Locking device for railway contact net

Abstract

According to the locking device for the railway overhead line system, the main nut is locked through the lock catch nut with the rotating direction opposite to that of the main nut, the contact faces of the main nut and the lock catch nut are mutually embedded through the knurls, and the anti-loosening effect is remarkably enhanced through the sawtooth gasket. 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 railway electrified contact networks requires that "after the fastening device is installed, the nut's loosening torque must be no less than the tightening torque." Existing nuts have a limited use and storage period. Furthermore, they are difficult to use. The workpiece must be thoroughly cleaned and dried before applying the glue. Furthermore, they cannot be used immediately after application; the glue must fully set to withstand the vibrations of operation. Because the contact network constantly requires adjustments to the height of the conductors and tracks, fasteners must be loosened and retightened. These glue-coated screws are difficult to loosen with a wrench and sometimes have to be sawed off. Even after loosening, the residual glue is extremely difficult to remove, making use extremely inconvenient.

[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 provides a locking device for railway contact network, the main body of which is a bolt body equipped with a main nut and a locking nut, the main nut and the locking nut respectively forming 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 being located on the outside of the main nut, and is characterized in that: the end faces on one side opposite to each other of the main nut and the locking nut are provided with knurling with protrusions, a serrated washer is connected to the outer sleeve of the screw between the main nut and the locking nut, the serrated washer is provided with a circle of spring sheet around the inner circumference or the outer circumference, one radial end of the spring sheet is integrated with the serrated washer, and the other end is a free end, the free end is twisted 10° to 40° relative to the plane of the serrated washer, so that the two sides of the spring sheet protrude from the two side faces of the serrated washer, and the free end in the axial direction is covered by the knurling.

[0009] Furthermore, the thickness of the free end of the spring sheet is 0 to 1 / 3 smaller than the width of the groove between the knurled protrusions, and the knurled pattern is a bidirectional cross-spiral involute centered on the bolt axis.

[0010] As an embodiment, the serrated washer is made of Q235A, and the main nut and lock nut matching the serrated washer are made of 45# steel.

[0011] As an embodiment, the hardness of the serrated washer is not higher than HB175, and the hardness of the main nut and the lock nut matched with the serrated washer is not lower than HB195.

[0012] The locking nut has a cylindrical relief groove coaxially with the screw hole on one end surface adjacent to the main nut. The diameter of the relief groove is 0-1.5mm larger than the root diameter of the locking thread, and the depth is 2-3 times the pitch of the locking thread. This makes it easier to screw the locking nut into the screw and ensure a close fit with the main nut.

[0013] Preferably, the root diameter of the main thread is 0 to 1.5 mm larger than the crest diameter of the locking thread.

[0014] As an embodiment, the main thread is a fine thread and the locking thread is a coarse thread, thereby taking advantage of both the anti-loosening feature of the fine thread and the high load-bearing advantage of the coarse thread.

[0015] Furthermore, 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 transverse dimension that is small on the outside and large on the inside, so as to play a role of mutual restraint between the knurling protrusions and thus restrain the loosening of the nut as a whole.

[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 tightened, the knurling of the main nuts and the lock nut on both sides increases the friction coefficient between the main nut and the lock nut several times, connecting the main nut and the lock nut as one, and even if there is rotation, they will rotate synchronously as a whole. The main thread and the lock thread rotate in opposite 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. However, this rotation direction will only make the lock nut move forward, clamping the main nut tighter, thereby preventing the main nut from loosening.

[0019] Inserting a serrated washer between the main nut and the lock nut makes it easier to secure the two nuts together during tightening. The serrated washer's spring blade easily fits into the knurled grooves, deforming and compressing them, connecting the two nuts together. Furthermore, the serrated washer's spring blade increases the axial force on the main and lock nuts, further increasing friction between them.

[0020] The knurling groove of the bidirectional spiral involute makes it easy to embed the spring piece of the serrated washer and gradually clamp it, which also strengthens the clamping force of the knurling groove on the serrated washer spring piece. The main nut and the lock nut are connected as one through the serrated washer.

[0021] 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, which expands the connection point from one or two planes to one of the double nuts, making the connection more stable, and the locking and stability are doubled.

[0022] 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

[0023] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present utility model.

[0024] Figure 2 yes Figure 1 Right view of .

[0025] Figure 3 The present invention is a structural schematic diagram of an embodiment of a lock nut.

[0026] Figure 4 yes Figure 3 Left view of .

[0027] Figure 5 It is a structural schematic diagram of a vertical cross section of a knurling embodiment.

[0028] Figure 6 It is a schematic diagram of the serrated pad structure.

[0029] Figure 7 yes Figure 6 Middle AA section view.

[0030] In the figure: 1-bolt head, 2-screw, 3-main nut, 4-serrated washer, 5-locking nut, 8-locking thread, 9-relief groove, 11-main thread, 12-bolt body, 13-knurling, 14-spring leaf. DETAILED DESCRIPTION

[0031] 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.

[0032] like Figure 1 In the embodiment shown in FIG, the present invention is a 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.

[0033] 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.

[0034] The end surfaces of the main nut 3 and the lock nut 5 on one side thereof are both provided with a 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 In this embodiment, the lock nut 5 adjacent to the main nut 3 is provided with a truncated cone, the outer diameter of the truncated cone is tangent to the outer hexagon of the nut, and the knurling 13 is provided on the top surface of the truncated cone.

[0035] The main nut 3 and the lock nut 5 are connected as a whole. Even if there is rotation, the main nut 3 and the lock nut 5 will rotate synchronously as a whole. The rotation directions of the main thread 3 and the lock thread 5 are opposite. Since the front end of the main nut is pressed against the clamping object and cannot move forward, when it tends to move backward, the lock nut 5 rotates in the same direction. However, this rotation direction will only make the lock nut 5 move forward, clamping the main nut 3 tighter, thereby preventing the main nut 3 from loosening.

[0036] 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.

[0037] like Figure 1 , provided with a serrated washer 4, which is sleeved on the outside of the screw 2 between the main nut 3 and the lock nut 5. The serrated washer 4 is provided with a circle of spring sheets 14 around the inner or outer periphery, such as Figure 6 、 7 In the embodiment, the spring sheet 14 is arranged around the inner periphery, and the outer periphery is smooth, and the sharp spring sheet 14 will not scratch the operator. The shape of the serrated washer 4 is as follows Figure 6 、 7 As shown, one radial end of the spring sheet 14 is integrated with the serrated washer 4, and the other end is a free end. Figure 6 The outer end of the middle spring leaf 14 is integral with the serrated washer 4, while the inner end is a free end. The free end is twisted 10° to 40° relative to the plane of the serrated washer 4, so that both sides of the spring leaf 14 protrude from the two side surfaces of the serrated washer 4. The free end is covered by the knurling 13 in the axial direction.

[0038] When using the serrated washer 4, the thickness of the free end of the spring sheet 14 is set to be equal to or 0 to 1 / 3 smaller than the groove width of the knurling 13. Figure 4 The pattern of the knurling 13 is a bidirectional cross spiral involute centered on the bolt axis.

[0039] The serrated washer 4 facilitates the integration of the main nut 3 and the lock nut 5 during tightening. The spring leaf 14 of the serrated washer 4 easily fits into the knurled groove and deforms and compresses the main nut 3 and the lock nut 5, thereby integrating them. The spring leaf 14 of the serrated washer increases the axial force applied to the main nut 3 and the lock nut 5, further increasing the friction between them.

[0040] The bidirectional spiral involute knurling makes the width of the groove gradually change. During the tightening process of the nut, the spring piece is embedded in the groove between the knurled protrusions and is gradually clamped, thereby strengthening the clamping force of the knurled groove on the serrated washer spring piece 14.

[0041] As an example, the serrated washer 4 is made of Q235A steel, and the main nut and lock nut it mates with are made of 45# steel. The serrated washer 4 is less hard than the lock nut, and under the pressure of the lock nut 5 and main nut 3, it deforms and partially embeds into the knurled grooves, significantly increasing friction.

[0042] In another embodiment, the serrated washer need not be made of metal. Its hardness should be no higher than HB175, and the hardness of the main nut and lock nut mating with it should be no lower than HB195. The serrated washer 4 is made of a material with a high coefficient of friction and a lower hardness than the lock nut. Under the pressure of the lock nut 5 and main nut 3, the serrated washer 4 is easily deformed and partially embedded in the knurled groove, significantly increasing the friction between the lock nut 5 and main nut 3.

[0043] 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.

[0044] During actual operation, the main nut 3 is screwed in and tightened against the clamped object, and then the serrated 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 serrated washer 4 are used to lock them together. By using a torque wrench, the locking device can be applied to the set torque value, and then it can be put into use immediately. When loosening, it is only necessary to loosen the nut according to the usual nut loosening method, but a larger torque value needs to be applied. After sample testing, the loosening torque is not less than 60 N when the locking torque is 44 N, which far exceeds the requirement of the industry technical standard that the loosening torque is not less than the locking torque. It is far ahead of the current technical level of anti-loosening bolts.

[0045] 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.

[0046] 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.

[0047] When the device of the present invention 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.

[0048] The above embodiments can be used interchangeably or superimposed, or used simultaneously.

[0049] 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 locking device for a railway contact network, wherein the main body is a bolt body (12) equipped with a main nut (3) and a locking nut (5), wherein the main nut (3) and the locking nut (5) respectively form a thread pair with a main thread (11) and a locking thread (8) at the tail of a screw rod (2) of the bolt body in counter-rotating directions, and the locking nut (5) is located outside the main nut (3), characterized in that: The end faces of the main nut (3) and the locking nut (5) on one side opposite to each other are both provided with knurling (13) with protrusions, and a serrated washer (4) is connected to the outer sleeve of the screw (2) between the main nut (3) and the locking nut (5), and a circle of spring sheet (14) is provided around the inner circumference or outer circumference of the serrated washer (4), and one radial end of the spring sheet (14) is integrated with the serrated washer (4), and the other end is a free end, and the free end is twisted 10° to 40° relative to the plane of the serrated washer (4), so that both sides of the spring sheet (14) protrude from the two side faces of the serrated washer (4), and the free end in the axial direction is covered by the knurling (13).

2. The locking device for railway contact network according to claim 1, characterized in that: The thickness of the free end of the spring sheet (14) is 0 to 1 / 3 smaller than the width of the groove between the protrusions of the knurling (13), and the pattern of the knurling (13) is a bidirectional cross spiral involute centered on the axis of the bolt.

3. The locking device for railway contact network according to claim 1, characterized in that: The serrated washer (4) is made of Q235A, and the main nut (3) and the lock nut (5) matched with the serrated washer (4) are made of 45# steel.

4. The locking device for railway contact network according to claim 1, characterized in that: The hardness of the serrated washer (4) is not higher than HB180, and the hardness of the main nut (3) and the lock nut (5) matched with the serrated washer (4) is not lower than HB195.

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

7. The 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 locking device for railway contact network according to claim 1, 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.

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