Knurling locking device for railway contact net

Abstract

The utility model provides a knurling locking device for a railway overhead line system, which adopts a lock catch nut opposite to a main nut in rotating direction to lock the main nut, and the contact surfaces of the main nut and the lock catch nut are mutually embedded through knurls. The axial force generated by tightening the lock catch nut presses the end faces of the main nut and the lock nut, so that the main nut, the lock catch nut and the bolt are rigidly and fixedly connected. The utility model perfectly realizes the purposes of ideally locking a target object, fixedly connecting the nut relative to the matched screw rod, conveniently locking and loosening, and immediately putting into use after quick locking.

Description

Technical Field

[0001] The utility model relates to the technical field of fastening devices, in particular to a locking device for railway contact networks. Background Art

[0002] The latest industry standard for anti-loosening fasteners used on domestic electrified railway contact networks (Document No. 214 of the Ministry of Railways, Railway Transportation

[2012] ) requires that "after the fastening device is installed, the nut's loosening torque must be no less than the tightening torque." Previously, high-speed rail applications relied on imported technology, typically applying a special adhesive to the threaded portion before installation and tightening. This adhesive, imported from the United States or Japan, was expensive and had a limited shelf life. Furthermore, it was difficult to apply; the workpiece must be thoroughly cleaned and dried before application. Furthermore, the fasteners could not be put into use immediately after application; they had to fully solidify to withstand the vibrations of operation. Because the contact network frequently requires adjustments to the height of the conductors relative to the track, fasteners must be loosened and retightened. These adhesive-coated screws are difficult to loosen with a wrench, sometimes requiring sawing. Even after loosening, the residual adhesive is extremely difficult to dispose of, making it extremely inconvenient to use.

[0003] Even when conventional fasteners are used on low-speed rail contact lines, they still rely on a century-old, traditional method of securing them: using spring washers or winged washers. Since the locomotive's pantograph must maintain constant contact with the contact wires during operation, locomotive vibrations inevitably cause the contact line to vibrate. The faster the train, the more severe the vibration. This traditional method proves unreliable under intense vibrations. Loose screws can sometimes cause the contact line to collapse, leading to serious accidents. Furthermore, it fails to meet current industry technical standards.

[0004] Other fastening devices in the prior art, such as drilling holes through the nut and the screw after the nut is tightened, inserting a pin, and then applying glue, are also extremely inconvenient to operate and cannot be carried out on-site, especially at high altitude.

[0005] If nylon thread pairs are used, not only will the cost be high, but they will also age easily and be short-lived.

[0006] If double nuts that are opposite to each other are used, it is easy to tighten and can prevent loosening within a certain range. However, after the vibration test, it still does not meet the requirements of the industry technical standards. Summary of the Invention

[0007] The technical problem to be solved by the utility model is to provide a locking device for railway contact network, which can effectively realize the locking of the target object, and can still meet the technical requirement that the loosening torque exceeds the tightening torque after the vibration test, and the locking and loosening process of the device is simple and convenient.

[0008] The utility model discloses a knurled locking device for railway contact network, the main body of which is a bolt body equipped with a main nut and a locking nut, and is characterized in that: the main nut and the locking nut respectively form a thread pair with the main thread and the locking thread at the tail of the screw of the bolt body in counter-rotating directions, the locking nut is located on the outside of the main nut, and the end faces of the main nut and the locking nut on the opposite side are both integrally provided with knurling.

[0009] Furthermore, the transverse dimension of the protrusion in the longitudinal section of the knurling is 0.5 to 3 mm, and the transverse dimension of the protrusion in the longitudinal section of the knurling is equivalent to the width of the groove.

[0010] As an embodiment, a washer is connected to the outer sleeve of the screw between the main nut and the lock nut.

[0011] Preferably, in the above embodiment, the hardness of the washer is less than HB170.

[0012] The locking nut is provided with a cylindrical relief groove coaxially with the screw hole on one end face adjacent to the main nut. The diameter of the relief groove is 0 to 1.5 mm larger than the root diameter of the locking thread, and the depth is 2 to 3 times the pitch of the main thread.

[0013] The root diameter of the main thread is 0 to 1.5 mm larger than the top diameter of the locking thread.

[0014] The main thread is a fine thread, and the locking thread is a coarse thread.

[0015] Preferably, the height difference between the top and bottom of the knurling is 0.1-1 mm, and the knurling protrusion is columnar or terraced with a lateral dimension that is small on the outside and large on the inside.

[0016] The utility model perfectly realizes that the target object can be locked ideally, the nut can be fixed relative to the matched screw rod, and the locking and loosening operations can be conveniently performed, and the nut can be put into use after being quickly locked.

[0017] After sample testing, the loosening torque is no less than 60 N when the locking torque is 44 N, far exceeding the industry technical standard requirement that the loosening torque should be no less than the locking torque. It is far ahead of the current level of anti-loosening bolt technology.

[0018] Through the knurling on the opposite side end faces of the main nut and the lock nut, when the nuts are locked, the protrusions and grooves of the knurling of the main nuts and lock nuts on both sides are embedded and pressed against each other, and the friction coefficient between the main nut and the lock nut is increased several times; and the mutually embedded knurling connects the main nut and the lock nut as one, and even if there is rotation, they will rotate synchronously as a whole, and the main thread and the lock thread have opposite rotation directions. Since the main nut is pressed against the clamped object and cannot move forward, the lock nut rotates in the same direction when it tends to move backward, but this rotation direction will only make the lock nut move forward, clamping the main nut tighter, thereby preventing the main nut from loosening.

[0019] The main thread is a fine thread, while the locking thread is a coarse thread, combining the anti-loosening properties of the fine thread with the high load-bearing capacity of the coarse thread. However, the difference in pitch between the fine and coarse threads also hinders the simultaneous loosening and removal of the main and locking threads. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present utility model.

[0021] Figure 2 yes Figure 1 Right view of .

[0022] Figure 3 The present invention is a structural schematic diagram of an embodiment of a lock nut.

[0023] Figure 4 yes Figure 3 Left view of .

[0024] Figure 5 It is a structural schematic diagram of a vertical cross section of a knurling embodiment.

[0025] In the figure: 1-bolt head, 2-screw, 3-main nut, 4-washer, 5-locking nut, 8-locking thread, 9-relief groove, 11-main thread, 12-bolt body, 13-knurling. DETAILED DESCRIPTION

[0026] The present invention is further described below with reference to the accompanying drawings and examples. In this specification, a bolt body 12 is provided with a bolt head 1 at one end. A screw 2 is integrally mounted behind the bolt head 1. The tail of the screw 2 is threaded. If the bolt head is oriented forward or forward, the threads are located at the tail or rear of the screw. A polished rod or a screw can be positioned between the threads and the bolt head 1. The bolt's clamping target is located between the bolt head 1 and the main nut 3.

[0027] like Figure 1 In the embodiment shown in FIG, the present invention comprises a knurled locking device for a railway contact network. The main body comprises a bolt body 12 with a bolt head 1 and a screw 2. The threaded portion of the screw 2 comprises a main thread 11 and a locking thread 8. The main thread 11 and the locking thread 8 have opposite rotation directions. A main nut 3 and a locking nut 5 are provided outside the main thread 11 and the locking thread 8, respectively. The main nut 3 and the main thread 11, and the locking nut 5 and the locking thread 8, respectively, form a thread pair. The locking nut 5 is located outside, i.e., at the rear, of the main nut 3.

[0028] like Figure 1The root diameter of the main thread 11 is 0-1.5 mm larger than the top diameter of the locking thread 8, and the outer diameter of the locking thread 8 is not larger than the main thread 11. The screw of the locking thread 8 is thinner to facilitate the main nut 3 to enter the main thread 11 smoothly.

[0029] Typically, the screw 2 is a straight rod, such as Figure 1 、 3 As shown, the locking nut 5 has a cylindrical relief groove 9 coaxially with the threaded hole at one end, adjacent to the main nut 3 (i.e., the front end). The diameter of the relief groove 9 is 0-1.5 mm larger than the root diameter of the locking thread 8, and its depth is 2-3 times the pitch of the main thread. The axial length of the relief groove 9 is less than its depth, allowing it to bypass the machined step, making it easier for the locking nut 8 to be screwed onto the screw and securely fit the main nut.

[0030] The end surfaces of the main nut 3 and the lock nut 5 on the opposite side are both provided with knurling 13 with grooves and protrusions. The protrusions of the knurling are staggered and distributed at different diameter positions. Figure 4 As shown, the height difference between the convex apex and the bottom of the groove of the knurling 13 is 0.1 to 1 mm. Figure 5 , is a schematic diagram of a vertical cross section of the knurling 13, the knurling 13 protrusion is columnar or has a table shape with a small outer side and a large inner side. Figure 5 When the main nut 3 and the lock nut 5 are tightened, as the lock nut 5 rotates relative to each other, the knurled protrusions will eventually embed into the knurled grooves on the opposite side, thereby playing the role of mutual restraint between the knurled protrusions, thereby restraining the loosening of the nut as a whole.

[0031] In this embodiment, the locking nut 5 adjacent to the main nut 3 is provided with a frustum, the outer diameter of the frustum is tangent to the outer hexagon of the nut, and the knurling 13 is provided on the top surface of the frustum.

[0032] like Figure 5 As shown, the transverse dimension L of the protrusion of the longitudinal section of the knurling 13 is set to be equivalent to the width of the groove, both of which are 0.5 to 3 mm. When the nut is tightened, the protrusions and grooves of the knurling of the main nut 3 and the lock nut 5 on both sides are embedded and pressed against each other, and the friction coefficient between the main nut 3 and the lock nut 5 is increased several times. The mutually embedded knurling connects the main nut 3 and the lock nut 5 as a whole. Even if there is rotation, the main nut 3 and the lock nut 5 will rotate synchronously as a whole. The main thread 3 and the lock thread 5 have opposite rotation directions. Since the front end of the main nut is pressed against the clamping object and cannot move forward, when there is a backward tendency, the lock nut 5 rotates in the same direction. However, this rotation direction only makes the lock nut 5 move forward, clamping the main nut 3 more tightly, thereby preventing the main nut 3 from loosening.

[0033] For example, when the lock nut 5 is rotated clockwise, it advances with the threads, while the main nut 3 rotates in the opposite direction. When the main nut 3 is rotated counterclockwise, it advances, and when it is rotated clockwise, it retreats. During the tightening operation, the main nut 3 is rotated counterclockwise to advance and tighten against the clamped object, then the lock nut 5 is tightened clockwise. The knurled surfaces of the main and lock threads 3 and 5 lock the lock nut 5 together. At this point, the lock nut 5's forward movement is blocked. If it tends to move backward, it is rotated clockwise, and the lock nut 5 follows suit. However, clockwise rotation only advances the lock nut 5, tightening the main nut 3 and preventing it from loosening.

[0034] As an example, Figure 1 A washer 4 is provided, which is fitted over the screw 2 between the main nut 3 and the lock nut 5. The washer preferably has a hardness less than HB170. Under the pressure of the knurled main nut 3 and the lock nut 5, the washer 4 with a lower hardness tends to deform in the area exposed to the knurled protrusions and embed into the knurled grooves, creating greater frictional resistance. This connects the main nut 3 and lock nut 5 into a single piece.

[0035] Washer 4 facilitates the integration of main nut 3 and lock nut 5 during tightening. The deformed portion of washer 4 easily fits into the knurled groove, deforming and compressing it, connecting the main nut 3 and lock nut 5 together. This increases the axial force applied to the main nut 3 and lock nut 5, further enhancing the friction between them.

[0036] During actual operation, the main nut 3 is screwed in and tightened against the clamped object, then the washer 4 is inserted, and then the lock nut 5 is tightened. The knurling on the contact surface of the main thread 3 and the lock thread 5 and the washer 4 are locked together.

[0037] As an example, the main thread 11 is a fine thread, and the locking thread 8 is a coarse thread. The pitch of the main thread 11 is smaller than the pitch of the locking thread 8. This simultaneously takes advantage of the anti-loosening properties of the fine thread and the high load-bearing advantage of the coarse thread.

[0038] When the device is operating, under normal circumstances, the lock nut may rotate loose in the forward direction due to vibration, but this is prevented by the friction of the knurled end surface or the installed washer, so the self-locking mechanism is safe. If the saddle taper pin and the lock nut are not manually loosened in advance, the entire mechanism cannot be disassembled.

[0039] The above embodiments can be used interchangeably or superimposed, or used simultaneously.

[0040] The above description is only a preferred embodiment of the present invention. The above examples do not impose any form of limitation on the essential content of the present invention. After reading this specification, ordinary technicians in the relevant technical field make any simple modifications or deformations to the above specific implementation methods based on the technical essence of the present invention, as well as equivalent embodiments that may be changed or modified into equivalent changes using the technical content disclosed above, all fall within the scope of the technical solution of the present invention and do not deviate from the essence and scope of the present invention.

Claims

1. A knurled locking device for a railway contact network, the main body of which is a bolt body (12) equipped with a main nut (3) and a lock nut (5), characterized in that: The main nut (3) and the locking nut (5) respectively form a thread pair with the main thread (11) and the locking thread (8) at the tail of the screw rod (2) of the bolt body in opposite directions. The locking nut (5) is located outside the main nut (3). The end surfaces of the main nut (3) and the locking nut (5) on one side opposite to each other are integrally provided with knurling (13). The height difference between the top and bottom of the knurling (13) is 0.1-1 mm, and the knurling (13) protrusion is columnar or table-shaped with a transverse dimension that is small outside and large inside; the transverse dimension of the protrusion of the longitudinal section of the knurling is 0.5-3 mm, and the transverse dimension of the protrusion of the longitudinal section of the knurling (13) is equivalent to the width of the groove.

2. The knurled locking device for railway contact network according to claim 1, characterized in that: A washer (4) is provided on the outer sleeve of the screw rod (2) between the main nut (3) and the lock nut (5).

3. The knurled locking device for railway contact network according to claim 2, characterized in that: The hardness of the washer (4) is less than HB170.

4. The knurled locking device for railway contact network according to claim 1, characterized in that: The locking nut (5) is provided with a cylindrical relief groove (9) coaxially with the screw hole on one end surface adjacent to the main nut (3). The diameter of the relief groove (9) is 0-1.5 mm larger than the root diameter of the locking thread (8), and the depth is 2-3 times the pitch of the main thread.

5. The knurled locking device for railway contact network according to claim 1, characterized in that: The root diameter of the main thread (11) is 0-1.5 mm larger than the top diameter of the locking thread (8).

6. The knurled locking device for railway contact network according to claim 1, characterized in that: The main thread (11) is a fine thread, and the locking thread (8) is a coarse thread.

Images