Taper pin locking device for railway contact net
By adopting the reverse thread design of the main nut and lock nut, as well as the saddle taper pin and knurled structure in the tapered pin locking device for railway contact network, the problem of preventing the fastening device from loosening in a vibration environment is solved, and efficient locking effect and stability are achieved, meeting industry standards.
Patent Information
- Application Number
- CN202422604455.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-26
- Publication Date
- 2025-09-09
- Estimated Expiration
- 2034-10-26
AI Technical Summary
Existing railway contact network fastening devices are difficult to meet the anti-loosening requirements of industry technical standards under vibration environments, and are inconvenient to operate. In particular, the traditional methods used on high-speed railways are unreliable and pose safety hazards.
The thread pair consists of a main nut and a lock nut with opposite thread rotation directions. Combined with the saddle taper pin and knurling design, the friction and connection stability are increased. The tapered saddle taper hole and the embedding of the lock nut and the screw form a stable nut connection.
It achieves that when the locking torque is greater than 20N under vibration conditions, the loosening torque is not less than the locking torque, which significantly improves the fastening effect, meets industry standards, and simplifies the operation process.
Smart Images
Figure CN223318242U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of fastening devices, in particular to a cone pin locking device for a railway contact network. 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. Utility Model Content
[0007] The technical problem to be solved by the utility model is to provide a tapered pin locking device for railway contact network, which can effectively realize the locking of the target object and still meet the technical requirement that the loosening torque exceeds the tightening torque after the vibration test.
[0008] The utility model discloses a tapered pin 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 behind the main nut, the axial length of the locking thread differs from the maximum axial dimension of the thread of the locking nut by no more than 1 / 4, and a saddle tapered pin parallel to the axis is embedded in the seam between the tail end faces of the screw and the locking nut.
[0009] The saddle taper pin is embedded in a 1:50 saddle taper hole, and 1-3 saddle taper holes are provided between the lock nut and the lock thread; the large end surface of the saddle taper pin is provided with an internal screw hole to facilitate the removal of the saddle taper pin when loosening the nut.
[0010] The end surfaces on one side opposite to the main nut and the lock nut are both provided with knurling with grooves and protrusions.
[0011] The transverse dimension of the protrusion of the knurled longitudinal section is equivalent to the width of the groove.
[0012] The transverse dimension of the protrusion of the knurled longitudinal section is 0.5 to 3 mm, which is equivalent to the width of the groove.
[0013] If there are two or three saddle taper holes and saddle taper pins, they are preferably evenly distributed in an annular manner at the joint between the lock nut and the lock thread.
[0014] Preferably, the root diameter of the main thread is 0 to 1.5 mm larger than the crest diameter of the locking thread.
[0015] For the transition platform and the screw tail, the lock nut has a cylindrical relief groove coaxially with the screw hole at one end adjacent to the main nut. The diameter of the relief groove is 0-1.5mm larger than the root diameter of the lock thread, and the depth is 2-3 times the lock thread pitch. This makes it easier to screw the lock nut into the screw and ensure a close fit with the main nut.
[0016] In one embodiment, the main thread is a fine thread and the locking thread is a coarse thread, thereby simultaneously utilizing the anti-loosening feature of the fine thread and the high load-bearing advantage of the coarse thread.
[0017] 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 smaller outer side and a larger inner side, so as to play a role of mutual restraint between the knurling protrusions and thus restrain the loosening of the nut as a whole.
[0018] The utility model perfectly realizes that the target object can be ideally locked, the nut is fixed relative to the matched screw rod, and the nut can be put into use after being locked.
[0019] The saddle taper pin is forcefully pressed into between the lock nut and the screw through the tapered saddle taper hole, pressing the lock nut and the screw together as one, greatly increasing the friction between the lock nut and the screw.
[0020] After sample testing, it was found that when the locking torque is greater than 20 Newtons, the loosening torque is not less than the locking torque, far exceeding the industry technical standard requirement of loosening torque not less than the locking torque. It is ahead of the current level of anti-loosening bolt technology.
[0021] 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.
[0022] The front end of the main nut is pressed against the clamp, and the main nut and the lock nut are connected as one through the knurled and serrated washers. The rear part of the lock nut connects the lock nut and the screw as one through the saddle taper pin, expanding the connection point from one or two planes to one of the double nuts. The connection is more stable, and the locking and stability are multiplied. Therefore, the fastening effect is far superior to the fastening method of the eccentric nut.
[0023] 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
[0024] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present utility model.
[0025] Figure 2 yes Figure 1 Right view of .
[0026] Figure 3 The present invention is a structural schematic diagram of an embodiment of a lock nut.
[0027] Figure 4 yes Figure 3 Left view of .
[0028] Figure 5 It is a structural schematic diagram of a vertical cross section of a knurling embodiment.
[0029] In the figure: 1-bolt head, 2-screw, 3-main nut, 5-locking nut, 6-saddle taper pin, 7-saddle taper hole, 8-locking thread, 9-gap groove, 11-main thread, 12-bolt body, 13-knurling. DETAILED DESCRIPTION
[0030] 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.
[0031] like Figure 1 In the embodiment shown in FIG, the utility model shows a taper pin locking device for a railway contact network. The main body is a bolt body 12 with a bolt head 1 and a screw 2. The thread is provided at the rear of the screw 2 with a main thread 11 and a locking thread 8. The main thread 11 and the locking thread 8 have opposite thread rotation directions. The main thread 11 and the locking thread 8 are respectively provided with a main nut 3 and a locking nut 5. 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 the main nut 3, that is, at the rear.
[0032] like Figure 1 The 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 locking thread 8 is thinner to facilitate the main nut 3 to enter the main thread 11 smoothly.
[0033] Typically, the screw 2 is a straight rod, with the transition stage 10 and the screw tail as shown. Figure 1 、 3 As shown, the locking nut 5 has a cylindrical relief groove 9 coaxially with the threaded hole at one end, i.e., the front end, 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 locking thread 8. The transition step 10 is a machined step with an axial length less than the depth of the relief groove 9. The relief groove 9 can pass over the transition step 10, making it easier for the locking nut 8 to be screwed into the screw and fit closely with the main nut.
[0034] In the first embodiment, the axial length of the locking thread 8 is no more than 1 / 4 of the maximum axial length of the thread of the locking nut 5, or the tail end of the locking nut 5 is substantially flush with the tail end of the screw 2. Figure 2 As shown, 1 to 3 saddle taper pins 6 parallel to the axis are embedded in the joint between the end faces of the screw 2 and the lock nut 5.
[0035] The saddle taper pin 6 is embedded in the 1:50 saddle taper hole 7. If there are two or three saddle taper holes 7 and saddle taper pins 6, they are evenly distributed in an annular shape at the joint between the lock nut 5 and the lock thread 8.
[0036] The taper pin 6 is pressed into the space between the lock nut 5 and the screw rod 2 through the tapered taper hole 7, thereby tightly connecting the lock nut 5 and the screw rod 2 together, greatly increasing the friction between the lock nut and the screw rod. In order to facilitate disassembly, the large end surface of the taper pin 6 is provided with an internal threaded hole.
[0037] During operation, after the main nut 3 and the lock nut 5 are tightened, a torque wrench can be used to increase the lock nut 5 to the specified torque. A pistol drill is then used to drill the threaded joint between the main bolt 3 and the lock nut 5, and a 1:50 taper hole is formed. The matching taper pin 6 is then forcibly pressed in. The taper pin 6 is a self-tapping screw with an external thread. Since the taper pin 6 prevents the lock nut and the main bolt from rotating, the entire device naturally has excellent anti-loosening performance. The large end of the taper pin 6 is provided with a threaded inner hole to facilitate the removal of the taper pin 6 after the disassembly screw is screwed in. The direction in which the disassembly screw is screwed in is the same direction in which the taper pin 6 is loosened.
[0038] Example 2, based on Example 1, the end surfaces of the main nut 3 and the lock nut 5 on one side opposite to each other are both provided with knurling 13 with grooves and protrusions. 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.
[0039] 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.
[0040] The transverse dimension of the protrusion in the longitudinal cross-section of the knurling 13 is set to be equal to the width of the groove. When the nut is tightened, the protrusions and grooves of the knurling on the main nut 3 and the lock nut 5 on both sides interlock and compress each other, increasing the friction coefficient between the main nut 3 and the lock nut 5 several times. The interlocking 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. Because the front end of the main nut is pressed against the clamping object and cannot move forward, the lock nut 5 rotates in the same direction when it tends to move backward. However, this rotation direction only causes the lock nut 5 to move forward, clamping the main nut 3 more tightly, thus preventing the main nut 3 from loosening.
[0041] 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.
[0042] In the third embodiment, 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 that of the locking thread 8. This simultaneously leverages the anti-loosening properties of the fine thread and the high load-bearing advantages of the coarse thread.
[0043] The front end of the main nut 3 is pressed against the clamping object, and the main nut and the lock nut are connected as one through the knurled and serrated washers. The rear part of the lock nut connects the lock nut and the screw as one through the saddle taper pin, and the connection point is expanded from one or two planes to a double nut as one. The connection is more stable, and the locking and stability are multiplied. Therefore, the fastening effect is far superior to the fastening method of the eccentric nut.
[0044] 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 internal serrated pad, 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.
[0045] The above embodiments can be used interchangeably or superimposed, or used simultaneously.
[0046] 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 taper pin 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 (2) of the bolt body in counter-rotating directions. The locking nut (5) is located behind the main nut (3). The axial length of the locking thread (8) is no more than 1 / 4 of the maximum axial dimension of the thread of the locking nut (5). A saddle taper pin (6) parallel to the axis is embedded in the seam between the tail end faces of the screw (2) and the locking nut (5).
2. The taper pin locking device for railway contact network according to claim 1, characterized in that: The saddle taper pin (6) is embedded in the saddle taper hole (7) with a ratio of 1:
50. One to three saddle taper holes (7) are provided between the lock nut (5) and the lock thread (8). The large end surface of the saddle taper pin (6) is provided with an internal screw hole.
3. The taper pin locking device for railway contact network according to claim 1, characterized in that: The end surfaces of the main nut (3) and the locking nut (5) on one side opposite to each other are both provided with raised knurling (13).
4. The railway contact network taper pin locking device according to claim 3, characterized in that: The transverse dimension of the protrusion of the knurled longitudinal section is 0.5-3 mm, which is equivalent to the width of the groove.
5. The taper pin 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 at one end adjacent to the main nut (3). The diameter of the relief groove (9) is 0 to 1.5 mm larger than the root diameter of the locking thread (8), and the depth is 2 to 3 times the pitch of the locking thread (8).
6. The taper pin 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).
7. The taper pin 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.
8. The taper pin locking device for railway contact network according to claim 3, characterized in that: The height difference between the top and bottom of the knurling (13) is 0.1-1 mm, and the knurling (13) is convex in the shape of a column or a table with a smaller outer side and a larger inner side.