Automatic ball valve welding method and system based on PLC and storage medium

Abstract

The invention relates to the technical field of welding, and discloses a PLC-based ball valve automatic welding method and system and a storage medium, the method is based on a ball valve placed on the center of a rotary table, and specification parameters of the ball valve are obtained; the reducing height direction of the ball valve is used as a height position, and the position of the ball valve on a rotating plane is used as an angle position; the center position of the side plane of the ball valve is defined as a first height and a first angle; the welding gun is driven to move to a first height from a set initial position; driving the turntable to rotate to a first angle; a starting point position for welding is positioned on the side face of the ball valve, the height position of the starting point position is a first height, and the angle position of the starting point position is a second angle; wherein the absolute value of the difference between the first angle and the second angle is greater than a preset reference angle value; the welding gun is driven to arc at the starting point position, the rotating disc rotates, and the welding gun conducts surfacing on the surface of the ball valve; and the welding gun changes the lane at the second angle. According to the scheme, automatic welding of the ball valve is achieved, and the production efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of welding technology, and in particular to a PLC-based ball valve automatic welding method, system and storage medium. Background Art

[0002] A ball valve is a valve that rotates around its axis. In order to improve wear resistance, corrosion resistance or hardness, it is necessary to weld wear-resistant materials, corrosion-resistant materials or high-hardness materials on the surface of the ball valve.

[0003] In the field of ball valve outer surface cladding, the existing process usually requires arc starting at the center height of the ball valve. When the side close to the machine is selected as the arc starting point, the welding forward rotation is combined with the wire feeding operation mode. During the welding process, when the welding gun runs to the edge of the side channel, it is necessary to manually stop the welding, and then manually turn the turntable to rotate the ball valve, move the workpiece to the edge of the other side of the side channel, and then manually adjust the X-axis displacement to make the tungsten needle of the welding gun close to the surface of the workpiece, restart the arc and continue cladding, and complete the outer surface cladding by repeating the above operations many times. This process relies on manual control of the position conversion of the welding arc starting point and the arc stopping point, and requires frequent equipment parameter adjustment and mechanical position calibration, which requires extremely high proficiency and experience of the operator.

[0004] However, the existing methods have technical defects: manual intervention leads to discrete distribution of arc starting and arc stopping positions. In multi-layer cladding, the welding process needs to be interrupted many times, and manual positioning errors will accumulate layer by layer, which can easily cause welding defects such as porosity, slag inclusion, and poor fusion. It is easy to form an uneven fusion transition zone on the surface of the cladding layer, which seriously affects the bonding strength and corrosion and wear resistance of the cladding layer on the outer surface of the ball valve. Summary of the invention

[0005] In order to realize automatic welding of the surface of a ball valve and improve production efficiency, the present application provides a PLC-based ball valve automatic welding method, system and storage medium.

[0006] In the first aspect, the present application provides a PLC-based ball valve automatic welding method, which adopts the following technical solution: A PLC-based ball valve automatic welding method comprises the following steps: Based on the ball valve placed on the center of the turntable, obtain the specification parameters of the ball valve; The variable diameter height direction of the ball valve is taken as the height position, and the position of the ball valve on the rotation plane is taken as the angle position; the center position of the side plane of the ball valve is defined as the first height and the first angle; Driving the welding gun to move from a set initial position to the first height; driving the turntable to rotate to the first angle; The starting point of the welding is positioned on the side of the ball valve, the height position of the starting point is a first height, and the angle position of the starting point is a second angle; wherein the absolute value of the difference between the first angle and the second angle is greater than a preset reference angle value; The welding gun is driven to start an arc at the starting position, the turntable is driven to rotate, and the welding gun performs surfacing welding on the surface of the ball valve; and the welding gun is driven to change lanes at the second angle.

[0007] By adopting the above technical solution, the automation of ball valve surface welding is realized through a series of PLC-based automated operations, such as obtaining ball valve specification parameters, driving the precise movement of welding guns and turntables, etc. Compared with the existing process that relies on frequent manual control of the position conversion of welding arc starting point and arc stopping point, frequent adjustment of equipment parameters and calibration of mechanical position, the manual operation links are reduced, and the operator does not need to repeatedly perform complex manual operations, saving a lot of time, thereby significantly improving production efficiency. By accurately calculating the positions of arc starting and arc stopping points, they are evenly distributed and flat at the edge of the side channel. By defining the height position and angle position of the ball valve, and based on this, accurately positioning the welding starting position and the change position, the error accumulation caused by inaccurate manual positioning can be effectively avoided, thereby reducing the occurrence of welding defects such as pores, slag inclusions, and poor fusion, and improving the bonding strength and corrosion resistance and wear resistance of the cladding layer on the outer surface of the ball valve.

[0008] Optionally, the step of positioning the starting point of welding on the side of the ball valve further includes the following sub-steps: The ball valve is defined at a first optional position on the curved surface on one side of the side plane, and at a second optional position on the curved surface on the other side of the side plane; Calculating the distance between the first optional position and the welding machine position to which the welding gun belongs as a first distance, and calculating the distance between the second optional position and the welding machine position to which the welding gun belongs as a second distance; wherein the first distance is smaller than the second distance; If the first optional position is selected as the starting position, the starting position is close to the welding machine and controls the rotation direction of the turntable to be the first direction; if the second optional position is selected as the starting position, the starting position is far away from the welding machine and controls the rotation direction of the turntable to be the second direction.

[0009] By adopting the above technical solution, by calculating the distance between the first optional position and the second optional position and the welding machine, and selecting the starting position and the corresponding turntable rotation direction according to the distance, the welding process can be made more in line with the process requirements, thereby optimizing the welding forming effect. When the starting position is close to the welding machine, the turntable forward welding is selected. This combination method can make the feeding and melting of the welding wire more uniform during the welding process, which is conducive to forming a beautiful and smooth weld. On the contrary, when the starting position is far away from the welding machine, the welding reversal is adopted, which can also ensure the stability of the welding process and ensure the forming quality of the weld.

[0010] Optionally, the feeding direction after the welding gun is aligned with the ball valve is taken as the X-axis, the variable diameter height direction of the ball valve is taken as the Y-axis, the rotation direction of the ball valve on the rotation plane is taken as the T-axis, and the center position of the side plane of the ball valve is defined as the zero point of the Y-axis and 90 degrees of the T-axis; A starting point is located on the side curved surface of the ball valve, the Y axis of the starting point is the zero point, and the T axis of the starting point is zero degrees.

[0011] By adopting the above technical solution and constructing a three-dimensional coordinate system, the calculation of the welding gun position, the ball valve rotation angle and different height positions during the welding process becomes extremely intuitive and simple. The PLC system can quickly and accurately calculate the parameters corresponding to each action based on this clear coordinate system, greatly simplifying the control logic. The precise coordinate definition provides an accurate positioning reference for the welding process. In the multi-layer cladding process, the starting and ending positions of each layer of welding can be accurately set according to this coordinate system. Since the position of each welding can be accurately mapped to the coordinate system, the cumulative error caused by unclear position definition is avoided. Taking the side curved surface welding as an example, the clear starting position (Y-axis zero point, T-axis zero degree) ensures the consistency of the arc starting position each time, so that the starting point of each layer of weld can be accurately overlapped, thereby effectively reducing the generation of welding defects, improving the bonding strength and surface quality of the cladding layer, and ensuring the high precision and stability of the welding process.

[0012] Optionally, the step of driving the welding gun to change lanes at the second angle further includes the following sub-steps: Starting the arc from the starting point to start welding, and driving the turntable to rotate; Stopping the arc when the welding gun contacts the first side edge of the side plane; Controlling the welding gun to move backward and driving the turntable to rotate; When the welding gun passes through the second side edge of the side plane, controlling the welding gun to approach the ball valve and start an arc; The turntable is driven to continue rotating, and when the welding gun passes the second angle, the track is changed along the variable diameter height direction.

[0013] By adopting the above technical solution, the arc is accurately stopped when the welding gun contacts the first side of the side plane, the boundary of the single welding area is controlled, and edge welding defects are avoided. Then, the welding gun is retreated, the turntable is rotated, and the arc is started again to ensure a smooth transition of welding on both sides of the side plane, reduce multi-layer cladding defects, and improve welding quality; the lane changing process is automatically executed according to the preset logic, reducing manual intervention, improving the degree of welding automation and production efficiency; when the welding gun passes the second angle, the lane is changed in the direction of the variable diameter height, optimizing the welding path, reducing invalid actions, improving welding efficiency and reducing costs; at the same time, the design is highly flexible and can automatically adjust the action parameters according to different ball valve specifications and parameters to enhance the adaptability and versatility of the equipment.

[0014] Optionally, the step of using the welding gun to perform surfacing welding on the surface of the ball valve further includes the following sub-steps: Determining whether the welding gun passes through the side plane according to the Y-axis height of the welding gun, and if not, driving the turntable to rotate to maintain the welding state of the welding gun until the Y-axis height of the welding gun reaches a preset set height; When the welding gun passes the second angle, it changes lanes along the variable diameter height direction.

[0015] By adopting the above technical solution and through fine control of the welding gun during the cladding process, significant advantages in many aspects are demonstrated. By judging whether the welding gun passes through the side plane based on the Y-axis height of the welding gun, it can ensure that a stable welding state is maintained when welding in non-side plane areas. As long as the welding gun has not reached the preset set height, the turntable continues to rotate, and the welding gun welds stably, ensuring the continuity of the welding process, avoiding unnecessary arcing and arcing, effectively reducing the occurrence of welding defects, and improving welding quality. At the same time, it is clear that when the welding gun passes the second angle, it changes lanes along the variable diameter height direction, making the welding path planning more scientific and reasonable. On the basis of ensuring full coverage of the welding area, invalid welding actions are avoided, greatly improving welding efficiency.

[0016] Optionally, the lane changing step further includes the following sub-steps: The specification parameters include the side plane diameter, the main ball diameter and the lane change arc length; Calculating the ratio of the side plane diameter to the main ball diameter to obtain a first gain value; Calculating a ratio of the lane changing arc length to a preset reference arc length to obtain a second gain value; The speed of changing the welding gun is positively correlatedly adjusted according to the first gain value; the larger the first gain value is, the faster the speed of changing the welding gun is; the smaller the first gain value is, the slower the speed of changing the welding gun is; The rotation speed of the turntable during lane changing is positively adjusted according to the second gain value; the larger the second gain value, the larger the rotation speed of the turntable; the smaller the second gain value, the smaller the rotation speed of the turntable.

[0017] By adopting the above technical solution, the first gain value is obtained by calculating the ratio of the side plane diameter and the main ball diameter, and the welding gun change speed is positively adjusted accordingly, which can ensure that the welding gun change process is adapted to the ball size when welding ball valves of different specifications. When the first gain value is large, that is, the side plane diameter is relatively large relative to the main ball diameter, the welding gun change speed is accelerated, so that the welding process can be more in line with the actual structure of the ball valve, avoiding insufficient welding or excessive welding due to improper change speed, thereby improving the welding quality and consistency of the weld. The turntable speed is positively adjusted based on the ratio of the change arc length and the preset reference arc length (the second gain value), which effectively improves the welding efficiency. When the second gain value is large, it means that the change arc length is long, and the turntable speed is increased, so that the ball valve can be rotated to the appropriate position faster in unit time, reducing the waiting time during the welding process, and the welding gun can quickly enter the next welding area to achieve efficient welding.

[0018] Optionally, the method further comprises the following steps: Obtain the latest quality data of multiple processed historical products; Calculating an average value of a plurality of the quality data; Calculating a mass ratio of the average value to a preset reference mass value; The rotation speed of the turntable is adjusted according to the positive correlation of the mass ratio when the welding gun passes through the side plane; the larger the mass ratio, the greater the rotation speed of the turntable; the smaller the mass ratio, the smaller the rotation speed of the turntable.

[0019] By adopting the above technical solution, the quality ratio between the average value and the preset reference quality value is calculated based on the quality data of multiple latest processed historical products, and the rotation speed of the turntable is adjusted accordingly when the welding gun passes through the side plane. The larger the quality ratio, that is, the better the quality of the historical product, the higher the rotation speed of the turntable. This means that in the welding process, the production mode of high-quality products has been effectively learned from and strengthened. Increasing the rotation speed of the turntable accordingly with the improvement of the quality of historical products can speed up the production rhythm while ensuring the welding quality. In the case of side arc welding, the appropriate speed increase can reduce the welding time of a single product, so that the equipment can complete the processing of more products per unit time.

[0020] Optionally, the method further comprises the following steps: Calculating a plurality of change trend values ​​of the quality data; The rotation speed of the turntable is adjusted according to the positive correlation of the change trend value when the welding gun approaches the side plane; the larger the change trend value, the greater the rotation speed of the turntable; the smaller the change trend value, the smaller the rotation speed of the turntable.

[0021] By adopting the above technical solution, when the historical product quality shows an upward trend, that is, the larger the change trend value, the turntable speed is increased. This adjustment can better adapt to the rhythm requirements of high-quality product production. For example, in side arc stop welding, a faster speed can make the welding heat input more reasonable and the weld cooling speed more ideal, thereby promoting a more perfect fusion of welding materials and parent materials, effectively improving the quality and aesthetics of the weld. On the contrary, if the quality shows a downward trend, reducing the speed can make the welding process more refined, reduce defects caused by excessive speed, ensure stable welding quality, meet the actual situation of product quality changes, and achieve precise control. Dynamically adjusting the speed according to the trend of quality data changes can flexibly control production efficiency on the basis of ensuring welding quality.

[0022] In the second aspect, the present application provides a PLC-based ball valve automatic welding system, which adopts the following technical solution: A PLC-based ball valve automatic welding system comprises a processor, wherein the processor executes the steps of any one of the above-mentioned PLC-based ball valve automatic welding methods.

[0023] In a third aspect, the present application provides a storage medium, which adopts the following technical solution: A storage medium stores a program, and when the program is executed by a processor, the steps of any one of the above-mentioned PLC-based ball valve automatic welding methods are implemented.

[0024] In summary, the present application includes at least one of the following beneficial technical effects: With the help of PLC to realize automated operation, we can get rid of the dependence on frequent manual control of welding arc starting, arc stopping point position conversion, equipment parameter adjustment, and mechanical position calibration, thus saving a lot of time.

[0025] Accurately calculate the arc starting and stopping points to make them evenly distributed and flat on the edge of the side channel, avoid the accumulation of manual positioning errors, reduce welding defects such as pores, slag inclusions, and poor fusion, and enhance the bonding strength and corrosion resistance and wear resistance of the cladding layer on the outer surface of the ball valve. When cladding multiple layers, each layer is closely connected and the quality of the cladding layer is reliable.

[0026] A three-dimensional coordinate system is constructed with the welding gun feed direction as the X-axis, the ball valve variable diameter height direction as the Y-axis, and the rotation direction of the rotating plane as the T-axis. The center position of the side plane is defined as the key coordinate point. The PLC system is simplified to calculate the welding gun position, ball valve rotation angle and different height positions, providing an accurate positioning reference for welding, reducing welding defects, and ensuring high-precision and stable welding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a step diagram of a ball valve automatic welding method based on PLC.

[0028] Figure 2 It is a coordinate diagram for ball valve welding. DETAILED DESCRIPTION

[0029] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings.

[0030] In the description of this specification, the description with reference to the terms "certain embodiments", "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0031] The present application embodiment discloses a PLC-based ball valve automatic welding method, referring to Figure 1 and Figure 2 , including the following steps: The ball valve is precisely placed at the center of the turntable, and the built-in sensors and data acquisition modules are used to quickly and accurately obtain the various specifications of the ball valve. These parameters cover the ball valve's diameter, side plane dimensions, variable diameter height, and other key data closely related to the welding process. For example, the main ball diameter of different models of ball valves varies from tens of millimeters to several meters, and the ratio of the side plane diameter to the main ball diameter is also different.

[0032] Construct a position coordinate system, set the variable height direction of the ball valve as the height position, and use the Y axis to represent it. Define the position of the ball valve on the rotating plane as the angle position, which is recorded by the T axis. Define the center position of the side plane of the ball valve as the first height and the first angle, that is, the zero point of the Y axis and the ninety degrees of the T axis. Through a clear coordinate definition method, an accurate positioning reference is provided for subsequent welding operations. For example, in the process of multi-layer cladding, the starting and ending positions of each layer of welding can be accurately set according to this coordinate system, avoiding the accumulation of welding errors caused by vague position definition.

[0033] After obtaining the parameters and establishing the coordinate system, the control system issues a command to drive the welding gun to move smoothly and accurately from the preset initial position to the first height along the predetermined motion trajectory. During this process, the welding gun's movement speed, acceleration and other parameters are accurately calculated and controlled to ensure that it can reach the specified position quickly and accurately. At the same time, the turntable is also driven by the motor to accurately rotate to the first angle according to the preset angle value.

[0034] On the side of the ball valve, the system locates the starting point of welding according to a preset algorithm. The height position of the starting point is maintained at the first height, and the angle position is set to the second angle. The absolute value of the difference between the first angle and the second angle is greater than the preset reference angle value. By reasonably setting this angle difference, the welding gun can better avoid the side plane of the ball valve during welding.

[0035] When all the preliminary preparations are completed, the system issues a command to drive the welding gun to start the arc at the starting position. At this time, the turntable starts to rotate at a uniform speed, driving the ball valve to rotate synchronously, and the welding gun continues to perform surfacing operations on the surface of the ball valve. During the entire welding process, the system monitors key parameters such as the position of the welding gun, welding current, voltage, and the speed of the turntable in real time, and dynamically adjusts according to the preset control strategy to ensure the stability and consistency of the welding process. When the welding gun runs to the second angle, the system issues a command again to drive the welding gun to change lanes according to the pre-planned path. This lane changing process has also been carefully designed to ensure that the welding gun can smoothly switch from the current welding path to the next path, and continue to perform efficient and high-quality surfacing on other areas of the ball valve.

[0036] Through automated operation, manual operation links are greatly reduced. Operators only need to complete simple tasks such as placing the ball valve and inputting parameters in the early stage, and the subsequent welding process is automatically completed by the system. This not only saves a lot of time and significantly improves production efficiency, but also accurately calculates the positions of the arc starting and arc stopping points so that they are evenly distributed and flat at the edge of the side channel. For example, in the multi-layer cladding process, the system can accurately control the positions of the arc starting and arc stopping points of each layer of welding according to the preset algorithm, ensuring that the connection between the welds of each layer is tight and uniform, effectively avoiding the accumulation of errors caused by inaccurate manual positioning. This precise positioning method can effectively reduce the occurrence of welding defects such as pores, slag inclusions, and poor fusion, thereby significantly improving the bonding strength and corrosion resistance and wear resistance of the cladding layer on the outer surface of the ball valve.

[0037] In order to ensure that the welding process achieves better results, the method also includes the following steps: Specific positions are defined on the curved surfaces on both sides of the side plane of the ball valve. The first optional position is precisely delineated on the curved surface on one side of the side plane, and at the same time, the second optional position is clearly defined on the curved surface on the other side of the side plane. The determination of these two positions comprehensively considers many factors such as the structural characteristics of the ball valve, the welding process requirements, and the layout of the welding equipment. In particular, different surfacing treatment methods are selected according to the selection of the starting point position.

[0038] The distance between the first optional position and the welding machine position to which the welding gun belongs is calculated, which is defined as the first distance; similarly, the distance between the second optional position and the welding machine position is calculated, which is the second distance. In the actual measurement process, a high-precision laser distance sensor or a measurement system based on machine vision is used to ensure the accuracy of the distance measurement. Moreover, the selection of the two optional positions makes the first distance smaller than the second distance.

[0039] The starting position is selected and the direction of rotation of the turntable is controlled according to the calculated distance result. If the first optional position is selected as the starting position after comprehensive evaluation, the starting position is relatively close to the welding machine. In order to match this position characteristic, the control system will automatically adjust and control the direction of rotation of the turntable to the first direction, which is usually set to the forward direction. When the turntable rotates forward, the feeding and melting process of the welding wire during the welding process can be made more uniform in combination with the working parameters of the welding machine. During the welding process, the stable output of current and voltage, coupled with the uniform rotation of the ball valve driven by the forward rotation of the turntable, enables the welding wire to be clad on the surface of the ball valve at an appropriate speed and angle, which is conducive to the formation of a beautiful and smooth weld. For example, when welding a thin-walled ball valve, this combination of being close to the welding machine and the turntable rotating forward can better control the welding heat input, avoid deformation of the ball valve due to heat, and ensure the quality and appearance of the weld. On the contrary, if the second optional position is selected as the starting position, the position is far away from the welding machine. In this case, the control system will set the rotation direction of the turntable to the second direction, generally the reverse direction. When the starting position is far away from the welding machine, the welding reversal method can also ensure the stability of the welding process. Due to the distance from the welding machine, the arc length and heat distribution during the welding process will be different, and the reversal of the turntable can make the ball valve pass under the welding gun at a suitable speed, ensuring a more reasonable match between the welding current, voltage and wire feeding speed. In this way, even under unfavorable conditions where the starting position is far away from the welding machine, the forming quality of the weld can be fully guaranteed. For example, when welding a large-diameter ball valve, the second optional position may be more conducive to fully covering the welding area. Through welding reversal, the welding material can be evenly clad on the surface of the ball valve to form a high-quality weld, effectively avoiding welding defects that may occur due to remote locations.

[0040] By calculating the distance between the first optional position and the second optional position and the welding machine, and cleverly selecting the starting position and the corresponding turntable rotation direction according to the distance, this method can make the welding process more in line with complex and changeable process requirements in all aspects, fundamentally optimize the welding forming effect, and greatly improve the quality and reliability of ball valve welding.

[0041] The feeding direction after the welding gun is aimed at the ball valve is taken as the X-axis. The value of the X-axis represents the vertical distance between the welding gun and the Y-axis. The height direction of the variable diameter of the ball valve is taken as the Y-axis, and the rotation direction of the ball valve on the rotating plane is taken as the T-axis to construct a three-dimensional coordinate system. The center position of the side plane of the ball valve is defined as the zero point of the Y-axis and the 90 degrees of the T-axis.

[0042] The starting point is located on the side curved surface of the ball valve. The Y axis of the starting point is zero point, and the T axis of the starting point is zero degree. This means that the starting point of welding starts from the side curved surface of the ball valve and is not close to the edge of the side plane. Since the ball valve is a spherical structure as a whole, in order to ensure the quality of welding, welding is done from bottom to top. After half of the ball valve surface is welded, the ball valve will reverse the angle and start welding again, also from bottom to top.

[0043] Use the welding gun to find the center of the side channel, set the Y-axis zero point here, and set the T-axis to 90 degrees, so that the PLC can automatically calculate the arc start, arc stop position, and the change of the ball valve diameter through the Y-axis height. The T-axis is set to 90 degrees, which is convenient for the sliding shoe to change lanes in the cladding area.

[0044] By accurately matching the position of each welding to the coordinate system, the cumulative error caused by unclear position definition is effectively avoided. The starting point of each layer of weld can accurately coincide with the preset (Y-axis zero point, T-axis zero degree) position, ensuring the high precision and stability of the welding process. This not only effectively reduces the occurrence of welding defects such as pores, slag inclusions, and lack of fusion, but also significantly improves the bonding strength of the cladding layer.

[0045] The step of driving the welding gun to change lanes at the second angle also includes the following sub-steps: When welding begins, the welding gun starts arcing at the starting point. At this moment, the current is instantly connected, the arc flashes between the welding gun and the surface of the ball valve, and the high temperature quickly melts the welding material, and the surface of the ball valve begins to be surfacing. At the same time, the turntable is driven by the motor and rotates smoothly at a preset stable speed. This allows the welding gun to weld evenly and continuously along the curved surface of the ball valve, ensuring the quality and consistency of the weld.

[0046] When the welding gun gradually moves during the welding process and contacts the first side of the side plane, the system immediately issues a command and the welding gun quickly stops the arc. Through precise sensor feedback and algorithm calculation, the system can cut off the current and extinguish the arc in time when the welding gun reaches the first side of the side plane. Precise arc stopping can accurately control the boundary of a single welding area, effectively avoiding welding defects such as undercut and burn-through caused by excessive welding at the edge of the side plane.

[0047] After the arc is stopped, the control system controls the welding gun to retreat along a specific path. The parameters such as the distance and speed of the welding gun retreat are closely related to the welding process and the structural characteristics of the ball valve. In this embodiment, the welding gun retreats to a set distance from the side plane of the ball valve, thereby avoiding the structure on the side plane of the ball valve. While the welding gun retreats, the turntable continues to rotate, driving the ball valve to continue rotating. This design allows the ball valve to continue to move to a suitable position during the retreat of the welding gun to prepare for the subsequent re-arc. For example, in some cases, the distance that the welding gun retreats may need to be adjusted according to the width of the side plane and the characteristics of the welding material to ensure that the welding parameters are maintained at the optimal state when the arc is re-started.

[0048] When the welding gun passes the second side of the side plane, the control system issues another command to control the welding gun to approach the ball valve again and start the arc quickly. At this time, the arc is ignited again and the welding operation continues. During the arc starting process again, the system accurately controls the welding gun position, current and voltage and other parameters to ensure that the arc can be started smoothly at the new position and the welding process can be smoothly connected to avoid welding defects.

[0049] The turntable continues to rotate at a preset speed, driving the ball valve to rotate continuously. When the welding gun passes the second angle during the rotation process, the system drives the welding gun to change lanes along the variable diameter height direction, that is, the Y-axis direction, according to the pre-set logic, that is, to increase the set distance upward. During the lane change process, the system will comprehensively consider various factors, such as the specification parameters of the ball valve, the thickness of the current welding layer, and the welding quality requirements, and accurately control the movement speed, direction, and adjustment of the welding parameters of the welding gun. For example, for ball valves of different specifications, the variable diameter height is different, and the moving distance and speed of the welding gun will also change accordingly when changing lanes. Through this precise control, the welding path can be optimized, unnecessary invalid actions can be reduced, and the welding efficiency can be greatly improved. In traditional welding processes, due to the lack of such precise lane change control, invalid actions such as empty travel of the welding gun and repeated welding often occur, which not only wastes time and welding materials, but also may affect the welding quality. However, this method can greatly shorten the welding time and reduce production costs while ensuring the welding quality through precise lane change operations.

[0050] The step of surfacing the surface of the ball valve with a welding gun also includes the following sub-steps: During the entire cladding process, the system closely monitors the running status of the welding gun at all times, and obtains the Y-axis height data of the welding gun in real time according to the update of the welding gun lane change data. Based on these precise data, the system can quickly and accurately determine whether the welding gun passes through the side plane of the ball valve. In the actual welding scene, when the welding gun starts to move from the initial position to the surface of the ball valve and starts welding, its Y-axis height is at a low value. As the turntable drives the ball valve to rotate continuously, the welding gun welds along the curved surface of the ball valve, and the Y-axis height gradually changes. As the height of the welding gun rises, the curved surface to be welded on the surface of the ball valve no longer has a side plane area, that is, after a circle of cladding, the lane is directly changed, and the driving turntable rotates at a stable speed. There is no need for the welding gun to retreat to stop the arc and start the arc in the middle. At the same time, the welding gun maintains the current welding state, and key parameters such as welding current, voltage and wire feeding speed remain constant. This process ensures that welding in non-side plane areas can be carried out smoothly and continuously. When the Y-axis height of the welding gun reaches the preset set height, it means that the cladding of the upper hemisphere of the ball valve is completed. In the process where arc stopping is not required, when the system detects that the welding gun has passed the second angle during rotation, it will immediately drive the welding gun to change lanes along the variable diameter height direction, that is, the Y-axis direction according to the pre-set program logic. This method can significantly shorten the welding cycle while ensuring the welding quality through precise lane changing operations, providing strong support for enterprises to improve production efficiency and reduce production costs.

[0051] The lane changing step also includes the following sub-steps: Specifications include the side plane diameter, main ball diameter and change arc length; these parameters fully reflect the structural characteristics of the ball valve and the key dimensions involved in the welding process. The side plane diameter determines the size of the side area of ​​the ball valve, the main ball diameter reflects the overall size of the ball, and the change arc length is directly related to the length of the arc covered by the change operation during the welding process. In actual ball valve production, these parameters will show a wide range of variations depending on the model, purpose and design requirements of the ball valve.

[0052] The first gain value is obtained by calculating the ratio of the side plane diameter to the main ball diameter.

[0053] The ratio of the lane changing arc length to a preset reference arc length is calculated to obtain a second gain value.

[0054] The speed of changing the welding gun lane is positively adjusted according to the first gain value; the larger the first gain value, the faster the welding gun lane is; the smaller the first gain value, the slower the welding gun lane is. As shown in the case in Table 1, when the first gain value is large, it means that the diameter of the side plane is relatively large relative to the diameter of the main ball. At this time, in order to make the welding process fit the actual structure of the ball valve closely and avoid insufficient welding or excessive welding, the system will automatically speed up the speed of changing the welding gun lane. In the welding of large ball valves, due to the large area of ​​the side plane, if the speed of changing the welding gun lane is too slow, the welding time in the side plane area will be too long, which may cause local overheating, welding deformation or reduced welding quality; and speeding up the speed of changing lanes can make the welding process more efficient and evenly cover the side plane area, ensuring the quality and consistency of the weld. On the contrary, when the first gain value is small, the system will reduce the speed of changing the welding gun lane accordingly to ensure the precision and accuracy of welding.

[0055] Table 1 Lane changing speed table corresponding to various specifications of ball valves According to the second gain value, the rotation speed of the turntable during the lane change is positively adjusted; the larger the second gain value, the larger the rotation speed of the turntable; the smaller the second gain value, the smaller the rotation speed of the turntable. As shown in the case in Table 2, when the second gain value is large, it indicates that the lane change arc length is long. In this case, increasing the rotation speed of the turntable has significant advantages. For example, in the welding of ball valves with some special structures, the lane change arc length may occupy a large proportion of the entire welding path. By increasing the speed of the turntable, the ball valve can be rotated to the appropriate position faster per unit time, greatly reducing the waiting time during the welding process. The welding gun can quickly enter the next welding area to achieve efficient welding. On the contrary, when the second gain value is small, the speed of the turntable will also be reduced accordingly to ensure that the welding process can be carried out smoothly and accurately within a shorter lane change arc length, avoiding the occurrence of welding defects due to excessive speed.

[0056] Table 2 Rotary speed table corresponding to ball valves in various situations Through this precise calculation and dynamic adjustment method, this method can achieve the optimal match between the welding gun change speed and the turntable speed during the welding process of ball valves of different specifications. It not only ensures the perfect adaptation of the welding process to the size and structure of the ball, effectively improving the welding quality, but also significantly improves the welding efficiency by optimizing the change process, providing strong technical support for the high-quality and high-efficiency production of ball valves.

[0057] The method further comprises the steps of: The system will regularly and automatically obtain the quality data of multiple recently processed historical products. These quality data come from a wide range of sources and are accurate, including but not limited to weld appearance quality inspection data, such as weld flatness, the presence or absence of defects such as pores and cracks; weld internal quality data, such as the fusion status and inclusion distribution of the weld obtained through non-destructive testing; and product performance-related quality data, such as the overall sealing performance test results and compressive strength values ​​of ball valves after welding. By collecting these data in all directions, the comprehensive quality status of the product can be accurately reflected.

[0058] After obtaining a large amount of quality data, the system immediately starts the internal data analysis program to deeply process the data. Calculate the average of multiple quality data. For example, if the weld strength data of 10 recently completed ball valve products are collected, which are 500MPa, 520MPa, 490MPa, 510MPa, 530MPa, 505MPa, 515MPa, 485MPa, 525MPa, and 508MPa, respectively, the system will accumulate these data, that is, 500+520+490+510+530+505+515+485+525+508=5088MPa, and then divide it by the number of data 10 to get the average value of 508.8MPa. By calculating the average value, the interference of individual abnormal data on the overall quality assessment can be effectively eliminated, making the quality assessment results more representative and stable.

[0059] Next, the system compares the calculated average value with the preset reference mass value to obtain the mass ratio. This preset reference mass value is not determined arbitrarily, but is determined after comprehensive consideration of many factors such as long-term production practice experience, industry standards, and product design requirements. For example, for a specific model of ball valve, the design requires that the weld strength must reach 500MPa or more. Based on the high-quality product data produced in the past and the industry standards, the reference mass value is set to 500MPa. If the calculated mass average is 508.8MPa, then the mass ratio is 508.8÷500=1.0176.

[0060] Subsequently, the system makes a positive correlation adjustment to the rotation speed of the turntable when the welding gun passes through the side plane according to this quality ratio. The larger the quality ratio, the better the quality of the historical product. At this time, the system will automatically increase the rotation speed of the turntable. In the actual welding process, this operation is of great significance. For example, in the side arc welding link, when the turntable speed increases, the ball valve can rotate to the appropriate position faster per unit time, so that the welding gun can complete the welding of the side plane area more quickly. Under the premise of ensuring the welding quality, the production rhythm is greatly accelerated. Assuming that it originally takes 10 minutes to complete the side plane welding of a ball valve at a certain speed, as the quality of the historical product improves, the quality ratio increases, and the system increases the turntable speed, it only takes 8 minutes to complete the same side plane welding, and the welding time of a single product is significantly reduced. This means that the equipment can complete the processing of more products per unit time, greatly improving production efficiency. In this way, the system can continuously learn from and strengthen the production model of high-quality products, realize the virtuous cycle of the production process, and continuously improve product quality and production efficiency.

[0061] The method further comprises the steps of: During the continuous welding production, the system regularly calculates the trend values ​​of multiple quality data. In order to obtain comprehensive and accurate quality data, the system not only collects detailed records of appearance quality indicators such as weld flatness, the presence of pores, undercuts and other defects, but also covers the internal quality inspection results of welds, such as the key information such as the internal fusion state and inclusion distribution of welds obtained by non-destructive testing technology, and also includes relevant data on the overall performance of the product, such as the sealing performance test value of the ball valve after welding, the actual test results of the pressure resistance, etc. By extensively collecting these multi-dimensional quality data, a solid data foundation is provided for subsequent analysis.

[0062] On the premise of having a large amount of quality data, the system uses advanced data analysis algorithms to calculate the trend value. For example, the linear regression analysis method is used to arrange the quality data over a period of time in chronological order to construct a data sequence. Assume that in 10 consecutive production batches, the weld strength data of the product is 480MPa, 490MPa, 500MPa, 515MPa, 530MPa, 540MPa, 550MPa, 565MPa, 580MPa, and 590MPa. Through linear regression analysis, the slope of the data sequence is calculated, and the slope can be used as the trend value of the quality data. In this example, the calculated slope is a positive value, indicating that the product quality is showing an upward trend. This scientific calculation method can accurately reflect the trend of quality data changes over time or production batches.

[0063] Based on the calculated change trend value, the system will automatically adjust the rotation speed of the turntable when the welding gun approaches the side plane. When the historical product quality shows an upward trend, that is, the larger the change trend value, the system will decisively increase the rotation speed of the turntable. Taking the key link of side arc stop welding as an example, at a higher turntable speed, the ball valve can rotate to the welding position at a faster speed, which makes the heat input distribution during welding more uniform and reasonable. Since the welding material can cover a larger area more quickly per unit time, the heat can be transferred to the base material more evenly, avoiding local overheating or overcooling. At the same time, the faster rotation speed also makes the cooling speed of the weld more ideal. At the appropriate cooling rate, the welding material and the base material can fully diffuse and fuse to form a denser and more uniform weld structure, thereby effectively improving the quality and aesthetics of the weld. The weld surface is smoother and flatter, and the internal structure is tighter, which greatly enhances the strength and corrosion resistance of the weld.

[0064] On the contrary, if the quality data shows a downward trend, that is, when the trend value is small, the system will reduce the speed of the turntable in time. In this case, reducing the speed can make the welding process more refined. During the welding process, the welding gun has more time to accurately operate each welding point, and the welding current, voltage and feeding speed of the welding material can be more accurately controlled. This can effectively reduce various welding defects that may be caused by excessive speed, such as pores, lack of fusion, cracks, etc. By reducing the speed, the stability of the welding process is ensured, and the welding quality can be maintained at a relatively high level, which is in line with the actual situation of product quality changes and realizes precise control of the welding process.

[0065] By dynamically adjusting the turntable speed according to the trend of quality data changes, this method can flexibly control production efficiency while ensuring welding quality. When product quality is in an upward stage, increasing the speed can make full use of the good production situation, speed up the production rhythm, and increase the output of products per unit time; when the quality fluctuates or decreases, reducing the speed to ensure quality and avoid a large number of defective products due to the pursuit of speed, thus finding the best balance between quality and efficiency and providing strong support for enterprises to achieve efficient and stable production.

[0066] When placing the ball valve at the center of the turntable, the welding gun can be used to assist in correcting the center of the circle. To correct the center of the circle: first move the crossbeam through the equipment operation panel so that the tungsten needle of the welding gun is aligned with a point on the upper plane of the ball valve, then rotate the turntable and fine-tune the position of the ball valve so that the ball valve and the welding gun are concentric.

[0067] An embodiment of the present application further discloses a PLC-based ball valve automatic welding system, comprising a processor, wherein the processor executes the steps of any one of the above-described PLC-based ball valve automatic welding methods.

[0068] An embodiment of the present application further discloses a storage medium, in which a program is stored. When the program is executed by a processor, the steps of any one of the above-mentioned PLC-based ball valve automatic welding methods are implemented.

[0069] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A PLC-based ball valve automatic welding method, characterized in that: The steps include: Based on the ball valve placed on the center of the turntable, obtain the specification parameters of the ball valve; The variable diameter height direction of the ball valve is taken as the height position, and the position of the ball valve on the rotation plane is taken as the angle position; the center position of the side plane of the ball valve is defined as the first height and the first angle; Driving the welding gun to move from a set initial position to the first height; driving the turntable to rotate to the first angle; The starting point of the welding is positioned on the side of the ball valve, the height position of the starting point is a first height, and the angle position of the starting point is a second angle; wherein the absolute value of the difference between the first angle and the second angle is greater than a preset reference angle value; The welding gun is driven to start an arc at the starting position, the turntable is driven to rotate, and the welding gun performs surfacing welding on the surface of the ball valve; and the welding gun is driven to change lanes at the second angle.

2. The PLC-based ball valve automatic welding method according to claim 1 is characterized in that: The step of positioning the starting point of welding on the side of the ball valve further includes the following sub-steps: The ball valve is defined at a first optional position on the curved surface on one side of the side plane, and at a second optional position on the curved surface on the other side of the side plane; Calculating the distance between the first optional position and the welding machine position to which the welding gun belongs as a first distance, and calculating the distance between the second optional position and the welding machine position to which the welding gun belongs as a second distance; wherein the first distance is smaller than the second distance; If the first optional position is selected as the starting position, the starting position is close to the welding machine and controls the rotation direction of the turntable to be the first direction; if the second optional position is selected as the starting position, the starting position is far away from the welding machine and controls the rotation direction of the turntable to be the second direction.

3. The PLC-based ball valve automatic welding method according to claim 1 is characterized in that: The feeding direction after the welding gun is aligned with the ball valve is taken as the X-axis, the variable diameter height direction of the ball valve is taken as the Y-axis, the rotation direction of the ball valve on the rotation plane is taken as the T-axis, and the center position of the side plane of the ball valve is defined as the zero point of the Y-axis and 90 degrees of the T-axis; A starting point is located on the side curved surface of the ball valve, the Y axis of the starting point is the zero point, and the T axis of the starting point is zero degrees.

4. The PLC-based ball valve automatic welding method according to claim 3 is characterized in that: The step of driving the welding gun to change lanes at the second angle further includes the following sub-steps: Starting the arc from the starting point to start welding, and driving the turntable to rotate; Stopping the arc when the welding gun contacts the first side edge of the side plane; Controlling the welding gun to move backward and driving the turntable to rotate; When the welding gun passes through the second side edge of the side plane, controlling the welding gun to approach the ball valve and start an arc; The turntable is driven to continue rotating, and when the welding gun passes the second angle, the track is changed along the variable diameter height direction.

5. The PLC-based ball valve automatic welding method according to claim 4 is characterized in that: The step of surfacing the surface of the ball valve with the welding gun further includes the following sub-steps: Determining whether the welding gun passes through the side plane according to the Y-axis height of the welding gun, and if not, driving the turntable to rotate to maintain the welding state of the welding gun until the Y-axis height of the welding gun reaches a preset set height; When the welding gun passes the second angle, it changes lanes along the variable diameter height direction.

6. The PLC-based ball valve automatic welding method according to claim 1 is characterized in that: The lane changing step further includes the following sub-steps: The specification parameters include the side plane diameter, the main ball diameter and the lane change arc length; Calculating the ratio of the side plane diameter to the main ball diameter to obtain a first gain value; Calculating a ratio of the lane changing arc length to a preset reference arc length to obtain a second gain value; The speed of changing the welding gun is positively correlatedly adjusted according to the first gain value; the larger the first gain value is, the faster the speed of changing the welding gun is; the smaller the first gain value is, the slower the speed of changing the welding gun is; The rotation speed of the turntable during lane changing is positively correlatedly adjusted according to the second gain value; the larger the second gain value, the larger the rotation speed of the turntable; the smaller the second gain value, the smaller the rotation speed of the turntable.

7. The PLC-based ball valve automatic welding method according to claim 1 is characterized in that: The method further comprises the steps of: Obtain the latest quality data of multiple processed historical products; Calculating an average value of a plurality of the quality data; Calculating a mass ratio of the average value to a preset reference mass value; adjusting the rotation speed of the turntable when the welding gun passes through the side plane in a positive correlation with the mass ratio; The larger the mass ratio is, the larger the rotation speed of the turntable is; and the smaller the mass ratio is, the smaller the rotation speed of the turntable is.

8. The PLC-based ball valve automatic welding method according to claim 7 is characterized in that: The method further comprises the steps of: Calculating a plurality of change trend values ​​of the quality data; According to the change trend value, the rotation speed of the turntable is adjusted when the welding gun approaches the side plane in a positive correlation; the larger the change trend value, the greater the rotation speed of the turntable; The smaller the change trend value is, the smaller the rotation speed of the turntable is.

9. A PLC-based ball valve automatic welding system, characterized in that: It comprises a processor, in which the steps of the PLC-based ball valve automatic welding method as described in any one of claims 1 to 8 are executed.

10. A storage medium, characterized in that: The medium stores a program, and when the program is executed by the processor, the steps of the PLC-based ball valve automatic welding method described in any one of claims 1 to 8 are implemented.

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