CN220668111U - Self-locking bolt - Google Patents

Abstract

The utility model discloses a self-locking bolt, which comprises a screw rod (3) and a bolt head (2), wherein a spiral external thread (7) is arranged on at least the side part of a cylinder at the external end of the screw rod (3), the external end face (12) of the hexagonal bolt head of the bolt head (2) is perpendicular to the symmetry axis of the screw rod (3), the external or internal side of the bolt head (2) is a cylinder with a regular hexagonal side or a regular tetragonal side, and the internal end face (6) of the hexagonal or tetragonal bolt head, which is coaxially connected with the screw rod (3), of the bolt head (2), is characterized in that: the symmetry axis of the inner end face (6) of the bolt head and the symmetry off-axis angle of the screw rod (3) form an alpha degree, and alpha is more than or equal to 1'. Ltoreq.3 degrees. The self-locking bolt (1) has the advantages of simple structure, excellent anti-loosening performance, easy processing and low cost.

Description

Self-locking bolt

Technical Field

The utility model relates to the field of anti-loosening fasteners, in particular to a self-locking bolt.

Background

Screw bolts are screwed and fixed in screw holes on vibration mechanical equipment and instruments, so that the screw bolts gradually rotate backwards and loosen due to strong vibration, and accidents are caused. Therefore, the utility model of a plurality of anti-loose and self-locking bolts has the following defects: the utility model discloses a self-locking bolt as in CN213575099U, its characterized in that: the locking thread section is located the body of rod and keeps away from head one end, and the deformation groove is located between locking thread section and the load-bearing thread section, forms eccentric angle between the central axis of locking thread section and the central axis of load-bearing thread. The deformation groove between the locking thread section and the bearing thread section is easy to be used due to assembly and disassembly, the self-locking bolt is fatigued and broken from the deformation groove under the vibration working condition, the self-locking bolt is invalid, the service life is shortened, the structure is complex, the processing is difficult, and the use cost is high.

The locking self-locking bolt that moves like CN201284783Y discloses, characterized by: the lower end face of the prismatic clamping table of the bolt body is provided with a groove, a jacking spring and a steel ball are arranged in the groove, and the distance between the lower end face of the prismatic clamping table protruding out of the bolt body after the steel ball is positioned is approximately one third of the diameter of the steel ball. The product needs to be punched on the inner end face of the bolt head, so that the hole is close to the screw rod, the punching clamp is difficult to be close to the construction, in addition, the steel ball is difficult to seal the hole opening, the spring is small, the elasticity is small, the pressure of the rolling steel ball is small, the impact resistance vibration is difficult to play in practice, the design is complex, the processing is difficult, the cost is high, and the product cannot be practically applied.

Disclosure of Invention

In view of the above, the utility model aims to overcome the defects of the self-locking bolt in the prior art and provide the self-locking bolt which has the advantages of good self-locking performance, simple structure, easy processing, low cost and repeated use.

In order to achieve the above purpose, the technical scheme of the utility model is realized as follows:

the self-locking bolt comprises a screw rod and a bolt head, wherein a spiral external thread is arranged on at least part of the peripheral side surface of a cylinder at the outer end of the screw rod, the outer end surface of a hexagonal or tetragonal bolt head of the bolt head is perpendicular to the symmetry axis of the screw rod, and the outer or inner side surface of the bolt head is a cylinder with a regular hexagonal side or a tetragonal side; the bolt head with the coaxial hexagonal or four corners bolt head terminal surface that links to each other of screw rod, its characterized in that:

the eccentric angle alpha between the symmetry axis of the inner end surface of the bolt head and the symmetry axis of the screw rod;

further, the angle of the off-axis angle alpha is more than or equal to 1'. Ltoreq.alpha.ltoreq.3°;

further, the off-axis angle α is preferably 5'; or 15'; or 30'; or 45'; or 1 °;

the final contact line CD between the inner end surface of the bolt head and the fastened piece on the inner end surface of the bolt head moves from the axle center on the inner end surface of the bolt head to the hexagonal edge of the bolt head; or when the contact line CD moves to the hexagonal edge, namely the inner end surface of the whole bolt head is a chamfer with a chamfer angle gamma; the selection and determination of the value of the off-axis angle alpha is related to the length of the screw rod, the gap between the screw rod outer wire and the screw hole and the diameter parameter of the screw rod, so that the free loosening of a self-locking bolt in the screw hole can be prevented, the inner end surface of the bolt head is ensured to be fully contacted with the upper fastened piece to the greatest extent, the value of the included angle beta between the inner end surface of the bolt head and the upper fastened piece is reduced as much as possible, the contact surface between the two is fully increased, and the pretightening force of the self-locking bolt is increased under certain pressure;

further, the size of the chamfer of the inner end surface is at least more than half of the inner end surface of the bolt head, and the inner end surface of the bolt head is not included.

A self-locking bolt processing method comprises the following steps: one of the following alternatives is selected:

1. cold heading and cold pressing, placing blanks in a die of an automatic cold heading machine or a press machine at room temperature, applying pressure to the die, deforming the blanks in a die cavity by utilizing the relative movement of an upper die and a lower die, reducing the height and increasing the cross section, and the cold heading and cold pressing machine is characterized in that: the die wall of the die cavity corresponding to the inner end face of the bolt head is at least more than half of the inner end face of the bolt head forming an off-axis angle alpha, or the inner end face of the bolt head forming an oblique cutting angle gamma angle in the whole off-axis angle, and alpha is more than or equal to 1' < 3 degrees; preferably, the off-axis angle α is 5'; or 15'; or 30'; or 45'; or 1 °; thus, the thickest thickness or depth of the chamfer is also determined;

2. cutting, turning and milling, bolt head processing, screw rod portion processing and screw thread processing, its characterized in that: clamping and fixing the axle center and the off-axis angle alpha of the bolt body by using a clamp, then rotating the clamp, and turning the inner end surface bevel angle of the bolt head of the bolt body to be removed by using a fixed cutter, wherein the specific angle, the area size, the depth or the called thickness are as required;

3. polishing by using a polishing tool, which is characterized in that: if grinding wheels, files, file wheels and the like are used, the inner end surface of the bolt body is polished to remove the inclined surface of the inner end surface of the annular bolt head, and the specific polishing angle, area, size, depth or thickness are as required;

4. printing by 3D, which is characterized in that: designing a bolt body diagram with the oblique angle of the inner end face of the annular bolt head removed into a 3D graph, printing out the self-locking bolt by using a 3D printer, wherein the shape, the area, the size, the specification, the depth or the thickness of the self-locking bolt and the oblique angle of the inner end face of the bolt head are the same as those of the self-locking bolt, and the materials are selected;

5. the method is characterized by comprising the following steps of: forging or extruding the inner end face of the inclined bolt head of the required bolt head by using a simple inclined plane pressing die.

The principle of the utility model against loosening is analyzed as follows:

beta is the included angle between the inner end face of the bolt head of the self-locking bolt and the fastened piece on the upper surface, the smaller the included angle beta is, the better the included angle beta is, firstly, the screw is guaranteed to be inclined in the screw hole to the greatest extent, the screw is inclined in the screw hole and cannot be inclined any more, and then the inner end face of the bolt head is considered to be fully contacted with the fastened piece on the upper surface as far as possible, so that the self-locking bolt can be locked in the screw hole of the fastened piece on the lower surface to achieve the best anti-loosening effect.

A is a falling inclined pivot I of a self-locking bolt end and a screw hole; b is a falling inclined pivot II between the root of the self-locking bolt and the screw hole of the fastened piece; CD is the final contact line between the interior terminal surface of the bolt head of a kind of self-locking bolt and the upper quilt fastener, and the CD line is offset in one side of the interior terminal surface of bolt head forever, just so can guarantee that the screw rod of a kind of self-locking bolt falls to incline in the screw, also only falls to incline, just can guarantee that a kind of self-locking bolt that A point, B point and CD line are fixed and the upper quilt fastener and the lower quilt fastener are fixed to lock in an organic whole, can not have the not hard up at all to reach the purpose of the locking of case.

The screw rod can be discharged from the screw hole only after the bolt head of the self-locking bolt is loosened by tools such as a wrench and the like, and the screw rod is released from the inclined locking state in the screw hole, so that the outer wire of the screw rod is in clearance with the inner wire of the screw hole and is not inclined, or the inner wire and the outer wire are mutually parallel to rotate, so that the screw rod can be reused next time. In practical application, the inner wire and the outer wire can not damage the threads of the inner wire and the outer wire after falling obliquely, and can be completely reused for multiple times.

In summary, the self-locking bolt and the processing method thereof have the following advantages:

1. the utility model based on the existing bolt has strong universality;

2. the cold heading process or the existing common bolt re-cutting processing process is used, the processing speed is high, simplicity is realized, the inclination of the changed inner end surface is extremely small, the cold heading die is not damaged, the production cost is saved as compared with the common bolt production, and the production and the processing are easier;

3. the installation operation of the scheme is the same as that of a common bolt, and no special tool is needed;

4. the self-locking bolt has good anti-loosening performance, after the self-locking bolt is fastened, due to the small gap between the outer thread of the bolt and the inner thread of the screw hole and the angle gamma of the chamfer angle of the inner end surface of the bolt head, the self-locking bolt is inclined in the screw hole, and the inclined binding is more stable and reliable along with the increase of the pretightening force, and can not loosen at all, so the self-locking bolt is more firm in loosening than the existing product and has better effect;

5. besides the integral self-locking bolt, no additional vulnerable parts exist, so that the fault rate is almost not generated, the anti-loose function maintenance is avoided, and the actual requirements can be met.

Drawings

FIG. 1 is a front view of a self-locking bolt of the present utility model;

FIG. 2 is a cross-sectional view of M-M of FIG. 1;

FIG. 3 is another cross-sectional view of M-M of FIG. 1;

fig. 4 is a schematic view of the installation of fig. 1 in use.

In the figure:

1. a self-locking bolt; secondly, a bolt head; thirdly, a screw rod;

4. the upper fastened part; fifth, the lower part is fastened; sixthly, the inner end face of the bolt head;

7. an outer thread; eighthly, screw holes; seventhly, an inner wire;

10. chamfering; 11, the outer end of the screw rod; sixthly, the outer end face of the bolt head;

13. hexagonal sides; 14, a gap between the screw outer wire and the screw inner wire;

alpha, off-axis angle;

beta. The included angle between the inner end surface of the bolt head and the upper fastened piece;

gamma, chamfer angle;

A. the outer end of the screw rod and a falling inclined pivot I of the screw hole;

B. a second inclined pivot is arranged between the root of the screw rod and the screw hole of the fastened piece;

cd, final line of contact between the inner face of the bolt head and the upper fastened part.

Detailed Description

The utility model will now be further described with reference to the accompanying drawings and examples:

in fig. 1-2, a self-locking bolt 1 is formed by integrally connecting a coaxial screw rod 3 and a bolt head 2 at a position where an inner end surface 6 is a chamfer 10, wherein a part of circumferential side surface of a cylinder at least at the outer end 11 of the screw rod is provided with a spiral outer wire 7, a hexagonal or tetragonal bolt head outer end surface 12 of the bolt head 2 is vertical to the symmetrical axis of the screw rod 3, the bolt head 2 is an outer hexagonal or an inner hexagonal or an outer tetragonal or a cylinder of the outer tetragonal or an inner tetragonal, the symmetrical axis of the inner end surface 6 of the bolt head is a deflection angle alpha of the symmetrical axis of the screw rod 3, and the deflection angle alpha is 1 '. Ltoreq.alpha.ltoreq.3 degrees, and if alpha is 1' or 5'; or 15'; or 30'; or 45'; or 1', or 3 °; the size of the chamfer 10 of the inner end face 6 of the bolt head is at least more than half of the inner end face 6, to the chamfer 10 of the inner end face 6 of the whole bolt head, but does not comprise half of the inner end face 6 of the bolt head; i.e. the final line of contact CD between the inner end face 6 of the bolt head 2 and the upper fastened part 4, moves from the axial centre on the inner end face 6 of the bolt head to the hexagonal edge of the bolt head 2.

As shown in fig. 3, the selection and determination of the value of the off-axis angle α is related to parameters such as the length of the screw 3, the gap between the outer wire 7 of the screw 3 and the screw hole 8, and the diameter of the screw 3, so as to ensure that not only a self-locking bolt 1 is prevented from vibrating in the screw hole 8 and loosening freely, but also the inner end surface 6 of the bolt head 2 is ensured to be fully contacted with the upper fastened piece 4 to the greatest extent, and the value of the included angle β between the inner end surface 6 of the bolt head 2 and the upper fastened piece 4 is reduced as much as possible, so that the contact surface between the two is fully increased, and thus the pretightening force of the self-locking bolt 1 is increased under certain pressure.

In fig. 3 and 4, or when the contact line CD moves to the hexagonal edge on the inner end surface 6 of the bolt head, that is, the whole inner end surface 6 is a chamfer 10 with a chamfer angle γ, the value of the chamfer angle γ is the same as that of the off-axis angle α, but the positions are different, the orientations are different by 90 °, and other structures are the same as those described in fig. 1-2, and will not be repeated.

In fig. 4, the outer end 11 of the threaded rod 3 of the self-locking bolt 1 firstly penetrates into the threaded hole 8 of the upper fastened member 4, and then is screwed into the threaded hole 8 of the lower fastened member 5, and the bolt head 2 is screwed by a tool, at this time, the final contact line CD between the inner end surface 6 of the bolt head 2 and the upper fastened member 4 tightly abuts against the upper surface of the upper fastened member 4, so that the oblique falling point B between the root of the threaded rod 3 and the upper fastened member 4 tightly abuts against one edge of the mouth of the upper threaded hole 8 of the upper fastened member 4, and simultaneously, the oblique falling pivot a of the outer end 11 of the threaded rod and the threaded hole 8 tightly abuts against the inner wire 9 of the lower fastened member 5 near the bottom.

The processing method of the self-locking bolt comprises the following steps:

the first method comprises the steps of cold heading and cold pressing, wherein a blank is placed in a die of an automatic cold heading machine or a press machine at room temperature, pressure is applied to the die, the blank is deformed in a die cavity by utilizing relative movement of an upper die and a lower die, the height is reduced, the cross section is increased, and the die wall corresponding to the inner end face 6 of a bolt head 2 in the die cavity is formed to have an off-axis angle gamma of between 1 'and 3 degrees, such as 1'; or 15'; or 30'; or 45'; or 1 °; or 3 °.

The second method, cutting, turning and milling, machining the bolt head 2, machining the screw 3 and machining the threads, which are machining processes which will be known to those of ordinary skill in the art, is not repeated, except that the shaft of the bolt body, the off-axis angle alpha, is clamped and fixed by a clamp, then the clamp is rotated, and the inner end face bevel angle of the bolt body to be removed is turned by a fixed cutter, and the specific angle, area size, depth or called thickness are as described above.

In the third method, polishing is performed by using a polishing tool, such as a grinding wheel, a file wheel and the like, and the inner end surface 6 of the bolt head of the bolt body is polished to remove the inclined surface of the inner end surface 6 of the annular bolt head, wherein the polishing angle, area, size, depth or thickness are as described in the above requirements.

In the fourth method, the bolt body diagram with the oblique angle of the inner end face of the annular bolt head removed is designed into a 3D graph, and then the 3D printer is used for printing out the self-locking bolt 1, the shape, the area, the size, the specification, the depth or the thickness of the bolt head inner end face 6 oblique angle is the same as that of the previous one, and the materials are selected.

The fifth method is to forge or extrude the inner end surface 6 of the bolt head 2 which is needed to be inclined by using a simple inclined plane pressing die, and the inner end surface 6 is in specific shape, area, size specification, depth or thickness.

The self-locking bolt 1 is made of metal, such as carbon steel, stainless steel, titanium alloy, alloy steel, high-temperature alloy and the like; or non-metallic, such as carbon fiber, plastic, nylon, graphene, and the like.

The utility model relates to an upper part and a lower part; "inner", "outer"; the orientation or positional relationship indicated by "bottom", "mouth", etc. is based on the orientation or positional relationship shown in the drawings, and is merely for convenience of description and simplification of description, and does not indicate or imply that the apparatus or parts referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the utility model, the terms mounted, connected should be construed broadly, for example, integrally connected may be directly connected or indirectly connected as a whole through intermediaries, and the specific meaning of the terms in the present utility model may be understood by those of ordinary skill in the art in the specific case.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather, the utility model is to be construed as limited to the appended claims.

Claims (5)

1. The self-locking bolt comprises a screw rod (3) and a bolt head (2), wherein a spiral outer wire (7) is arranged on the screw rod (3) at least on part of the circumferential side surface of a cylinder at the outer end (11) of the screw rod, the hexagonal or four-corner outer end surface (12) of the bolt head (2) is perpendicular to the symmetry axis of the screw rod (3), and the outer or inner side surface of the bolt head (2) is a cylinder with a regular hexagonal side or four-corner side; the bolt head (2) is coaxial with the hexagonal or tetragonal bolt head inner end surface (6) connected with the screw rod (3), and is characterized in that:

an off-axis angle alpha of the symmetry axis of the inner end surface (6) and the symmetry axis of the screw (3).

2. The self-locking bolt of claim 1, wherein: the angle of the off-axis angle alpha is more than or equal to 1'. Ltoreq.alpha.ltoreq.3°.

3. The self-locking bolt of claim 2, wherein: the off-axis angle alpha is 5'; or 15'; or 30'; or 45'; or 1 °.

4. A self-locking bolt according to any one of claims 1-3, wherein: a final contact line CD between the inner end surface (6) of the bolt head (2) and the upper fastened piece (4) moves from the axis on the inner end surface (6) of the bolt head to the hexagonal edge of the bolt head (2); or when the contact line CD moves to the hexagonal edge, namely the whole inner end surface (6) of the bolt head is a chamfer surface (10) with a chamfer angle gamma; the selection and determination of the value of the off-axis angle alpha is related to the length of the screw (3), the clearance between the external thread (7) of the screw (3) and the screw hole (8), and the diameter parameters of the screw (3).

5. The self-locking bolt of claim 1, wherein: the size of the chamfer (10) of the inner end surface (6) is at least more than half of the inner end surface (6) of the bolt head, and the chamfer does not comprise half of the inner end surface of the bolt head.