CN105478959B - Underwater dry-type electric arc welder and welding method with nozzle - Google Patents

Abstract

The invention discloses an underwater dry arc welding welding device with a nozzle and a welding method. The welding device includes a welding torch, gas supply equipment and a control unit: the welding torch includes a gun barrel and a welding handle, and the gun barrel is provided with Air inlet, the gun barrel is provided with an automatic clamping mechanism for assembling welding rods. In the axial direction, one side lumen of the gun barrel is connected with the gas outlet end of the gas supply equipment through the air inlet, and the port of the side lumen It is equipped with a gas nozzle and an end cover that can be opened and turned. The end cover is automatically controlled and closed by an elastic mechanism; The mechanism drives the barrel to move in the axial direction. The invention is novel in design, convenient in operation, and easy to realize. The protection gas is sprayed from the nozzle of the welding torch to quickly form a dry environment in a local space, and can ensure the drying of the welding rod during underwater welding.

Description

Underwater dry arc welding welding device with nozzle and welding method

technical field

The invention belongs to the field of mechanical processing and relates to underwater welding technology, in particular to an underwater dry arc welding welding device with a nozzle and a welding method.

Background technique

At present, underwater welding is becoming an increasingly popular and practical welding technology, especially suitable for many occasions where underwater parts need to be repaired in ships and marine engineering. However, due to the influence of the working environment, there are still many implementations of underwater welding. The technical difficulties include that the weld seam and welding materials are easy to enter water, which leads to an increase in the hydrogen content of the weld seam, the safety hazard caused by the conductivity of water, and the fact that workers cannot see the position of the arc and weld seam clearly when welding in water. Skill requirements are relatively high, among which, the waterproof problem of weld seam and welding materials is the most prominent when welding in water. Most of the traditional underwater dry welding technology is to use the drainage device to form a dry closed space, and then carry out the welding method. For example, some predecessors added a welding cover to the helmet, and used air drainage in the welding cover to form a dry space. Although this method can maximize the same effect as welding in water and welding on shore, the cost is huge and the device is complicated. , and time-consuming and labor-intensive, it is often not suitable for repairing welded structures in water, especially emergency repairs. In the existing welding methods, using underwater electrode arc welding to compare welding wire will save a very long wire feeding hose and a large welding wire reel and other mechanisms, so underwater electrode arc welding is currently the most promising water welding method. The following welding method. Therefore, it is particularly urgent and important to develop a welding torch device that can solve the waterproof problem of underwater welding rods, reduce the requirements for workers' operating skills when welding in water, and ensure the safety of welders.

Contents of the invention

The technical purpose of the present invention is to provide an underwater dry arc welding torch device with a nozzle and a welding method that can improve the deficiencies of the prior art, and utilize gas drainage to create a dry environment suitable for welding.

In order to realize the above-mentioned technical purpose, the technical solution disclosed in the present invention is:

The underwater dry arc welding welding device with a nozzle is characterized in that it includes a welding torch, a gas supply device and a control unit:

The welding torch includes a gun barrel and a welding handle. The gun barrel is provided with an air inlet, and the gun barrel is provided with an automatic clamping mechanism for assembling welding rods. In the axial direction, one side of the gun barrel passes through the air inlet and the The gas outlet end of the gas supply equipment is connected, and the port of the side lumen is provided with a gas nozzle and an end cap that closes the port. A propulsion mechanism is provided in the side lumen, and the automatic clamping mechanism is installed on the propulsion mechanism, and is driven by the propulsion mechanism to move in the axial direction of the gun barrel. The gas supply equipment, the automatic clamping mechanism, and the propulsion mechanism are respectively connected to the control unit.

On the basis of the above scheme, further improved or preferred technical schemes also include:

The welding device is also provided with a welding rod warmer, and the welding rod warmer is provided with a cylinder cavity that can be placed on the gun barrel of the welding torch. The inner opening is flipped and closed automatically by the elastic mechanism. The welding rod is positioned and installed on the central axis of the cylinder cavity, and one welding rod is stored in the cylinder cavity of an insulator.

The welding rod warmer is equipped with a sealing ring on the outside of the end cover, and the inner diameter of the sealing ring matches the outer diameter of the barrel section of the welding torch that can be inserted into the barrel cavity, so that the gun barrel can just be inserted into the sealing ring to prevent it from being inserted into the insulator. water.

Considering that in the underwater environment, it is difficult to judge the use degree of the welding rod solely by eyesight, and the propulsion mechanism or the automatic clamping mechanism is easy to burn out, a temperature sensor can be installed on the propulsion mechanism or the automatic clamping mechanism, and the temperature sensor and the The control unit is connected. Using the principle that the arc is close to the temperature sensor and the temperature will rise sharply when the electrode is about to finish welding, the arc is automatically extinguished, which further reduces the operational difficulty of welding in water.

The middle part of the barrel of the welding torch is provided with a guide rail that restricts the movement direction of the propulsion mechanism. The guide rail is electrically connected to the welding power supply through a cable. As a component of the electrode, the welding rod is electrically connected to the guide rail through an automatic clamping mechanism.

The propulsion mechanism preferably adopts a double-acting cylinder or a hydraulic cylinder, and the chuck of the automatic clamping mechanism is installed on the piston rod extending out of the cylinder body; a current sensor for detecting the welding current is provided in the welding circuit, and the cylinder or hydraulic cylinder is used The air inlet or liquid inlet of the chamber that pushes the piston rod to the side of the barrel port is controlled to open and close through the proportional solenoid valve. The current sensor and the proportional solenoid valve are respectively connected with the control unit, and the control unit controls the opening and closing according to the current sensor. The output signal controls the opening of the proportional solenoid valve.

A kind of underwater dry arc welding welding method using the underwater dry arc welding welding device with nozzle as mentioned above is characterized in that its welding process comprises the following steps:

Use the current sensor to detect the current signal of the welding circuit, and output the detection signal to the control unit;

After the welding process starts, continuously introduce airflow to the gas nozzle of the welding torch, open the end cover of the gun barrel, and drain the water in the welding area around the gas nozzle;

Start the welding torch propulsion mechanism to push the electrode to the barrel port. When the electrode touches the workpiece, a current is generated in the welding circuit, and the current sensor outputs a corresponding detection signal to the control unit. The control unit controls the propulsion mechanism to pull the electrode back for a certain distance to ignite arc, and then control the propulsion mechanism to push the electrode forward for welding;

The temperature sensor is used to judge the positional relationship between the automatic clamping device or the propulsion mechanism and the arc in the welding area, and output a detection signal to the control unit. When the electrode is sent to the preset stop point or the temperature exceeds the preset temperature, the control unit automatically controls the extinguishing arc.

Further technical solutions include:

Measure the proportional relationship between the welding current and the welding rod feeding speed before welding. During the welding process, the control unit adjusts the pushing speed of the propulsion mechanism according to the detection signal of the current sensor, so that the feeding speed of the welding rod matches the melting speed .

The propulsion mechanism preferably adopts a double-acting cylinder or a hydraulic cylinder, and the chuck of the automatic clamping mechanism is installed on the piston rod extending out of the cylinder body, and the cylinder or hydraulic cylinder is used to push the piston rod to the gun barrel port side. The air inlet or liquid inlet of the chamber is opened and closed by a proportional solenoid valve, and the control unit controls the opening of the proportional solenoid valve according to the output signal of the current sensor, thereby adjusting the propulsion speed of the air cylinder or hydraulic cylinder.

Further, the process of described welding method assembling welding rod is:

Introduce airflow to the gas nozzle of the welding torch, use the airflow to push open and close the end cover of the gun barrel, drain the water around the nozzle, align the nozzle of the gun barrel with the port of the welding rod insulator, use the gun barrel to push the end cover of the insulator open, and put the gun The tube is inserted into the barrel cavity of the insulator, and the automatic clamping mechanism in the gun barrel clamps the welding rod after touching the welding rod, and the gun barrel is withdrawn from the insulator, so that the welding rod is assembled in the gun barrel.

Beneficial effect:

The welding device and welding method of the present invention are novel in design, convenient in operation, safe in use and easy to realize. The protective gas is sprayed from the gas nozzle of the welding torch to quickly form a dry environment in a local space, and it can ensure that the welding rods during underwater welding The invention has low implementation cost, is easy to operate, is suitable for popularization and use, and can realize a high-quality, high-efficiency, time-saving and labor-saving underwater arc welding welding process.

Description of drawings

Fig. 1 is the structural representation of welding torch;

Fig. 2 is the structural representation of warmer;

Fig. 3 is a working principle diagram of the control unit;

Figure 4 is a block diagram of the principle of automatic arc extinguishing of electrodes;

Fig. 5 is the schematic flow sheet of welding process;

In the figure: 1-welding handle, 2-cable, 3-welding button, 4-pause button, 5-feed button, 6-air supply button, 7-air inlet, 8-air inlet, 9-piston rod, 10-gas nozzle, 11-piston rod guide rail, 12-waterproof insulating jacket, 13-end cover, 14-elastic mechanism, 15-electromagnetic chuck, 16-temperature sensor, 17-welding rod, 18-air inlet.

Among Fig. 2: 19-waterproof thermal insulation jacket, 20-elastic mechanism, 21-sealing ring, 22-end cover, 23-welding rod, 24-fixed support.

detailed description

In order to clarify the technical scheme and technical purpose of the present invention, the present invention will be further introduced below in conjunction with the accompanying drawings and specific embodiments.

The utility model relates to an underwater dry arc welding welding device with a nozzle, which includes a welding torch, a gas supply device, a welding rod warmer, a circuit control system and the like.

The circuit control system is composed of a PLC-based control unit, solenoid valves (including proportional solenoid valves), temperature sensors, current sensors, displacement sensors and other parts respectively connected to the control unit.

As shown in Figure 1, the welding torch includes a gun barrel and a welding handle 1 provided with control buttons such as a welding button 3, a pause button 4, a strip feeding button 5, a reply button, an air supply button 6, and a clip button. There is a waterproof insulating jacket12.

The gun barrel is provided with an air inlet 18, and the gun barrel is provided with an automatic clamping mechanism for assembling the welding rod 17. In this embodiment, an electromagnetic clamping mechanism is used. In the axial direction of the gun barrel, the lumen on one side of the gun barrel is connected to the gas outlet end of the gas supply device through the air inlet 18, and the port of the side lumen is provided with a gas nozzle 10 and an end cap for closing the port 13. The end cover 13 is mounted on the gun barrel through a hinge, can be opened and turned over, and is automatically controlled and closed by an elastic mechanism 14 (such as a torsion spring); The propulsion mechanism, the electromagnetic clamping mechanism is installed on the end of the piston rod 9 of the double-acting miniature cylinder stretching out from the cylinder body, under the control of the control unit, it is driven by the cylinder to move in the axial direction of the gun barrel to complete the welding rod 17 Push and pull action.

Described temperature sensor is installed on the collet of electromagnetic clamping mechanism, and the middle part of gun barrel is provided with the guide rail 11 that constrains double-acting miniature cylinder piston rod 9 movement direction, and described guide rail 11 is electrically connected with welding power source by cable 2, as electrode The welding rod 17 is electrically connected with the guide rail 11 through an electromagnetic clamping mechanism to form a welding circuit.

The welding circuit is provided with a current sensor that detects the welding current, and the double-acting miniature cylinder is used to control the opening and closing of the air inlet 7 of the cavity that the piston rod 9 is pushed to one side of the gun barrel port through a proportional electromagnetic valve 1A4, and the other The air inlet 8 of the side cavity is controlled by a solenoid valve 1A2.

As shown in Figure 2, the electrode warmer is provided with a waterproof insulation jacket 19 and a cylinder cavity for storing electrodes 23, and the cylinder cavity port is provided with a cylinder cavity end cover 22 with a closed port, and the cylinder cavity end cover 22 is installed by a hinge On the welding rod warmer, it can be turned inside and closed automatically by the elastic mechanism 20 (such as a torsion spring). The welding rod 23 is positioned and installed on the central axis of the cylinder cavity through the fixed bracket 24, which is convenient for the electromagnetic clamping mechanism in the welding torch. Alignment, and only one welding rod is stored in one insulator cavity. The welding rod warmer is equipped with a sealing ring 21 on the outside of the end cover, and the inner diameter of the sealing ring 21 fits with the outer diameter of the welding torch barrel section that can be inserted into the cylinder cavity.

When welding, press the welding button 3 on the welding handle 1, the coil of the proportional solenoid valve 1A4 is energized, the position of the valve core moves, compressed air enters from the air inlet 7 of the double-acting miniature cylinder, and the cylinder piston rod 9 is guided along the guide rail 11 Direction moves downward, and welding rod 17 is sent down. After the electrode 17 comes into contact with the workpiece, the output signal of the control unit immediately closes the proportional solenoid valve 1A4, opens the solenoid valve 1A2 of the air inlet 8 that controls the upward movement of the piston rod, and ignites the arc after the electrode 17 moves back for 0.5s. After 0.5s, the control unit outputs a signal to close the air inlet 8, and open the proportional solenoid valve 1A4 to continue sending the electrode 17 downward for welding. The chuck upper end of electromagnetic tightening mechanism is equipped with temperature sensor, and when welding rod 17 was about to finish welding, temperature sensor is owing to this moment from the arc position closer, and temperature rises sharply. The control unit outputs the signal, the input terminal of the solid-state relay SSR loses the signal, the output terminal is disconnected, and the welding arc is extinguished to prevent the piston rod 9 and the collet from being burned out. During welding, the downward feeding speed of the electrode 17 is the downward movement speed of the piston 9, and the downward movement speed of the piston rod 9 is adjusted by the opening of the proportional solenoid valve 1A4. Before the arc is struck, the proportional solenoid valve 1A4 The opening is always kept at the maximum; after the arc is struck, the welding current is transmitted to the AD module EM235 of the PLC control unit through the current sensor inside the welding power supply, and the digital quantity module of the PLC outputs a PWM signal to a proportional solenoid valve 1A4 coil after being amplified. 4~20mA analog signal proportional to welding current. The opening degree of the proportional solenoid valve 1A4 is proportional to the analog quantity. The proportional relationship between the welding current and the down-moving speed of the piston rod is determined through the process test in advance to ensure that the feeding speed of the electrode is equal to the melting speed.

This embodiment relies on the up and down movement of the double-acting miniature cylinder piston rod 9 to realize the automatic feeding and withdrawal functions of the welding rod 1. This is mainly to avoid manual feeding of the welding rod in water and reduce the difficulty of operation. The size design of the gas nozzle 10 should be moderate in size. If it is too large, it will be inconvenient to operate the welding torch, and if it is too small, the protection range will be too small, and the weld seam will be easily immersed in water after the arc. The clamping of the welding rod is realized by the electromagnetic clamping mechanism, and the waterproofing in the welding process is mainly guaranteed by the high-speed shielding gas ejected from the gas nozzle 10 .

When adopting the underwater dry arc welding welding device with nozzle of the present invention to carry out welding, it can be implemented according to the following steps:

Step 1: Before launching into the water, turn on the welding machine and PLC control cabinet on the shore and set the welding current.

Step 2: After launching into the water, send shielding gas and install the first welding rod.

Press the air supply button 6 on the welding handle 1, the PLC control unit outputs a signal to control the coil of the electromagnetic valve 1A1 of the shielding gas to be energized, and the electromagnetic valve 1A1 is opened. The output gas of the gas supply equipment on shore is sent in from the nozzle air inlet 18, pushes away the end cover 13 below the nozzle, and discharges the water body around the welding area. At this moment, both the piston rod 9 and the electromagnetic chuck are at the initial position at the top dead center, and the gun barrel of the welding torch is inserted into the barrel cavity of the insulator. head contact. Now click the clip button on the welding handle, the coil of the electromagnetic chuck is energized, and the welding rod 23 is clamped. After the welding rod 23 ends are clamped, the gun barrel is withdrawn from the barrel chamber of the waterproof warmer. The end cover 22 upper end of electrode warmer is equipped with rubber sealing ring, under the effect of elastic mechanism 20, end cover 11 can be closed very soon after electrode warmer separates with welding torch, unlikely immersion.

Step 3: After adjusting the position of the welding torch, press the welding button 3. The PLC control unit output signal controls the coil of the proportional solenoid valve 1A4 to be energized, the piston rod 9 of the double-acting miniature cylinder moves down along the guide rail 11, and the welding rod 17 is sent downward rapidly. After the welding rod 17 touches the workpiece, the PLC control unit detects the welding current and outputs a control signal to de-energize the coil of the proportional solenoid valve 1A4, power the solenoid valve 1A2, move the piston rod upward for 0.5s, withdraw the electrode, and ignite the arc. After 0.5s, the coil of the proportional solenoid valve 1A4 is energized again, the solenoid valve 1A2 is de-energized, and the electrode continues to be fed for welding. The downward movement speed of the piston rod 9 is matched with the welding current through the underwater welding process test.

Step 4: When the electrode is nearly finished welding, the temperature sensor on the upper part of the electromagnetic chuck senses the temperature, and the PLC control unit outputs a signal to automatically extinguish the welding arc to prevent the piston rod 9 and the electromagnetic chuck from being burned out. The operator should release the welding button 3 immediately after finding that the arc is extinguished. Now, the piston rod 9 of the double-acting miniature cylinder should be at the bottom dead center connected with the electromagnetic chuck. At this time, the return button on the welding handle is pressed, the coil of the solenoid valve 1A2 is energized, the piston rod 9 moves up, and when it reaches the top dead center, the displacement sensor is triggered, the coil of the solenoid valve 1A2 loses power, and the piston rod 9 stops at top dead center position. At this time, press the clip button on the welding handle again to reset the clip button. The coil KA3 of the electromagnetic chuck loses power, and the unburned stub of the welding rod automatically falls off from the barrel port.

Step 4: Repeat the action of installing the welding rod in step 2. After the welding rod is clamped, repeat the action of step 3 for welding. If it is necessary to suspend the processing of the workpiece during the welding process, press the pause button 4 on the welding handle. At this time, the PLC control unit outputs a signal to control the proportional solenoid valve 1A4 coil and the solenoid valve 1A2 coil. Sent, the arc goes out. Piston rod 9 stays in situ. If you want to weld again, press the pause button 4 again, the button is reset, the coil of the proportional solenoid valve 1A4 is energized again, the electrode is sent down, and the action of pulling the electrode back to strike the arc is as described in step 3.

Step 5: At the end of the welding process, first press the clip button on the welding handle to remove the stump of the welding rod. Then click the air supply button 6 to reset the air supply button 6. At this time, the solenoid valve core of the shielding gas is reset, and the shielding gas is turned off. The end cap 13 at the nozzle place is closed under the action of the elastic mechanism 14 to prevent water immersion in the gun barrel port (nozzle). Finally, click the return button on the welding handle 1, and the piston rod 9 returns to the top dead center position to prepare for the next welding.

The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the industry should understand that the present invention is not limited by the above-mentioned embodiments. What are described in the above-mentioned embodiments and the description only illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will also have For various changes and improvements, the protection scope of the present invention is defined by the appended claims, description and their equivalents.

Claims (5)

1. The underwater dry arc welding welding device with a nozzle is characterized in that it includes a welding torch, a gas supply device, a control unit, and an electrode warmer: The welding torch includes a gun barrel and a welding handle. The gun barrel is provided with an air inlet, and the gun barrel is provided with an automatic clamping mechanism for assembling welding rods. In the axial direction, one side of the gun barrel passes through the air inlet and the The gas outlet end of the gas supply equipment is connected, and the port of the side lumen is provided with a gas nozzle and an end cap that closes the port. A propulsion mechanism is provided in the side lumen, and the automatic clamping mechanism is installed on the propulsion mechanism, and is driven by the propulsion mechanism to move in the axial direction of the gun barrel. The gas supply equipment, the automatic clamping mechanism, and the propulsion mechanism are respectively connected to the control unit; The welding rod warmer is provided with a cylinder cavity that can be placed on the gun barrel of the welding torch, and a cylinder cavity end cover with a closed port is provided at the cylinder cavity port. , the welding rod is positioned and installed at the central axis of the barrel cavity, and a welding rod is stored in the barrel cavity of an insulator, and a sealing ring is installed on the outside of the end cover of the welding rod warmer, and the inner diameter of the sealing ring is compatible with the welding torch that can be inserted into the barrel cavity The outer diameter of the barrel section fits; The propulsion mechanism is a double-acting cylinder or a hydraulic cylinder, and the chuck of the automatic clamping mechanism is installed on the piston rod extending out of the cylinder body; The welding circuit is provided with a current sensor to detect the welding current, and the air cylinder or hydraulic cylinder is used to push the piston rod to the side of the gun barrel port. The current sensor and the proportional solenoid valve are respectively connected with the control unit, and the control unit controls the opening of the proportional solenoid valve according to the output signal of the current sensor. 2. The underwater dry arc welding device with a nozzle according to claim 1, wherein a temperature sensor is installed on the propulsion mechanism or the automatic clamping mechanism, and the temperature sensor is connected to the control unit . 3. the underwater dry arc welding welding device with nozzle according to claim 1, it is characterized in that, the middle part of welding torch gun barrel is provided with the guide rail of constraint propulsion mechanism motion direction, guide rail is electrically connected with welding power source by cable, as An integral part of the electrode, the electrode is electrically connected to the guide rail through an automatic clamping mechanism. 4. a kind of underwater dry arc welding welding method with the underwater dry arc welding welding device of the band nozzle claimed in claim 1, is characterized in that, its welding process comprises the following steps: Use the current sensor to detect the current signal of the welding circuit, and output the detection signal to the control unit; After the welding process starts, continuously introduce airflow to the gas nozzle of the welding torch, open the end cover of the gun barrel, and drain the water in the welding area around the gas nozzle; Start the welding torch propulsion mechanism to push the electrode to the barrel port. When the electrode touches the workpiece, a current is generated in the welding circuit, and the current sensor outputs a corresponding detection signal to the control unit. The control unit controls the propulsion mechanism to pull the electrode back for a certain distance to ignite arc, and then control the propulsion mechanism to push the electrode forward for welding; The temperature sensor is used to judge the positional relationship between the automatic clamping device or the propulsion mechanism and the arc in the welding area, and output a detection signal to the control unit. When the electrode is sent to the preset stop point or the temperature exceeds the preset temperature, the control unit automatically controls the extinguishing arc; The welding method also includes: Measure the proportional relationship between the welding current and the welding rod feeding speed before welding. During the welding process, the control unit adjusts the pushing speed of the propulsion mechanism according to the detection signal of the current sensor, so that the feeding speed of the welding rod matches the melting speed ; The propulsion mechanism is a double-acting cylinder or a hydraulic cylinder, and the chuck of the automatic clamping mechanism is installed on the piston rod extending out of the cylinder body, and the cylinder or hydraulic cylinder is used to push the piston rod to one side of the barrel port The air inlet or liquid inlet of the chamber is opened and closed by a proportional solenoid valve, and the control unit controls the opening of the proportional solenoid valve according to the output signal of the current sensor, thereby adjusting the propulsion speed of the air cylinder or hydraulic cylinder. 5. underwater dry arc welding welding method according to claim 4, is characterized in that, the process of its assembling electrode is: Introduce airflow to the gas nozzle of the welding torch, use the airflow to push open and close the end cover of the gun barrel, drain the water around the nozzle, align the nozzle of the gun barrel with the port of the welding rod insulator, use the gun barrel to push the end cover of the insulator open, and put the gun The tube is inserted into the barrel cavity of the insulator, and the automatic clamping mechanism in the gun barrel clamps the welding rod after touching the welding rod, and the gun barrel is withdrawn from the insulator, so that the welding rod is assembled in the gun barrel.