brings convenience to the machinery industry. However, it has an inevitable weakness. Under the action of severe shock, vibration or variable load, or when the temperature changes greatly, the threaded connection may loosen or even completely disengage. In real life, product failures, machine failures, disintegration, and even machine crashes caused by loose threaded connections are not uncommon. Therefore, how to ensure the reliability of the threaded connection and prevent the threaded connection from loosening is an important aspect to effectively ensure product quality and improve product reliability. The thread anti-loosening problem has become a practical technical problem that needs to be solved urgently.

In order to solve the loosening problem of the connectors, scientists and engineers from many countries in the world have done a lot of experiments and researches since the birth of the threaded connectors.

There are many methods of anti-loosening. According to different working principles, anti-loosening methods are divided into frictional anti-loosening and mechanical anti-loosening. In addition, there are some special anti-loosening methods, such as thread riveting, punching point anti-loosening, and adhesive anti-loosening between thread pairs.

Friction anti-loosening is the most widely used anti-loosening method. This method generates a positive pressure between the thread pairs that does not change with the external force to generate friction that can prevent the relative rotation of the thread pairs. This positive pressure can be achieved by pressing the thread pair axially or simultaneously in two directions. For example, elastic washers, double nuts, self-locking nuts and nylon insert locknuts are used. This anti-loosening method is more convenient for the disassembly of the nut, but in the case of shock, vibration and variable load, the pre-tightening force will decrease due to the loosening of the bolt at the beginning, and the pre-tightening force will gradually decrease as the number of vibrations increases. It will cause the nut to loosen and the threaded connection to fail.

The second way is mechanical anti-loosening. It is used to directly limit the relative rotation of the thread pair. Such as the use of cotter pins, series steel wires and washers, etc. This mode causes disassembly to be inconvenient.

Contents of the invention

The fundamental problem of bolted connection anti-loosening is to prevent the relative rotation of the thread pair. In order to prevent the relative rotation of the thread pair, it is necessary to try to increase the pressure and friction between the thread pairs, or increase the friction point at the same time, increase the additional friction force, and increase the total friction limit value to prevent the thread pair relative rotation.

When the material is constant, the coefficient of friction can no longer be changed, only to increase the interaction force between thread pairs or increase the number of friction points.

After the thread is pre-tightened, it is usually only affected by a single axial pre-tightening force. The pre-tightening force is usually 50-70% of the material yield strength σs, and the maximum cannot exceed 80%, which limits the improvement of the thread pair by increasing the pre-tightening force. the friction between them. If we can add an external force in the lateral direction, the resultant force of the lateral external force and the axial pretightening force will be much greater than the single axial pretightening force, and the pressure and friction between the formed thread pairs will be greater, which can prevent the screw thread Vice relative rotation.

The utility model uses a double nut composed of an elastic protruding nut and a round table hexagonal nut to pretighten the thread, not only by the normal axial pretightening force, but also by a transverse external force, forming a thread pair. Greater pressure and friction. At the same time, an additional friction point is added to increase the additional friction force, improve the total friction limit value, and prevent the thread pair from rotating relative to each other.

The technical solution adopted by the utility model to solve its technical problems:

A double-nut anti-loosening bolt group consisting of elastic raised nuts and round platform hexagonal nuts is characterized in that: it includes elastic raised nuts, round platform hexagonal nuts, and bolts; the elastic protrusions of the elastic raised nuts are round Arc-shaped, semi-cylindrical or cylindrical, made of elastic material, located on one end face of the nut, upright, perpendicular to the end face of the nut; the hexagonal nut of the circular platform is composed of two parts: a circular platform body and a regular hexagonal cylinder. The bottom is connected to the regular hexagonal cylinder, the small bottom of the round table is an end face of the nut, and the side of the round table diverges and slopes outward; the height of the round table is greater than the height of the elastic protrusion, and the position of the elastic protrusion is located in the axial projection area of the side of the round table.

An operation method for a double-nut anti-loosening bolt group composed of elastic protruding nuts and round table hexagon nuts. The end face points to the screw-in end of the nut of the bolt rod to pre-tighten the working connection; then the elastic protrusion of the raised nut is screwed in opposite to the round end of the hexagonal nut of the round table until the raised nut tightens the hexagonal nut of the round table to reach the specified maximum Stop tightening until the preload is reached.

The beneficial effect of the utility model is that the upright elastic protrusion of the protruding nut interacts with the side of the round table of the hexagonal nut of the round table, and when the thread pair is pre-tightened, in addition to the axial pre-tightening force, an additional radial force is added , forming greater pressure and friction between thread pairs. At the same time, due to the interaction between the elastic protrusion and the wedge-shaped side, an additional friction point is added, which increases the additional pressure and friction, and improves the total friction limit value, which is much larger than that of ordinary pre-tightening bolts. The limit value of the generated friction force has a better anti-loosening effect, which can prevent the relative rotation of the thread pair. It has good reliability and practicability, and can be used in places with severe shock, vibration, alternating load, or large temperature changes, effectively reducing the maintenance and repair of threaded connections, and improving the safety and utilization of equipment.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Fig. 1 is a schematic diagram of an axial section of the coupling assembly of the present invention.

Fig. 2 is an axial sectional view of a hex nut with a round platform.

Fig. 3 is a front view of the end face of the hexagon nut of the round platform.

Fig. 4 is an axial sectional view of the elastic protruding nut.

Fig. 5 is a front view of the protruding end face of the elastic protruding nut.

Fig. 6 is a front view of the end face of the circular platform when the side surface of the circular platform is corrugated.

In the picture: 1. Round table hex nut 2. Round table 3. Nut with elastic protrusion

4. Bolt 5. Upright Elastic Protrusion 6. Washer

7. Connected workpiece 1 8. Connected workpiece 2. 9. Corrugated arc surface.

Detailed ways

In the embodiment of Fig. 1, a double-nut anti-loosening bolt group consisting of an elastic protruding nut (3) and a round platform hexagonal nut (1) includes a round platform hexagonal nut (1), a elastic protruding nut (3), Bolts (4). The upright elastic protrusion (5) of the band elastic protrusion nut (3) is arc-shaped, made of elastic material, located on an end face of the protrusion nut (3), upright, and the protrusion nut (3) The ends are vertical. The hexagonal nut (1) of the round platform (1) is composed of two parts, the round platform (2) and the regular hexagonal cylinder, the large bottom of the round platform (2) is connected with the regular hexagonal cylinder, and the small bottom of the round platform (2) is an end face of the nut. The side of the round table (2) diverges and inclines outward; the height of the round table (2) is greater than that of the elastic protrusion (5), and the position of the elastic protrusion (5) is located in the axial projection area of the side of the round table.

During use, the hex nut (1) of the round table is screwed into the screw rod (4), so that the hexagonal end face is in contact with the workpiece support surface (7), and the end face of the round table points to the nut screw-in end of the bolt rod (4), and the workpiece (7, 8) Connection pre-tightening; then the elastic protrusion (5) of the raised nut (3) is opposite to the round end of the round hex nut (1), and then screwed into the screw (4). The raised nut (3) rotates continuously, and the elastic protrusion (5) moves down gradually, and interacts with the side of the round platform gradually. Because the side of the round platform diverges outwards, the expansion of the side of the round platform presses the upright elastic protrusion (5) to produce elastic deformation and tilts outward, and the upright elastic protrusion (5) reacts to give the round platform hex nut (1) a lateral force. The more the protruding nut (3) is screwed down, the larger the elastic deformation of the upright elastic protrusion (5) is, and the greater the interaction force between the upright elastic protrusion (5) and the hex nut (1) is. When the protruding nut (3) tightens the hexagonal nut (1) to reach the specified maximum pre-tightening force, not only the axial force acting on the contact surface of the two nuts and the thread pair is the largest, but also the interaction between the two nuts The lateral force is also the largest. The lateral acting force of the protruding nut (3) refers to away from the axis, and the lateral acting force of the hex nut (1) of the round table points to the axis.

At this time, in addition to the axial pretightening force suffered by ordinary double nuts for anti-loosening, the thread pair has an additional radial force, which forms greater pressure and friction between the thread pairs. At the same time, because of the interaction between the elasticity and the wedge-shaped side, an additional friction point is added, which increases the additional friction force and improves the total friction limit value, which is much greater than the friction force produced by ordinary double nuts. If the limit value is lower, the anti-loosening effect will be better, which can prevent the relative rotation of the thread pair.

The side of the round table hex nut (1) can be made into a corrugated shape composed of a series of continuous arc surfaces, which is beneficial for the upright elastic protrusion (5) to interlock with the corrugated arc surface (9) after the protruding nut (3) is tightened . The fitting and interlocking effect and the raised edge of the adjacent circular arc concave surface have a strong mechanical resistance to the sliding of the upright elastic protrusion (5), which further locks the thread pair and prevents the thread pair from rotating relative to each other.

Claims (1)

1. A double-nut anti-loosening bolt group consisting of an elastic raised nut and a round platform hexagonal nut is characterized in that: it includes a band elastic raised nut, a round platform hexagonal nut, and a bolt; the elastic protrusion with the elastic raised nut It is arc-shaped, semi-cylindrical or cylindrical, made of elastic material, located on one end surface of the nut, upright, and perpendicular to the end surface of the nut; the hexagonal nut of the round platform is composed of two parts: a round platform body and a regular hexagonal cylinder. The large bottom of the round table is connected to the regular hexagonal cylinder, the small bottom of the round table is an end face of the nut, and the side of the round table diverges and tilts outward; the height of the round table is greater than the height of the elastic protrusion, and the elastic protrusion is located in the axial projection area of the side of the round table.