A replaceable stray current-proof insulating pre-buried bushing

Abstract

The present invention discloses a replaceable anti-stray current insulating embedded sleeve, comprising: an outer sleeve and an inner sleeve. The embedded sleeve has a double sleeve structure. When the rail is subjected to a large impact load under special working conditions or fails due to wear and tear after long-term use, the inner sleeve thread can be cut off by external force, and the inner sleeve is sacrificed to ensure that the outer sleeve is not affected. The inner sleeve can be quickly replaced later to ensure that the rail can resume normal operation of the railway in a short time after being subjected to a large external impact or failing due to wear and tear after long-term use. The clamping ring can lock the fastening position of the two to prevent the inner sleeve from loosening during use and during the removal of the bolts, reduce the impact of large external impacts on the rail and the aging of the single sleeve on the stability of the fasteners and the rail, and the clamping ring has the advantages of high reliability, simple installation, and convenient disassembly.

Description

Technical Field

[0001] The invention relates to the technical field of rail transportation, and in particular to a replaceable stray current proof insulating pre-buried bushing. Background Art

[0002] The insulating embedded sleeve is one of the main components of the track structure in the rail transit system and is an important component connecting the fasteners and the ballast. It mainly provides two functions. First, it uses the friction between the threaded contact surface of the bolt and the embedded sleeve to fasten the rail; second, it uses the material properties and structural properties of the embedded sleeve itself to insulate the fastener from the concrete. The damage and failure of the insulating embedded sleeve will lead to a decline in the overall function of the fastener, endangering driving safety. In the initial stage of design and installation, the performance of the insulating embedded sleeve can meet the use requirements, but with the operation of the railway, especially in harsh areas, it is easy to crack the body and damage the thread under the dual effects of environmental aging and wheel-rail vibration and impact, endangering driving safety. At this time, the sleeve needs to be replaced.

[0003] At present, the common method for replacing casings on ordinary roads is to melt the casings and pull them out of the roadbed concrete, then expand the concrete installation hole and embed the replaced casings into the roadbed concrete by pouring special concrete. This construction method is extremely inefficient and costly. Current conduction is easy to occur between the casing and the fastener bolts, causing insulation failure of the entire fastener system. In addition, the casing is easy to rotate under the influence of vibration, impact and environmental aging, resulting in failure of the fastener bolt locking force, affecting driving safety. Summary of the invention

[0004] In view of the above problems, the present invention aims to provide a replaceable anti-stray current insulating pre-buried bushing, including an outer bushing and an inner bushing. The cooperation of the two enhances the insulation and stability of the fastener and the guide rail, and after the performance of the inner bushing decreases, it can be disassembled from the outer bushing and replaced, which greatly reduces the maintenance and inspection cycle of the rail. At the same time, the inner bushing can sacrifice itself after the rail is impacted by a large external force to ensure the integrity of the outer bushing. By replacing the inner bushing, the maintenance work of the rail is completed, ensuring that the train can resume operation in a short time.

[0005] In order to achieve the above-mentioned object, the technical solution adopted by the present invention is as follows: a replaceable stray current insulation pre-buried bushing, characterized in that it comprises: an outer bushing vertically buried in the ballast bed contacted by the rails, used for positioning and fastening the rail fasteners, and insulating the rail fasteners from the ballast bed;

[0006] The inner sleeve is fitted and fastened in the outer sleeve and is used to cooperate with the fastening bolts of the rail fastener to insulate and fasten the rail fastener to the ballast bed. The inner sleeve can be detached from the outer sleeve when the outer sleeve is fixed.

[0007] Preferably, the outer wall of the inner sleeve and the inner wall of the outer sleeve are threadedly matched and fastened, and the screw thread of the inner wall of the outer sleeve has an arc surface at the top and inclined surfaces on both sides of the arc surface inclined outward and extending to the inner wall of the outer sleeve, the similar inclined surfaces of adjacent screw threads and the inner wall of the outer sleeve form a trapezoidal screw thread groove, and the screw threads and screw thread grooves on the outer wall of the inner sleeve match the trapezoidal screw thread grooves and screw threads on the inner wall of the outer sleeve.

[0008] Preferably, the inner wall at the top end of the outer sleeve extends downward with a shoulder of a certain height, the top end of the inner sleeve is flush with the shoulder surface, and a clamping ring is provided on the surface, the top surface of which is flush with the top end surface of the outer sleeve, the inner diameter is equal to that of the inner sleeve, and the clamping ring is used to limit the inner sleeve.

[0009] Preferably, the top surface of the shoulder and the top surface of the inner sleeve are provided with first and second grooves which are corresponding to each other and which are connected in sequence when the inner sleeve and the outer sleeve are fastened, and a clamping block which is clamped in the first and second grooves at the same time is provided on the bottom surface of the clamping ring.

[0010] Preferably, the card blocks are at least one less than the number of the first card slots or the second card slots.

[0011] Preferably, the outer wall of the outer sleeve is provided with a reverse thread which is opposite to the thread matching direction between the outer sleeve and the inner sleeve.

[0012] Preferably, the inner wall of the outer sleeve and the outer wall of the inner sleeve at the bottom of the shoulder surface are both provided with symmetrical semicircular arc-shaped sealing grooves.

[0013] Preferably, the anti-shear area of ​​the inner wall thread of the outer sleeve is more than 1.5 times the anti-shear area of ​​the outer wall thread of the inner sleeve.

[0014] The beneficial effects of the present invention are as follows: (1) The embedded sleeve has a double sleeve structure. When the rail is subjected to a large impact load under special working conditions, the inner sleeve can be cut off by the action of external force, and the inner sleeve is sacrificed to ensure that the outer sleeve is not affected. The inner sleeve can be quickly replaced later to ensure that the rail can resume normal operation of the railway in a short time after being subjected to a large external force impact. (2) The clamping ring arranged between the outer sleeve and the inner sleeve can lock the fastening position of the two to prevent the inner sleeve from loosening, so that the two form a relatively high integrated structure, provide better insulation and fastening effect for the rail fasteners, and reduce the impact of large external force impact on the rail and the aging of the single sleeve on the stability of the fasteners and rails. In addition, the clamping ring has the advantages of high reliability, simple installation, and convenient disassembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a three-dimensional structural diagram of the embedded sleeve of the present invention.

[0016] Figure 2 For the present invention Figure 1 Section view.

[0017] Figure 3 It is a three-dimensional structural diagram of the outer sleeve of the present invention.

[0018] Figure 4 It is a three-dimensional structural diagram of the inner sleeve of the present invention.

[0019] Figure 5 It is a three-dimensional structural diagram of the clamp ring of the present invention.

[0020] Figure 6 It is a schematic diagram of the shear resistance section of the outer thread of the inner casing of the present invention (as shown at A in the figure).

[0021] Figure 7 It is a schematic diagram of the shear resistance section of the inner thread of the outer sleeve of the present invention (as shown at B in the figure). DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0023] Refer to the attached Figures 1 to 7 The replaceable anti-stray current insulating embedded sleeve shown includes: an outer sleeve 1, which is vertically buried in the roadbed that contacts the rails. With the development of railway construction technology, the roadbed for track laying has been replaced by a geological roadbed made of concrete instead of gravel. Therefore, during implementation, the outer sleeve 1 of the present invention is vertically penetrated and buried in the roadbed made of concrete for fixation. It is mainly used to position and tighten the rail fasteners and to insulate the rail fasteners from the roadbed, to avoid potential safety hazards caused by the contact and conduction between the rails and the roadbed and to affect driving safety. The outer sleeve 1 is preferably made of reinforced non-metallic material, such as nylon, which has the characteristics of insulation, wear resistance and high strength, and its working resistance is ≥10 9 Ω.

[0024] In order to solve the problem of decreased protective performance of the outer sleeve 1 caused by long-term use in harsh environments, an inner sleeve 2 is installed in the outer sleeve 1 in a cooperated and fastened manner. The inner wall of the inner sleeve 2 has an internal thread for cooperating with the fastening bolts of the rail fastener to insulate and fasten the rail fastener to the ballast bed (the inner sleeve 2 has higher insulation performance than the outer sleeve 1). The inner sleeve 2 can be detached from the outer sleeve 1 when the outer sleeve 1 is fixed. Among them, the inner sleeve 2 assists the outer sleeve 1 to achieve two layers of insulating protection between the rail fastener and the ballast bed. When the outer sleeve 1 and the inner sleeve 2 are used for a long time, their main insulation performance decreases. Due to the fixed contact between the outer sleeve 1 and the concrete ballast bed, it is very difficult to replace, and it is not convenient to inspect and maintain the safety of the rail within a certain period. Therefore, by disassembling the inner sleeve 2 and separating it from the outer sleeve 1, the inner sleeve 2 is replaced in one direction. Compared with the single-layer insulation of the outer sleeve 1, this structure and replacement method not only improves the insulation between the rail and the ballast bed, but also greatly reduces the difficulty of replacing the outer sleeve 1, shortens the rail inspection and maintenance cycle, and improves the overall operation efficiency of the railway.

[0025] In order to facilitate the rapid assembly of the inner sleeve 2 into the outer sleeve 1 and the rapid replacement of the inner sleeve 2, the outer wall of the inner sleeve 2 and the inner wall of the outer sleeve 1 are threadedly matched and tightened, and the thread of the inner wall of the outer sleeve 1 has a circular arc surface 1a at the top and inclined surfaces 1b on both sides of the circular arc surface 1a that are inclined outward and extend to the inner wall of the outer sleeve 1, and the adjacent inclined surfaces 1b of the adjacent threads form a trapezoidal thread groove 1c with the inner wall of the outer sleeve 1, and the thread and thread groove of the outer wall of the inner sleeve 2 match the trapezoidal thread groove 1c and thread of the inner wall of the outer sleeve 1. Compared with the contact of the conventional circular arc surface, the inclined surface contact between the thread of the inner sleeve 2 and the trapezoidal thread groove 1c of the outer sleeve 1 increases the effective contact area and friction of the thread, thereby preventing the inner sleeve 2 from being loosened due to the vibration of the train, affecting the fastening effect of the rail fastener on the rail and the running safety of the train. At the same time, the different structural characteristics of the screw thread and the screw thread groove also avoid the connection stability between the inner sleeve 2 and the outer sleeve 1 caused by disengagement and deflection.

[0026] In order to further improve the tightness of the matching installation between the inner sleeve 2 and the outer sleeve 1, the inner wall of the top end of the outer sleeve 1 extends downward with a shoulder 11 of a certain height, the top end of the inner sleeve 2 is flush with the surface of the shoulder 11, and a clamping ring 3 is provided on the surface, the top surface of which is flush with the top end surface of the outer sleeve 1, the inner diameter is equal to that of the inner sleeve 2, and is used to limit the inner sleeve 2. Since the inner sleeve 2 is used to cooperate with the fastening bolt of the rail fastener, the fastening bolt is also inserted into the clamping ring 3. When the fastening bolt is fastened to the inner sleeve 2, the fastening bolt is tightly attached to the surface of the clamping ring 3. Compared with the direct contact between the fastening bolt and the inner sleeve 2, the clamping ring 3 increases the friction contact surface, thereby effectively improving the fastening effect of the fastening bolt and the inner sleeve 2. Furthermore, the clamping ring 3 has the function of contacting the outer sleeve 1 and the inner sleeve 1 at the same time, so as to prevent the outer sleeve 1 or the inner sleeve 1 from rotating under the effects of vibration, impact and environmental aging, which may cause the locking force of the fastener bolt to fail and affect driving safety. That is, when one of the outer sleeve 1 or the inner sleeve 1 ages, the other can still be tightly attached to the clamping ring 3, so as to ensure the tightness and stability of the fastening bolt.

[0027] In order to further effectively and reliably restrict the relative sliding of the inner sleeve 2 with respect to the outer sleeve 1, the top surface of the shoulder 11 and the top surface of the inner sleeve 2 are provided with a first clamping groove 101 and a second clamping groove 102 which are correspondingly penetrated in the tightened state of the inner sleeve 2 and the outer sleeve 1, and a clamping block 31 which is clamped in the first clamping groove 101 and the second clamping groove 102 is provided on the bottom surface of the clamping ring 3. The effect achieved is: when the inner sleeve 2 is threadedly fastened in the outer sleeve 1, and in the state of the tight fit, the first clamping groove 101 on the shoulder 11 of the outer sleeve 1 and the second clamping groove 102 on the inner sleeve 2 are aligned and penetrated, and then the clamping block 31 of the clamping ring 3 is clamped into the first clamping groove 101 and the second clamping groove 102 penetrated, and the fixing effect of the outer sleeve 1 is used as support to restrict the inner sleeve 2, so as to ensure that the two have reliable tightness, thereby improving the stability of the rail fastener and the rail and the running safety of the train.

[0028] In order to improve the waterproof, corrosion and structural stability of the embedded sleeve as a whole, the preferred clamping ring 3 is tightly matched with the inner wall of the outer sleeve 1. However, in order to facilitate the removal of the inner sleeve 2 at a later time, the clamping block 31 is at least one less than the first clamping groove 101 or the second clamping groove 102. That is, when the inner sleeve 2 is replaced at a later time, the fastening bolts of the rail fastener are first removed, and then the clamping block 31 is at least one less than the first clamping groove 101 or the second clamping groove 102, ensuring that at least one empty groove through the first clamping groove 101 and the second clamping groove 102 is not closed by the clamping block 31. In this case, an auxiliary tool can be used to extend into the empty groove and act on the clamping ring 3, and the clamping ring 3 can be removed to break away from the restriction on the inner sleeve 2 and the outer sleeve 1, and finally the inner sleeve 2 can be removed for replacement.

[0029] In order to further improve the fastening of the outer sleeve 1 and the concrete ballast and overcome the impact of uncertainty caused by the rails, the outer wall of the outer sleeve 1 is provided with a reverse thread 1d in the opposite direction of the thread matching direction between the outer sleeve 1 and the inner sleeve 2. The reverse thread 1d can increase the contact area between the outer sleeve 1 body and the concrete ballast and effectively prevent the outer sleeve 1 from shaking and falling off; and the reverse thread 1d and the inner wall of the outer sleeve 1 and the inner sleeve 2 thread matching direction are opposite, which can provide better torque when replacing the inner sleeve 2 and prevent the outer sleeve 1 from detaching. When the inner sleeve 2 and the outer sleeve 1 are installed, the tightening direction of the inner sleeve 1 is opposite to the disassembly direction. In order to avoid the loosening of the outer sleeve 1, a special tool can be used to fit in the first card slot 101 to limit the fastening position of the outer sleeve 1 to overcome the torque of the inner sleeve 2 and complete the assembly of the inner sleeve 1.

[0030] In order to further improve the waterproofness of the embedded sleeve as a whole, the inner wall of the outer sleeve 1 and the outer wall of the inner sleeve 2 at the bottom of the shoulder 11 surface are both provided with symmetrical semicircular arc-shaped sealing grooves 103. A sealing ring (preferably a sealing ring or a sealing strip, not shown in the figure) is provided in the sealing groove 103.

[0031] In order to further cope with the greater impact on the rails (such as the impact of natural disasters such as earthquakes), the shearing area of ​​the inner wall thread of the outer sleeve 1 is more than 1.5 times the shearing area of ​​the outer wall thread of the inner sleeve 2. The purpose is that when subjected to a large impact load under special working conditions, the inner sleeve 2 can be cut off by external force, and the inner sleeve 2 can be sacrificed to ensure that the outer sleeve 1 is not affected. The inner sleeve 2 can be quickly replaced later to ensure that the rails can resume normal operation of the railway in a short time after being impacted by a large external force. Therefore, when selecting materials, the wear resistance and strength of the outer sleeve 1 are 5% to 30% higher than those of the inner sleeve 2.

[0032] The principle of the present invention is: a detachable inner sleeve 2 is assembled in the outer sleeve 1, and the fastening position of the two is locked by a clamp ring to prevent loosening, so that the two form a relatively high integrated structure, provide better insulation and fastening effects for the rail fasteners, and reduce the impact of large external force impacts on the rails and the aging of single sleeves on the stability of the fasteners and rails. When the rails are subjected to large impact loads under special working conditions, the inner sleeve 2 can be cut off by the action of external force, and the inner sleeve 2 can be sacrificed to ensure that the outer sleeve 1 is not affected. The inner sleeve 2 can be quickly replaced later to ensure that the rails can resume normal operation of the railway in a short time after being subjected to large external force impacts.

[0033] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A replaceable anti-stray current insulating pre-buried bushing, characterized in that: include: An outer sleeve (1) is vertically buried in the ballast bed where the rails contact, and is used to position and fasten the rail fasteners and to insulate the rail fasteners from the ballast bed; an inner sleeve (2) which is fitted and fastened in the outer sleeve (1) and is used to cooperate with the fastening bolts of the rail fastener to insulate and fasten the rail fastener to the ballast bed; the inner sleeve (2) can be detached from the outer sleeve (1) when the outer sleeve (1) is fixed; The outer wall of the inner sleeve (2) and the inner wall of the outer sleeve (1) are threadedly matched and fastened, and the thread of the inner wall of the outer sleeve (1) has a circular arc surface (1a) at the top and inclined surfaces (1b) on both sides of the circular arc surface (1a) that are inclined outward and extend to the inner wall of the outer sleeve (1), and the adjacent inclined surfaces (1b) of the adjacent thread and the inner wall of the outer sleeve (1) form a trapezoidal thread groove (1c), and the thread and thread groove of the outer wall of the inner sleeve (2) match the trapezoidal thread groove (1c) and thread of the inner wall of the outer sleeve (1); The inner wall of the top end of the outer sleeve (1) extends downwardly to form a shoulder (11) of a certain height, the top end of the inner sleeve (2) is flush with the surface of the shoulder (11), and a clamping ring (3) is provided on the surface, the top surface of the clamping ring (3) being flush with the top end surface of the outer sleeve (1) and having an inner diameter equal to that of the inner sleeve (2) and used for limiting the position of the inner sleeve (2); A first clamping groove (101) and a second clamping groove (102) which are correspondingly connected when the inner sleeve (2) and the outer sleeve (1) are fastened are arranged on the top surface of the shoulder (11) and the top surface of the inner sleeve (2) at intervals in the circumferential direction, and a clamping block (31) which is clamped in the first clamping groove (101) and the second clamping groove (102) at the same time is arranged on the bottom surface of the clamping ring (3); The outer wall of the outer sleeve (1) is provided with a reverse thread (1d) in the opposite direction of the thread matching direction between the outer sleeve (1) and the inner sleeve (2); The outer sleeve (1) is made of a reinforced non-metallic material; the clamping ring (3) is tightly fitted with the inner wall of the outer sleeve (1).

2. The replaceable anti-stray current insulating pre-buried bushing according to claim 1, characterized in that: The number of the card blocks (31) is at least one less than the number of the first card slots (101) or the second card slots (102).

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