CN220769922U - Anti-theft and anti-loose bolt and nut assembly - Google Patents

Abstract

The utility model discloses an anti-theft and anti-loose bolt and nut assembly, wherein the shapes of a nut and a bolt head are round, gaps are formed in the outer circumferential surfaces of the nut and the bolt head, each gap forms a stress surface and an auxiliary surface, and a special spanner acts on the stress surface and can only be screwed in one direction. The inner circumferential surface of the nut is provided with a nut groove, and a plastically deformed nut pin rod is plugged into the nut groove. The outer thread circumference of the bolt rod is provided with a bolt groove which extends to the bolt head or the bolt tail, and a plastically deformed bolt pin rod is plugged in the bolt groove to prevent the fastened thread from loosening. The utility model can only rotate unidirectionally and can not be disassembled, and the locking is achieved by utilizing the plastic deformation of the pin rod.

Description

Anti-theft and anti-loose bolt and nut assembly

Technical Field

The utility model is applied to the field of fasteners, relates to nuts and bolts, and particularly relates to a nut and bolt assembly with anti-theft and anti-loose functions.

Background

Fasteners are commonly screw nuts, and there are a number of patent applications in terms of anti-loosening and anti-theft of screws. Some patent applications use special tools to install, so as to achieve the anti-theft purpose, such as an anti-theft locknut component disclosed in CN218882738U, and a special internal pentahedron wrench is needed. The bolt or nut disclosed in CN2866936Y must be a universal sleeve with a matched external shape and size. The CN210068698U discloses a special anti-theft bolt and a wrenching tool, wherein the top plane of a round bolt head body is provided with two spherical blocks which are symmetrically arranged and protrude upwards; the longitudinal sections of the two spherical blocks form an insertion opening of a straight-line type screwing tool, and the special screwing tool is required to be used for installation. Most patent applications adopt the structure theftproof, like the anti-loose antitheft bolt disclosed in CN2646463Y, a groove which longitudinally penetrates through the thread is formed in the stud, the inner diameter of the gasket is provided with a bulge which is meshed with the groove, the upper surface and the lower surface of the nut are provided with serrated grooves along the circumferential direction, the serrated grooves are matched with the notch side of the gasket, the groove of the stud is matched with the bulge to fix the gasket, and the gasket is matched with the serrated grooves through the notch to prevent the nut from reversing so as to realize the antitheft effect. The anti-theft nut disclosed in CN2791331Y has a smooth outer circle side, and a conical nut with ratchets distributed on the top end, and can be only fastened unidirectionally but not disassembled by using a special tool. If the disassembly is needed, a cylindrical jacket with threads and a hexagonal outer side is additionally arranged on the outer side of the cylindrical jacket. The CN204164143U discloses a bolt with an anti-theft device, wherein the anti-theft device at the head of the bolt comprises a unidirectional stress groove, and a stress block is in an inclined semicircular shape and is screwed by unidirectional stress. Can not be disassembled by an ordinary wrench after being screwed. The nut disclosed in CN114893491a has too many components, including a first inverted T-shaped bolt, a second inverted T-shaped bolt, a slider, a block, an inverted L-shaped block, a first spring, a second spring, a third spring, etc., and the manufacturing cost is insufficient to support the market popularization. The riveting type bolt fastening anti-loosening/anti-theft combined structure disclosed in CN201747746U has the advantages that the anti-loosening principle is not complex, but the structure processing difficulty is slightly high, and the manufacturing cost is high. The anti-theft nut provided with the sealing plate disclosed by CN202228517U is used for installing the anti-theft device in a notch of an internal thread of the nut and fixing the anti-theft device by the sealing plate and a jurisdiction. Although this patent has fewer parts or shorter processing steps than the two patent applications, there are still many problems of parts and mounting steps. CN209164314U discloses an antitheft bolt assembly, the fixed protection head of bolt head, round nut and hexagon nut are screwed in proper order on the screw rod, and one side equidistant a plurality of jacks that are equipped with of hexagon nut are equipped with the gag lever post in the jack, and the one end of gag lever post runs through the jack and extends to the opposite side of hexagon nut, and one side equidistant a plurality of standing grooves that are equipped with of hexagon nut, the bottom of standing groove is equipped with the screw through-hole, and screw through-hole is corresponding with the jack. The structure of this patent application is somewhat complex, requiring more precise processing capabilities. Few patents provide different anti-theft ideas, such as anti-disassembly bolts disclosed in CN201059311Y, and the wrench head is twisted off by using the tightening force of the bolts so as not to be disassembled.

Disclosure of Invention

The utility model solves the technical problems that: the anti-theft and anti-loose bolt and nut assembly can only be screwed in a unidirectional rotation mode and cannot be disassembled in a reverse rotation mode, and anti-theft is achieved. The pin rod is adopted to increase the rotation resistance of the screw thread, so that the looseness prevention is realized.

The technical scheme adopted by the utility model is as follows: a bolt and nut assembly capable of preventing theft and loosening is characterized in that the shapes of a nut and a bolt head are round, symmetrical notches are formed in the outer circumferential surfaces of the nut and the bolt head, and each notch forms a planar stress surface and an auxiliary surface of an arc surface. A longitudinal nut groove is processed on the inner circumferential surface of the nut, and a plastically deformed nut pin is plugged into the nut groove. The outer thread circumference of the bolt rod is provided with a longitudinal bolt groove which extends to the bolt head or the bolt tail, the bolt groove is plugged with a plastically deformed bolt pin, and the nut pin and the bolt pin can be inserted separately or simultaneously. The plastically deformed pin is used to increase friction and prevent loosening of the fastened threads.

Furthermore, the connecting lines of the two symmetrically matched stress surfaces and the center of the nut are on the same straight line, and the special spanner acts on the stress surfaces to realize unidirectional screwing.

Further, the auxiliary surface replaces the cambered surface with a plane. The plane and the cambered auxiliary surface can enable the special spanner to slip reversely.

Further, the nut groove is matched with the bolt groove of the bolt tail in an aligned mode, and the plastically deformed nut pin rod is plugged. In order to achieve good matching of the threads and the adjusting angles, the number of the nut grooves is preferably three uniformly distributed, and the number of the bolt grooves is preferably five uniformly distributed.

The beneficial effects of the utility model are as follows: the utility model adopts the design of the notches on the outer circumferences of the nut and the bolt head as a unidirectional rotation structure, is not detachable, and realizes theft prevention. The plastic deformation of the pin rod is utilized to achieve the anti-loose effect.

Drawings

FIG. 1 is a schematic perspective view of a nut according to example 1;

FIG. 2 is a schematic top view of FIG. 1;

FIG. 3 is a schematic perspective view of a bolt according to example 1;

FIG. 4 is a schematic top view of FIG. 2;

FIG. 5 is a schematic view showing the fastening state of the assembly of example 1, and also A-A cross-sectional schematic view of FIG. 6;

FIG. 6 is a schematic top view of FIG. 5;

FIG. 7 is a schematic top view of the nut of example 2;

FIG. 8 is a schematic top view of a bolt according to example 2;

FIG. 9 is a perspective view of a bolt according to example 3;

FIG. 10 is a schematic diagram showing the assembly of a bolt and a nut according to embodiment 3;

fig. 11, fig. 12 and fig. 13 are different distribution diagrams of the nut groove and the bolt groove according to embodiment 3, respectively;

in the figure: 1-nut, 2-nut groove, 3-auxiliary surface, 4-notch, 5-stress surface, 6-special spanner, 7-bolt head, 8-bolt shank, 9-bolt groove, 10-bolt pin, 11-work piece, 12-nut pin, 13-bolt hole.

Detailed Description

Example 1

The bolt-nut assembly of this embodiment is shown in fig. 1-6, wherein fig. 1 and fig. 2 are schematic views of the nut structure, fig. 3 and fig. 4 are schematic views of the bolt structure, fig. 5 and fig. 6 are schematic views of the bolt-nut assembly, and the section lines in fig. 6 are not cross-sectional views, but are shown for comparison.

The nut 1 has a circular shape instead of a regular hexagonal shape. On its outer circumference, symmetrical notches 4 are machined, each notch 4 forming two faces on the outer circumference of the nut 1, one of which is the bearing face 5 and the other is the auxiliary face 3. The stress surface 5 is a plane, and the drawing shows that the connecting line of the two symmetrically matched stress surfaces is in the same straight line with the center of the nut, namely, the connecting line is consistent with the diameter of the outer circle of the nut, so that the rotation center of the torque born by the stress surface is consistent with the rotation center of the nut. The connecting line of the stress surface is not required to be on a straight line, is not required to be consistent with the diameter, can be screwed by unidirectional stress, and can also be used. The nut inner bore is internally threaded and on the inner circumferential surface a longitudinal nut groove 2 is machined. The number of the nut grooves 2 may be one or two or more, and in this embodiment, two symmetrical grooves are shown.

The bolt comprises a bolt head 7 and a bolt rod 8, the shape of the bolt head 7 is basically consistent with that of the nut 1, the bolt head is also round, symmetrical notches 4 are processed on the outer circumferential surface of the bolt head, the notches 4 form two surfaces on the outer circumferential surface of the bolt head, one surface is a stress surface 5, and the other surface is an auxiliary surface 3. The stress surface 5 is a plane, and the connecting line of the two symmetrically matched stress surfaces is preferably in the same straight line with the center of the bolt head, namely, the connecting line is consistent with the diameter of the outer circle of the bolt head. A longitudinal bolt groove 9 is formed in the outer circumferential surface of the upper end of the bolt shank 8, and the bolt groove 9 extends downward to the threaded portion of the bolt shank 8, and extends upward through to the bolt head 7. The bolt recess 9 may be one or two or more. In order to facilitate the formation of the bolt grooves 9, in this embodiment, two symmetrical bolt grooves 9 are designed at the junction of the bearing surface 5 and the auxiliary surface 3.

In the case of tightening the workpiece 11 with the bolt and the nut according to the present embodiment, it is necessary to use the special spanner 6 shown in fig. 2 and 4, and the special spanner 6 applies a clockwise rotation moment to the stress surface 5, so that the nut and the bolt can be screwed clockwise (the fastener is usually screwed clockwise, and the reverse buckle can reverse the stress surface). After the fixed workpiece 11 is screwed, the bolt pin 10 is plugged or hammered into the longitudinal bolt groove 9, the nut pin 12 is plugged or hammered into the longitudinal nut groove 2, and the bolt pin 10 and the nut pin 12 are preferably made of low-carbon steel with low strength and good plasticity. After the bolt pin 10 is plastically deformed, the external threads of the bolt are partially filled, so that the friction force between the external threads and the bolt hole 13 is increased, and the loosening of the bolt is avoided. After the nut pin 12 is plastically deformed, the internal thread of the nut and the external thread of the bolt are partially filled, so that the loosening resistance of the threaded connection is increased, and the loosening of the nut is avoided. The nut runner 12 may be used alone, preferably simultaneously with the bolt runner 10.

In the embodiment, the special spanner 6 is adopted to apply the tightening torque of the fastener on the stress surface 5, so that the nut and the bolt can only rotate in one direction for tightening, and the nut and the bolt cannot be loosened or disassembled in the opposite direction due to the stress surface without torque, thereby achieving the anti-theft effect. The screw thread is partially filled by the deformation of the pin rod, so that the screw thread loosening can be prevented.

Example 2

This example is a modification of example 1. In embodiment 1, if the auxiliary surface 3 is very close to the wrench, the planar auxiliary surface 3 may hinder the reverse rotation of the wrench. As shown in fig. 2, the special spanner 6 is in point contact with the upper auxiliary surface 3, but may be in surface contact with the lower auxiliary surface 3, so that the lower planar auxiliary surface 3 can also bear a certain reverse torque without slipping of the upper auxiliary surface. If the pin is not inserted and the bolt and nut are not tightened, there is a possibility of loosening the nut and bolt. For this purpose, the planar auxiliary surface in embodiment 1 is changed to an arc auxiliary surface as shown in fig. 7 and 8. In this way, the bolt and the nut can only be screwed down clockwise, and the arc auxiliary surface 3 is in point contact with the upper and lower sides of the wrench (in the direction of top view), so that the auxiliary surface 3 cannot bear reverse torque, and the nut and the bolt cannot be unscrewed even if the special wrench 6 is used, thereby realizing the anti-theft effect.

Example 3

This example is an improvement of the bolts based on example 2. The bolt structure is shown in fig. 9, a plurality of longitudinal bolt grooves 9 are formed in the bottom of the bolt rod 8 along the length direction of the bolt rod, and the bolt grooves 9 are matched with the nut grooves 2. That is, the bolt groove 9 is machined in the male screw portion and extends to the bolt tail.

Fig. 10 is a schematic diagram of the assembly of the nut and the bolt in this embodiment, when the bolt groove 9 is aligned up and down with the nut groove 2, the nut pin 12 is plugged or hammered into the nut groove, and the deformation capability of the nut pin 12 is utilized to partially fill the internal and external threads and the gap between the bolt hole 13, so as to increase the loose friction force of the bolt and avoid the loosening of the bolt.

Fig. 11-13 illustrate different mating patterns of nut grooves and bolt grooves, the nut grooves being hatched for ease of comparison. As shown in fig. 11, the two nut grooves are matched with the 9 bolt grooves, the adjusting angle is 20 degrees, the adjusting angle is the maximum rotation angle of the nut, and the alignment matching can be realized by one nut groove and one bolt groove. The number of the bolt grooves is 360/20/2=9 and is odd, so that the bolt grooves can be uniformly distributed. As shown in fig. 12, the three nut grooves are matched with 6 bolt grooves, the adjustment angle is 20 degrees, and since the number of the bolt grooves is 360/20/3=6, and is an integral multiple of three, the bolt grooves cannot be uniformly distributed, otherwise, every 20 degrees of adjustment cannot be achieved, and one nut groove is always aligned with one bolt groove. The more the number of grooves is, the larger the damage to the threads is, the fewer the number of the grooves is, the adjustment angle is increased, and the alignment of the nut grooves and the bolt grooves in the elastic deformation range is not facilitated. The most suitable quantity and distribution are shown in figure 13, five bolt grooves are uniformly distributed on the bolt rod 8, three nut grooves are uniformly distributed on the nut, and the uniform distribution is convenient for die processing. The adjustment angle is also proper at 24 degrees. As shown by the angle in fig. 13, there is always one nut recess and one bolt recess for alignment matching every 24 ° of clockwise rotation.

The special spanner is matched with the utility model, and the special spanner in the drawings of the utility model is only schematic in the application of a novel patent on the same day.

The manufacturing process flow of the nut is consistent with that of a conventional nut, cold heading or hot heading is carried out, and then the internal thread is tapped. The regular hexagonal mold is changed into a round mold, and the notch 4 and the nut groove 2 are molded at one time. The manufacturing process flow of the bolt is consistent with that of a conventional bolt, cold heading or hot heading is carried out, and then external threads are formed by rolling. The notch 4 and the bolt groove 9 are formed in one step. That is, the improvement of the structure of the utility model does not basically affect the manufacturing process flow and the manufacturing cost of the bolt and the nut, and has the advantage of low price compared with other anti-theft nuts.

The utility model utilizes the design of the outer circumferences of the nut and the bolt head to be of a unidirectional rotation structure, thereby preventing disassembly and realizing theft prevention. The plastic deformation of the pin rod is utilized to achieve the anti-loose effect.

Claims (6)

1. The utility model provides a theftproof locking bolt and nut subassembly, includes nut and bolt, the bolt includes bolt head (7) and bolt rod (8), nut and bolt head (7) appearance are circular, its characterized in that: symmetrical notches (4) are formed in the outer circumferential surfaces of the nuts and the bolt heads (7), and each notch (4) forms a plane stress surface (5) and an auxiliary surface (3) of an arc surface; a longitudinal nut groove (2) is formed in the inner circumferential surface of the nut; the circumference of the external thread of the bolt rod (8) is provided with a longitudinal bolt groove (9), and the bolt groove (9) extends to the head or the tail of the bolt.

2. The antitheft and anti-loose bolt-nut assembly of claim 1, wherein: the connecting line of the two symmetrically matched stress surfaces (5) and the center of the nut are on the same straight line.

3. The antitheft and anti-loose bolt-nut assembly of claim 1, wherein: the auxiliary surface (3) replaces the cambered surface with a plane.

4. The antitheft and anti-loose bolt-nut assembly of claim 1, wherein: the nut groove (2) is matched with the bolt groove (9) at the tail of the bolt in an aligned mode, and a plastically deformed nut pin rod (12) is plugged in the nut groove.

5. The antitheft and anti-loose bolt-nut assembly of claim 4, wherein: the nut grooves (2) are uniformly distributed in three, and the bolt grooves (9) are uniformly distributed in five.

6. The antitheft and anti-loose bolt-nut assembly of claim 1, wherein: the nut groove (2) is internally plugged with a plastically deformed nut pin (12) and/or the bolt groove (9) is plugged with a plastically deformed bolt pin (10).