Welding and reaming method for discharge spout of precious metal bushing plate

Abstract

The invention relates to a discharge spout welding and chambering method for a precious metal bushing, in particular to a discharge spout welding and chambering method for the precious metal bushing, which is characterized in that a welding calibration unit for acquiring optimal welding parameters and a chambering calibration unit for acquiring optimal chambering parameters are arranged; the welding rectangular coordinate robot and the chambering rectangular coordinate robot are respectively controlled to perform welding and chambering on the discharge spout by adopting optimal welding parameters and optimal chambering parameters obtained through a calibration experiment in advance, so that the welding and chambering quality of the discharge spout is ensured while the production efficiency of a product is considered.

Description

Technical Field

[0001] The invention relates to the field of precious metal product processing, and in particular to a leakage nozzle welding and hole expansion method for a precious metal leakage plate. Background Art

[0002] The precious metal drain plate is one of the key devices in glass fiber manufacturing. The overall structure, especially the design and molding quality of the drawing drain nozzle, directly affects the quality of the glass fiber and the production cost.

[0003] The welding and hole enlarging of precious metal leak plates and leak nozzles were previously done manually. As we all know, relying on manual methods to implement the welding and hole enlarging processes of leak plates and leak nozzles not only has low production efficiency, but also cannot guarantee product quality. In order to avoid many disadvantages of manual production, automation is usually used to weld and enlarge leak plates and leak nozzles. However, since these technologies are not mature and practical, there are still many problems: For example, in terms of hole expansion technology, the "A Type of Automatic Hole Expanding Equipment for Leakage Nozzles" with publication number CN217253029U draws the actual position diagram of the leakage nozzle by taking regional photos of the leakage plate, taking multiple photos of the leakage nozzles in the overlapping area, and taking the average of the two photos to determine the final position of the leakage nozzle. Although this method only requires two samples, the production efficiency is not low. However, it is not realistic to accurately determine the final position of the leakage nozzle only by relying on the average of the two samples. That is, the error of this hole expansion method is large, the hole expansion quality is not good, and there is still a possibility that the final position of the leakage nozzle will be offset from the actual position, which affects the quality of the product and is not practical.

[0004] For another example, in terms of welding, the operating mechanism disclosed in the publication number CN112388112A, "A Platinum Wire Drawing Leakage Plate Automatic Welding Equipment and Platinum Wire Drawing Leakage Plate Manufacturing Process", is a dual-axis drive of the X-axis and Y-axis, but no Z-axis drive. When the leak plate is assembled, there is a possibility that the assembly pressure is too large, causing the leak plate to be slightly deformed. Since the equipment does not have a Z-axis drive and the welding head is fixed in the Z-axis direction, it is impossible to adjust the position of the welding head in the Z-axis direction in real time and correct the deviation of the welding point in the Z-axis direction. When using this equipment to weld the leak plate nozzle, it is easy to have inadequate welding, which affects the quality of the product and is not very practical.

[0005] Moreover, in the "A Platinum Wire Drawing Leakage Plate Automatic Welding Equipment and Platinum Wire Drawing Leakage Plate Manufacturing Process" with publication number CN112388112A, during the welding process of the leak nozzle, it is necessary to proofread the preset drawings and the photographed graphics, and determine the position of the welding gun head by judging the standard base points on the preset drawings and the real-time position of the center of the leak nozzle to be welded. Although this method can greatly improve the welding quality of the product, it ignores the efficiency problem in actual work. Once the standard base point of the preset drawing does not overlap with the real-time position of the center of the leak nozzle, the equipment will not be able to automatically proceed to the next step. At this time, production can only be continued by relying on the staff to recalibrate the preset drawings and restart the equipment, which is time-consuming and labor-intensive, and has extremely low practicality.

[0006] In summary, the current automated welding and hole expansion process for leaky plate leaky holes is either to blindly improve production efficiency while ignoring product quality (i.e. hole expansion quality, welding quality), or to focus too much on product quality assurance while ignoring the importance of production efficiency. How to strike a balance between production efficiency and product quality has always been a problem that technicians in this field need to solve. Summary of the invention

[0007] The purpose of the present invention is to provide a method for welding and expanding the hole of a leak nozzle of a precious metal leak plate in response to the corresponding deficiencies in the prior art. By setting a welding calibration unit for obtaining optimal welding parameters and a hole expansion calibration unit for obtaining optimal hole expansion parameters, the optimal welding parameters and the optimal hole expansion parameters obtained in advance through calibration experiments are used to control a welding rectangular coordinate robot and a hole expansion rectangular coordinate robot to weld and expand the leak nozzle, respectively, so as to ensure the quality of the leak nozzle welding and hole expansion while taking into account the production efficiency of the product.

[0008] The objective of the present invention is achieved by adopting the following scheme: A method for welding and expanding a leak nozzle of a precious metal leak plate comprises the following steps: 1) A welding calibration unit for obtaining optimal welding parameters is provided in the intelligent control system of the automatic welding device, and a hole expansion calibration unit for obtaining optimal hole expansion parameters is provided in the intelligent control system of the automatic hole expansion device; 2) Determine the best welding solution for the leak nozzle through welding calibration experiments; 3) Determine the best hole expansion scheme for the nozzle through hole expansion calibration experiment; 4) According to the best welding parameters in the best welding scheme, the nozzles on the precious metal leak plate are welded in sequence under the control of the welding PLC controller of the automatic welding device; 5) According to the optimal hole expansion parameters of the optimal hole expansion scheme, the leak nozzles on the precious metal leak plate are expanded in turn under the control of the hole expansion PLC controller of the automatic hole expansion device.

[0009] Preferably, in step 2), determining the best welding solution for the nozzle through a welding calibration experiment includes the following steps: 2-1) According to the geometric parameters of the leak plate and leak nozzle to be welded, determine the value range of welding parameters according to empirical values; 2-2) Arrange and combine the values ​​within the range of welding parameters to form several test welding plans; 2-3) Under the control of the welding PLC controller, the leak nozzle assembled on the precious metal leak plate is automatically welded according to the several trial welding schemes obtained in step 2-2), and the acceptance data of each trial welding scheme is recorded and stored in the welding calibration unit; 2-4) Select the trial welding plan with the best welding quality from a number of welding acceptance data as the best welding plan for the leak plate and leak nozzle, and use the automatic welding device to perform automatic welding according to the best welding plan.

[0010] Preferably, in step 3), determining the best hole expansion scheme for the nozzle through a hole expansion calibration experiment includes the following steps: 3-1) According to the geometric parameters of the leak plate and leak nozzle to be expanded, determine the value range of the expansion parameters according to empirical values; 3-2) Arrange and combine the values ​​within the range of hole expansion parameters to form several trial hole expansion schemes; 3-3) Under the control of the hole expansion PLC controller, the nozzle welded on the precious metal leak plate is automatically expanded according to the several trial hole expansion schemes obtained in step 3-2), and the acceptance data of each trial hole expansion scheme is recorded and stored in the hole expansion calibration unit; 3-4) A trial hole expansion plan with the best hole expansion quality is selected from a number of hole expansion acceptance data as the best hole expansion plan for the leak plate and leak nozzle, and the automatic hole expansion device is used to automatically expand the hole according to the best hole expansion plan.

[0011] Preferably, the geometric parameters of the leak plate include the number of leak plate holes, the leak plate hole diameter, and the leak plate thickness, and the geometric parameters of the leak nozzle include the leak nozzle outer diameter, the leak nozzle inner diameter, and the leak nozzle height.

[0012] Preferably, the welding parameters include welding scanning speed, welding direction, inter-hole welding connection mode, welding current, welding current judgment threshold, welding speed, welding diameter, arc extinction delay time and the initial distance between the bottom of the welding gun and the upper surface of the leak plate.

[0013] Preferably, the hole expansion parameters include the hole expansion scanning speed, the hole expansion robot moving speed, the drill bit rotation speed, the drill bit descending speed, the drill bit diameter and the initial distance between the bottom of the drill bit and the upper surface of the leak plate.

[0014] Preferably, in step 4), the nozzles on the precious metal leak plate are welded in sequence under the control of a welding PLC controller of an automatic welding device, including: 4-1) Turn on the power of the automatic welding device, initialize the state of the automatic welding device, and return the position of the welding rectangular coordinate robot to the origin; 4-2) Select the corresponding optimal welding parameters according to the models of the leak plate and leak nozzle by operating the human-machine interface of the automatic welding device; 4-3) Clamp the precious metal bushing to be welded on the workbench of the automatic welding device; 4-4) Start the automatic welding device and weld all the drain nozzles to be welded on the drain plate.

[0015] Preferably, in step 5), the nozzles on the precious metal leaking plate are expanded in sequence under the control of the expansion PLC controller of the automatic expansion device, including: 5-1) Turn on the power of the automatic hole reaming device, initialize the state of the automatic hole reaming device, and return the position of the hole reaming rectangular coordinate robot to the origin; 5-2) By operating the human-machine interface of the automatic hole expansion device, select the corresponding optimal hole expansion parameters according to the models of the leak plate and leak nozzle; 5-3) Clamp the precious metal leak plate with the leak nozzle welded on the workbench of the automatic hole expanding device; 5-4) Start the automatic hole expanding device to expand the inner hole of the leak nozzle welded on the precious metal leak plate.

[0016] Preferably, in step 4), when the automatic welding device welds all the nozzles to be welded to the precious metal drain plate, it includes the following two modes: Overall scanning welding mode: ⑴ Select the number of nozzles or the number of nozzles to be welded through the human-machine interface; (2) The automatic welding device scans and stores all the positions of the nozzles to be welded in step (1) and then welds the nozzles; Local scanning welding mode: ⑴ The automatic welding device obtains the position of a leak nozzle on the leak plate by scanning, and then welds the leak nozzle according to the position of the leak nozzle; ⑵ Repeat step ⑴ until all the drain nozzles on the drain plate are welded.

[0017] The beneficial effects of the present invention are as follows: 1) A welding calibration unit for obtaining optimal welding parameters is provided in the intelligent control system of the automatic welding device, and a hole expansion calibration unit for obtaining optimal hole expansion parameters is provided in the intelligent control system of the automatic hole expansion device; 2) Determine the best welding solution for the leak nozzle through welding calibration experiments; 3) Determine the best hole expansion scheme for the nozzle through hole expansion calibration experiment; 4) According to the best welding parameters in the best welding scheme, the nozzles on the precious metal leak plate are welded in sequence under the control of the welding PLC controller of the automatic welding device; 5) According to the optimal hole expansion parameters of the optimal hole expansion scheme, the leak nozzles on the precious metal leak plate are expanded in turn under the control of the hole expansion PLC controller of the automatic hole expansion device.

[0018] The present invention is provided with a welding calibration unit for obtaining optimal welding parameters and a hole expansion calibration unit for obtaining optimal hole expansion parameters. The optimal welding parameters and the optimal hole expansion parameters obtained in advance through calibration experiments are used, and an automatic welding device and an automatic hole expansion device are controlled to perform leaky nozzle welding and hole expansion respectively. While improving the welding speed and the hole expansion speed, the quality of welding and hole expansion is greatly improved.

[0019] Preferably, the welding parameters include welding scanning speed, welding direction, inter-hole welding connection mode, welding current, welding current judgment threshold, welding speed, welding diameter, arc extinction delay time and the initial distance between the bottom of the welding gun and the upper surface of the leak plate.

[0020] Preferably, the hole expansion parameters include the hole expansion scanning speed, the hole expansion robot moving speed, the drill bit rotation speed, the drill bit descending speed, the drill bit diameter and the initial distance between the bottom of the drill bit and the upper surface of the leak plate.

[0021] The present invention finds out various parameter types that affect the welding quality and hole expansion quality of the nozzle during welding and hole expansion through experiments, and determines the specific values ​​corresponding to different nozzles and leak plates through calibration experiments, which serve as guiding data for the welding process and hole expansion process, thereby greatly improving the quality of welding and hole expansion.

[0022] Preferably, the geometric parameters of the leak plate include the number of leak plate holes, the leak plate hole diameter, and the leak plate thickness, and the geometric parameters of the leak nozzle include the leak nozzle outer diameter, the leak nozzle inner diameter, and the leak nozzle height.

[0023] Usually, the geometric parameters of the leak plate and the leak nozzle are provided by the leak plate and the leak nozzle manufacturer (such as drawings, etc.). Of course, in actual work, some geometric parameters of the leak plate can also be obtained by scanning the scanning device on the automatic welding device, such as the number of leak plate holes, the leak plate hole diameter, the leak nozzle outer diameter, the leak nozzle inner diameter, and the actual distribution of each leak nozzle on the leak plate, so that the parameter values ​​obtained in the subsequent calibration experiment are more in line with the actual situation and the calibration accuracy is improved.

[0024] Preferably, in step 4), when the automatic welding device welds all the nozzles to be welded to the precious metal drain plate, it includes the following two modes: Overall scanning welding mode: ⑴ Select the number of nozzles or the number of nozzles to be welded through the human-machine interface; (2) The automatic welding device scans and stores all the positions of the nozzles to be welded in step (1) and then welds the nozzles; The overall scanning welding mode performs an overall scan of all the nozzles on the entire precious metal leak plate. This method can obtain complete welding layout information, ensure that the welding parameters remain relatively consistent throughout the entire welding area, so that the welding quality of each nozzle is more uniform and stable, reduce quality fluctuations caused by differences in welding parameters, and improve the overall quality and performance of the leak plate.

[0025] In the actual welding process, there is no need to frequently adjust the equipment parameters to adapt to the welding requirements of different leak nozzles. For example, if there are dozens of leak nozzles of the same specifications to be welded to the leak plate, after scanning to determine that their material, size and other parameters are the same, you can use unified welding current, voltage and speed parameters for welding, which reduces the time for adjusting parameters when welding each leak nozzle, and greatly improves the overall efficiency of welding. It is also easy to integrate with automated production lines, and can realize functions such as automatic identification of leak plate shape, positioning of leak nozzles, and automatic planning of welding paths, reducing manual intervention, reducing labor intensity and the impact of human factors on welding quality, and improving the automation level and stability of production.

[0026] Local scanning welding mode: ⑴ The automatic welding device obtains the position of a leak nozzle on the leak plate by scanning, and then welds the leak nozzle according to the position of the leak nozzle; ⑵ Repeat step ⑴ until all the drain nozzles on the drain plate are welded.

[0027] The local scanning welding mode is to scan only one leak and its corresponding welding position each time. This method can accurately scan and weld each leak or specific local area, and can better adapt to the individual differences and special requirements of the leak. For example, for the position deviation and size abnormality of individual leaks, separate precise welding can be performed to improve the pertinence and adaptability of welding. During the welding process, if a leak or a local area is found to require special treatment, such as adjusting welding parameters, repair welding, etc., the operation can be performed more flexibly without affecting the welding progress of the entire leak plate and the welding quality of other leaks, so as to facilitate timely resolution of individual problems arising during the welding process.

[0028] The advantages of the present invention are as follows: ① The present invention is provided with a welding calibration unit for storing optimal welding parameters and a hole expansion calibration unit for storing optimal hole expansion parameters. The optimal welding parameters and optimal hole expansion parameters obtained in advance through calibration experiments are used to control the welding rectangular coordinate robot and the hole expansion rectangular coordinate robot to perform leaky nozzle welding and hole expansion respectively. While improving the welding speed and hole expansion speed, the quality of welding and hole expansion is greatly improved.

[0029] ② The welding rectangular coordinate robot of the automatic welding device adopted in the present invention is provided with a Z-axis guide rail, so that the intelligent control system can control the movement of the welding gun in the vertical direction, effectively avoiding the technical defects of the "A platinum wire drawing leak plate automatic welding equipment and platinum wire drawing leak plate manufacturing process" with publication number CN112388112A, and effectively improving the quality of leak nozzle welding.

[0030] The automatic welding device adopted in the present invention, when positioning the leak nozzle, the intelligent control system controls the movement of the welding rectangular coordinate robot by combining the distribution map of the leak nozzles on the leak plate, so that the welding visual recognition device scans the leak nozzles one by one, directly obtains the coordinate position of the leak nozzle, and realizes the positioning of the leak nozzle, effectively avoiding the technical defects of "A platinum drawing leak plate automatic welding equipment and platinum drawing leak plate manufacturing process" with publication number CN112388112A, and greatly improving the efficiency of leak nozzle welding.

[0031] ③ When positioning the leak nozzle, the automatic hole expanding device adopted in the present invention controls the movement of the hole expanding rectangular coordinate robot by combining the distribution map of the leak nozzles on the leak plate, so that the hole expanding visual recognition device scans the leak nozzles one by one, directly obtains the coordinate position of the leak nozzle, and realizes the positioning of the leak nozzle, which effectively avoids the technical defects of "A leak nozzle automatic hole expanding device" with publication number CN217253029U and greatly improves the quality of hole expansion. Glossary

[0032] Arc extinction delay time: in the present invention, it refers to the time interval from the issuance of an arc extinction command (such as a control signal to cut off the circuit) to the actual complete extinction of the arc during the arc extinction process; Scanning speed: It is used to indicate the time required for the visual recognition device to identify a hole position on the leak plate. The value of "scanning speed" in the present invention actually includes the time taken by the visual recognition device to complete the recognition of the center position of the current hole position after moving from the previous hole position to the hole position to be identified, and the time taken by the visual recognition device to move from the current hole position to the next hole position; Welding speed: It is used to indicate the time required to weld a nozzle on the precious metal leak plate. The value of "welding speed" in the present invention actually includes the time taken by the reaming device to move from the upper nozzle position to the nozzle position to be welded during the process of welding the nozzle to the precious metal leak plate, and the time taken by the reaming device to move from the current nozzle position to the next nozzle position.

[0033] The precious metal leak plate after the leak nozzles are assembled: in the present invention, it refers to the precious metal leak plate that has been assembled and installed in the respective leak nozzle assembly holes, but has not yet been welded or expanded. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of the automatic welding device of the present invention; Figure 2 It is a schematic structural diagram of the automatic hole enlarging device of the present invention; Figure 3 for Figure 1 A magnified image of point A; Figure 4 for Figure 2 The enlarged view of point B; Figure 5 This is a schematic diagram of the distribution of the precious metal nozzles on the drain plate in the present invention; Figure 6 The welding procedure logic diagram of the present invention; Figure 7 Logic diagram of the hole expansion program of the present invention. DETAILED DESCRIPTION

[0035] like Figures 1 to 7 As shown, a method for welding and expanding a leak nozzle of a precious metal leak plate comprises the following steps: 1) A welding calibration unit for obtaining optimal welding parameters is provided in the intelligent control system of the automatic welding device, and a hole expansion calibration unit for obtaining optimal hole expansion parameters is provided in the intelligent control system of the automatic hole expansion device; 2) Determine the best welding solution for the leak nozzle through welding calibration experiment in the following way: 2-1) According to the geometric parameters of the leak plate and leak nozzle to be welded, determine the value range of welding parameters according to empirical values; The geometric parameters of the leak plate include the number of leak plate holes, the leak plate hole diameter, and the leak plate thickness. The geometric parameters of the leak nozzle include the leak nozzle outer diameter, the leak nozzle inner diameter, and the leak nozzle height.

[0036] The welding parameters include welding scanning speed, welding direction, hole-to-hole welding connection mode, welding current, welding current judgment threshold, welding speed, welding diameter, arc extinguishing delay time and initial distance between the bottom of the welding gun and the upper surface of the leak plate.

[0037] 2-2) Arrange and combine the values ​​within the range of welding parameters to form several test welding plans; In actual application, the test step length corresponding to each welding parameter can be set according to the quality requirements, so as to obtain the value of the welding parameter before the permutation and combination. For example, the welding parameters and the corresponding test step lengths are as follows: 2-2-1) The welding scanning speed is 200-400ms / hole, and the test step of the welding scanning speed can be set to 100ms / hole; For example, the data involved in the arrangement and combination are 200, 300, and 400 ms / hole.

[0038] 2-2-2) The welding directions include straight line welding and zigzag welding. The hole-to-hole welding connection methods include non-arc extinguishing welding and arc extinguishing welding. The arc extinguishing delay time is 100 to 200 ms, and the test step of the arc extinguishing delay time can be set to 50 ms.

[0039] For example, the data involved in the permutation and combination are 100 ms, 150 ms, and 200 ms.

[0040] 2-2-3) The welding diameter is +0.5~+0.7mm of the outer diameter of the drain nozzle, the welding speed is 200~400ms / hole, and the initial distance between the bottom of the welding gun and the upper surface of the drain plate is 0.5~1mm; The test step length of the welding diameter can be set to 0.1 mm, the test step length of the welding speed can be set to 50ms / hole, and the test step length of the initial distance between the bottom of the welding gun and the upper surface of the leak plate can be set to 0.1 mm.

[0041] For example, the welding diameter data participating in the permutation and combination are 0.5 mm, 0.6 mm, and 0.7 mm; the welding speed data participating in the permutation and combination are 200 ms / hole, 250 ms / hole, 300 ms / hole, 350ms / hole, and 400ms / hole; the initial distance data between the bottom of the welding gun and the upper surface of the leak plate participating in the permutation and combination are 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, and 1 mm.

[0042] 2-2-4) The welding current includes the central welding current and the peripheral welding current. The central welding current is 35~45A and the peripheral welding current is 40~55A. The test step length of the central welding current can be set to 5 A, and the test step length of the peripheral welding current can be set to 1 A. Similarly, several data of the central welding current and the peripheral welding current participating in the permutation and combination can be obtained.

[0043] 2-2-5) The welding current judgment threshold is set according to the distribution of the leak nozzles on the leak plate and the required product quality. The test step length of the welding current judgment threshold can be set to 1.

[0044] In the present invention, the intelligent control system divides the nozzles into several layers according to the nozzle distribution diagram of the precious metal leak plate and the distance between each nozzle and the edge of the leak plate. The welding current judgment threshold represents the number of nozzle layers on the leak plate from the edge of the leak plate to the center of the leak plate. The actual coordinate position obtained by scanning is compared with the coordinate position of the nozzle distribution diagram of the metal leak plate in the intelligent control system to obtain the actual nozzle layer number to which the nozzle belongs, and the actual nozzle layer number is compared with the welding current judgment threshold to determine whether the nozzle belongs to a peripheral nozzle or a central nozzle: ① The actual number of leak nozzle layers is less than or equal to the welding current judgment threshold. The leak nozzle is judged to be a peripheral leak nozzle, and the welding gun is connected to the peripheral welding current; ② The actual number of leak layers > the welding current judgment threshold, and the leak is judged to be a middle leak, so the welding gun is connected to the middle welding current.

[0045] 2-3) Under the control of the welding PLC controller, the leak nozzle assembled on the precious metal leak plate is automatically welded according to the several trial welding schemes obtained in step 2-2), and the acceptance data of each trial welding scheme is recorded and stored in the welding calibration unit; 2-4) Select the trial welding plan with the best welding quality from a number of welding acceptance data as the best welding plan for the leak plate and leak nozzle, and use the automatic welding device to perform automatic welding according to the best welding plan.

[0046] 3) Determine the best hole expansion scheme for the nozzle through hole expansion calibration experiment in the following way: 3-1) According to the geometric parameters of the leak plate and leak nozzle to be expanded, determine the value range of the expansion parameters according to empirical values; The hole expansion parameters include hole expansion scanning speed, hole expansion robot moving speed, drill bit rotation speed, drill bit descending speed, drill bit diameter and the initial distance between the bottom of the drill bit and the upper surface of the leaking plate.

[0047] 3-2) Arrange and combine the values ​​within the range of hole expansion parameters to form several trial hole expansion schemes; In practical applications, the test step length corresponding to each hole expansion parameter can be set according to the quality requirements of the nozzle hole expansion, which is used to obtain the value of the hole expansion parameter before the arrangement and combination. For example, the hole expansion parameters and the corresponding test step lengths are as follows: 3-2-1) The hole expansion scanning speed is 200-400ms / hole, and the hole expansion robot moving speed is 200-400ms / hole; The test step length of the hole expansion scanning speed can be set to 100ms / hole, and the test step length of the hole expansion robot movement speed can be set to 100ms / hole; 3-2-2) The drill speed is 1000-3000 rpm and the drill descent speed is 1-3 mm / s; The test step length of drill speed can be set to 1000 rpm, and the test step length of drill descent speed and drill diameter can be set to 1mm / s; 3-2-3) The initial distance between the bottom of the drill bit and the upper surface of the leak plate is 0.5 to 1 mm, and the test step length of the initial distance between the bottom of the drill bit and the upper surface of the leak plate can be set to 0.1 mm.

[0048] 3-3) Under the control of the hole expansion PLC controller, the nozzle welded on the precious metal leak plate is automatically expanded according to the several trial hole expansion schemes obtained in step 3-2), and the acceptance data of each trial hole expansion scheme is recorded and stored in the hole expansion calibration unit; 3-4) A trial hole expansion plan with the best hole expansion quality is selected from a number of hole expansion acceptance data as the best hole expansion plan for the leak plate and leak nozzle, and the automatic hole expansion device is used to automatically expand the hole according to the best hole expansion plan.

[0049] During the welding process of precious metal nozzles, tiny inward protrusions will be generated at the nozzle weld, and the protrusion height range is approximately 0.01mm to 0.02mm. The automatic hole enlarging method of the present invention can accurately enlarge these inwardly protruding parts, thereby ensuring that the inner diameter of the weld part is consistent with the inner diameter of the nozzle as a whole, so as to meet the corresponding process standards and usage requirements.

[0050] 4) According to the best welding parameters in the best welding scheme, the nozzles on the precious metal leak plate are welded in sequence under the control of the welding PLC controller of the automatic welding device in the following manner: 4-1) Turn on the power of the automatic welding device, initialize the state of the automatic welding device, and return the position of the welding rectangular coordinate robot to the origin; 4-2) Select the corresponding optimal welding parameters according to the models of the leak plate and leak nozzle by operating the human-machine interface of the automatic welding device; 4-3) Clamp the precious metal bushing to be welded on the workbench of the automatic welding device; 4-4) Start the automatic welding device and weld all the drain nozzles to be welded on the drain plate.

[0051] It is worth noting that when the nozzles on the precious metal leak plate are welded in sequence under the control of the welding PLC controller of the automatic welding device, two welding modes are usually included (overall scanning welding mode and local scanning welding mode). In the actual production process, different scanning welding modes can be selected according to specific quality requirements, for example: Overall scanning welding mode: ⑴ Select the number of nozzles or the number of nozzles to be welded through the human-machine interface; ⑵ The automatic welding device scans and stores all the positions of the nozzles to be welded in step ⑴, and then welds the nozzles, as follows: ① The welding visual recognition device moves to the scanning position and scans the nozzles on the leak plate in the scanning order (generally sequential scanning, that is, scanning a row of nozzles completely along the Y-axis direction, then moving a nozzle position along the X-axis, and then scanning in the opposite direction along the Y-axis, and repeating this process until all the nozzles on the leak plate are scanned), and obtains the coordinates of the current nozzle and the distance to the next nozzle in turn, and feeds the data back to the intelligent control system; ② According to the data feedback obtained in step ①, the intelligent control system controls the welding gun to move to the leak position to be welded; ③ The welding gun is connected to the corresponding welding current according to the set welding parameters to weld the leakage nozzle on the leakage plate; ④ Repeat steps ② to ③ above to complete the welding of each leak nozzle on the leak plate in turn.

[0052] Local scanning welding mode: ⑴ The automatic welding device obtains the position of a leak nozzle on the leak plate by scanning, and then welds the leak nozzle according to the position of the leak nozzle; ⑵ Repeat step ⑴ until all the drain nozzles on the drain plate are welded.

[0053] 5) According to the optimal hole expansion parameters of the optimal hole expansion scheme, the nozzles on the precious metal leak plate are expanded in sequence under the control of the hole expansion PLC controller of the automatic hole expansion device in the following manner: 5-1) Turn on the power of the automatic hole reaming device, initialize the state of the automatic hole reaming device, and return the position of the hole reaming rectangular coordinate robot to the origin; 5-2) By operating the human-machine interface of the automatic hole expansion device, select the corresponding optimal hole expansion parameters according to the models of the leak plate and leak nozzle; 5-3) Clamp the precious metal leak plate with the leak nozzle welded on the workbench of the automatic hole expanding device; 5-4) Start the automatic hole expanding device to expand the inner hole of the leak nozzle welded on the precious metal leak plate.

[0054] The method for welding and expanding the hole of the nozzle of the above-mentioned precious metal leak plate, the automatic welding device and the automatic hole expanding device for improving the welding and hole expanding quality include a welding workbench 1, a hole expanding workbench 20, a welding rectangular coordinate robot 5 installed on the welding workbench 1, and a hole expanding rectangular coordinate robot 8 installed on the hole expanding workbench 20, and a human-machine interface 18 for issuing instructions to the intelligent control system. In the present invention, the intelligent control system compiles algorithms and programs suitable for the operation of the automatic welding device and the automatic hole expanding device in the PLC controller by combining the distribution map of the nozzles on the leak plate and the working paths of manual welding and manual hole expanding, which are used to realize the functions of nozzle position recognition, nozzle welding action and nozzle hole expanding action, and establish a simple-to-operate and comprehensive human-machine interface 18 to issue instructions for the precious metal leak plate, nozzle welding and nozzle hole expanding.

[0055] The rectangular coordinate robot includes a welding rectangular coordinate robot 5 and a hole-expanding rectangular coordinate robot 8. The welding rectangular coordinate robot 5 for welding the leak nozzle and the welding fixture 3 for fixing the leak plate are arranged on the welding workbench 1 of the automatic welding device. The welding fixture 3 includes a leak plate fixture for installing the leak plate and a water-cooling plate arranged below the leak plate fixture. The water-cooling plate is provided with a water-cooling channel inside. When the external cooling water source flows through the water-cooling plate, the water flow will absorb the heat from the fixture and the leak plate and take it out of the fixture, so that during the welding process, the temperature of the welding fixture 3 and the leak plate is relatively stable to avoid overheating. A plurality of mounting grooves are arranged on the top of the leak plate fixture. The position and size of the mounting grooves are adapted to the leak nozzle on the leak plate, so as to facilitate the fixing of the leak plate and ensure the parallelism requirement between the surface of the leak plate and the workbench.

[0056] The end effector of the welding rectangular coordinate robot 5 is a welding gun 4 for welding leak nozzles. The welding gun 4 is electrically connected to a welding machine 2 for generating welding energy. The intelligent control system adjusts the corresponding welding parameters (inter-hole welding connection method, welding current, arc extinction delay time) by controlling the welding machine 2. The connecting cable between the welding gun 4 and the welding machine 2 is fixed by a wire tube fixing 19.

[0057] A welding visual recognition device 6 for identifying the position of each leak nozzle on the leak plate and a distance sensor 7 for detecting the deformation of the leak plate are provided on the side of the welding gun 4. The distance sensor 7 is electrically connected to the PLC controller. Specifically, the distance sensor 7 is used to detect the deformation of the leak plate on the Z axis, and the obtained data is fed back to the PLC controller, so that the PLC controller controls the movement of the welding rectangular coordinate robot, thereby adjusting the height of the welding gun and improving the quality of the leak plate welding. The welding visual recognition device 6 and the welding machine 2 are both electrically connected to the welding calibration unit set on the welding workbench 1 of the automatic welding device, which is used to obtain and store the optimal welding parameters of the leak nozzle.

[0058] A hole-expanding rectangular coordinate robot 8 for expanding the hole of the nozzle and a hole-expanding fixture 9 for fixing the leak plate are arranged on the hole-expanding workbench 20 of the automatic hole-expanding device. The end effector of the hole-expanding rectangular coordinate robot 8 is a hole-expanding device 10 for expanding the hole of the nozzle. A hole-expanding visual recognition device 11 is arranged beside the hole-expanding device 10. The hole-expanding visual recognition device 11 is used to identify the center position of each nozzle on the leak plate. The hole-expanding visual recognition device 10 is electrically connected to the hole-expanding calibration unit arranged on the hole-expanding workbench 20 of the automatic hole-expanding device, and is used to obtain and store the optimal hole-expanding parameters of the nozzle. The welding calibration unit is connected to the welding PLC controller, and the hole expansion calibration unit is connected to the hole expansion PLC controller.

[0059] The rectangular coordinate robot includes an X-axis guide rail 12, a Y-axis guide rail 13 and a Z-axis guide rail 14. Two X-axis guide rails 12 are arranged on the welding workbench 1 and the hole-expanding workbench 20. The two ends of the Y-axis guide rail 13 are respectively connected to the first slider 15 on the X-axis guide rail 12. The Z-axis guide rail 14 is connected to the second slider 16 arranged on the Y-axis guide rail 13. The Z-axis guide rail 14 is provided with a third slider 16. The welding gun 4, the welding visual recognition device 6 and the distance sensor 7 are installed on the third slider 17 of the welding rectangular coordinate robot 5. The hole-expanding device 10 and the hole-expanding visual recognition device 11 are installed on the third slider 17 of the hole-expanding rectangular coordinate robot 8. The welding visual recognition device 6 and the hole-expanding visual recognition device 11 are both high-pixel industrial cameras.

[0060] The X-axis guide 12, the Y-axis guide 13 and the Z-axis guide 14 all use linear motors. The accuracy of the above linear motors is 0.5μm. Specifically, the X-axis guide 12, the Y-axis guide 13 and the Z-axis guide 14 are magnetic guides, and coils are energized inside the above-mentioned first slider 15, the second slider 16 and the third slider 17 to generate a magnetic field, which interacts with the magnetic material in the magnetic guide rails to generate a driving force, and pushes the above-mentioned sliders to slide on the magnetic guide rails, thereby realizing the omnidirectional movement of the end effector. The present invention uses a linear motor as a driving method to control the movement of the welding rectangular coordinate robot 5 and the hole expansion rectangular coordinate robot 8, and has the advantages of being quiet, stable, precise, and highly controllable.

[0061] According to the method for welding and expanding the hole of the leaking nozzle of the precious metal leaking plate of the present invention, the automatic welding device and the automatic hole expanding device are used to perform Examples 1, 2, and 3 as follows: Embodiment 1: A leak plate with 400 leak nozzle mounting holes is used for welding and hole expansion. The leak plate thickness is 2.0 mm, the hole diameter of the leak nozzle mounting hole is 2.7 mm, and each leak nozzle has an outer diameter of 2.7 mm, an inner diameter of 1.8 mm, and a height of 6.5 mm.

[0062] Embodiment 2: A leak plate with 800 leak nozzle mounting holes is used for welding and hole expansion. The bottom plate thickness is 1.8 mm, the bottom plate hole diameter is 2.6 mm, the leak nozzle outer diameter is 2.6 mm, the inner diameter is 1.8 mm, and the height is 6.0 mm.

[0063] Embodiment 3: A leak plate with 1200 leak nozzle mounting holes is used for welding and hole expansion. The bottom plate thickness is 1.6 mm, the bottom plate hole diameter is 2.6 mm, the leak nozzle outer diameter is 2.6 mm, the inner diameter is 1.7 mm, and the height is 6.5 mm.

[0064] 1. The range of the optimal welding parameters for welding the leak plate and the leak nozzle of each embodiment using an automatic welding device is determined through calibration experiments as follows: ⑴ The welding scanning speed is 200-400ms / hole; ⑵ The welding direction includes straight welding and Z-shaped welding, and the hole welding connection mode includes non-arc extinguishing welding and arc extinguishing welding, where the arc extinguishing delay time is 100-200ms; ⑶ The welding diameter is +0.5~+0.7mm of the outer diameter of the drain nozzle, the welding speed is 200~400ms / hole, and the initial distance between the bottom of the welding gun and the upper surface of the drain plate is 0.5~1mm; (4) The welding current includes the central welding current and the peripheral welding current. The central welding current is 35-45A and the peripheral welding current is 40-55A. ⑸ The welding current judgment threshold is set according to the distribution of leak nozzles on the leak plate and the required product quality.

[0065] 2. The range of values ​​of the optimal hole-expanding parameters when the automatic hole-expanding device is used to expand the hole of the nozzle of each embodiment is determined through calibration experiments as follows: ⑴ The hole expansion scanning speed is 200-400ms / hole, and the hole expansion robot moving speed is 200-400ms / hole; ⑵ The drill speed is 1000-3000 rpm and the drill descent speed is 1-3 mm / s; ⑶ The initial distance between the bottom of the drill bit and the upper surface of the leak plate is 0.5-1 mm, and the test step length of the initial distance between the bottom of the drill bit and the upper surface of the leak plate can be set to 0.1 mm.

[0066] 3. Arrange and combine the values ​​within the value ranges of the above-mentioned welding parameters and hole expansion parameters to form several nozzle welding schemes and nozzle hole expansion schemes, and use automatic welding devices and automatic hole expansion devices to weld nozzles on precious metal leak plates and expand the nozzles after welding according to the parameter values ​​corresponding to all nozzle welding schemes and nozzle hole expansion schemes, and record and store the welding acceptance data corresponding to each nozzle welding scheme and the hole expansion acceptance data corresponding to each nozzle hole expansion scheme; finally, select the nozzle welding scheme with the best welding quality and the nozzle hole expansion scheme with the best hole expansion quality from the several welding acceptance data and the several hole expansion acceptance data, and use the parameter values ​​corresponding to the nozzle welding scheme and the nozzle hole expansion scheme as the optimal welding parameters of the leak plate and the nozzle, and the optimal hole expansion parameters of the nozzle in Examples 1, 2, and 3, as follows: Example 1

[0067] Optimal welding parameters: The welding scanning speed is 400ms / hole, the welding direction is linear welding, the welding connection method between holes is non-extinguishing arc welding, the welding diameter is the outer diameter of the nozzle + 0.5mm (the welding diameter is 3.2mm), the welding speed is 350ms / hole, and the initial distance between the bottom of the welding gun and the upper surface of the drain plate is 0.8mm; The welding current includes the central welding current and the peripheral welding current. The central welding current is 45A, the peripheral welding current is 53A, and the welding current judgment threshold is 3: The actual number of leak nozzle layers is ≤3, and the leak nozzle is judged to be a peripheral leak nozzle, and the welding gun is connected to the peripheral welding current 53A; The actual number of leak nozzle layers is > 3, and the leak nozzle is judged to be a middle leak nozzle, so the welding gun is connected to the middle welding current of 45A.

[0068] Optimal hole expansion parameters: The hole expansion scanning speed is 200ms / hole, the hole expansion robot moving speed is 200ms / hole, the drill speed is 1000 rpm, the drill lowering speed is 1mm / s, the initial distance between the bottom of the drill and the upper surface of the leak plate is 0.6mm, and the drill diameter is 1.8mm. Example 2

[0069] Optimal welding parameters: The welding scanning speed is 200ms / hole, the welding direction is Z-shaped welding, the welding connection method between holes is arc extinguishing welding, the arc extinguishing delay time is 200ms, the welding diameter is the outer diameter of the drain nozzle + 0.5mm (the welding diameter is 3.1mm), the welding speed is 200ms / hole, and the initial distance between the bottom of the welding gun and the upper surface of the drain plate is 0.6mm; The welding current includes the central welding current and the peripheral welding current. The central welding current is 35A, the peripheral welding current is 40A, and the welding current judgment threshold is 1: The actual number of leak nozzle layers is ≤1, and the leak nozzle is judged to be a peripheral leak nozzle, and the welding gun is connected to the peripheral welding current of 40A; The actual number of leak nozzle layers>1, it is judged that the leak nozzle belongs to the middle leak nozzle, and the welding gun is connected to the middle welding current 35A.

[0070] Optimal hole expansion parameters: The hole expansion scanning speed is 300ms / hole, the hole expansion robot moving speed is 300ms / hole, the drill speed is 2000 rpm, the drill lowering speed is 2mm / s, the initial distance between the bottom of the drill and the upper surface of the leak plate is 0.8mm, and the drill diameter is 1.7mm. Example 3

[0071] Optimal welding parameters: The welding scanning speed is 300ms / hole, the welding direction is linear welding, the welding connection method between holes is arc extinguishing welding, the arc extinguishing delay time is 150ms, the welding diameter is the outer diameter of the drain nozzle + 0.5mm (the welding diameter is 3.1mm), the welding speed is 300ms / hole, and the initial distance between the bottom of the welding gun and the upper surface of the drain plate is 0.1mm; The welding current includes the central welding current and the peripheral welding current. The central welding current is 40A, the peripheral welding current is 45A, and the welding current judgment threshold is 2: The actual number of leak nozzle layers is ≤2, and the leak nozzle is judged to be a peripheral leak nozzle, and the welding gun is connected to the peripheral welding current of 45A; The actual number of leak nozzle layers is >2, and the leak nozzle is judged to be a middle leak nozzle, so the welding gun is connected to the middle welding current 40A.

[0072] Optimal hole expansion parameters: The hole expansion scanning speed is 400ms / hole, the hole expansion robot moving speed is 400ms / hole, the drill speed is 3000 rpm, the drill lowering speed is 3mm / s, the initial distance between the bottom of the drill and the upper surface of the leak plate is 1.0mm, and the drill diameter is 1.7mm.

[0073] The quality of the leak plate and leak nozzle welded in the above three embodiments is tested, and it is found that the welding quality of the leak plate and the leak nozzle is extremely high (the yield rate of the leak nozzle welding is 99.9%~99.95%) because the error caused by the factors affecting the welding quality is minimized as much as possible during the welding process. The weld seam is tested by color flaw detection (the weld seam width is 1.8mm~2.0mm), and no leakage occurs. And the fullness of the weld seam is extremely high by naked eye observation. It can be seen that the present invention can be used for welding of leak plates and leak nozzles of different models, and greatly improves the quality of welding while ensuring the working efficiency of welding.

[0074] The quality of the nozzles after hole expansion in the above three embodiments is inspected. Since the present invention minimizes the error caused by the factors affecting the hole expansion quality during hole expansion, the quality of the nozzle hole expansion is extremely high (the yield rate of the nozzle hole expansion is 99.9% to 99.95%), which meets the requirements. By using the color flaw detection method for inspection, there is no situation where the nozzle is drilled through by the drill bit due to eccentric hole expansion. It can be seen that the present invention can be used for hole expansion of nozzles on leak plates of different models, and can take into account both the work efficiency of hole expansion and the quality requirements of hole expansion.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for welding and expanding the nozzle of a precious metal bushing, characterized in that: The following steps are involved: 1) A welding calibration unit for obtaining optimal welding parameters is provided in the intelligent control system of the automatic welding device, and a hole expansion calibration unit for obtaining optimal hole expansion parameters is provided in the intelligent control system of the automatic hole expansion device; 2) Determine the best welding solution for the leak nozzle through welding calibration experiments; 3) Determine the best hole expansion scheme for the nozzle through hole expansion calibration experiment; 4) According to the best welding parameters in the best welding scheme, the nozzles on the precious metal leak plate are welded in sequence under the control of the welding PLC controller of the automatic welding device; 5) According to the optimal hole expansion parameters of the optimal hole expansion scheme, the leak nozzles on the precious metal leak plate are expanded in turn under the control of the hole expansion PLC controller of the automatic hole expansion device.

2. A method for welding and expanding a nozzle of a precious metal bushing according to claim 1, characterized in that: In step 2), the best welding solution for the leak nozzle is determined through a welding calibration experiment, including the following steps: 2-1) According to the geometric parameters of the leak plate and leak nozzle to be welded, determine the value range of welding parameters according to empirical values; 2-2) Arrange and combine the values ​​within the range of welding parameters to form several test welding plans; 2-3) Under the control of the welding PLC controller, the leak nozzle assembled on the precious metal leak plate is automatically welded according to the several trial welding schemes obtained in step 2-2), and the acceptance data of each trial welding scheme is recorded and stored in the welding calibration unit; 2-4) Select the trial welding plan with the best welding quality from a number of welding acceptance data as the best welding plan for the leak plate and leak nozzle, and use the automatic welding device to perform automatic welding according to the best welding plan.

3. The method for welding and expanding the nozzle of a precious metal bushing according to claim 1, characterized in that: In step 3), the optimal hole expansion scheme of the nozzle is determined through hole expansion calibration experiment, including the following steps: 3-1) According to the geometric parameters of the leak plate and leak nozzle to be expanded, determine the value range of the expansion parameters according to empirical values; 3-2) Arrange and combine the values ​​within the range of hole expansion parameters to form several trial hole expansion schemes; 3-3) Under the control of the hole expansion PLC controller, the nozzle welded on the precious metal leak plate is automatically expanded according to the several trial hole expansion schemes obtained in step 3-2), and the acceptance data of each trial hole expansion scheme is recorded and stored in the hole expansion calibration unit; 3-4) A trial hole expansion plan with the best hole expansion quality is selected from a number of hole expansion acceptance data as the best hole expansion plan for the leak plate and leak nozzle, and the automatic hole expansion device is used to automatically expand the hole according to the best hole expansion plan.

4. A method for welding and expanding a nozzle of a precious metal bushing according to claim 2 or 3, characterized in that: The geometric parameters of the leak plate include the number of leak plate holes, the leak plate hole diameter, and the leak plate thickness. The geometric parameters of the leak nozzle include the leak nozzle outer diameter, the leak nozzle inner diameter, and the leak nozzle height.

5. The method for welding and expanding the nozzle of a precious metal bushing according to claim 2, characterized in that: The welding parameters include welding scanning speed, welding direction, hole-to-hole welding connection mode, welding current, welding current judgment threshold, welding speed, welding diameter, arc extinguishing delay time and initial distance between the bottom of the welding gun and the upper surface of the leak plate.

6. A method for welding and expanding a nozzle of a precious metal bushing according to claim 3, characterized in that: The hole expansion parameters include hole expansion scanning speed, hole expansion robot moving speed, drill bit rotation speed, drill bit descending speed, drill bit diameter and the initial distance between the bottom of the drill bit and the upper surface of the leaking plate.

7. The method for welding and expanding the nozzle of a precious metal bushing according to claim 1, characterized in that: In step 4), the nozzles on the precious metal leak plate are welded in sequence under the control of the welding PLC controller of the automatic welding device, including: 4-1) Turn on the power of the automatic welding device, initialize the state of the automatic welding device, and return the position of the welding rectangular coordinate robot to the origin; 4-2) Select the corresponding optimal welding parameters according to the models of the leak plate and leak nozzle by operating the human-machine interface of the automatic welding device; 4-3) Clamp the precious metal bushing to be welded on the workbench of the automatic welding device; 4-4) Start the automatic welding device and weld all the drain nozzles to be welded on the drain plate.

8. The method for welding and expanding the nozzle of a precious metal bushing according to claim 1, characterized in that: In step 5), the nozzles on the precious metal leak plate are expanded in sequence under the control of the hole expansion PLC controller of the automatic hole expansion device, including: 5-1) Turn on the power of the automatic hole reaming device, initialize the state of the automatic hole reaming device, and return the position of the hole reaming rectangular coordinate robot to the origin; 5-2) By operating the human-machine interface of the automatic hole enlarging device, select the corresponding optimal hole enlarging parameters according to the models of the leak plate and leak nozzle; 5-3) Clamp the precious metal leak plate with the leak nozzle welded on the workbench of the automatic hole expanding device; 5-4) Start the automatic hole expanding device to expand the inner hole of the leak nozzle welded on the precious metal leak plate.

9. The method for welding and expanding the nozzle of a precious metal bushing according to claim 1, characterized in that: In step 4), when the automatic welding device welds all the nozzles to be welded to the precious metal drain plate, it includes the following two modes: Overall scanning welding mode: ⑴ Select the number of nozzles or the number of nozzles to be welded through the human-machine interface; (2) The automatic welding device scans and stores all the positions of the nozzles to be welded in step (1) and then welds the nozzles; Local scanning welding mode: ⑴ The automatic welding device obtains the position of a leak nozzle on the leak plate by scanning, and then welds the leak nozzle according to the position of the leak nozzle; ⑵ Repeat step ⑴ until all the drain nozzles on the drain plate are welded.

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