Turnout steel rail flash welding construction method

Abstract

The invention relates to the technical field of turnout steel rail flash welding construction methods, in particular to a turnout steel rail flash welding construction method which comprises the following operation steps: S1, construction preparation; s2, a lengthened guide rail is replaced, and a steel rail is sawn; s3, adjusting the position of the turnout rail; s4, aligning a welding machine; s5, welding is conducted; s6, normalizing the welding head; s7, rough grinding; s8, flaw detection of the welding head; s9, fine grinding is conducted; during use, through two operation modes of different turnout welding processes, namely forward entering welding, entering of the highway-railway dual-purpose turnout rail welding machine along the direction of a turnout main line, six-time station adjustment and one-time line switching operation, turnout inside welding, welding in sequence, reverse entering welding and reverse entering of the highway-railway dual-purpose turnout rail welding machine from a side line can be completed, and the turnout inside welding can be completed. The welding sequence is adjusted to adapt to the structural characteristics of the turnout, welding in the turnout can be completed through two-time standing, the adjusting time is greatly shortened, the highway-railway dual-purpose turnout rail welding machine can be preferentially arranged to reversely enter the turnout according to the site construction requirement, and the alignment frequency is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of turnout rail flash welding construction methods, and in particular to a turnout rail flash welding construction method. Background Art

[0002] As the core track structure of high-speed railways, continuous welded rail tracks use continuously long welded rails in combination with precision fasteners, turnouts and other facilities, effectively eliminating the adverse factors of traditional jointed railways, significantly reducing the impact and vibration during train operation, ensuring high smoothness and stability of the track, and thus reducing the track maintenance burden. With the rapid development of high-speed railways, higher requirements are put forward for the construction of continuous welded rail tracks.

[0003] During the construction process of rail welding, the welding quality becomes the key factor affecting the service life of rail joints. Currently, the main welding forms for continuous welded rail tracks of high-speed railways are mobile flash welding, gas pressure welding and thermite welding. Among them, mobile flash welding and gas pressure welding belong to pressure welding, and thermite welding belongs to filling and casting welding. Due to different welding forms, there are significant differences in the performance of welded joints. The performance of mobile flash welding and gas pressure welding is significantly better than that of thermite welding. According to the maintenance experience in recent years, the fatigue damage and low collapse diseases of thermite welds are significantly increasing compared with those of mobile gas pressure welds and flash welds. After testing, the tensile, compressive and fatigue strengths of gas pressure welds and flash welds of rails are better than those of thermite welds. To reduce the risk of weld damage, flash welding is used to weld the rails in the main line and arrival and departure line turnouts. Relatively speaking, flash welding has fewer defects and accounts for the largest proportion in applications. Its main defects exist inside the weld; the welding joint quality of gas pressure welding and thermite welding is poor. The rail breakage rate of mobile flash welded joints is one-fifth of that of thermite welded joints and one-third of that of gas pressure welded joints. As an important part of railways, turnouts are the key to realizing the conversion of vehicle tracks. They are usually laid in large quantities at stations and marshalling yards to fully exert the operation capacity of the line. Due to the large number of joints, complex curves and concentrated distribution in the turnout area, it is often a high-incidence area for train operation safety accidents. Therefore, the welding of turnout joints is the top priority for railways to achieve continuous welded rail tracks, and the welding quality of its joints is directly related to the operation safety of the entire line.

[0004] The existing turnout welding process mainly uses a single operation method for welding turnout in both forward and reverse directions, greatly increasing the adjustment time during welding by the welding machine, reducing the construction efficiency, and increasing the alignment times and auxiliary operation time during construction organization. Summary of the Invention

[0005] The technical problem to be solved by the present invention is as follows: in order to solve the problem that the existing turnout welding process mainly adopts a single operation method for welding turnouts in both forward and reverse directions, which greatly increases the adjustment time during the welding of the welding machine, reduces the construction efficiency, and increases the alignment times and auxiliary operation time during construction organization, a turnout rail flash welding construction method is provided herein.

[0006] The technical solution adopted by the present invention to solve its technical problems is as follows: a turnout rail flash welding construction method includes the following operating steps:

[0007] S1. Construction preparation;

[0008] S2. Replace the extended guide rail and saw cut the rail;

[0009] S3. Adjust the position of the turnout rail;

[0010] S4. Align the welding machine;

[0011] S5. Weld;

[0012] S6. Normalize the weld head;

[0013] S7. Rough grinding;

[0014] S8. Detect the weld head;

[0015] S9. Finish grinding;

[0016] S10. Check the flatness;

[0017] S11. Lock the track;

[0018] Among them, in step S2 during construction preparation, according to the different turnout laying in each station, conduct a construction survey in advance, make a path plan for the rail welding machine for railway-highway dual-purpose turnouts, compile a flow chart of the rail welding machine for railway-highway dual-purpose turnouts entering and leaving the turnout on the station yard plan, and use a modified rear axle excavator to cooperate with manual labor to replace the extended guide rail according to the path of the rail welding machine for railway-highway dual-purpose turnouts entering and leaving the turnout. The replacement sequence is carried out according to the welding sequence of entering the turnout in the forward and reverse directions;

[0019] When the rail welding machine for railway-highway dual-purpose turnouts enters the turnout in the forward direction, the specific operating steps are as follows:

[0020] S2.1. The rail welding machine for railway-highway dual-purpose turnouts moves straight ahead in front of the turnout, removes the straight stock rail at the end of the turnout, replaces guide rail A and guide rail B, moves guide rail E towards the end of the turnout, separates the root end of the curved switch rail, the short-side clamp of the rail welding machine for railway-highway dual-purpose turnouts is at the front end of the turnout, and weld the first welding point at the end of guide rail A away from guide rail E;

[0021] S2.2. The rail welding machine for combined railway and road switches moves to the frog, and the head of the rail welding machine for combined railway and road switches rotates 180°. Considering the melting amount, saw the guide rail A, and weld the second welding point at one end of the guide rail A close to the guide rail E and the third welding point at one end of the guide rail B.

[0022] S2.3. The rail welding machine for combined railway and road switches retreats to the heel end of the curved switch rail, and the head of the rail welding machine for combined railway and road switches rotates 180°. The curved switch rail is reset for secondary positioning. For the guide rail B, calculate the sawing value considering the melting amount and the coefficient of thermal expansion of the rail, and saw the rail, and weld the fourth welding point at the other end of the guide rail B.

[0023] S2.4. The rail welding machine for combined railway and road switches moves to the front of the turnout and turns to the curved track. The curved basic rail and the turnout tail rail are removed, the guide rails C and D are replaced, the guide rail F moves towards the turnout tail, the heel end of the straight switch rail is peeled off, and the fifth welding point at one end of the guide rail D far from the guide rail F is welded.

[0024] S2.5. The rail welding machine for combined railway and road switches moves to the frog, and the head of the rail welding machine for combined railway and road switches rotates 180°. Considering the melting amount, saw the guide rail D, and weld the sixth welding point at one end of the guide rail D close to the guide rail F and the seventh welding point at one end of the guide rail C.

[0025] S2.6. The rail welding machine for combined railway and road switches retreats to the heel end of the straight switch rail, and the head of the rail welding machine for combined railway and road switches rotates 180°. The straight switch rail is reset for secondary positioning. For the guide rail C, calculate the sawing value considering the melting amount and the coefficient of thermal expansion of the rail, and saw the rail, and weld the eighth welding point at the other end of the guide rail C.

[0026] When the rail welding machine for combined railway and road switches enters the turnout in the reverse direction, the specific operation steps are as follows:

[0027] S2.7. The rail welding machine for combined railway and road switches moves straight from the turnout tail, replaces the guide rails A, B, C, and D, welds the short-side clamp of the rail welding machine for combined railway and road switches towards the frog end, and welds the first welding point at one end of the guide rail A close to the guide rail E, the second welding point at the other end of the guide rail B, the third welding point at one end of the guide rail D close to the guide rail F, and the fourth welding point at one end of the guide rail C.

[0028] S2.8. Remove the fasteners of the curved switch rail and the straight switch rail, form a dislocation with the guide rails B and C, and perform rust removal and grinding in advance.

[0029] S2.9. Support the lifting legs of the rail welding machine for railway-highway dual-use switches, remove the rail at the turnout tail of the guide rail, saw the guide rail A or guide rail D according to the amount of melting, move the guide rail A and guide rail E, and guide rail D + guide rail F towards the turnout tail to ensure they are inserted into the groove. For the straight track, install one rail every five rails, restore the train operation conditions, ensure that the rail welding machine for railway-highway dual-use switches can move to the heel end of the switch rail, support with the lifting legs on both sides, rotate the head of the rail welding machine for railway-highway dual-use switches by 180°, weld the fifth welding point at the end of guide rail A away from guide rail E and the seventh welding point at the end of guide rail D away from guide rail F. Reset the curved switch rail and the straight switch rail to the center for secondary positioning. Consider the amount of melting and the coefficient of thermal expansion of the rail to calculate the sawing value for sawing guide rail B and guide rail C. Weld the sixth welding point at one end of guide rail B and the eighth welding point at the other end of guide rail C.

[0030] Preferably, in some embodiments, step S1 includes the following steps:

[0031] S1.1. Ballast the turnout and complete the rough adjustment, and all geometric dimensions of the turnout meet the requirements.

[0032] S1.2. Determine the process parameters of the mobile flash welding, complete the type inspection and obtain the inspection report.

[0033] S1.3. Load, unload and transport the extended rail parts of the turnout to the position of the rails to be replaced.

[0034] Preferably, in some embodiments, when adjusting the position of the turnout rails in step S3, after replacing the extended rail parts, check the rail misalignment, the relative position between the switch rail and the stock rail, the squareness of the tip of the switch rail, and the position of the mother and son blocks of the retainer. When welding the heel end of the switch rail, it is necessary to perform a reset and a secondary check, considering the amount of melting.

[0035] Preferably, in some embodiments, step S5 includes the following steps:

[0036] S5.1. According to the investigation of the turnout in the station, formulate the flash welding sequence of the turnout, clarify the dynamic and static ends of each welding head, use the hydraulic leg support system of the railway-highway dual-purpose vehicle, and cooperate with the integrated 180° rotating head of the turnout flash welding machine to realize the rapid conversion of the dynamic and static ends of each welding joint and the variable cross-section end of the AT rail. At the same time, use the construction technology of rail extension and precise control to ensure that the structural dimension accuracy of the turnout after welding meets the requirements.

[0037] S5.2. After the alignment of the rail and the head is completed, start the butt welding work. It should be noted that the working surface must be used as the reference to control the misalignment deviation of the rail head working surface and the misalignment deviation of the rail bottom edge. Operate the rail welding machine for railway-highway dual-use switches to clamp the rail and weld the rail, and timely re-align the rail of the curved track that has been shifted according to the welding requirements of the rail welding machine for railway-highway dual-use switches.

[0038] S5.3. After welding is completed, the rail welding machine must be lifted quickly, the weld bead removed, and the upsetting allowance of the rail head, rail bottom, and the slope of the top surface of the rail bottom controlled. Weld slag should not be squeezed into the base metal and should not scratch the base metal. Check the appearance quality of the long rail welding joint and mark the welding joint. The mark should be at the same side of the rail waist, 1 - 3 m in front of the welding joint, and should be clear and upright.

[0039] S5.4. Fill in the "Field Flash Welding Record Form" in a timely manner.

[0040] In some preferred embodiments, step S6 includes the following steps:

[0041] S6.1. During normalizing, use a thermometer to measure the normalizing temperature. The surface temperature of the rail head during heating should be controlled at 900 ± 20 °C, and the surface temperature of the rail bottom foot should be controlled at 800 °C - 850 °C. The rail head is cooled by natural cooling.

[0042] S6.2. Before operation, check the condition of the medium-frequency normalizing equipment, check whether the connecting wires and cooling water pipes are damaged or leaking, whether there are foreign objects in the induction coil, check whether the cooling water level meets the requirements, and the cooling water temperature should be lower than 25 °C.

[0043] S6.3. Before installation, clean the normalizing joint, clean up conductive substances such as iron slag, and remove combustibles near the joint.

[0044] S6.4. The normalizing coil is strictly prohibited from contacting the rail to prevent the coil from generating sparks and burning out the coil and the normalizing transformer.

[0045] S6.5. Installation and disassembly must be carried out under power-off conditions. First, place the normalizing equipment more than 600 mm away from the weld to prevent scalding caused by excessive weld head temperature. The induction coil must be installed vertically, and the two coil fixing bolts must be tightened and installed firmly without looseness. During the loading and unloading process, the transformer must be held firmly to prevent it from tipping over and damaging the equipment during loading and unloading.

[0046] In some preferred embodiments, step S7 includes the following steps:

[0047] S7.1. Before rough grinding operation, measure the upsetting allowance first. Grind the non-working surface, rail jaw, and the upper surface of the rail bottom corner of the joint area according to the upsetting allowance. For the unevenness of the welding joint caused by the deviation of the rail shape and size, it can be trimmed by means of smooth grinding.

[0048] S7.2. After the rough grinding operation is completed, the grinding allowance for the bottom surface and non-working surface of the joint rail should be 0 - +0.5 mm; the grinding range for the upper surface of the rail bottom corner is that the inward grinding width of the upper surface of the rail bottom corner is more than 45 mm, the longitudinal weld is centered, and the grinding width to both sides is more than 85 mm, and it should not be under-ground.

[0049] S7.3. Apply appropriate feed during grinding, and avoid under-grinding the surface, or blackening or bluing.

[0050] S7.4. After rough grinding, the ground surface shall be smooth and flat, meeting the flaw detection requirements.

[0051] Preferably, in some embodiments, step S8 includes the following steps:

[0052] S8.1. The instrument used for joint flaw detection is an ultrasonic flaw detector.

[0053] S8.2. During the flaw detection of the welded joint, the ground surface shall be smooth, free of welding slag, and the grinding range shall meet the needs of scanning. The temperature of the weld shall be cooled below 40°C or the natural rail temperature.

[0054] S8.3. Fill in the records in a timely manner after flaw detection is completed.

[0055] Preferably, in some embodiments, step S9 includes the following steps:

[0056] S9.1. Before grinding, the temperature within the welded joint and the 1 m range at both ends shall be below 50°C. Measure the flatness in the horizontal and vertical directions within the 500 mm range on both sides of the weld, determine the appropriate grinding feed, and then perform profiling grinding on the rail top surface and the working edge of the rail head side within the 400 mm range on both sides of the weld.

[0057] S9.2. Prevent local overheating and blackening / bluing of the rail surface during grinding.

[0058] S9.3. Use a profiling grinding machine to finish the profile of the rail top surface and the working edge of the rail head side of the welded joint, and maintain the rail profile shape.

[0059] S9.4. The upper fillets of the rail head and rail bottom shall be smooth within 1 m. The rail welded joint shall be ground smoothly within the 150 mm range on both sides of the weld on the upper surface of the rail bottom and within the 35 mm range from the edge of both rail bottom corners. There shall be no obvious indentation, impact mark, or scratch defects within the 100 mm range on both sides of the weld.

[0060] Preferably, in some embodiments, there shall be no cracks, obvious indentation, scratches, impact damage, electrode burns, or grinding burns on the surface of the welded joint and the nearby rails in step S10, and the grinding depth of the base metal is less than 0.5 mm.

[0061] Preferably, in some embodiments, after the turnout joint is welded and the rail temperature is within the designed locking rail temperature range in step S11, fasteners are installed on the line to lock the line.

[0062] The beneficial effects of the present invention are as follows: When the flash welding construction method for turnout rails of the present invention is used, through the operation modes of two different turnout welding processes, that is, entering for welding in the forward direction, the rail welding machine enters along the main line direction of the turnout, and it is necessary to complete the in-switch welding through six station position adjustments and one line transfer operation, and the welding is carried out in sequence. Entering for welding in the reverse direction, the rail welding machine enters reversely from the side line, and the welding sequence is adjusted to adapt to the structural characteristics of the turnout. The in-switch welding can be completed with two station position adjustments, greatly reducing the adjustment time and improving the construction efficiency. During construction organization, according to the on-site construction requirements, the rail welding machine for the combined railway and road turnout can be preferentially arranged to enter the turnout in the reverse direction, reducing the number of alignment times and shortening the auxiliary operation time. If it is necessary to enter in the forward direction due to site conditions restrictions, it is necessary to plan the line transfer path in advance to ensure the rapid positioning of the welding machine, avoiding the problems that the existing turnout welding process mainly adopts a single operation mode for welding turnouts in both forward and reverse directions, greatly increasing the adjustment time during welding of the welding machine, reducing the construction efficiency, increasing the number of alignment times and the auxiliary operation time during construction organization. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The present invention will be further described below with reference to the drawings and embodiments.

[0064] Figure 1 It is a schematic diagram of welding the turnout by entering in the forward direction in the present invention;

[0065] Figure 2 It is a schematic diagram of the steps of welding the turnout by entering in the forward direction in the present invention Figure 1 ;

[0066] Figure 3 It is a schematic diagram of the steps of welding the turnout by entering in the forward direction in the present invention Figure 2 ;

[0067] Figure 4 It is a schematic diagram of the steps of welding the turnout by entering in the forward direction in the present invention Figure 3 ;

[0068] Figure 5 It is a schematic diagram of the steps of welding the turnout by entering in the forward direction in the present invention Figure 4 ;

[0069] Figure 6 It is a schematic diagram of the steps of welding the turnout by entering in the forward direction in the present invention Figure 5 ;

[0070] Figure 7 It is a schematic diagram of the steps of welding the turnout by entering in the forward direction in the present invention Figure 6 ;

[0071] Figure 8 It is a schematic diagram of welding the turnout by entering in the reverse direction in the present invention;

[0072] Figure 9 It is a schematic diagram of the steps of welding the turnout by entering in the reverse direction in the present invention Figure 1 ;

[0073] Figure 10 is a schematic diagram of the reverse entry turnout welding step in the present invention Figure 2 ;

[0074] Figure 11 is a schematic diagram of the reverse entry turnout welding step in the present invention Figure 3 ;

[0075] Figure 12 is a schematic diagram of the reverse entry turnout welding step in the present invention Figure 4 . Specific embodiments

[0076] The present invention will be further described in detail below in conjunction with embodiments:

[0077] The present invention is not limited to the following specific embodiments. Those of ordinary skill in the art can implement the present invention in other various specific embodiments according to the content disclosed in the present invention, or those that adopt the design structure and idea of the present invention and make simple changes or modifications all fall within the protection scope of the present invention. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0078] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality" is two or more.

[0079] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0080] Such asFigures 1 - 12 As shown in the figure, a method for flash welding of turnout rails includes the following operation steps:

[0081] S1. Construction preparation, and step S1 includes the following steps:

[0082] S1.1. Ballast cleaning and rough adjustment of the turnout are completed, and the geometric dimensions of the turnout meet the requirements.

[0083] S1.2. Determine the process parameters of the mobile flash welding, complete the type inspection and obtain the inspection report.

[0084] S1.3. Load, unload and transport the lengthened rail parts of the turnout to the position of the rails to be replaced.

[0085] S2. Replace the lengthened guide rails and saw cut the rails. In step S2 during construction preparation, according to the different turnout layouts at each station, conduct a construction survey in advance, plan the path of the rail welding machine for both railway and road use, prepare a flow chart for the rail welding machine for both railway and road use to enter and exit the turnout on the station yard plan, and use a modified rear axle excavator in cooperation with manual labor to replace the lengthened guide rails according to the path of the rail welding machine for both railway and road use to enter and exit the turnout. The replacement sequence is carried out according to the welding sequence of entering the turnout in the forward and reverse directions. During welding, it should be noted that, according to the welding head sequence of the turnout welding, replace the lengthened rail parts of the turnout one by one, and strictly execute according to the "static" end and the "moving" end during welding; the fasteners removed at the "static" end only need to meet the welding requirements, and there should be no displacement at the "static" end during welding. All the fasteners and connecting parts at the "moving" end are removed and cushioned with rollers to ensure a free state. When sawing the rails before welding each pair of welding heads, it is necessary to consider the actual length of the guide rail, the length of the rail end collapse surface, and the welding temperature of the switch rail to saw cut the rails. When sawing, the perpendicularity of the rail end is less than 0.5 mm. Before welding, it is necessary to check the perpendicularity of the rail end and the rust removal quality of the rail end and the conductive surface of the rail waist, polish the contact area of the rail waist of the electrode jaws of the rail welding machine for both railway and road use, lift the two rails to be welded to a certain height for alignment and clamping of the rail welding machine for both railway and road use. The lifting height should be determined according to the type of sleeper and fastener.

[0086] When the rail welding machine for both railway and road use enters the turnout in the forward direction, the specific operation steps are as follows:

[0087] S2.1. The rail welding machine for both railway and road use travels straight in front of the turnout, removes the straight stock rail at the turnout tail, replaces guide rail A and guide rail B, the guide rail E moves towards the turnout tail, and the root end of the curved switch rail is peeled off. The short side clamp of the rail welding machine for both railway and road use is at the front end of the turnout, and weld the first welding point at the end of guide rail A away from guide rail E to weld the root end of the straight stock rail and the other end of guide rail A together. The root end of the straight stock rail is the static end, and the other end of guide rail A is the moving end.

[0088] S2.2. The rail welding machine for combined railway and road switches moves to the frog, and the head of the rail welding machine for combined railway and road switches rotates 180°. Considering the melting amount, saw the guide rail A, and weld the second welding point at one end of the guide rail A close to the guide rail E, so as to realize welding one end of the guide rail A and the other end of the guide rail E together. One end of the guide rail A is the static end, and the other end of the guide rail E is the moving end, as well as the third welding point at one end of the guide rail B, so as to realize welding one end of the guide rail B and the other end of the front curved rail of the frog together. One end of the guide rail B is the moving end, and the other end of the front curved rail of the frog is the static end;

[0089] S2.3. The rail welding machine for combined railway and road switches retreats to the heel end of the curved switch rail, and the head of the rail welding machine for combined railway and road switches rotates 180°. The curved switch rail is reset for secondary positioning. The guide rail B is sawed considering the melting amount and the calculated sawing value of the steel rail temperature expansion coefficient, and the fourth welding point at the other end of the guide rail B is welded, so as to realize welding the other end of the guide rail B and one end of the heel end of the curved switch rail together. The other end of the guide rail B is the static end, and one end of the heel end of the curved switch rail is the moving end;

[0090] S2.4. The rail welding machine for combined railway and road switches moves to the front of the turnout and turns to the curved rail. The tail rail of the curved basic rail at the turnout is removed, the guide rails C and D are replaced, the guide rail F moves towards the turnout tail, the heel end of the straight switch rail is pulled out, and the fifth welding point at the end of the guide rail D far from the guide rail F is welded, so as to realize welding the other end of the guide rail D and one end of the heel end of the curved basic rail together. The other end of the guide rail D is the moving end, and one end of the heel end of the curved basic rail is the static end;

[0091] S2.5. The rail welding machine for combined railway and road switches moves to the frog, and the head of the rail welding machine for combined railway and road switches rotates 180°. Considering the melting amount, saw the guide rail D, and weld the sixth welding point at one end of the guide rail D close to the guide rail F, so as to realize welding one end of the guide rail D and the other end of the guide rail F together. One end of the guide rail D is the static end, and the other end of the guide rail F is the moving end, as well as the seventh welding point at one end of the guide rail C, so as to realize welding one end of the guide rail C and one end of the front straight rail of the frog together. One end of the guide rail C is the moving end, and the other end of the front straight rail of the frog is the static end;

[0092] S2.6. The rail welding machine for combined railway and road switches retreats to the heel end of the straight switch rail, and the head of the rail welding machine for combined railway and road switches rotates 180°. The straight switch rail is reset for secondary positioning. The guide rail C is sawed considering the melting amount and the calculated sawing value of the steel rail temperature expansion coefficient, and the eighth welding point at the other end of the guide rail C is welded, so as to realize welding the other end of the guide rail C and one end of the front straight rail of the frog together. The other end of the guide rail C is the static end, and one end of the front straight rail of the frog is the moving end;

[0093] When the rail welding machine for combined railway and road switches enters the turnout in the reverse direction, the specific operation steps are as follows:

[0094] S2.7. The rail welding machine for the combined railway and road turnout runs straight at the turnout tail, replaces guide rails A, B, C, and D, and welds the short-side clamp of the rail welding machine for the combined railway and road turnout towards the frog end. Weld the first welding point at one end of guide rail A close to guide rail E, realizing the welding of the other end of guide rail A and one end of guide rail E together. The other end of guide rail A is the moving end, and one end of guide rail E is the static end. Weld the second welding point at the other end of guide rail B, realizing the welding of the other end of guide rail B and one end of the curved front stock rail of the frog together. The other end of guide rail B is the moving end, and one end of the curved front stock rail of the frog is the static end. Weld the third welding point at one end of guide rail D close to guide rail F, realizing the welding of the other end of guide rail D and one end of guide rail F together. The other end of guide rail D is the moving end, and one end of guide rail F is the static end. And weld the fourth welding point at one end of guide rail C, realizing the welding of the other end of guide rail C and one end of the straight front stock rail of the frog together. The other end of guide rail C is the moving end, and one end of the straight front stock rail of the frog is the static end;

[0095] S2.8. Remove the fasteners of the curved switch rail and the straight switch rail, form a dislocation with guide rails B and C, and perform rust removal and grinding in advance;

[0096] S2.9. The rail welding machine for the combined railway and road turnout raises the outriggers for support, removes the turnout tail rail, saws guide rail A or guide rail D according to the burn-off amount, moves guide rails A and E, and guide rails D + guide rails F towards the turnout tail to ensure they are in the groove. For the straight track, every fifth rail is lifted up, and the train operation condition is restored to ensure that the rail welding machine for the combined railway and road turnout can move to the heel end of the switch rail. Support with the outriggers on both sides, rotate the head of the rail welding machine for the combined railway and road turnout by 180°, and weld the fifth welding point at the end of guide rail A far from guide rail E, realizing the welding of one end of guide rail A and the other end of the heel end of the straight basic rail together. One end of guide rail A is the moving end, and the other end of the heel end of the straight basic rail is the static end. And weld the seventh welding point at the end of guide rail D far from guide rail F, realizing the welding of one end of guide rail D and the other end of the heel end of the curved basic rail together. One end of guide rail D is the moving end, and the other end of the heel end of the curved basic rail is the static end. Reset the curved switch rail and the straight switch rail to the center for secondary positioning. Consider the burn-off amount and the rail temperature expansion coefficient of the rail to calculate the sawing value for sawing guide rails B and C. Weld the sixth welding point at one end of guide rail B, realizing the welding of one end of guide rail B and the other end of the heel end of the curved switch rail together. One end of guide rail B is the static end, and the other end of the heel end of the curved switch rail is the moving end. And weld the eighth welding point at the other end of guide rail C, realizing the welding of one end of guide rail C and the other end of the heel end of the straight switch rail together. One end of guide rail C is the static end, and the other end of the heel end of the straight switch rail is the static end;

[0097] S3. Adjust the position of the switch rail. When adjusting the position of the switch rail in step S3, after the replacement of the extended rail section is completed, check the stagger of the rails, the relative position between the switch rail and the stock rail, and the position of the male and female blocks of the square limiter at the tip of the switch rail. The distance from the tip of the switch rail to the turnout front is 1951 mm, the squareness of the tip of the switch rail shall not be greater than 5 mm, and the difference in the gaps on both sides of the position of the male and female blocks of the limiter shall not be greater than 0.5 mm. When welding the heel end of the switch rail, it is necessary to perform a reset and a secondary inspection, taking into account the melting amount.

[0098] S4. Align the welding machine. For rail welding, first align the rail welding machine for the railway-highway dual-purpose turnout. The on-site person in charge gives an order to command the railway-highway dual-purpose turnout rail welding machine to move to the designated position, that is, to move to a position where the first pair of wheels of the railway-highway dual-purpose turnout rail welding machine is about 3.4 m away from the welding center line.

[0099] S5. Welding. Step S5 includes the following steps:

[0100] S5.1. According to the investigation of the station turnout, formulate the flash welding sequence of the turnout, clarify the dynamic and static ends of each welding head, use the hydraulic leg support system of the railway-highway dual-purpose vehicle, and cooperate with the integrated 180° rotating head of the turnout flash welding machine to realize the rapid conversion of the dynamic and static ends of each welding joint and the variable cross-section end of the AT rail. At the same time, use the construction technology of rail guide extension and precise control to ensure that the structural dimension accuracy of the turnout after welding meets the requirements.

[0101] S5.2. After the alignment of the rail and the welding head is completed, start the butting work. It should be noted that the working surface must be used as the reference; the misalignment deviation of the working surface of the rail head shall not be greater than 0.2 mm, and the misalignment deviation of the edge of the rail bottom shall not be greater than 1 mm; operate the railway-highway dual-purpose turnout rail welding machine to clamp the rail and weld the rail, and timely re-align the rail of the already deflected curve according to the welding requirements of the railway-highway dual-purpose turnout rail welding machine.

[0102] S5.3. After welding is completed, the welding machine must be quickly lifted to remove the welding bead. The upsetting allowance for the rail head, rail bottom, and the slope of the top surface of the rail bottom of the welding joint shall not be greater than 1 mm, and the upsetting allowance for other positions shall not be greater than 2 mm. The welding slag shall not be squeezed into the base metal; the welding slag shall not scratch the base metal. Check the appearance quality of the long rail welding joint and mark the welding joint. The mark shall be on the same side of the rail waist 1 - 3 m in front of the welding joint, and the mark shall be clear and regular.

[0103] S5.4. Timely fill in the "Field Flash Welding Record Sheet".

[0104] S6. Normalizing the welding head. Step S6 includes the following steps:

[0105] S6.1. When normalizing, use a thermometer to measure the normalizing temperature. The surface temperature of the rail head during heating shall be controlled at 900 ± 20 °C, the surface temperature of the rail bottom foot shall be controlled at 800 °C - 850 °C, and the rail head is cooled by natural cooling.

[0106] S6.2. Before operation, check the condition of the medium-frequency normalizing equipment, check whether the connecting wires and cooling water pipes are damaged or leaking, whether there are foreign objects in the induction coil, check whether the cooling water level meets the requirements, and the cooling water temperature should be lower than 25 degrees;

[0107] S6.3. Before installation, clean the normalizing joint, clean up conductive substances such as iron slag, and remove combustibles near the joint;

[0108] S6.4. The normalizing coil is strictly prohibited from contacting the rail to prevent the coil from generating sparks and burning out the coil and the normalizing transformer;

[0109] S6.5. Installation and disassembly must be carried out under power-off conditions. First, place the normalizing equipment more than 600 mm away from the weld to prevent scalding caused by too high temperature of the welding head. The induction coil must be installed vertically, and the two coil fixing bolts must be tightened and installed firmly without looseness. It is strictly prohibited to use deformed or non-conforming bolts. During the loading and unloading process, the transformer must be held firmly to prevent it from tipping over and damaging the equipment during loading and unloading;

[0110] S7. Rough grinding, and step S7 includes the following steps:

[0111] S7.1. Before rough grinding operation, the excess flash allowance should be measured first. Grind the non-working surface, rail jaw, and upper surface of the rail bottom corner of the joint area according to the excess flash allowance. For the welding joint unevenness caused by the deviation of the rail shape and size, it can be trimmed by the method of smooth grinding;

[0112] S7.2. After the rough grinding operation is completed, the grinding allowance for the bottom surface and non-working surface of the joint rail should be 0 to +0.5 mm; the grinding range for the upper surface of the rail bottom corner is: the inward grinding width of the upper surface of the rail bottom corner is more than 45 mm, the longitudinal weld is centered, and the grinding width to both sides is more than 85 mm, and it shall not be under-ground;

[0113] S7.3. When grinding, give an appropriate feed amount, and do not under-grind the surface, and there shall be no blackening and bluing phenomena;

[0114] S7.4. After rough grinding, the grinding surface must be smooth and flat, meeting the requirements of flaw detection;

[0115] S8. Weld head flaw detection, and step S8 includes the following steps:

[0116] S8.1. The instrument used for joint flaw detection inspection is an ultrasonic flaw detector;

[0117] S8.2. When detecting the weld head, the grinding surface should be smooth, flat, and free of welding slag. The grinding range should be able to meet the needs of scanning. The weld temperature should be cooled to below 40 °C or the natural rail temperature. The flaw detection operation technology should meet the requirements of "Rail Welding - Part 1: General Technical Conditions" (TB / T 1632.1 - 2014);

[0118] S8.3. Fill in the "Ultrasonic Flaw Detection Record of Welded Rail Joints at the Construction Site" in a timely manner after flaw detection is completed;

[0119] S9. Finish fine grinding. Step S9 includes the following steps:

[0120] S9.1. Before grinding, the temperature within the welded joint and the 1m range at both ends should be below 50°C. The straightness in the horizontal and vertical directions within 500mm on both sides of the weld should be measured to determine the appropriate grinding feed rate, and then the rail top surface and the working edges of the rail head sides within a 400mm range on both sides of the weld should be profiled and ground;

[0121] S9.2. Do not apply excessive force during grinding to prevent local overheating and blackening or bluing of the rail surface;

[0122] S9.3. Use a profiled grinding machine to perform shape finishing on the rail top surface and the working edges of the rail head sides of the welded joint, and the rail profile shape should be maintained. The shape finishing should not cause any mechanical damage or thermal damage to the welded joint or the rail. The method of shape finishing should not be used to correct the out-of-tolerance straightness deviation and the out-of-tolerance joint misalignment;

[0123] S9.4. The upper fillets of the rail head and the rail bottom should be smooth within 1m. The rail weld head should be ground smoothly within 150mm on both sides of the weld on the upper surface of the rail bottom and within 35mm from the edges of both rail bottom corners on both sides. There should be no obvious indentation, impact mark, or scratch defects within 100mm on both sides of the weld;

[0124] S10. Straightness inspection. After the welded joint is shape-finished in step S10, within the 1m range centered on the weld as shown in Table 1 below, the surface unevenness of the rail top surface should meet the requirements: not more than 0.2mm within any 200mm section, and not more than 0.1mm within any 100mm section. There are no surface unevenness requirements for the pits in the unground area of the base metal surface;

[0125] There should be no cracks, obvious indentation, scratches, impact injuries, electrode burns, or grinding burns on the surface of the welded joint and the nearby rail. The grinding depth of the base metal should be less than 0.5mm;

[0126] Table 1

[0127] Part Rail top surface Inner working surface of rail head Flatness 0 to +0.2 mm 0 to +0.3 mm

[0128] S11. Line locking. After the turnout joint welding is completed and the rail temperature is within the designed locking rail temperature range, when installing and locking the line by fastening the fasteners on the next sleeper every two sleepers, fix the sleeper and the track to ensure the displacement safety of the rail welding machine for the railway-highway dual-use turnout on the track. Then, complete all the remaining fasteners and require timely and comprehensive re-tightening of the fastener bolts. The middle lower jaw of the elastic strip of the concrete sleeper should be in contact with the gauge retaining plate or the torque of the fastener bolt should reach 120 - 150 N.m.

[0129] When the above turnout rail flash welding construction method is used, the head of the rail welding machine for railway-highway dual-use turnout has a 180° rotation function, which can quickly switch the welding directions of the moving and static ends, significantly improving the turnout welding efficiency.

[0130] Entering the turnout in the forward direction: It is necessary to complete the in-switch welding through six station position adjustments and one line transfer operation, and the process is relatively complex.

[0131] Entering the turnout in the reverse direction: Only two station positions are required to complete the in-switch welding, greatly reducing the adjustment time and improving the construction efficiency.

[0132] During construction organization, according to the on-site construction requirements, the rail welding machine for railway-highway dual-use turnout can be preferentially arranged to enter the turnout in the reverse direction to reduce the number of alignments and shorten the auxiliary operation time. If it is necessary to enter in the forward direction due to on-site conditions, the line transfer path needs to be planned in advance to ensure the rapid positioning of the rail welding machine for railway-highway dual-use turnout.

[0133] Based on the ideal embodiments of the present invention as inspiration, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A construction method for flash welding of turnout rails, characterized in that, It includes the following operation steps: S1. Construction preparation; S2. Replace the extended guide rails and saw cut the rails; S3. Adjust the position of the switch rails; S4. Align the welding machine; S5. Welding; S6. Normalize the weld head; S7. Rough grinding; S8. Detect the weld head for flaws; S9. Fine grinding; S10. Check the straightness; S11. Lock the track; Among them, in step S2 during construction preparation, according to the different laying of turnouts at each station, conduct a construction survey in advance, make a path plan for the rail welding machine for the railway-highway dual-purpose turnout, compile a flow chart of the rail welding machine for the railway-highway dual-purpose turnout entering and leaving the turnout on the station yard plan, and use the modified rear axle excavator to cooperate with manual labor to replace the extended guide rails according to the path of the rail welding machine for the railway-highway dual-purpose turnout entering and leaving the turnout. The replacement sequence is carried out according to the welding sequence of entering the turnout in the forward and reverse directions; When the rail welding machine for the railway-highway dual-purpose turnout enters the turnout in the forward direction, the specific operation steps are as follows: S2.

1. The rail welding machine for the railway-highway dual-purpose turnout walks straight in front of the turnout, removes the straight stock rail at the turnout tail, replaces guide rail A and guide rail B, moves guide rail E towards the turnout tail, separates the heel of the curved switch rail, welds the short-side clamp of the rail welding machine for the railway-highway dual-purpose turnout at the front end of the turnout, and welds the first welding point at the end of guide rail A far from guide rail E; S2.

2. The rail welding machine for the railway-highway dual-purpose turnout walks to the frog, rotates the head of the rail welding machine for the railway-highway dual-purpose turnout by 180°, saw cuts guide rail A considering the melting amount, welds the second welding point at the end of guide rail A close to guide rail E, and the third welding point at one end of guide rail B; S2.

3. The rail welding machine for the railway-highway dual-purpose turnout retreats to the heel of the curved switch rail, rotates the head of the rail welding machine for the railway-highway dual-purpose turnout by 180°, resets the curved switch rail for secondary positioning, saw cuts the rail of guide rail B considering the melting amount and the calculated sawing value of the rail temperature expansion coefficient, and welds the fourth welding point at the other end of guide rail B; S2.

4. The rail welding machine for the railway-highway dual-purpose turnout walks to the front of the turnout and turns to the curved track, removes the straight stock rail at the turnout tail of the curved stock rail, replaces guide rail C and guide rail D, moves guide rail F towards the turnout tail, separates the heel of the straight switch rail, and welds the fifth welding point at the end of guide rail D far from guide rail F; S2.

5. The rail welding machine for the railway-highway dual-purpose turnout walks to the frog, rotates the head of the rail welding machine for the railway-highway dual-purpose turnout by 180°, saw cuts guide rail D considering the melting amount, welds the sixth welding point at the end of guide rail D close to guide rail F, and the seventh welding point at one end of guide rail C; S2.

6. The rail welding machine for the railway-highway dual-purpose turnout retreats to the heel of the straight switch rail, rotates the head of the rail welding machine for the railway-highway dual-purpose turnout by 180°, resets the straight switch rail for secondary positioning, saw cuts the rail of guide rail C considering the melting amount and the calculated sawing value of the rail temperature expansion coefficient, and welds the eighth welding point at the other end of guide rail C; When the rail welding machine for the railway-highway dual-purpose turnout enters the turnout in the reverse direction, the specific operation steps are as follows: S2.

7. The rail welding machine for the railway-highway dual-purpose turnout walks straight at the turnout tail, replaces guide rail A, guide rail B, guide rail C, and guide rail D, welds the short-side clamp of the rail welding machine for the railway-highway dual-purpose turnout towards the frog end, and welds the first welding point at the end of guide rail A close to guide rail E, the second welding point at the other end of guide rail B, the third welding point at the end of guide rail D close to guide rail F, and the fourth welding point at one end of guide rail C; S2.

8. Remove the fasteners of the curved switch rail and the straight switch rail, form a dislocation with guide rail B and guide rail C, and conduct rust removal and grinding in advance; S2.

9. Support the lifting legs of the rail welding machine for dual-purpose railway and highway turnouts, remove the rail at the turnout tail of the guide rail, saw the guide rail A or guide rail D according to the amount of melting, move the guide rail A and guide rail E, and guide rail D + guide rail F towards the turnout tail to ensure they are in the groove. For the straight track, every fifth rail is lifted and the first one is left unchanged. Restore the train operation conditions to ensure that the rail welding machine for dual-purpose railway and highway turnouts can move to the heel end of the switch rail. Support with the lifting legs on both sides, rotate the head of the rail welding machine for dual-purpose railway and highway turnouts by 180°, weld the fifth welding point at the end of guide rail A away from guide rail E and the seventh welding point at the end of guide rail D away from guide rail F. Reset the curved switch rail and the straight switch rail to the center for secondary positioning. Consider the amount of melting and the coefficient of thermal expansion of the rail to calculate the sawing value for sawing guide rail B and guide rail C. The welding point at one end of guide rail B is the sixth welding point, and the welding point at the other end of guide rail C is the eighth welding point.

2. The flash welding construction method of turnout rails according to claim 1, characterized in that, Among them, step S1 includes the following steps: S1.

1. Ballast cleaning and rough adjustment of the turnout are completed, and the geometric dimensions of the turnout meet the requirements. S1.

2. Determine the process parameters of the mobile flash welding, complete the type inspection and obtain the inspection report. S1.

3. Load, unload and transport the lengthened rail parts of the turnout to the position of the rail parts to be replaced.

3. A turnout rail flash welding construction method according to claim 1, characterized in that: Among them, when adjusting the position of the turnout rails in step S3, after replacing the lengthened rail parts, check the misalignment of the rails, the relative position between the switch rail and the stock rail, the squareness of the tip of the switch rail, and the position of the master and slave blocks of the retainer. When welding the heel end of the switch rail, it is necessary to reset and conduct a secondary inspection, considering the amount of melting.

4. A turnout rail flash welding construction method according to claim 1, characterized in that, Among them, step S5 includes the following steps: S5.

1. According to the investigation of the turnout in the station, formulate the flash welding sequence of the turnout, clarify the dynamic and static ends of each welding head, use the hydraulic support system of the rail welding vehicle for dual-purpose railway and highway, and cooperate with the integrated 180° rotating head of the turnout flash welding machine to realize the rapid conversion of the dynamic and static ends of each welding joint and the variable cross-section end of the AT rail. At the same time, apply the construction technology of rail lengthening and precise control to ensure that the structural dimension accuracy of the turnout after welding meets the requirements. S5.

2. After the alignment of the rail and the head is completed, start the butt welding work. It should be noted that the working surface must be used as the reference to control the misalignment deviation of the working surface of the rail head and the misalignment deviation of the edge of the rail bottom. Operate the rail welding machine for dual-purpose railway and highway to clamp the rail and weld the rail, and timely re-align the rail of the curved track that has been shifted according to the welding requirements of the rail welding machine for dual-purpose railway and highway. S5.

3. After welding, the welding machine must be quickly lifted, the welding bead must be removed, and the upsetting allowance of the rail head, rail bottom and the slope of the top surface of the rail bottom of the welding joint should be controlled. The welding slag should not be squeezed into the base metal, and the welding slag should not scratch the base metal. Check the appearance quality of the welded joint of the long rail and mark the welded joint. The mark should be at the same side of the rail waist 1 - 3m in front of the welded joint, and the mark should be clear and regular. S5.

4. Fill in the "Field Flash Welding Record Sheet" in a timely manner.

5. A turnout rail flash welding construction method according to claim 1, characterized in that Among them, step S6 includes the following steps: S6.

1. During normalizing, use a temperature measuring instrument to measure the normalizing temperature. The surface temperature of the rail head during heating should be controlled at 900 ± 20 °C, and the surface temperature of the rail bottom should be controlled at 800 °C - 850 °C. The rail head is cooled by natural cooling. S6.

2. Before operation, check the condition of the medium-frequency normalizing equipment, check whether the connecting wires and cooling water pipes are damaged or leaking, whether there are foreign objects in the induction coil, check whether the cooling water level meets the requirements, and the cooling water temperature should be lower than 25°C; S6.

3. Before installation, clean the normalizing joint, clean up conductive substances such as iron slag, and remove combustibles near the joint; S6.

4. The normalizing coil is strictly prohibited from contacting the rail to prevent the coil from generating sparks and burning out the coil and the normalizing transformer; S6.

5. Installation and disassembly must be carried out under power-off conditions. First, place the normalizing equipment more than 600 mm away from the weld to prevent burns caused by excessive temperature of the welding head. The induction coil must be installed vertically, and the fixing bolts of the two coils must be tightened and installed firmly without looseness. During the loading and unloading process, the transformer must be held firmly to prevent it from tipping over and damaging the equipment during loading and unloading.

6. A turnout rail flash welding construction method according to claim 1, characterized in that, Among them, step S7 includes the following steps: S7.

1. Before rough grinding operation, the excess material for removing the burr should be measured first. Grind the non-working surface of the rail, the rail jaw, and the upper surface of the rail bottom corner in the joint area according to the excess material for removing the burr. For the unevenness of the welded joint caused by the deviation of the rail shape and size, it can be trimmed by means of smooth grinding; S7.

2. After the rough grinding operation is completed, the grinding allowance for the bottom surface and non-working surface of the joint rail should be 0 to +0.5 mm; the grinding range for the upper surface of the rail bottom corner is that the width of the inward grinding on the upper surface of the rail bottom corner is more than 45 mm, the longitudinal weld is centered, and the width of the grinding on both sides is more than 85 mm, and it shall not be ground less; S7.

3. When grinding, give an appropriate feed, and do not grind less than the surface, and there shall be no blackening and bluing phenomena; S7.

4. After rough grinding, the grinding surface must be smooth and flat, meeting the flaw detection requirements.

7. A turnout rail flash welding construction method according to claim 1, characterized in that, Among them, step S8 includes the following steps: S8.

1. The instrument used for joint flaw detection is an ultrasonic flaw detector; S8.

2. When detecting the welding head, the grinding surface should be smooth, free of welding slag, and the grinding range should meet the needs of scanning. The temperature of the weld should be cooled below 40°C or the natural rail temperature; S8.

3. Fill in the record in time after flaw detection is completed.

8. A turnout rail flash welding construction method according to claim 1, characterized in that Among them, step S9 includes the following steps: S9.

1. Before grinding, the temperature of the welded joint and the 1 m range at both ends should be below 50°C. The straightness in the horizontal and vertical directions within 500 mm on both sides of the weld should be measured to determine the appropriate grinding feed amount, and then the top surface of the rail and the working edge of the rail head side within the 400 mm range on both sides of the weld should be profiled grinding; S9.

2. Prevent local overheating of the rail surface and blackening and bluing during grinding; S9.

3. Use a profiled grinding machine to finely finish the shape of the top surface of the welded joint and the working edge of the rail head side, and the rail profile shape should be maintained; S9.

4. The upper fillets of the rail head and rail bottom should be smooth within 1 m. The rail weld should be ground flat within 150 mm on both sides of the upper surface of the rail bottom and within 35 mm from the edge of both rail bottom corners. There should be no obvious indentation, impact mark, and scratch defects within 100 mm on both sides of the weld.

9. A turnout rail flash welding construction method according to claim 1, characterized in that: Among them, in step S10, there should be no cracks, obvious indentation, scratches, impact injuries, electrode burns, and grinding burns on the surface of the welded joint and the nearby rail, and the grinding depth of the base metal is less than 0.5 mm.

10. A turnout rail flash welding construction method according to claim 1, characterized in that: After the turnout joint welding is completed in step S11, when the rail temperature is within the designed locking rail temperature range, fasteners are installed on the line to lock the line.

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