Welding process for inspection door of straddle type monorail vehicle

Abstract

The invention discloses a straddle type monorail vehicle inspection door welding process, and relates to the technical field of welding. The method comprises the following steps that firstly, a supporting frame and a perforated plate are prepared; secondly, the perforated plate and the supporting frame are welded together through laser welding; thirdly, after laser welding is completed, preheating treatment is conducted on a welding area; fourthly, the welding area in the third step is placed in welding gas, and the temperature is gradually reduced; 5, a supporting frame and an upper apron board are prepared; sixthly, the supporting frames are spliced, and argon arc welding is used for welding; according to the invention, rivet riveting is replaced by laser welding, so that the perforated plate is mounted more firmly, and the risk that people are hurt by objects falling from high altitude due to rivet falling during high-altitude operation of the railway vehicle is also eliminated. The apron board inspection door adopts a welding mode of combining argon arc welding and electric resistance welding, so that the phenomena of layering, degumming, bubbling, bulging and the like of the apron board inspection door are solved.

Description

Technical Field

[0001] The invention relates to the technical field of welding, and in particular to a welding process for an inspection door of a straddle-type monorail vehicle. Background Art

[0002] A straddled monorail is a transportation system that uses a single track to support and guide vehicles. Compared to conventional railway systems, the main features of a straddled monorail are that there is only one track and the vehicles are suspended above or below the track, rather than touching the track with wheels like conventional trains.

[0003] The monorail skirts currently used in China have the following defects:

[0004] 1. Rivets often break and fall off at the installation position of the perforated plate, posing a safety risk.

[0005] 2. Skirt inspection doors are prone to delamination, degumming, bubbling and bulging due to aging of adhesive.

[0006] Therefore, a welding process for the inspection door of a straddle-type monorail vehicle is proposed. Summary of the invention

[0007] The purpose of the present invention is to solve the problems mentioned in the above background technology, and provide a welding process for the inspection door of a straddle-type monorail vehicle.

[0008] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0009] A welding process for a straddle-type monorail vehicle inspection door comprises the following steps:

[0010] Step 1: Prepare the support frame and perforated plate;

[0011] Step 2: Weld the perforated plate and the support frame together by laser welding;

[0012] Step 3: After laser welding is completed, preheat the welding area;

[0013] Step 4: Place the welding area in step 3 in welding gas and gradually reduce the temperature;

[0014] Step 5: Prepare the support frame and upper skirt board;

[0015] Step 6: Splice the support frame and weld it using argon arc welding;

[0016] Step 7: Assemble the support frame and the upper skirt plate and connect them by resistance welding;

[0017] Step 8: After welding is completed, post-heat treatment is performed on the welding areas in steps 6 and 7;

[0018] Step 9: Place the welded area from step 8 in a furnace to cool naturally.

[0019] Furthermore, in the step 1, the welding surface is cleaned in advance using a suitable cleaning agent and tool.

[0020] Furthermore, in the step 2, the laser power of the laser welding is 3000 W, the welding speed is 150 mm / s, the wire feeding speed is 50 m / min, and the welding distance is 1.5 mm.

[0021] Furthermore, in both step 2 and step 6, argon gas is continuously introduced for protection, and the argon gas flow rate is 10 L / min.

[0022] Furthermore, in step six, the current is set to 120 amperes, the voltage is set to 15 volts, and the weld diameter is set to 1.6 mm. In step seven, the welding time is set to 1 second and the pressure is set to 400 Newtons.

[0023] Furthermore, in step eight, the treatment is performed by tempering, and the tempering temperature is 300-600 degrees Celsius, and the holding time is 1-2 hours. The thermal stress generated during the welding process will cause residual stress in the welded joint, which may cause cracks, deformation and failure.

[0024] The beneficial effects of the present invention are as follows:

[0025] 1. The present invention uses laser welding instead of rivet riveting, which makes the installation of perforated plates more secure and eliminates the risk of falling objects and injuring people when rail vehicles are running at high altitudes due to rivet shedding. The skirt inspection door adopts a welding method combining argon arc welding and resistance welding, which solves the problems of stratification, debonding, blistering and bulging of the skirt inspection door.

[0026] 2. The process steps of the present invention include key links such as pre-welding cleaning, laser welding, argon arc welding, resistance welding and post-heat treatment, which can effectively prevent oxidation and pollution, reduce the occurrence of internal defects in welds, eliminate the thermal stress generated during welding, reduce the residual stress of welded joints, and improve the strength and toughness of welded joints, thereby improving the overall welding quality, thereby ensuring the stability and reliability of the welding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the skirt plate inspection door structure of the present invention;

[0028] Figure numerals: 1 support frame, 2 upper skirt plate, 3 perforated plate. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In addition, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0032] The electrical components mentioned in this article are all connected to an external main controller and 220V mains electricity, and the main controller can be a conventional known device for controlling a computer or the like.

[0033] In the description of the embodiments of the present invention, it should be noted that the terms "inside", "outside", "upper", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] like Figure 1 As shown, a welding process for a straddle-type monorail vehicle inspection door comprises the following steps:

[0035] Step 1: Prepare the support frame 1 and the perforated plate 3 to provide materials for subsequent welding work;

[0036] Step 2: Weld the perforated plate 3 and the support frame 1 together by laser welding; laser welding has the characteristics of high energy density, small weld and narrow heat-affected zone, which can achieve fast and accurate welding. Laser welding can generate a high-power density heat source, so that the welding process can be completed quickly, thereby reducing heat input and heat effects, and maintaining the original mechanical properties of the workpiece to the greatest extent.

[0037] Step 3: After laser welding, preheat the welding area. After laser welding, the temperature of the weld and heat-affected zone will be very high. As the cooling process proceeds, residual stress and deformation will occur in the weld and heat-affected zone. If these residual stress and deformation cannot be fully released and repaired, it will have a negative impact on the performance and life of the welded parts. At this time, it is particularly important to repair the residual stress and deformation by preheating the welding area.

[0038] Step 4: Place the welding area in step 3 in the welding gas and gradually reduce the temperature; gradually reducing the temperature provides sufficient cooling time for the welding area to avoid the formation of welding defects such as cold cracks caused by excessive cooling. The gradual reduction of temperature also helps the welded joint gradually form a stable organizational structure during the cooling process.

[0039] Step 5: Prepare the support frame 1 and the upper skirt board 2;

[0040] Step 6: Splice the support frame 1 and use argon arc welding for welding; argon arc welding has good welding quality and stable arc characteristics, and can achieve deeper welds and higher welding speeds, thereby improving work efficiency.

[0041] Step 7: Insert the upper skirt plate 2 into the support frame 1 for assembly and connect them by resistance welding; resistance welding is a fast and stable connection method. When the current flows through the joint area, it generates instantaneous high temperature, causing plastic deformation at the welding interface, thereby achieving connection. Resistance welding can provide high-strength welds to ensure the reliability of the connection.

[0042] Step 8: After welding is completed, the welding area in steps 6 and 7 is post-heat treated; through post-heat treatment, residual stress is eliminated, the microstructure and performance of the material are improved, thereby improving the strength, toughness and corrosion resistance of the welded joint.

[0043] Step 9: Place the welded area in the furnace for natural cooling. Placing the welded area in the furnace for natural cooling helps to stabilize the weld structure and make the grains inside the weld uniform and fine. Natural cooling can avoid structural abnormalities and stress concentration caused by excessive cooling speed, thereby improving the quality and performance of the welded joint.

[0044] In step 1, the welding surface is cleaned in advance using suitable cleaning agents and tools. This ensures that grease, stains, oxides and other contaminants are removed. This will reduce the risk of oxidation on the welding surface and improve the welding quality.

[0045] In step 2, the laser power of laser welding is 3000 W, the welding speed is 150 mm / s, the wire feeding speed is 50 m / min, and the welding distance is 1.5 mm.

[0046] In both step 2 and step 6, argon gas is continuously introduced for protection, and the argon gas flow rate is 10 liters / minute. As an inert gas, argon gas can provide protection during the welding process, preventing the molten metal from reacting with oxygen, nitrogen, etc. in the air, thereby avoiding oxidation and contamination.

[0047] In step 6, the current is set to 120 amps, the voltage is 15 volts, and the weld diameter is 1.6 mm. In step 7, the welding time is set to 1 second and the pressure is 400 Newtons. By applying current and voltage, the welding arc can generate enough heat to melt the workpiece and the welding wire. Under the action of the arc, the molten metal is transferred from the welding wire to the workpiece to form a weld.

[0048] In step eight, the treatment is carried out by tempering, and the tempering temperature is 300-600 degrees Celsius, and the holding time is 1-2 hours. The thermal stress generated during the welding process will cause residual stress in the welded joint, which may cause cracks, deformation and failure. Post-heat treatment can release the residual stress in the welding area in an orderly manner by controlling the temperature and time, thereby reducing the risk of instability and deformation of the welded joint. During the welding process, due to transient high temperature and rapid cooling, the organizational structure of the welding area usually changes, forming defects such as hardened areas, grain coarsening or uneven organization. Post-heat treatment can promote grain recrystallization, twin removal and organizational homogenization through reheating and insulation, thereby improving the mechanical properties and reliability of the welding area, and tempering can reduce the hardness and improve the toughness.

[0049] In summary: the present invention uses laser welding instead of rivet riveting, the installation of the perforated plate is more secure, and the risk of falling objects and injuring people due to rivet falling off when the rail vehicle is running at high altitude is eliminated. The skirt inspection door adopts a welding method combining argon arc welding and resistance welding, which solves the problems of stratification, degumming, blistering and bulging of the skirt inspection door. The process steps of the present invention include key links such as pre-weld cleaning, laser welding, argon arc welding, resistance welding and post-heat treatment, which can effectively prevent oxidation and pollution, reduce the generation of internal defects in the weld, eliminate the thermal stress generated during the welding process, reduce the residual stress of the weld joint, and improve the strength and toughness of the weld joint, improve the overall welding quality, thereby ensuring the stability and reliability of the welding process.

[0050] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A welding process for a straddle-type monorail vehicle inspection door, characterized in that: The following steps are involved: Step 1: Prepare a support frame (1) and a perforated plate (3); Step 2: Welding the perforated plate (3) and the support frame (1) together by laser welding; Step 3: After laser welding is completed, preheat the welding area; Step 4: Place the welding area in step 3 in welding gas and gradually reduce the temperature; Step 5: Prepare the support frame (1) and the upper skirt board (2); Step 6: Splice the support frame (1) and weld it using argon arc welding; Step 7: Assemble the support frame (1) and the upper skirt plate (2), and connect them by resistance welding; Step 8: After welding is completed, post-heat treatment is performed on the welding areas in steps 6 and 7; Step 9: Place the welded area from step 8 in a furnace to cool naturally.

2. A welding process for a straddle-type monorail vehicle inspection door according to claim 1, characterized in that: In the step 1, the welding surface is cleaned in advance using a suitable cleaning agent and tool.

3. The welding process for the inspection door of a straddle-type monorail vehicle according to claim 1 is characterized in that: The laser power of the laser welding in step 2 is 3000 W, the welding speed is 150 mm / s, the wire feeding speed is 50 m / min, and the welding distance is 1.5 mm.

4. A welding process for a straddle-type monorail vehicle inspection door according to claim 3, characterized in that: In both step 2 and step 6, argon gas is continuously introduced for protection, and the argon gas flow rate is 10 L / min.

5. The welding process for the inspection door of a straddle-type monorail vehicle according to claim 1 is characterized in that: In step six, the current is set to 120 amperes, the voltage is set to 15 volts, and the weld diameter is set to 1.6 mm. In step seven, the welding time is set to 1 second and the pressure is set to 400 Newtons.

6. The welding process for the inspection door of a straddle-type monorail vehicle according to claim 1 is characterized in that: In step eight, the treatment is performed by tempering, and the tempering temperature is 300-600 degrees Celsius, and the holding time is 1-2 hours. The thermal stress generated during the welding process will cause residual stress in the welded joint, which may cause cracks, deformation and failure.

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