Self-locking fastening device for railway contact net

Abstract

The utility model relates to the technical field of fastening devices, in particular to a self-locking fastening device for a railway overhead line system, which comprises a bolt, a main nut and a lock catch nut, the bolt is provided with a first thread and a second thread, the thread diameter and the thread pitch of the first thread are different from those of the second thread, and the main nut and the lock catch nut are arranged in a staggered mode. The screwing direction of the first thread is opposite to the screwing direction of the second thread, the main nut is matched with the first thread, the lock catch nut is matched with the second thread, and a straddle screw is installed in a seam between the lock catch nut and the bolt. The product is provided with the lock catch nut with the rotating direction opposite to that of the main nut, and the lock catch nut is a first structure for preventing the main nut from loosening; a perforation screw is arranged on the joint of the lock catch nut and the bolt, and is a second structure for preventing the main nut from loosening; the product is simple in structure, low in cost, reliable in locking, convenient to mount and dismount and wide in application range, all-weather operation can be realized, and the operation benefit of equipment is greatly improved.

Description

Technical Field

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

[0002] The anti-loosening fasteners used on the railway electrification contact network of my country's high-speed railway (high-speed railway) are mainly imported from foreign technology. Usually, a special adhesive is applied to the threaded part before installation and tightening. This adhesive must be imported from the United States or Japan, is very expensive, has a limited use and storage period, and is very troublesome to use. The workpiece must be thoroughly cleaned and dried before applying the adhesive, and it is inconvenient to construct on rainy, foggy, sunny, windy and frozen days. It cannot be put into use immediately after construction. It must wait until the adhesive is completely solidified before it can withstand the vibration force during work. Since the contact network needs to adjust the height of the wire and the track from time to time, the fasteners have to be loosened and retightened. This kind of screw coated with adhesive is difficult to loosen with a wrench, and sometimes has to be sawed off; even if it is loosened, it is extremely difficult to deal with the residual glue.

[0003] Ordinary fasteners are used on the electrified contact network of low-speed railways, and the anti-loosening measures are still the old traditional method that has been used for more than a hundred years, that is, adding a spring washer or a winged washer. Since the pantograph of the locomotive must keep in contact with the wires on the electrified contact network at all times when the train is running, the vibration of the front of the train will inevitably cause the electrified contact network to shake. The faster the speed, the more severe the shaking. This traditional anti-loosening method is very unreliable when there is severe shaking. Sometimes the electrified contact network collapses due to loose screws, causing very serious accidents. Utility Model Content

[0004] This product provides a self-locking fastening device for high-speed rail (low-speed rail has better effect) contact network, which adopts the end face with knurling structure or lock nut with internal serrated washer installed in the opposite direction of the main nut and several saddle screws to prevent the main nut from loosening and locking. The end faces of the main nut and the lock nut are rigidly fixed together with knurling structure or internal serrated washer. Since the thread diameter and pitch of the main nut and the lock nut are different, as long as the main nut and the lock nut are connected, if the lock nut does not move, any vibration force will not cause the bolt and the main nut to rotate relative to each other and loosen, so its anti-loosening is absolutely reliable. After the lock nut is tightened, the main nut and the lock nut adopt the "reverse buckle" structure with opposite thread directions. When the main nut is rotated to the left and tends to loosen, the lock nut follows the left rotation, but the lock nut is designed with left thread. Its left rotation will only make the lock nut move forward and clamp the main nut more tightly, thereby preventing the main nut from loosening. The contact end faces of the main nut and the lock nut adopt a knurled structure, which increases the friction coefficient several times, or an internal serrated washer is installed between the main nut and the lock nut. These measures are also to increase the firmness of the connection. This device also uses a saddle screw, which naturally makes the main nut and the lock nut less likely to loosen after installation. Therefore, this product is a multi-insurance anti-loosening device. In addition, the main nut and the lock nut use different fine teeth, which not only increases the torque of the product, but also helps to prevent loosening, and has good reliability in use.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A self-locking fastening device for a railway contact network comprises a bolt, a main nut and a locking nut, wherein a first thread is arranged on the bolt and a second thread is arranged at a section of the bolt near the tail end, the thread diameter and the thread pitch of the first thread are different from the thread diameter and the thread pitch of the second thread, the rotation direction of the first thread is opposite to the rotation direction of the second thread, the main nut cooperates with the first thread, the locking nut cooperates with the second thread, a saddle screw is installed in the joint between the locking nut and the bolt, the thread diameter and the thread pitch of the main nut are different from the thread diameter and the thread pitch of the locking nut, and the rotation direction of the main nut is opposite to that of the locking nut.

[0007] As a further solution of the utility model: the end faces of the main nut and the locking nut are fixedly connected by a knurled structure, and the knurled structure can increase the friction coefficient and thus increase the connection firmness.

[0008] As a further solution of the utility model: a frustum is provided on one side of the locking nut close to the main nut, and the outer diameter of the frustum is tangent to the outer hexagon of the main nut, further ensuring the firmness of the connection between the locking nut and the main nut.

[0009] As a further solution of the utility model: the first thread is a right-hand thread, and the second thread is a left-hand thread. When the main nut is rotated counterclockwise and tends to loosen, the locking nut follows the counterclockwise rotation. However, the locking nut is designed to have a left-hand thread. Rotating the locking nut counterclockwise will only move the locking nut forward, which will clamp the main nut tighter, thereby preventing the main nut from loosening.

[0010] As a further solution of the utility model: the thread diameter of the first thread is slightly larger than the thread diameter of the second thread to ensure the firmness of the connection.

[0011] As a further solution of the utility model: a clearance hole is provided at the front end of the locking nut, the aperture of the clearance hole is slightly larger than the outer diameter of the first thread, and the depth of the clearance hole is three times the pitch of the second thread, ensuring that the contact surfaces of the main nut and the locking nut can be tightly attached during installation.

[0012] As a further solution of the utility model: an inner serrated washer is installed at the joint end faces of the main nut and the lock nut.

[0013] The installation method of the self-locking fastening device for railway contact network, the specific steps are as follows:

[0014] Insert the bolt into the connected part and screw the main nut on the bolt to make the main nut reach the normal working torque specified in the national standard and TB / T2075-2010;

[0015] Twist the lock nut on the bolt in the opposite direction until the lock nut reaches the specified torque, drill a hole on the bolt, and install a saddle screw in the hole.

[0016] Compared with the prior art, the beneficial effects of the utility model are:

[0017] First, this product is equipped with a lock nut that rotates in the opposite direction to the main nut. The lock nut and the main nut are reversed in the direction of rotation, so that when the main nut may loosen, the lock nut prevents the loosening from happening. This structure absolutely prevents the main nut and the bolt from rotating relative to each other (i.e. loosening). The axial force when the lock nut is tightened forces the end faces of the main nut and the lock nut with knurled structures to fit tightly, or an internal serrated washer is installed to ensure that the main nut and the lock nut are fixedly connected as one. This is the first structure to prevent the main nut from loosening.

[0018] Second, this product sets a saddle screw on the joint between the lock nut and the bolt, which is a second structure to prevent the main nut from loosening. Therefore, this is a mechanism with double braking and anti-loosening effects;

[0019] Third, this product has a simple structure, low cost, reliable locking, and easy installation and disassembly. It is suitable for high-speed railways and low-speed railways, has a wide range of applications, can achieve all-weather operation, and greatly improves the operating efficiency of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the self-locking fastening device for railway contact network in the embodiment of the utility model.

[0021] Figure 2 It is a side view of a self-locking fastening device for railway contact network in an embodiment of the utility model.

[0022] Figure 3 It is a front view of a bolt in an embodiment of the utility model.

[0023] Figure 4 It is a side view of a bolt in an embodiment of the utility model.

[0024] Figure 5 It is a front view of the main nut in the embodiment of the utility model.

[0025] Figure 6 It is a side view of the main nut in the embodiment of the utility model.

[0026] Figure 7 It is a front view of the locking nut in the embodiment of the utility model.

[0027] Figure 8 It is a side view of the locking nut in the embodiment of the utility model.

[0028] In the figure: 1-bolt, 2-main nut, 3-internal serrated washer, 4-lock nut, 5-saddle screw. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0030] The specific implementation of the present utility model is described in detail below in conjunction with specific embodiments.

[0031] See also Figure 1-Figure 8The utility model provides a self-locking fastening device for railway contact network, comprising a bolt 1, a main nut 2 and a locking nut 4, wherein the bolt 1 is provided with a first thread and a section of the bolt 1 near the tail end is provided with a second thread, the thread diameter and the thread pitch of the first thread are different from the thread diameter and the thread pitch of the second thread, the rotation direction of the first thread is opposite to the rotation direction of the second thread, the main nut 2 cooperates with the first thread, and the locking nut 4 cooperates with the second thread, and a saddle screw 5 is installed in the joint between the locking nut 4 and the bolt 1, the thread diameter and the thread pitch of the main nut 2 are different from the thread diameter and the thread pitch of the locking nut 4, the rotation direction of the main nut 2 is opposite to the rotation direction of the locking nut 4, so as to ensure that the whole device forms a reverse buckle structure, wherein the saddle screw 5 can be a self-tapping saddle screw, and when installing the self-tapping saddle screw, a drill gun is used to drill at the joint between the bolt 1 and the locking nut 4, only the bottom hole is drilled, and then the self-tapping saddle screw is forcibly screwed in. Since the self-tapping saddle screw is equivalent to a thread tap, the self-tapping saddle screw has excellent anti-loosening performance after being screwed in. When the main nut 2 is installed in place, tighten the lock nut 4 in the reverse direction. With such a structure, the bolt 1, the main nut 2 and the lock nut 4 are rigidly combined together, and with the auxiliary effect of the saddle screw 5, no matter what kind of vibration the mechanism is subjected to, the threaded connection will not be loose, and the lock nut 4 and the main nut 2 are in a "reverse buckle" or "reverse lock" relationship with each other. That is, the reverse loosening direction of the main nut 2 is exactly the forward tightening direction of the lock nut 4; conversely, the loosening and retreating direction of the lock nut 4 is also the forward tightening direction of the main nut 2. This design is to prevent the mechanism from being safely self-locked and anti-loose in case the main nut 2 and the lock nut 4 fail to work. The principle is as follows: if the main nut 2 is loosened due to possible reverse rotation and causes axial retreat, the lock nut 4 fixed to the main nut 2 will also reverse, but the lock nut 4 is a reverse thread, and its reversal will only move forward and cannot retreat. In this way, the lock nut 4 will firmly prevent the main nut 2 from retreating and loosening. This is the reverse self-locking principle, which is undoubtedly an important anti-loosening insurance measure for this mechanism. The saddle screw 5 also plays a vital role in the lock nut 4. It is also a requirement of the working principle and must be met during processing and manufacturing. This joint anti-self-locking function can be safely and reliably realized. If the saddle screw 5 and the lock nut 4 are not manually loosened in advance, the entire mechanism cannot be disassembled.

[0032] However, the situation is different when the device is manually disassembled. When disassembling, the saddle screw 5 must be removed separately first, and then the lock nut 4 is loosened. When loosening, the lock nut 4 is forcibly turned right with a wrench and twisted in a positive direction to rotate the lock nut 4 in the loosening direction. When the twisting force is too large, the lock nut 4 will retreat slightly. If the force is continued, it will deform more and retreat more. In this way, the lock nut 4 will be loosened. This process is called "unlocking". It is manually twisted with a wrench. When the device is working normally, no matter what kind of vibration, it is impossible to naturally cause such a large loosening torque to the lock nut 4, that is, the mechanism will not unlock naturally. This is because there is a blocking of the saddle screw 5. The force used to loosen the lock nut 4 is also greater than the force used to unscrew the general nut. Therefore, the anti-loosening device is completely safe and reliable in use.

[0033] After the device is disassembled according to the operating procedures, except for the saddle screw 5, all parts can be reused if there is no obvious damage, which can reduce the use cost to the greatest extent.

[0034] As an embodiment of the utility model, the end faces of the main nut 2 and the locking nut 4 are fixedly connected by a knurled structure. The knurled structure can increase the friction coefficient between the two, thereby increasing the firmness of the connection. When the locking nut 4 may loosen due to positive rotation due to vibration, it will be prevented by the friction force of the end face of the knurled structure. Therefore, the self-locking of the mechanism is safe, ensuring the anti-loosening effect.

[0035] It should also be noted that after the main nut 2 and the locking nut 4 are tightened, they both generate axial tension in the same direction on the bolt 1. Therefore, the actual tension on the bolt 1 is a combination of the effects of the locking nut 4 and the main nut 2. This allows the main nut 2 to be designed to be thinner, while the locking nut 4 only serves as an anti-loosening and braking function and can be thinner. As a result, the mechanism can be as light as possible.

[0036] As an embodiment of the utility model, a truncated cone is provided on one side of the lock nut 4 close to the main nut 2, and the outer diameter of the truncated cone is tangent to the outer hexagon of the main nut 2, further ensuring the firmness of the connection between the lock nut 4 and the main nut 2. Figure 3 and Figure 7 In the embodiment, the thread of the lock nut 4 is M2, which is a left-hand thread and matches the left-hand thread of the L2 section on the bolt 1, so the connection is firm.

[0037] As an embodiment of the present invention, the first thread is a right-hand thread, and the second thread is a left-hand thread. When the main nut 2 is rotated to the left and tends to loosen, the lock nut 4 is rotated to the left, but the lock nut 4 is a left-hand thread. The left rotation of the lock nut 4 will only make the lock nut 4 move forward, which will make the main nut 2 clamped tighter, thereby preventing the main nut 2 from loosening. Figure 3A right-hand thread M1 is processed on the L1 section of the bolt 1, and a left-hand thread M2 is processed on the L2 section of the bolt 1. The thread diameters and pitches of the right-hand thread M1 and the left-hand thread M2 are different, and the rotation directions are opposite, so that the reverse-thread structure of the lock nut 4 and the main nut 2 can be realized. The reverse loosening direction of the main nut 2 is exactly the forward tightening direction of the lock nut 4; conversely, the loosening and retreating direction of the lock nut 4 is also exactly the tightening forward direction of the main nut 2.

[0038] As an embodiment of the present invention, the diameter of the first thread is slightly larger than the diameter of the second thread to ensure the firmness of the connection. Figure 3 A right thread M1 is processed on the L1 section of the bolt 1, and a left thread M2 is processed on the L2 section of the bolt 1. The thread diameter of the right thread M1 is slightly larger than the thread diameter of the left thread M2, realizing reverse self-locking.

[0039] As an embodiment of the present invention, a clearance hole is provided at the front end of the lock nut 4, the aperture of the clearance hole is slightly larger than the outer diameter of the first thread, and the depth of the clearance hole is three times the pitch of the second thread, so as to ensure that the contact surfaces of the main nut 2 and the lock nut 4 can be tightly attached during installation. Figure 3 and Figure 7 The aperture D of the clearance hole is slightly larger than the outer diameter of the right thread M1 on the bolt 1, and the depth H of the clearance hole is three pitches of the left thread M2, which can ensure that the connection between the bolt 1 and the lock nut 4 is firm.

[0040] As an embodiment of the utility model, an internal serrated washer 3 is installed at the joint end faces of the main nut 2 and the locking nut 4. When the locking nut 4 may rotate forward and loosen due to vibration, it will be prevented by the installed internal serrated washer 3, so the self-locking of the mechanism is safe. The internal serrated washer 3 is made of corrosion-resistant material, which can ensure a rigid connection without being damaged by the external environment.

[0041] The utility model also provides an installation method for a self-locking fastening device for a railway contact network, and the specific steps are as follows:

[0042] Insert the bolt 1 into the connected part, and screw the main nut 2 on the bolt 1 to make the main nut 2 reach the normal working torque specified in the national standard and TB / T2075-2010 to ensure the connection firmness and anti-loosening effect;

[0043] The locking nut 4 is screwed on the bolt 1 in the reverse direction so that the locking nut 4 reaches the specified torque, and the saddle screw 5 is installed on the bolt 1.

[0044] The technical solution of this product is: including a bolt 1, a main nut 2, a locking nut 4, an end face knurling structure or an internal serrated washer 3, and a saddle screw 5, etc., all of which are to ensure the reliability of the connection. The bolt 1 is provided with a right thread, and a section of the bolt 1 near the tail end is provided with a left thread with a smaller thread diameter. The parameters of the thread diameter and pitch of the right thread and the left thread are different. The main nut 2 cooperates with the right thread of the bolt 1, and the locking nut 4 cooperates with the left thread of the bolt 1 to form a first safety mechanism with a reverse self-locking structure, which can prevent the main nut 2 and the bolt 1 from rotating relative to each other. The locking nut 4 and the bolt 1 are provided with a saddle screw 5 on the thread seam, which is the second structure to prevent the main nut 2 and the bolt 1 from rotating relative to each other, and has a double braking and anti-loosening effect, which is not only suitable for the electrified contact network of high-speed railways, but also more suitable for the electrified contact network of low-speed railways.

[0045] It should be noted that in the present invention, unless otherwise clearly specified and limited, the terms "rotate", "fix", "have" and the like should be understood in a broad sense, for example, it can be a welding connection, a bolt connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A self-locking fastening device for a railway contact network, comprising a bolt, a main nut and a lock nut, wherein the bolt is provided with a first thread and a section of the bolt near the tail end is provided with a second thread, characterized in that: The thread diameter and thread pitch of the first thread are different from the thread diameter and thread pitch of the second thread, the rotation direction of the first thread is opposite to the rotation direction of the second thread, the main nut cooperates with the first thread, the locking nut cooperates with the second thread, and a saddle screw is installed in the joint between the locking nut and the bolt.

2. The self-locking fastening device for railway contact network according to claim 1, characterized in that: The end faces of the main nut and the lock nut are fixedly connected via a knurled structure.

3. The self-locking fastening device for railway contact network according to claim 1, characterized in that: The first thread is a right-hand thread, and the second thread is a left-hand thread.

4. The self-locking fastening device for railway contact network according to claim 1 or 3, characterized in that: The thread diameter of the first thread is greater than the thread diameter of the second thread.

5. The self-locking fastening device for railway contact network according to claim 1, characterized in that: A clearance hole is provided at the front end of the lock nut, the diameter of the clearance hole is slightly larger than the outer diameter of the first thread, and the depth of the clearance hole is three times the pitch of the second thread.

6. The self-locking fastening device for railway contact network according to claim 1, characterized in that: An inner serrated washer is installed at the joint end surfaces of the main nut and the lock nut.

7. The self-locking fastening device for railway contact network according to claim 1, characterized in that: A frustum is provided on one side of the lock nut close to the main nut, and the outer diameter of the frustum is tangent to the outer hexagon of the main nut.

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