Lock washer

Abstract

This utility model discloses an anti-loosening washer, namely the edge-curving anti-loosening washer (1), which is a circular ring washer. Its features are: one side of the flat circular ring washer is squeezed and bent, and the chord direction is tilted downward or upward to form an asymmetrical prying pad structure with axial elastic force on the left and right sides. With the chord support surface (3) as the fulcrum, one side of the nut (12) is pryed, so that the left and right sides of the nut (12) on the threaded connection are unevenly stressed. It is fully tilted within the gap (22) between the inner thread (16) of the nut and the outer thread (17) of the bolt, forming a thread anti-loosening structure with sawtooth ripples and staggered peak and valley teeth. As the preload increases, the friction is very large, locking the nut (12) and the bolt (13). It has elasticity and can also prevent loosening in the axial direction within the elastic height range. It truly achieves three-dimensional anti-loosening. The structure is simple and the anti-loosening performance is excellent. It replaces the original flat elastic washer and is suitable for anti-loosening and fastening of various vibrating mechanical equipment.

Description

Technical Field

[0001] This utility model relates to the field of anti-loosening fasteners, and in particular to spring washers for preventing nuts from loosening on bolts. This asymmetrical anti-loosening washer is called "tilting edge anti-loosening elastic washer" or "tilting edge anti-loosening washer" based on its shape characteristics, or simply "tilting washer" or "tilting ring"; or it is called "pry edge anti-loosening washer" or simply "pry washer" or "pry ring" based on its function characteristics. Background Technology

[0002] Existing spring washers consist of an inner ring, an outer ring, and several wave-shaped spring plates. When the bolt or screw is tightened, the spring washer is compressed, generating a rebound force, thereby increasing the tightening force of the threaded connection. This design, under elastic vibration or impact, increases the axial pressure between the nut and the connected parts, thus increasing the friction between the threads and creating a resistive torque, thereby inhibiting nut loosening. It can prevent loosening under mild vibration conditions. However, in cases of severe vibration, actual testing shows that the nut loosens quickly; excessive preload can also cause the spring plate to open and swell, leading to failure. This type of anti-loosening structure is no longer recognized in Europe and America.

[0003] In addition, existing wave spring washers, which are metal washers with a special uniformly distributed wave structure, are placed between the nut and the connected parts on a bolt. They provide preload through their own elastic deformation. When the bolt or nut is subjected to external vibration, the wave spring washer can effectively absorb these forces and prevent the connection from loosening. However, because the rebound force between the nut and the fastener is uniformly distributed circumferentially during operation, under conditions of strong vibration, even though the internal thread of the nut and the external thread of the bolt are parallel helical meshing, the internal thread of the nut can still helically slip and loosen on the external thread of the bolt. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an anti-loosening washer that can significantly improve its anti-loosening performance under strong vibration conditions, ensuring that the inner thread of the nut is firmly locked on the outer thread of the bolt and will not rotate, slip, or loosen.

[0005] The anti-loosening washer described in this case is a circular ring washer, characterized in that:

[0006] The left or right side of the flat ring washer structure, which is less than half the length of the entire washer, is bent upwards or downwards by extrusion and bending processes, forming a "chord-curved edge". Then, it is heat-treated to make it elastically shaped. After the nut is removed, when the anti-loosening washer is in a free loose state, it can still return to its original curved edge state due to the elastic effect.

[0007] The anti-loosening washer has a chord-direction raised edge, meaning that in the circular flat washer, there is an elastic raised edge portion perpendicular to the radial direction in the chord direction.

[0008] The size of the warped portion of the anti-loosening washer is such that, after the anti-loosening washer is axially flattened, the axial elastic force on the left and right sides is asymmetrical.

[0009] The anti-loosening washer, the elastic force of the warped edge (5) is such that after the anti-loosening washer is axially flattened, the axial elastic prying force on the left and right sides of the nut is asymmetrical.

[0010] The anti-loosening washers have the same axial cross-section.

[0011] The axial cross-section of the anti-loosening washer may be rectangular or flattened elliptical.

[0012] The anti-loosening washer may be a closed loop or have an opening at any point.

[0013] The anti-loosening washer is made of non-metallic material, including: carbon fiber; fluoroplastic; nylon; or fiberglass.

[0014] The working mechanism of the anti-loosening washer is as follows: When the anti-loosening washer is squeezed by the nut and the fastener, the raised edge of the annular part, which is less than half the area of ​​the entire anti-loosening washer, is flattened. Its rebound force is large, which makes the left and right sides of the nut have unequal forces. If the bolt is upright, the nut will be higher on one side and lower on the other due to the elastic force; one side has a large elastic force and the other side has a small elastic force. The unfolded spiral internal thread of the nut and the external thread of the bolt form two sawtooth oblique waves with a staggered meshing state. Due to the effect of the spiral preload, the two mesh even more tightly. No matter how strong the vibration is, they will not rub against each other. The coefficient of friction between the two is quite large, and the friction force between them tends to be infinite, thus locking the nut and bolt and achieving a good anti-loosening effect.

[0015] The anti-loosening washers, for smaller sizes such as M10 or M16 and below, can be produced using stamping, laser cutting, or cold heading processes; while for larger sizes, such as M16 and above, they can be produced using cold heading, hot forging, turning, or heat treatment processes. The specific production processes are readily implemented by those skilled in the art without any creative effort, so they will not be elaborated upon here.

[0016] Compared with existing technologies, the anti-loosening washer described in this case has the following advantages: First, unlike the dotted flat washer described in patent authorization announcement number CN218509932U, "A Metal Washer, Its Anti-Loosening Structure and Anti-Loosening Thread Pair," which has two parallel ends and a fixed protrusion on at least one end, the dotted, thicker metal washer lacks elasticity and is not an elastic washer. It cannot maintain its anti-loosening effect for a long time within the elastic recovery range. This invention, however, achieves this, possessing a significant elastic anti-loosening feature. Second, the dots on the original dotted flat washer are welded on using a welding process, resulting in a small area that is easily flattened by high preload and fails. In contrast, the raised edge of this invention changes from a line contact fulcrum to a curved surface contact fulcrum, preventing flattening and loss of elasticity, thus maintaining long-term vibration anti-loosening performance. Third, the technical solution and product described in this case are easy to mass-produce and repeatedly use. Its anti-loosening performance adds axial anti-loosening compared to the dotted flat washer, truly achieving a three-dimensional vibration anti-loosening effect.

[0017] Compared to ordinary spring washers and wave spring washers, this product exhibits the following advantages: First, its asymmetrical anti-loosening structure ensures that the nut and bolt engage in staggered meshing under strong vibration, preventing loosening. This significantly surpasses the anti-loosening performance of symmetrical, easily slipping ordinary and wave spring washers. Theoretical analysis and actual testing have also proven that this product substantially improves its anti-loosening performance. Second, its use of an elastic closed-loop washer structure results in greater stability and strength; while existing spring washers and wave spring washers, with their open design, are prone to expansion and cracking under high preload vibration. Attached Figure Description

[0018] Figure 1 This is one of the three-dimensional views of the anti-loosening washer described in this case;

[0019] Figure 2 This is one of the front views of the anti-loosening washer described in this case;

[0020] Figure 3 yes Figure 2 Rear view;

[0021] Figure 4 yes Figure 2 Right view;

[0022] Figure 5 yes Figure 2 Left view;

[0023] Figure 6 yes Figure 2 AA cross-section view;

[0024] Figure 7 yes Figure 2 Top view;

[0025] Figure 8 yes Figure 2 Bottom view;

[0026] Figure 9 This is the second perspective view of the anti-loosening washer described in this case;

[0027] Figure 10 This is the second front view of the anti-loosening washer described in this case;

[0028] Figure 11 yes Figure 10 Rear view;

[0029] Figure 12 yes Figure 10 Right view;

[0030] Figure 13 yes Figure 10 Left view;

[0031] Figure 14 yes Figure 10 BB cross-section;

[0032] Figure 15 yes Figure 10 Top view;

[0033] Figure 16 yes Figure 10 Bottom view;

[0034] Figure 17 This is a schematic diagram of the assembly structure of the anti-loosening washer described in this case when used in a threaded pair.

[0035] In the picture:

[0036] 1. Anti-loosening washer 2. Chord support line

[0037] 3. Wire-direction support surface 4. Flat pad portion

[0038] 5. Curved edge 6. Inner circle

[0039] 7. Outer ring 8. Upper circular plane

[0040] 9. Lower circular plane; 10. Upper arc surface

[0041] 11. Lower arc surface; 12. Nut

[0042] 13. Bolts 14. Upper fasteners

[0043] 15. Lower fastener 16. Nut internal thread

[0044] 17. Bolt external thread 18. Bolt head

[0045] 19. Screw hole 20. Warp ring

[0046] 21. Curved edge of the string 22. Gap

[0047] D. Outer diameter d, Inner diameter

[0048] b. Width c. Thickness Detailed Implementation

[0049] The present invention will now be further described in conjunction with the accompanying drawings and embodiments:

[0050] This utility model Figures 1-17 In the ring, the chord-direction curved edge 21 is an elastic curved edge in the radial direction of the ring flat washer. The entire anti-loosening washer 1 is composed of the flat washer part 4 and the curved edge part 5.

[0051] The size of the warped portion 5 of the anti-loosening washer 1 is such that, after the anti-loosening washer 1 is axially flattened, the axial elastic force on the left and right sides is asymmetrical.

[0052] The elastic force of the anti-loosening washer 1 and the warped edge portion 5 is such that, after the anti-loosening washer 1 is axially flattened, the axial elastic prying force on the left and right sides of the nut 12 is asymmetrical.

[0053] The anti-loosening washers 1 have the same axial cross section, which may be rectangular or flattened elliptical. The anti-loosening washers 1 may be closed-loop or have a break at any point on the washer; examples will not be given here.

[0054] The anti-loosening washer 1 is made of non-metallic material, including: carbon fiber; fluoroplastic; nylon; or fiberglass.

[0055] The anti-loosening washer 1 is a spring lever-type washer structure with a curved surface as the chordal support line 2. The lever on the left side of the chordal support line 2 is longer, and the lever on the right side of the chordal support line 2 is shorter. The prying force is greatest at the highest point of the right lever, which elastically pries the lower right end of the nut 12. The left end of the lever is subjected to a large pre-tightening pressure from the lower left end of the nut 12. As it moves to the right, the pre-tightening pressure gradually decreases until it reaches the chordal support line 2. As the pre-tightening force of the nut 12 increases, the anti-loosening washer 1, on the fastener 14 or the nut 12, is gradually pressed from a single chordal support line 2 into a chordal support surface 3, until the entire anti-loosening washer 1 is flattened. Due to the chordal support line 2 or the chordal support surface... 3. The lever on the left is longer than the lever on the right, resulting in unequal lever arms. Therefore, the upward or downward prying force at the right end of the lever is much greater than the downward or upward pre-tightening pressure at the left end, creating an asymmetry in the elastic force on both sides of the nut 12. This acts as a lever for a pry bar. The anti-loosening washer 1 is a lever for an elastic pry bar. Therefore, a strong upward or downward prying force is applied to the right side of the nut 12, which is closer to the edge of the nut 12, along the chordal support line 2 or the chordal support surface 3. The left side is where the nut 12 applies less pressure to the anti-loosening washer 1. The anti-loosening washer 1 acts to pry the right side of the nut 12, resulting in a greater pressure on the right side and a smaller pressure on the left side between the nut 12 and the upper fastener 14. Therefore, the anti-loosening washer is also called a "pry edge anti-loosening washer," or simply "pry washer" or "pry ring."

[0056] Figures 1-8 In this case, the anti-loosening washer 1 is one of the anti-loosening washers. The anti-loosening washer 1 is a circular ring washer. The left or right side of the flat circular ring washer structure, less than half the length of the entire washer, is bent upwards or downwards through extrusion and bending processes, forming a chordally warped edge 21. In its free state, circular ring washers of the same or different thicknesses will warp upwards on at least one side, forming an asymmetrical elastic warping force. It then undergoes thermoforming treatment using normalizing + tempering + quenching + spring annealing. Cold-formed springs require stress relief treatment, and heat-resistant spring steel requires special treatment. Following standardized processing, after the nut 12 is pre-tightened, it can overcome the elastic warping force and flatten the anti-loosening washer 1, allowing it to flatten with the warped edge elasticity. The heat treatment process is as follows:

[0057] 1. Normalizing: Cool the anti-loosening washer 1 to 800-900℃, and then slowly cool it to enhance its hardness, elastic modulus and strength, so that it has better fatigue resistance;

[0058] 2. Tempering: Quench the anti-loosening washer 1 and allow it to undergo a certain degree of plastic deformation, then heat treat it to reduce its hardness while improving its toughness and ductility.

[0059] 3. Quenching: Heat the anti-loosening washer 1 to 800-900℃ and then cool it rapidly in water or oil to increase its hardness, but it is easy to become brittle and reduce its fatigue resistance;

[0060] 4. Annealing of elastic washers: Heat the anti-loosening washer 1 to 800℃~900℃ and then slowly cool it to improve its toughness and plasticity, reduce its hardness, and thus improve its fatigue resistance.

[0061] Anti-loosening washers 1 are compression springs and generally undergo heat treatment using at least spring annealing to improve their toughness and plasticity.

[0062] Figures 9-16 This is the second diagram of the anti-loosening washer described in this case, and... Figures 1-8 Unlike the anti-loosening washer 1 shown, both sides have an arc-shaped upward curve, or, viewed from the side, it has a "~" shape with one end curved upward and the other downward; or both ends curve upward, but the curvature of the upward and downward curves at both ends is asymmetrical. When the nut 12 is tightened, the upward elastic force on one side is not equal to the upward elastic force on the other side. Its working mechanism is similar to... Figures 1-8 The same applies, so I won't go into details here.

[0063] Figure 17 This is a schematic diagram of the assembly structure of the anti-loosening washer 1 used in the threaded pair structure described in this case. The raised edge of the anti-loosening washer 1 faces the upper fastener 16, and its inner ring 6 is fitted onto the bolt 13 between the nut 12 and the upper fastener 14. The pre-tightening flattens the anti-loosening washer 1, including the flat washer portion 4 that acts as a lever. When the anti-loosening washer 1 is squeezed by the upper and lower pre-tightening forces, the raised edge portion 5 of the raised annular portion is flattened. This anti-loosening washer forms a lever-like structure, with the chordal support line 2 or chordal support surface 3 moving left and right according to the magnitude of the pre-tightening force. The raised side of the raised edge 20 pries one end of the nut 12. Because the rebound force of the raised and flattened edge portion 5 of the anti-loosening washer 1 is large, this rebound force causes the left and right sides of the nut 12 to be subjected to unequal forces. At this point, bolt 13 is upright, while nut 12, due to its elasticity, is tilted to one side higher than the other; one side has greater elasticity, and the other side has less. The unfolded spiral internal thread 16 of the nut and the external thread 17 of the bolt form two oblique sawtooth-shaped ripples with staggered peaks and valleys. Due to the preload of the spiral, the two mesh even more tightly, and even with strong vibrations, they will not rub against each other. The coefficient of friction between them is quite large, and the frictional force between them tends to be infinite, thus locking nut 12 and bolt 13, thereby achieving a very good anti-loosening effect. The anti-loosening performance far exceeds that of ordinary flat washers, because after preloading, the internal thread 16 of the nut and the external thread 17 of the bolt are still two parallel spirals without elasticity, which are prone to parallel spiral rubbing, slippage, and loosening during vibration. The anti-loosening washer 1 described in this case truly achieves three-dimensional vibration anti-loosening within the elastic range of the warp height.

[0064] This utility model Figures 1-8 and Figures 9-16 The diagrams shown in the image depict the structure of two anti-loosening washers described in this case. The two washers are asymmetrical, with the anti-loosening washer 1, whose ends are raised, illustrating its use in the threaded assembly structure. Figure 17 The only difference in the diagram is the structure of the anti-loosening washer 1. The working mechanism is the same as described above, so it will not be elaborated here.

[0065] The two types of anti-loosening washers 1 described above function similarly to a ring-shaped pry bar in use, hence they are also referred to simply as "pry rings." During production, they can be formed by laser cutting of elastic steel plates, one-time stamping, or machining followed by extrusion. Then, they undergo quenching and medium-temperature tempering. Cold-formed, warped elastic washers require stress relief treatment, while heat-resistant spring steel requires special treatment specifications to ensure its elastic shape is set. The surface can be electroplated or coated with rust-proof and corrosion-proof materials, which can be achieved by ordinary technicians without creative effort. For critical anti-loosening washers 1, a high-pressure treatment is also required.

[0066] To ensure the reliable operation of the anti-loosening washer 1, its material must not only possess high tensile strength and yield strength, but also high elastic limit, fatigue limit, impact toughness, plasticity, and good heat treatment processability. In practice, spring steel is the most widely used material, and its varieties include carbon spring steel, low-manganese spring steel, silicon-manganese spring steel, chromium-vanadium steel, and stainless steel.

[0067] The specifications of the anti-loosening washer 1, including the curvature of the raised edge, the size of the raised edge, the diameter d of the inner ring 6, the diameter D of the outer ring 7, the thickness c and width b of the annular ring section, and the selection of materials, must fully consider its application, importance, the nature, size, and weight of the load it will be subjected to, its cyclic characteristics, operating temperature, surrounding medium, corrosion resistance, anti-magnetic properties, and other usage conditions, as well as processing, heat treatment, and economic factors, so that the selection result matches the actual requirements.

[0068] The asymmetrical chordal curved edge 21 structure simplifies the stamping process and molds, allowing for one-time molding at low cost. The unequal elasticity on the left and right sides ensures that the internal thread 16 of the nut is fully tilted within the gap 22 between it and the external thread 17 of the bolt, enabling the threads to mesh and lock the nut 12 onto the bolt 13 without loosening. This provides excellent anti-loosening performance, a simple structure, easy processing and use, and allows for repeated disassembly and reassembly. It eliminates the need to replace the original nut 12 and bolt 13; simply replacing the original ordinary flat washer and spring washer with the anti-loosening washer 1 described in this case achieves a significant anti-loosening effect. Actual testing has also demonstrated a substantial improvement in anti-loosening performance.

[0069] The terms "front" and "rear"; "large" and "small"; "inner" and "outer"; "left" and "right"; "up" and "down"; "upward" and "downward"; "beginning" and "end"; "long" and "short" used in this utility model to indicate orientation, area, position, or aspect are based on the orientation, area, position, or direction shown in the accompanying drawings. They are only for the convenience of describing the utility model and simplifying the description. In actual applications, the orientation, position, or direction can be interchanged, rotated, or reversed. They do not indicate or imply that the device or part referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. The terms "installation" and "connection" should be interpreted broadly. For example, an integrated connection can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood through the specific circumstances.

[0070] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of protection of the present utility model. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present utility model should be included within the scope of protection of the present utility model.

Claims

1. A locking washer, which is a circular ring washer, characterized in that: The left or right side of the flat ring washer structure, a portion of the ring edge less than half the length of the entire washer, is bent upward or downward by extrusion and bending processes, forming a "chord-oriented raised edge (21)". Then, through heat treatment, it is elastically shaped. After the nut is removed, when the anti-loosening washer (1) is in a free loose state, it can still restore its original raised edge state due to the elastic effect. The anti-loosening washer (1) has a chord-direction raised edge (21), that is, in the circular flat washer, there is an elastic raised edge portion (5) perpendicular to the radial direction of the chord. The size of the warped edge (5) of the anti-loosening washer (1) satisfies that the axial elastic force on the left and right sides is asymmetrical after the anti-loosening washer (1) is axially flattened. The elastic force of the anti-loosening washer (1) and the warped edge (5) is such that after the anti-loosening washer (1) is axially flattened, the axial elastic prying force on the left and right sides of the nut (12) is asymmetrical.

2. The anti-loosening washer (1) according to claim 1, characterized in that: The anti-loosening washers (1) have the same axial cross section.

3. The anti-loosening washer (1) according to claim 2, characterized in that: The axial cross section of the anti-loosening washer (1) is either rectangular or flattened elliptical.

4. The anti-loosening washer (1) according to claim 1, characterized in that: The anti-loosening washer (1) may be a closed loop or have an open end at any point on the washer.

5. The anti-loosening washer (1) according to claim 1, characterized in that: The anti-loosening washer (1) is made of non-metallic material, including: carbon fiber; fluoroplastic; nylon; or fiberglass.

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