CN113510341A - Pre-welding preheating device for electric heating ceramic plate of aluminum alloy traction and bolster buffering component of railway vehicle - Google Patents

Abstract

Preheating device before welding of rail vehicle aluminum alloy traction and bolster buffering part electrical heating ceramic plate belongs to aluminum alloy processing technology field, characterized by: several to tens groups of ceramic heating plates are fixed on the outer side surface of the front end plate needing to be heated and the designated positions of the profile inner cavities of the traction beam and the traction bolster front end beam in an F-clamp clamping mode, and several to tens groups of K-type thermocouples are adhered to the heating area of the traction bolster. The invention has the beneficial effects that: 1. the multi-position large-area simultaneous heating is realized, the preheating time is greatly reduced, and the production efficiency is improved; 2. the accuracy and the stability of the preheating temperature are improved, 3, welding deformation is controlled, the deformation after welding is reduced, and 4, the monitoring performance and the traceability of the preheating temperature are improved.

Description

Pre-welding preheating device for electric heating ceramic plate of aluminum alloy traction and bolster buffering component of railway vehicle

Technical Field

The invention belongs to the technical field of aluminum alloy processing, and relates to processing improvement of special aluminum alloy parts.

Background

The aluminum alloy traction and bolster buffering component is an important component of a railway vehicle body and is also a key stressed component of a vehicle body underframe, an aluminum plate and an aluminum profile with the thickness of more than 10mm (the maximum thickness can reach 110mm) are usually used as parts of the aluminum alloy traction and bolster buffering component, and the connection of all parts is completed by adopting a welding process of inert gas shielded welding (MIG welding). Such a component is required to bear not only the self weight of the whole train but also the traction force and the braking force of the train, so the weld fusion condition of the component directly influences the manufacturing quality of the whole train and the train operation safety.

According to the requirement of rail industry standard, when the thickness of the base metal is more than or equal to 8mm, the welding seam area needs to be preheated to 100-120 ℃ before welding so as to ensure the fusion quality. If the preheating is not carried out, quality defects such as poor fusion quality of the root of the welding seam, incomplete penetration of the welding seam and the like can occur. The wall thickness of all main structure materials of the traction and bolster buffering component is larger than the thickness, so that the whole traction and bolster buffering component is welded under the condition of preheating.

The conventional preheating method for producing the parts is to preheat the parts before welding by repeatedly baking and heating the workpieces by using a baking gun matched with oxyacetylene flame by an operator. However, the aluminum alloy material has extremely strong heat dissipation capability (the specific heat capacity is 0.88 multiplied by 10)³J/(KG. ℃) is 2 times of that of steel materials), the temperature rising area of the thick plate is very small and the temperature rising speed is slow and the temperature can not be kept only by manual flame heating,therefore, repeated heating and repeated measurement frequently occur during actual production, and the production efficiency is seriously influenced.

Disclosure of Invention

The purpose of the invention is: the pre-welding preheating device for the electric heating ceramic plate of the aluminum alloy traction and bolster buffering component of the railway vehicle is provided, and can simultaneously heat a to-be-welded area in multiple positions and a large area before welding so as to finish high-quality welding with the base metal thickness being more than or equal to 8 mm.

The technical scheme of the invention is as follows: the device consists of an MCU, a silicon controlled power regulator, a multi-path paperless temperature recorder, a heating plate and a K-type thermocouple.

Several to tens groups of ceramic heating plates are fixed on the outer side surface of the front end plate needing to be heated and the designated positions of the profile inner cavities of the traction beam and the traction bolster front end beam in an F-clamp clamping mode, and several to tens groups of K-type thermocouples are adhered to the heating area of the traction bolster.

The metal plate shell of the ceramic heating plate is filled with heat insulation cotton filler, and the upper surface of the metal plate shell is provided with a ceramic plate and a heating resistance wire.

The invention has the beneficial effects that:

1) realize multi-position and large-area simultaneous heating, greatly reduce preheating time and improve production efficiency

The preheating time of the draft plank parts is mainly dependent on the thickness of the material, with thicker materials taking longer and less area available for heating. When the conventional manual preheating method is adopted, an operator needs to repeatedly fire and heat the base material by using a baking gun until the temperature of the material meets the requirement. When products with complex welding structures and more welding lines are welded, due to the influences of welding positions, welding sequences and human factors in the welding process, the preheating process and the welding process are difficult to be well connected, and therefore the situation that the preheated welding lines are not met in temperature and need to be preheated when being prepared for welding often occurs in the actual production process. This repeated preheating takes up most of the welding process time and seriously affects the work efficiency and the production schedule. The technical scheme of preheating by adopting the electric heating equipment can thoroughly solve the problems of low temperature lifting speed and small temperature heating area maintenance by adding the heating plates at a plurality of positions and heating at the same time, can ensure that the temperature of all welding areas in the whole welding process is kept within a required range all the time, greatly reduces the production man-hour of welding personnel and improves the production efficiency. Compared with a manual flame preheating mode, the electric heating preheating process is expected to improve the production efficiency of the group welding procedure in the traction and bolster production by 30 percent.

2) Improve accuracy and stability of preheating temperature

In the conventional manual flame heating mode adopted at present, because the heat dissipation speed of the aluminum alloy material is high, the actual preheating temperature is higher or lower than the required temperature range possibly caused by the deviation of measuring time and measuring position of a welder during the welding of a long welding seam in the production operation process. If the preheating temperature is too low, the weld joint may not be welded at the correct preheating temperature, and the defects of incomplete penetration, poor fusion and the like may be caused. If the temperature is too high, the strength of the base material is affected to some extent. However, the adverse effects on the base metal and the welding seam due to the reasons are generated in the material, and the material is difficult to accurately identify through appearance inspection, so that certain potential safety hazards are generated on the product quality.

Adopt electrical heating equipment to preheat, at reasonable interpolation position, accessible equipment sets for heating temperature to the within range of requirement, crosses low automation if the temperature and heats the intensification excessively, and the automatic shutdown heating when the temperature reaches the requirement upper limit, this accuracy that has just improved whole welding process temperature control greatly has avoided preheating the quality problems that the temperature control link probably produced.

3) Welding deformation is controlled to reduce deformation after welding

Aluminum alloy materials can generate certain welding deformation after being welded, and the deformation is caused by cooling shrinkage of a welding line after being heated in the welding process. The larger the difference between the material temperature and the ambient temperature during welding, the larger the welding deformation after cooling shrinkage. The welding of the traction and bolster buffering component is characterized in that the welding material is thick, the structural strength of a workpiece is extremely high, when the welding deformation is large and the outline size exceeds the requirement of a drawing, the outline size is difficult to correct to a qualified state in a flame or mechanical adjustment and repair mode, and the risk of final size out of tolerance and even scrapping exists after production.

The conventional manual preheating process can only heat the position of a welding seam, most of base metal temperature is still in a room temperature state, and larger welding deformation can be generated due to higher temperature difference before and after welding. When the electric heating equipment is adopted for preheating, the traction and bolster buffering heating plate can heat large-area and multi-position simultaneously, so that the base metal temperature of the whole welding area is improved, the welding deformation is effectively reduced by a method for reducing the temperature difference of materials during welding, and the shape correction difficulty and the adjustment and repair time after welding can be greatly reduced.

4) Pre-heating temperature monitorability and traceability

Traction and bolster buffering parts are often more in welding seam types, welding areas are scattered, preheating time is long, and existing welding seam preheating temperature measurement is completed by using a handheld temperature measuring instrument for measurement by welding personnel. The temperature detection method is greatly influenced by human factors, and if a measurer does not heat according to requirements, an effective detection means is not available after welding to confirm the actual temperature condition during welding, so that the accurate monitoring of the temperature in the welding process and the data authenticity of the tracing process cannot be ensured. The electric heating equipment can increase the functions of thermocouple temperature measurement and control and temperature record storage, and can record the real-time temperature change of the designated position of the workpiece in the whole production process, and can quickly and accurately analyze and correspondingly process the reason according to the temperature record condition if the quality of the welding seam has a problem.

Drawings

FIG. 1 is a schematic diagram of an electrical heating apparatus of the present invention;

FIG. 2 is a schematic block diagram of the electrical heating apparatus of the present invention;

FIG. 3 is a circuit diagram of a thyristor power regulator for an electrical heating apparatus of the present invention;

FIG. 4 is a schematic view of a heating plate according to the present invention;

FIG. 5 is a schematic structural view of an aluminum alloy traction and bolster buffering component of a railway vehicle to be processed;

FIG. 6 is a schematic view of the position of the heating plate and thermocouple addition for traction and bolster;

FIG. 7 is a schematic view of the connection of the heating plates according to the present invention;

FIG. 8 is a schematic view of the thermocouple connection of the present invention;

FIG. 9 is a schematic view of the traction and bolster cushioning profile components and heating plate and thermocouple addition location of the present invention;

FIG. 10 is an additional schematic view of the heating plate of the inner cavity of the front beam section of the traction and bolster restraint system of the present invention;

fig. 11 is an additional schematic view of the heating plate of the inner cavity of the profile of the traction beam with the traction pillow and the slow traction beam.

Detailed Description

As shown in FIG. 1, A is MCU, B is SCR power regulator, C is temperature recorder, D is heating plate, E is thermocouple, and F is traction and bolster part.

As shown in figure 4, 2-1-1 is a crawler-type ceramic plate, 2-1-2 is a nickel-chromium alloy resistance wire, 2-1-3 is a heat insulation cotton filler, and 2-1-4 is a metal shell.

As shown in FIGS. 6 and 7, 1-1 is the front traction and bolster plate, 2-1 is heating plate A, 2-2 is heating plate B, 3-1 is thermocouple B, 3-2 is thermocouple B, and 9 is F-shaped clamp.

As shown in FIG. 8, 1-1 is the front end plate of the traction and bolster cushion, 3-1 is the thermocouple A, and 10 is the electric heating device.

As shown in fig. 9, 1-2 is the front end beam of the traction and bolster cushion (left), 1-3 is the front end beam of the traction and bolster cushion (right), 1-4 is the traction beam of the traction and bolster cushion (left), 1-5 is the traction beam of the traction and bolster cushion (right), 2-3 is the heating plate C, 2-4 is the heating plate D, 2-5 is the heating plate E, 2-6 is the heating plate F, 3-3 is the thermocouple C, 3-4 is the thermocouple D, 3-5 is the thermocouple E, and 3-6 is the thermocouple F. As shown in FIG. 10, 1-2 is the front beam (left) of the traction and bolster cushion, 2-3 is the heating plate C, 11 is the supporting aluminum block A.

As shown in fig. 11, the traction beams (left) are 1-4, the heating plates E are 2-5, and the supporting aluminum blocks B are 12.

1. Device architecture and principles

The electric heating preheating device mainly comprises an MCU, a silicon controlled power regulator, a multi-channel paperless temperature recorder, a heating plate and a K-type thermocouple. The heating plate and the K-type thermocouple can be divided into a plurality of groups of branches according to the heating position and connected to different positions of a heating part, the connection mode is as shown in figure 1, and the equipment structure is as shown in figure 2.

As shown in the figure 2, the device realizes the function of adjusting the temperature of the digital pid through the MCU, and the MCU is used for realizing the function of adjusting the temperature of the digital pid

The heating plate heats the traction and bolster part, real-time temperature monitoring of a heating region is carried out by the thermocouple and is fed back to the MCU, whether the temperature fed back by the thermocouple is within a required range is judged by the MCU according to set temperature parameter requirements, and the silicon controlled rectifier power regulator is controlled according to a judgment result to carry out heating power regulation, the automatic heating temperature control function of each ceramic heating plate in the preheating process before welding of the traction and bolster part is finally realized through the above circulation process, and the storage and recording functions of the temperature are realized through a multi-path paperless temperature recorder while heating.

The thyristor power regulator in the electric heating device regulates the power by regulating the equivalent voltage of the sinusoidal alternating current by using the principle of bidirectional thyristor chopping (see fig. 3 for a circuit diagram). The trigger circuit adopts a bidirectional diode, compared with a double-base diode trigger principle, the circuit has fewer used elements, is simple and easy to install and adjust, obtains trigger pulses by utilizing the turning characteristic of the bidirectional diode, and conducts the bidirectional diode VD to give trigger current to the bidirectional silicon controlled rectifier SCR when applied voltage is higher than the turning voltage. The numerical value of the potentiometer Rw determines the phase position of the voltage on the capacitor C in the R-C loop, when the voltage at two ends of the capacitor C reaches a certain numerical value, VD is conducted, and the silicon controlled electrode is discharged by the capacitor C, so that the conduction is triggered.

The ceramic heating plate for heating the traction and bolster cushioning component mainly comprises a metal shell, a crawler-type ceramic heating sheet, a nickel-chromium alloy resistance wire and high-temperature-resistant heat-insulating cotton, and the structure is shown in figure 4. The heating plate with the structure has the advantages of high temperature rising speed, high heat utilization rate and convenient operation. The heating effect is realized by laminating the surface of the heating plate with the ceramic plate with the heating position required by the traction and bolster in heating, and the actual shape and size can be designed and manufactured according to the structure and the adding position of the heating part required.

The stored recording of the heating temperature was achieved using a paperless temperature recorder. The paperless temperature recorder is a novel recorder integrating multiple functions of displaying, processing, recording, alarming, power distribution and the like, adopts NAND FLASH with ultra-large capacity as a storage medium of historical data, has the functions of multi-path output, on-screen display of measured data, historical curve parameter recording and the like, and provides an effective means for process recording, fault analysis and process parameter optimization of the traction and bolster production process.

The detection and feedback of the temperature are completed by a K-type patch thermocouple. The K-type thermocouple is a temperature sensor and mainly comprises a temperature sensing element, a mounting and fixing device, a wire collecting box and other main components. When the temperature-controlled type temperature-controlled pillow is used, the temperature-controlled type temperature-controlled pillow is stuck to a region where the heating temperature needs to be monitored through the high-temperature-resistant adhesive tape, and the temperature is automatically adjusted, controlled, recorded and stored in a data feedback mode finally through the cooperation of the silicon-controlled power regulator and the multi-path paperless temperature recorder.

2. Device application process

The traction and bolster buffering component of the conventional railway vehicle is mostly of a symmetrical structure and is formed by assembling and welding main structural components such as a front end plate, a front end beam, a traction beam, a connecting floor and the like, and the structure is shown in the following figure 5.

The specific process of the pre-welding preheating process of the electric heating equipment matched with the ceramic heating plate comprises the following steps:

taking the common traction and bolster structure shown in fig. 5 as an example, firstly, a heating plate with an appropriate size is fixed to the outer side surface (fig. 6 and 7) of the front end plate of the traction and bolster to be heated and the designated positions of the inner cavities (fig. 9, 10 and 11) of the sections of the front end beam of the traction and bolster and the traction beam of the traction and bolster by means of tool fixing, F clamp and the like, and a K-type patch thermocouple (fig. 8) of a corresponding circuit is adhered to each heating area for temperature monitoring and control. According to the scheme, the traction and bolster buffer of each structure can be added with heating plates and temperature thermocouples at multiple positions, so that the whole body of the main thick plate structure area is heated simultaneously.

After the heating plate and the thermocouple are connected, the maximum heating output power is set in the setting area of the silicon controlled power regulator of the control panel of the equipment so as to avoid the damage of the equipment caused by overhigh output power, and the MCU in the setting area of the MCU of the control panel sets heating parameters such as the upper limit of the heating temperature, the allowable temperature interval, the heating time and the like. And after the setting is finished, heating is started, the current real-time temperature state of each temperature measuring point is returned through a thermocouple, the heating is stopped when the temperature reaches the upper limit, the heating is recovered after the temperature is lower than the lower limit of a temperature allowable interval, the temperature of the product in the welding process is kept constant until the whole welding is finished by adjusting the temperature through electric heating equipment, and the recording and the storage of temperature data in the use process are realized through a paperless temperature recorder.

Claims (2)

1. Preheating device before welding of rail vehicle aluminum alloy traction and bolster buffering part electrical heating ceramic plate, characterized by: several to tens groups of ceramic heating plates are fixed on the outer side surface of the front end plate needing to be heated and the designated positions of the profile inner cavities of the traction beam and the traction bolster front end beam in an F-clamp clamping mode, and several to tens groups of K-type thermocouples are adhered to the heating area of the traction bolster.

2. The pre-welding ceramic plate preheating device for the electric heating ceramic plate of the aluminum alloy traction and bolster buffering component of the railway vehicle as claimed in claim, characterized in that: the metal plate shell of the ceramic heating plate is filled with heat insulation cotton filler, and the upper surface of the metal plate shell is provided with a ceramic plate and a heating resistance wire.

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