A double-end fastening bolt

Abstract

A double-end fastening bolt is used for locking a locking member on a base member at a locking hole of the base member, and is composed of a double-end bolt, a first nut, a first ratchet washer, a knurled layer of the base member, a knurled layer of the locking member, a second ratchet washer and a second nut in sequence. The first ratchet washer is provided with a knurled layer close to an end face of the first nut, and the second ratchet washer is provided with a knurled layer close to an end face of the second nut. The double-end fastening bolt realizes an extraordinary anti-loosening fastening effect, and the boundary line of the bidirectional spiral is not limited by the length of the bolt and the thickness of the locking member and the base member, so that the double-end fastening bolt has a wider application range and better application adaptability. Moreover, the above advantages can be realized by only two nuts.

Description

Technical Field

[0001] This utility model relates to mechanical fasteners, specifically a double-ended fastening bolt. Background Technology

[0002] The most convenient and quickest way to fasten fasteners is usually with screws or bolts. However, these fasteners are prone to loosening after a period of vibration, losing their tightening function, which can pose a safety hazard, especially in critical applications. Traditional methods for preventing bolt loosening include using reverse threads, Tang bolts with a pair of interlocking washers, eccentric nuts, spring washers, winged washers, double nuts, adhesive application, or nylon threaded pairs. These methods are not only complex to operate, but also fail to meet the residual torque requirements for high-specification applications after lateral vibration, such as the anti-loosening requirements for high-speed rail contact networks. The highest current standard is ISO 16130:2015, which requires the ratio of residual axial force to initial axial force after lateral vibration to be greater than 85%.

[0003] Double nuts with bidirectional threads have a particularly prominent role in preventing loosening and fastening. However, the dividing point of the bidirectional threads needs to be set between the two nuts. Since the thickness of the fastener is fixed, it is difficult to set the position of the bidirectional thread split line exactly to meet the requirements, which limits the adaptability of the anti-loosening bolt. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a double-ended fastening bolt that not only has a better anti-loosening effect, but is also more versatile, with the bidirectional thread position not limited by the bolt length and the thickness of the base component + locking component.

[0005] The double-ended anti-loosening locking bolt is used to lock the locking device onto the base component at the locking hole of the base component. It is characterized by being composed of a double-ended bolt and a first nut, a first ratchet washer, a knurled layer of the base component, a knurled layer of the locking device, a second ratchet washer, and a second nut, which are sequentially fitted around the double-ended bolt. The first ratchet washer has a knurled layer on the end face of the first nut adjacent to it, and the second ratchet washer has a knurled layer on the end face of the second nut adjacent to it.

[0006] Preferably, the double-ended bolt is threaded to the locking fastener, and the threads at the mating second nut and the locking fastener have opposite directions of rotation.

[0007] The first and second ratchet washers have ratchet teeth on the radial inner or outer ring of the washer. The ratchet teeth are twisted, and the two sides of the ratchet teeth protrude from the two end surfaces of the washer.

[0008] Preferably, the knurled layer has spiral knurled grooves, the width of which is interference-fitted with the ratchet teeth.

[0009] Preferably, the knurled layer has bidirectional spiral knurling grooves, the width of which smoothly narrows from the outer circle to the inner circle.

[0010] This invention achieves exceptional anti-loosening and fastening effects, and the dividing line of the bidirectional helix is ​​not limited by the bolt length or the thickness of the locking device plus the base component, thus having a wider range of applications and better adaptability. Moreover, these advantages can be easily achieved with just two nuts.

[0011] This utility model employs a ratchet washer in conjunction with knurled layers on both sides. The ratchet washer has ratchet protruding on both sides axially, and the two sides of the ratchet are respectively embedded in the knurled grooves of the knurled layer. Under tightening pressure, an interference fit is formed, which makes the first nut and the adjacent base component fixed together, and the second nut and the locking fastener fixed together. Because the ratchet is embedded in the knurled groove, the components on both sides are connected and cannot rotate relative to each other, so that the locking fastener and the base component cannot be loosened, thereby playing a role in preventing loosening.

[0012] Actual measurements show that this invention achieves a disassembly torque greater than the initial tightening torque, and the ratio of the residual axial force to the initial axial force after the transverse vibration test is greater than 90%, far exceeding the ISO16130:2015 standard. Attached Figure Description

[0013] Figure 1 This is a cross-sectional view of the utility model in use.

[0014] Figure 2 This is a view of the knurled end face of the lock nut.

[0015] Figure 3 This is a planar structural diagram of a ratchet washer.

[0016] Figure 4 yes Figure 3 Side view.

[0017] Figure 5 This is a planar structural diagram of another type of ratchet washer.

[0018] Figure 6 yes Figure 5 AA section view.

[0019] In the diagram: 1-First nut, 2-First ratchet washer, 3-Knurled layer, 4-Base component, 5-Locking component, 7-Second ratchet washer, 8-Second nut, 9-Double-ended bolt, 10-Fastening hole, 11-Knurled groove, 12-Ratchet. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments: In the description of the present invention, the terms "inner end face," "outer end face," etc., indicate the positional relationship based on the drawings and the orientation or positional relationship used. Relative to the center of the whole, the end face closer to the center is the inner end face, and the end face farther from the center is the outer end face. "Axial direction" refers to the direction of the bolt's central axis. This simplified description is only for ease of description and does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation; therefore, it should not be construed as a limitation of the present invention. Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0021] The double-ended bolt of this utility model has a bolt head without bulges, both ends of the bolt are studs, and the middle part can be a smooth rod or threaded.

[0022] like Figure 1 The double-ended anti-loosening locking bolt shown has the following overall structure in the installed state: a first nut 1, a first ratchet washer 2, a knurled layer 3 of a base component 4, a base component 4, a locking component 5, a knurled layer of the locking component 5, a second ratchet washer 7, and a second nut 8, all fitted around the double-ended bolt 9 in sequence. The first ratchet washer 2 is adjacent to the knurled layer 3 on the end face of the first nut 1 and the knurled layer on the end face of the base component 4, and the second ratchet washer 7 is adjacent to the knurled layer on the end face of the locking component 5 and the knurled layer on the end face of the second nut 8.

[0023] The first ratchet washer 2 and the second ratchet washer 7 have the same or similar structure, and ratchet teeth 12 are provided on the radial inner or outer ring of the washer, such as... Figure 3-6 As shown, the two sides of the ratchet 12 are partially cut off radially, making the ends free. The ratchet 12 is twisted around the ratchet centerline radially around the washer, and after twisting, the two sides of the ratchet 12 protrude from the two end surfaces of the washer. The first ratchet washer 2 and the second ratchet washer 7 are usually made of metal, especially elastic metal, so that the ratchets that are not embedded in the knurled groove 11 can act as elastic washers.

[0024] The knurled layer 3 is provided with spiral knurled grooves 11, and in the installed state, some of the knurled grooves 11 are interference-fitted with the ratchet teeth 12. Preferably, as shown in the figure... Figure 2As shown, the knurled layer 3 has bidirectional spiral knurled grooves 11, the width of which smoothly narrows from the outer circle to the inner circle. Simultaneously, the knurling also has knurled grooves 12 with opposite spiral directions. The width of the knurled grooves 11 is wider on the outer circle and narrower on the inner circle, with a smooth width variation. The narrower section has an interference fit with the protruding ratchet teeth 12 of the ratchet washer. The bidirectional spiral knurled grooves 11 have two advantages: during tightening, some of the ratchet teeth 12 embed into the knurled grooves 11 and are pressed into the narrower knurled grooves 11, forming an interference fit and securing the first nut 1 to the base component 4, or the second nut 8 and the locking fastener 5, as a single unit. During vibration, the reverse spiral knurled grooves 11 make the fit between the ratchet teeth 12 and the knurled grooves 11 even tighter. Although some of the ratchet teeth 12 are located in the knurled grooves 11, which tend to loosen during reverse movement, some ratchet teeth 12 remain within the narrower knurled grooves 11 during reverse movement, thus restraining the tendency to loosen and preventing the first nut 1 from being shaken by the base component 4, and the second nut 8 and the locking fastener 5. This prevents the fasteners from loosening even during vibration. As an example, the ratchet washer is made of Q235A steel, and the nut and bolt that mate with the ratchet washer are made of 45# steel. The ratchet washer has a lower hardness than the nut, and under the pressure of the nut, the ratchet washer deforms and partially embeds itself into the knurled grooves, significantly increasing the friction.

[0025] Preferably, the double-ended bolt 9 is threadedly connected to the locking member 5, and the threads at the mating second nut 8 and the locking member 5 have opposite directions of rotation. Taking the second nut 8 as an example, it moves forward when rotated counter-clockwise and backward when rotated clockwise. During the locking operation, the second nut 8 rotates counter-clockwise to tighten against the locking member 5, and the second ratchet washer 7, in conjunction with the knurling, secures the locking member 5 and the second nut 8 together. At this time, the locking member 5 is threadedly connected to the double-ended bolt and rotates in the opposite direction to the locking member 5. The tendency to rotate clockwise forward is blocked by the base member 4, and when there is a tendency to rotate backward, it rotates counter-clockwise. Since the second nut 8 is fixed together, it also rotates counter-clockwise in the same direction, but the counter-clockwise rotation only causes the second nut 8 to move forward, clamping them tighter, thus preventing the second nut 8 from loosening.

[0026] At this point, the position of the bidirectional thread dividing line is limited to the position between the second nut 8 and the locking member 5. Usually, the thickness of the base part 4 + locking part 5 of the one-way bolt is not within the preset range, so it is difficult to guarantee that the position of the bidirectional thread dividing line is between the second nut 8 and the locking member 5. Since a double-ended bolt is used, the position limitation of the bidirectional thread dividing line is broken. The bolt head is replaced by the first nut 1. Since the first nut 1 and the base part 4 are fitted with the first ratchet washer 2 and the knurled layer 3, they are fixed together under the action of tightening force. The fixed position can be changed according to the actual locking needs. Therefore, the position limitation of the bidirectional thread dividing line of the single-ended bolt is broken.

[0027] If two or more fasteners are connected, or if the component is large, it should be used as the base component 4. In this case, the base component will not rotate, and the first nut 1 is locked together. For smaller components and those with a single fastener, it should be used as the locking component 5, which is threadedly connected to a double-ended bolt.

[0028] In actual operation, a knurled layer 3 is pre-cut or chiseled at the end face connection between the base component 4 and the locking component 5 through hydrostatic pressure. First, the second nut 8 and the second ratchet washer 7 are fitted in. The bidirectional thread dividing line is screwed between the second nut 8 and the locking component 5. The second nut 8 is tightened appropriately. Then, the double-ended bolt 9 is inserted into the locking component 5 and the base component 4. At the other end, the first ratchet washer 2 and the first nut 1 are fitted in and tightened with a torque wrench. Finally, the locking nut 9 is tightened again with a torque wrench, completing the overall installation. The installed locking device can withstand impact and vibration. The residual axial force exceeds the requirement of the international standard ISO16130:2015 that the ratio of the residual axial force to the initial axial force after lateral vibration is greater than 85%, and the actual measurement exceeds 90%.

[0029] The above embodiments can be used interchangeably as needed.

Claims

1. A double-ended fastening bolt for locking a locking fastener (5) onto a base member (4) at a locking hole (10), characterized in that: It consists of a double-ended bolt (9) and a first nut (1), a first ratchet washer (2), a knurled layer (3) of a base component (4), a knurled layer of a locking component (5), a second ratchet washer (7), and a second nut (8) sequentially fitted around the double-ended bolt. The first ratchet washer (2) is adjacent to the end face of the first nut (1) with a knurled layer (3), and the second ratchet washer (7) is adjacent to the end face of the second nut (8) with a knurled layer.

2. The double-ended fastening bolt according to claim 1, characterized in that: The double-ended bolt (9) is threaded to the locking fastener (5), and the threads at the mating second nut (8) and the locking fastener (5) are opposite in direction.

3. The double-ended fastening bolt according to claim 1, characterized in that: The first ratchet washer (2) and the second ratchet washer (7) have ratchet teeth (12) on the radial inner or outer ring of the washer. The ratchet teeth (12) are twisted and the two sides of the ratchet teeth (12) protrude from the two end surfaces of the washer.

4. The double-ended fastening bolt according to claim 3, characterized in that: The knurled layer (3) is provided with a spiral knurled groove (11), the width of which is interference-fitted with the ratchet (12).

5. The double-ended fastening bolt according to claim 3, characterized in that: The knurled layer (3) is provided with bidirectional spiral knurled grooves (11), the width of which smoothly narrows from the outer ring to the inner ring.

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