Flash butt welding machine modernisation system and method

Abstract

The invention relates to the flash butt welding modernisation system and method, which integrate digital display, process memory, adjustable preheating system and gas protection systems by digitising the welding process from beginning to end in order to reduce operator impact on flash butt welding machines, provide more precise welding processes, increase welding quality, reduce the number of errors, expand the range of product materials to be welded, and prevent energy and material waste.

Description

[0001] FLASH BUTT WELDING MACHINE MODERNISATION SYSTEM AND METHOD

[0002] Technical Field of the Invention

[0003] The invention relates to the flash butt welding machine modernisation system and method.

[0004] The invention particularly relates to the flash butt welding modernisation system and method, which integrate digital display, process memory, adjustable preheating system and gas protection systems by digitising the welding process from beginning to end in order to reduce operator impact on flash butt welding machines, provide more precise welding processes, increase welding quality, reduce the number of errors, expand the range of product materials to be welded, and prevent energy and material waste.

[0005] State of the Art

[0006] Welding is one of the most widely used joining methods today. For this reason, the safety of the parts to be welded is of great importance for the reliability of the entire structure where welded joints are used.

[0007] Flash butt welding is a frequently used welded joining method today.

[0008] Flash butt welding method consists of heat, forging and stacking processes. The welding formed as a result of the preliminary heat formed due to the ohmic and contact resistances of metals against electricity and the continuation of this preliminary heat, the surfaces reaching a state of melting, and then stacking and forging applied with the help of mechanical and hydraulic systems is flash butt welding and it is an electric resistance welding.

[0009] In flash butt welding, the parts to be joined with the same cross-sectional dimensions are first stuffed into the moving jaws. The welding current is transmitted to the material via the moving jaws. The materials are brought into contact with each other and the passage of high-density current is ensured. The parts are joined each other face-to- face. A region is formed in the immediate vicinity of the part called the butt zone, which is affected by the high heat generated during the welding process and undergoes certain changes. This area is called the HAZ zone, which is under the influence of heat and may have different properties than the main material.

[0010] Although this method is mostly used in welding rail steels, it is also used in welding engine bodies, transformer tanks and steel containers, on bodies, axles, wheels, frames and other parts in automobile manufacturing, in production works, especially in the use of welding rods and pipes together, and in welding household appliances, refrigerators, agricultural equipment, metal sheets, rods, rod connection parts, etc. This method offers great advantages with its high thermal efficiency, simplicity and high speed. The biggest reason for its preference is that there are internal stresses in the part after welding and much less welding errors.

[0011] Although various suggestions and applications have been developed in the state of the art in which some feature improvements have been made to the flash butt welding machine for reasons such as improving the welding quality and reducing the number of errors, these developments are not sufficient. Some applications related to the inventions developed for this purpose are given below.

[0012] Patent document no “CN1306893A” in the state of the art is reviewed. In the invention that is the subject of the application, it is stated the walking speed of the moving plate in the flash butt welding machine and the welding voltage are set by program and the walking speed can be controlled by the welding current through negative feedback, and in the fixed flash period, the voltage changes continuously as the real average speed increase and the average speed is maintained at the pre-set level.

[0013] Patent document no “CN102328149A” in the state of the art is reviewed. Said invention describes a flash butt welding machine used to effectively improve the welding quality and efficiency of a chain. It is stated that the flash butt welding machine consists of a base, a frame, a feed drive device, a welding control system, a fixed workbench and a mobile workbench. The data of the welding process is recorded and stored in the database.

[0014] Patent document no “TR2018 / 12575” in the state of the art is reviewed. Said invention is a new generation flash butt welding machine that provides a more solid joint by performing welding at low amperage, and there is a sensor control unit that provides current control.

[0015] Patent document no “GB1202990A” in the state of the art is reviewed. In the invention that is the subject of the application, it is stated that the movement of the work pieces towards each other during the various stages of the welding process in flash butt welding comprises tools that are controlled in accordance with the voltage drop between the surfaces of the work pieces. It describes the slowing down of the speed in analogue flash butt welding and the transition to ideal burning.

[0016] It is known that the flash butt welding machine in the state of the art is equipped with digital screen control for welding data, recording of the process data, and preheating features. However, the fact that the welding is under the control of the operator and not sufficiently digitalised causes negativities such as the lack of good and stable welding quality, the deterioration in the structure of the material used, the increase in the number of welding errors, performing the processes with the trial and error method, energy waste, material waste, not being able to perform different preheating for different materials, and not being able to weld every material.

[0017] As a result, due to the negativities described above and the inadequacy of existing solutions on the subject, it has become necessary to make a development in the relevant technical field.

[0018] The Aim of the Invention

[0019] The invention is the flash butt welding modernisation system and method, which integrate digital display, process memory, adjustable preheating system and gas protection systems by digitising the welding process from beginning to end in order to reduce operator impact on flash butt welding machines, provide more precise welding processes, increase welding quality, reduce the number of errors, expand the range of product materials to be welded, and prevent energy and material waste.

[0020] The most important aim of the invention is to provide a digitalised flash butt welding machine that allows all adjustments to be made digitally and monitored throughout the process. Thus, more precise welding can be done, the number of errors decreases, and various costs such as material and energy waste can be saved. Another aim of the invention is to enable the input of welding parameters, precise adjustments and changes to be made, and the monitoring and control of all changes and process steps that occur during the process by means of the added digital screen.

[0021] Another aim of the invention is that any error that occurs during welding can be checked on the screen and the error process settings can be recorded by means of the digital memory, making it a reference for future work.

[0022] Another aim of the invention is to perform the adjustable preheating process by a PLC (Programmable Logic Controller) with smart software and the screen and memory card connected to it.

[0023] Another aim of the invention is to have an adjustable preheating process for materials where preheating is not sufficient. Thus, it helps the material reach the necessary temperature for melting. This also saves energy by reducing the main heating time.

[0024] Another aim of the invention is to be able to sinter with a flash butt welding machine. Thus, it allows for faster sintering of easy parts without the need for furnaces for sintering.

[0025] Another aim of the invention is to find a gas protection system that uses inert gases for metals that are sensitive to reacting with gases in the atmosphere, thus enabling the welding of these materials. Thus, the variety of materials that can be welded increases in the flash butt welding method.

[0026] Another aim of the invention is to adapt the atmosphere controlled chamber made of transparent PLA material, which has an inert gas hose and connection and is used to monitor the welding process with a welding mask, to the welding machine.

[0027] Another aim of the invention is to increase the variety of materials that can be welded by enabling hot flash butt welding with an adjustable preheating system.

[0028] Another aim of the invention is to create a database by recording the information of certain materials with certain alloy and geometry properties, which have been welded with the logdata feature, and to convert the resulting database into a pre-selected program. Another aim of the invention is to produce a digital flash butt welding from scratch, as well as to be applicable to existing manual flash butt welding machines.

[0029] The structural and characteristic features of the invention and all its advantages will be understood more clearly by the figures given below and the detailed description written with reference to these figures. For this reason, the evaluation should be made by taking these figures and detailed description into consideration.

[0030] Disclosure of the Invention

[0031] The invention relates to the flash butt welding modernisation system and method, which integrate digital display, process memory, adjustable preheating system and gas protection systems by digitising the welding process from beginning to end in order to reduce operator impact on flash butt welding machines, provide more precise welding processes, increase welding quality, reduce the number of errors, expand the range of product materials to be welded, and prevent energy and material waste.

[0032] The invention comprises a PLC (Programmable Logic Controller) working with an open loop method integrated into the flash butt welding machine and a screen and memory card working connected to it. By selecting the "Test" tab on the screen, piston forwardbackward movement is provided without welding; fan on-off operation, current on-off applications can be made by selecting on the screen; hot welding method I traditional cold welding method selection can be made on the screen for preheating before welding and creating more contact area (crater) on two surfaces; and in the hot welding method, how often the moving jaw will go back and forth for how many seconds and preheat can be determined. The time between the moment the parts touch each other and the moment the welding starts (interval) and the total welding time can be determined on the screen. While the welding time determined on the screen continues, the welding can be intervened and stop / start operations can be performed. It is possible to record all welding operations, successful or unsuccessful, with all parameter details (logdata) and transfer them to the computer. After successful welding operations, the alloy, dimensions and geometry of the material are recorded and a database integrated into the PLC system is created to be a reference for subsequent welding operations. In subsequent welding operations, when parts with an alloy and dimensions in the database are desired to be welded, the previously approved parameters can be run as a ready program and this database can be transferred to the computer. There is an atmosphere-controlled chamber made of transparent PLA material, which includes a movable and fixed jaw, has a 12-millimeter hole for high-purity (>99.99%) Argon or different inert gas hose connection, and can be monitored with a welding mask. By means of the invention, these features are added to the flash butt welding machine.

[0033] With the PLC system added to the machine, the parameters common to every flash butt welding machine, such as welding speed, current intensity, welding time, etc. are determined with numerical values via a digital screen. The change during the process is also monitored on the screen and intervention can be made in any negative situation.

[0034] The invention comprises a PLC that creates a database by recording information about the materials whose source, optimum parameters, type, alloy and geometric properties are determined, and converts the created database into a pre-selected program. The numerical data of each welding process performed with the PLC system is recorded in the memory. In this way, a data pool that can be looked back on is created. After successful welding processes, the alloy, dimensions and geometry of the material are recorded and a database integrated into the PLC system is created to be a reference for subsequent welding processes. In this way, when a part with an alloy and dimensions in the database is desired to be welded in subsequent welding processes, the parameters deemed appropriate in advance are run as a ready program. This minimises the dependency of the welding process on the operator and the inconsistency between processes.

[0035] Preheating, burning, pressing and accumulation and cooling processes in the standard flash butt welding method are under the control of the operator, as much as the operator's knowledge and experience. With the PLC system in the invention, all stages are digitally controlled. Since preheating is not a parameter but a process step that affects the welding quality and the material surface quality, the preheating time and preheating cycle are adjusted according to the material type and surface area size with the PLC system in the invention. In this way, since the material surfaces will be heated and cooled equally and homogeneously, higher quality welding connections will be obtained. In the invention, since the preheating period will be under our control, preheating will start with the first contact of the parts. However, here, the command given to the machine will determine how long and how many times they will touch and separate from each other. It will create a new roughness with each contact, thus the roughness will form along the entire surface. By means of the increasing contact points spreading over the entire surface, the burning and melting process that will occur after preheating will occur equally. Thus, due to the homogeneous thermal distribution, homogeneous melting and homogeneous welling, a higher quality and higher strength weld will be obtained. Since the cooling curve that will be formed will be homogeneous on the entire surface, the formation of a balanced crystal structure in the welding area will be ensured.

[0036] In addition, the adjustment of both the duration and the cycle of the preheating parameter will provide great advantage in welding materials with different diameters or different heat conduction coefficients.

[0037] By means of the atmosphere-controlled chamber, alloys that are likely to react with oxygen and are prone to oxidation do not experience any problems with electrical current conduction. In this way, the density of slag oxidised and thrown out of the flash zone and the resulting waste rate are reduced; It enables the welding of metals and / or alloys that are easily oxidised in atmospheric conditions, are highly prone to react with oxygen, and have low weldability such as aluminium (AI6061 , AI7075, AI4543 etc.), magnesium (AZ81 , AZ91 , AZ31 B etc.), and titanium (Grade 3, Grade 5, Grade 6, Grade 7 etc.).

[0038] By means of the integration of the hot flash butt welding method into the machine, high surface roughness and a preheating process are provided on the parts to be welded, thus a more homogeneous weld metal formation and homogeneous cooling accordingly.

[0039] To perform hot flash butt welding, materials must be connected to the fixed and mobile jaw and the chamber is closed. When this chamber is completely filled with inert gas, welding begins. By means of the PLC (Programmable Logic Controller) working with the open loop method integrated into the flash butt welding machine and the screen and memory card working with it, after testing the machine by performing piston forward-backward movement, fan on-off, current on-off exercises without welding from the "Test" tab on the screen, the hot welding method is selected from the hot welding method I traditional cold welding method selection, which is done to preheat before welding and create a larger contact area on the two surfaces. Then, in the hot welding method, the number of seconds and how often the moving jaw will preheat by going back and forth, the time between the moment the parts touch each other and the moment the welding starts (interval) and the total welding time are determined on the screen and the welding is started. The machine starts welding according to the set parameters and since the rough and indented surfaces of the parts to be welded will increase the initial contact surface, the arc starts simultaneously at several points, not at a single point. In the hot flash butt welding, which is done to increase the roughness on the surfaces, before the welding process in which continuous current passes starts, the moving jaw and the part connected to the jaw make strikes by moving back and forth to the part connected to the fixed jaw at the specified frequency. The current passes at each contact of the parts, the current is cut off when the jaw moves back and the micro-weld areas formed by this current are broken when the jaw moves back. This process continues until both surfaces become quite rough. Then, the continuous welding process starts and the material is welded for the specified time and the process is completed. This preheating system process increases the homogeneity of the welding area and the welding efficiency.

[0040] The modernisation of the flash butt welding machine is used to sinter simple parts. In this way, materials manufactured with the powder metallurgy method can be sintered well below the melting temperature with a short welding time and low current by connecting a single sample to two jaws. The designed atmosphere-controlled chamber is also actively used in the sintering process (magnesium, metal oxides, etc. metals show higher oxygen affinity at high temperatures). In this way, alloys that are prone to oxidation and have the possibility of reacting with oxygen can be used in the sintering process.

[0041] The invention can be used to produce a digital flash butt welding from scratch, as well as to be applicable to existing manual flash butt welding machines.

Claims

CLAIMS1. Flash butt welding machine modernisation system, comprising- the screen that allows performing piston forward -backward movement, fan on-off, current on-off practices without welding, allows selection of hot welding method I traditional cold welding method for preheating before welding and creating more contact area, i.e. crater, on two surfaces, allows the determination of the preheating time and preheating cycle according to the type of material and the size of the surface area in order to ensure equal and homogeneous heating of all surfaces and a homogeneous burning area in the hot welding method, and allows intervention in the welding process while the welding process is in progress, recording of all welding operations such as stop / start, successful or unsuccessful with all parameter details and transferring them to the computer,- a database integrated into the programmable logic controller system for recording the alloy, dimensions and geometry of the material after successful welding operations in order to be used as a reference for subsequent welding processes,- Programmable logic controller (PLC) that works with the open loop method connected to the display and memory card integrated into the flash butt welding machine, and allows the operation of previously approved parameters as a ready program and the transfer of this database to the computer when parts with an alloy and dimensions in the database are to be welded in subsequent welding operations, and- Atmosphere controlled chamber that accommodates the movable and fixed jaw, has a 12 mm hole for high purity Argon or different inert gas hose connection, and is made of transparent PLA material to be able to follow the welding process with a welding mask.

2. The flash butt welding machine modernisation system according to Claim 1 , comprising the PLC that enables the sintering process of simple metals to be carried out on this welding machine by means of the adjustable preheating.

3. The flash butt welding machine modernisation system according to Claim 1 , comprising adjustable preheating feature that ensures higher quality and higher strength welding when welding the material.

4. The flash butt welding machine modernisation system according to Claim 1 , comprising the PLC that creates a database by recording information about the materials whose source, optimum parameters, type, alloy and geometric properties are determined, and converts the created database into a preselected program.

5. The flash butt welding machine modernisation system according to Claim 1 , comprising the PLC, to which the screen and memory card in which the preheating parameters that enables the hot flash butt welding process to be carried out on the welding machine are determined are connected.

6. The flash butt welding machine modernisation system according to Claim 1 , comprising atmosphere-controlled chamber that enables welding or sintering of metals and / or alloys that are highly prone to react with oxygen.

7. The flash butt welding machine modernisation system according to Claim 6, wherein metals and / or alloys that are highly prone to react with oxygen and have low weldability are aluminium (AI6061 , AI7075, AI4543), magnesium (AZ81 , AZ91 , AZ31 B), titanium (Grade 3, Grade 5, Grade 6, Grade 7).

8. The flash butt welding machine modernisation method comprising- connecting the materials to be welded to the movable jaws by the operator and closing the atmosphere-controlled chamber,- selecting the system test from the screen and performing the system test by the PLC,- selecting the welding method on the screen,- entering the preheating time, preheating cycle number and total welding time on the screen according to the material type and surface area size,- filling the atmosphere-controlled chamber completely with inert gas,- starting the preheating process,- starting the continuous welding process, andremoval of the welded part by the operator.

9. The flash butt welding machine modernisation method according to Claim 8, wherein, in the process step of selecting the welding method on the screen, the selected method is cold flash butt welding. 1O.The flash butt welding machine modernisation method according to Claim 8, wherein, in the process step of selecting the welding method on the screen, the selected method is hot flash butt welding.

11. The flash butt welding machine modernisation method according to Claim 8, wherein, in the process step of starting the preheating process; the preheating process is creating micro welding zones by the movable jaw and the part attached to it hitting the part attached to the fixed jaw by moving back and forth at a specified frequency, thus ensuring that the surface of the material becomes rough.12.The flash butt welding machine modernisation method according to Claim 8, wherein it is possible to control and intervene in all process steps during the welding process from the screen.