Electric servo closed-loop control ultrasonic copper pipe seal welding device and method

Abstract

The invention relates to an electric servo closed-loop control ultrasonic copper pipe seal welding device and method, and belongs to the technical field of power ultrasonic application. A welding sound assembly and a mold closing assembly are arranged in a machine body assembly; according to the die assembly assembly, a driving structure is connected with the machine body assembly, the output end of the driving structure is connected with a reinforcement block, the rear end of a bottom die supporting frame is rotationally arranged between the welding sound assembly and the die assembly assembly, a spring, a rolling wheel and a bottom die are arranged on the front side of the bottom die supporting frame, and a reinforcement slope matched with the rolling wheel is arranged on the reinforcement block. The bottom die at the front end of the bottom die supporting frame corresponds to the welding sound assembly, and a displacement sensor is arranged below the reinforcement block. The control precision of the welding pressure and height can be remarkably improved, the fundamental conversion of the welding height from passive monitoring to active control is achieved, and a set of copper pipe sealing solution capable of achieving high-consistency and high-reliability welding is provided for the refrigeration industry.

Description

Technical Field

[0001] This invention relates to sealing and welding apparatus and method, belonging to the field of power ultrasonic application technology. Background Technology

[0002] In the production of refrigeration equipment such as refrigerators and air conditioners, the sealing and welding of refrigeration pipes is a core process that determines the overall performance, safety, and lifespan of the equipment. Even minor defects in the sealing quality can lead to refrigerant leakage, severely reducing the equipment's refrigeration efficiency and posing significant safety risks such as equipment explosion and environmental pollution. Given the massive annual production and widespread use of refrigeration equipment, ensuring the high reliability of welded joints has become a crucial step in safeguarding public safety and mitigating environmental risks. Therefore, it is necessary to improve the consistency of refrigeration copper pipe welding and sealing to reduce leakage risks and ensure the long-term safe and efficient operation of the equipment.

[0003] In the early stages of the refrigeration industry, the welding and sealing of refrigeration copper pipes mainly relied on manual brazing, where a copper block was first used to plug the end of the copper pipe before brazing. This brazing sealing process had significant drawbacks; the cleanliness of the weld surface, human error, and the quality of the brazing filler metal were all unstable, making defects in the weld joint highly likely. With the rapid development of ultrasonic metal welding technology, ultrasonic sealing equipment has been gradually applied to refrigeration industry production lines, driving process upgrades. Currently, portable ultrasonic copper pipe sealing equipment generally uses a pneumatic drive system. Air pressure pushes a piston, and a ramp force-increasing mechanism closes the upper and lower die plates to complete the shearing and sealing of the copper pipe. However, the pneumatic drive system has limitations: First, the pneumatic system can only roughly control the output thrust of the push rod, but due to the compressibility of air, it is difficult to achieve precise and stable control of welding pressure and height. Second, although traditional pneumatic pipe sealing welding equipment is equipped with a high-precision height detection function, it is essentially a passive monitoring system. The height information obtained can only be used for the acceptance judgment after welding, thus lacking the ability to actively control the welding height and making it difficult to achieve closed-loop control with a target height as the set value.

[0004] Therefore, there is an urgent need to propose an ultrasonic copper tube sealing and welding device and method with electric servo closed-loop control to solve the above-mentioned technical problems. Summary of the Invention

[0005] To address the aforementioned problems, an ultrasonic copper tube sealing and welding device and method with electric servo closed-loop control are provided. A brief overview of the invention is given below to provide a basic understanding of certain aspects of the invention. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention.

[0006] The technical solution of the present invention: An ultrasonic copper tube sealing and welding device with electric servo closed-loop control includes: a welding acoustic component and a mold closing component installed inside the body assembly; The mold clamping assembly includes: a drive structure connected to the body assembly; the output end of the drive structure connected to the force-increasing block; the rear end of the bottom mold support frame rotatably positioned between the welding acoustic component and the mold clamping assembly; a spring, rollers, and a bottom mold are provided on the front side of the bottom mold support frame; the spring presses against the welding acoustic component; the force-increasing block has a force-increasing ramp that cooperates with the rollers; the bottom mold at the front end of the bottom mold support frame is correspondingly positioned to the welding acoustic component; and a displacement sensor is provided below the force-increasing block.

[0007] Preferred: The drive structure includes: the output end of the servo motor is connected to the lead screw, the lead screw nut is fitted on the lead screw, the front end of the lead screw nut is connected to one end of the push rod, the lead screw nut is set inside the lead screw end housing, the lower side of the push rod is connected to one end of the sensor trigger rod, the other end of the sensor trigger rod passes through the linear slide on the lower side of the lead screw end housing and is set to correspond to the detection end of the displacement sensor, and the other end of the push rod is threaded to the rear side of the force booster block.

[0008] Preferably, the drive structure further includes: a servo motor, a motor end housing, a lead screw end housing, and a front cover connected sequentially from back to front. The bearing mounting component is connected to the outer motor end housing via a tapered roller bearing. One end of the bearing mounting component is connected to the output end of the servo motor via a first flat key, and the other end of the bearing mounting component is connected to the lead screw via a second flat key. A through hole is machined in the center of the front cover, and a copper bushing is installed inside the through hole. The front end of the push rod passes through the copper bushing, and a linear groove is provided on the inner wall of the lead screw end housing. A slider is provided on the outside of the lead screw nut, and the slider is slidably connected to the linear groove. The servo motor is connected to the body assembly via the motor end housing.

[0009] Preferably, the mold clamping assembly further includes: the lead screw end housing is connected to the sensor mounting base, the sensor mounting base is connected to the displacement sensor via a flat round head screw, and the spacing adjustment screw is threadedly connected to the inclined threaded hole.

[0010] Preferably, the welding acoustic assembly includes a transducer bracket, a piezoelectric transducer, an amplitude transformer, and a welding tool head, wherein the piezoelectric transducer, amplitude transformer, and welding tool head are connected sequentially from back to front, and the transducer bracket is detachably mounted on the outside of the piezoelectric transducer.

[0011] Preferably, the bottom mold is connected to the front end of the bottom mold support frame by bolts, and the bottom mold is set parallel to the front end of the welding tool head.

[0012] Preferably, the machine body assembly includes: a clamping set screw connected to an inclined machine body threaded hole; two symmetrically arranged clamping set screws with their protruding ends pressing against the lower part of the stepped section in the middle of the welding tool head; a first cylindrical pin detachably connected to the machine body is provided at the upper part of the stepped section in the middle of the welding tool head; a first needle roller bearing is connected to the machine body through a first snap ring hinge pin; a bottom mold support frame is rotatably connected to the machine body through a second snap ring hinge pin; and the lower part of the force-increasing block contacts the two first needle roller bearings.

[0013] Preferably, the body of the fuselage assembly includes: a rear cover and a front panel respectively provided on the rear and front sides of the symmetrically arranged left and right housings; a cable tray cover and a handle base provided on the upper side of the symmetrically arranged left and right housings from back to front; a bottom cover provided on the upper side of the symmetrically arranged left and right housings; the left and right ends of the first snap ring hinge pin, the first cylindrical pin, and the second snap ring hinge pin are respectively connected to the left and right housings; and inclined threaded holes for installing clamping set screws are machined on the left and right housings respectively.

[0014] Preferably, the left and right sides of the rear cover are connected to the left and right housings respectively via a connector. The connector includes a connecting piece with two through holes and a small screw passing through the through holes. The two small screws are detachably connected to the housing and the rear cover respectively. The rear side of the rear cover has a rear interface plate. The first wiring board and the second wiring board are set inside the rear cover. The welding sound component is electrically connected to the rear interface plate through the first wiring board. The mold closing component is electrically connected to the rear interface plate through the second wiring board. The handle is inserted into the rear side of the handle base and bolted to it. The handle base is provided with a switch button electrically connected to the wiring board. The handle base is provided with a lifting lug. The pin passes through the housing and is connected to the inner nut pin hole on the bottom cover plate. The machine body assembly also includes: a positioner upper cover plate, a positioner lower base plate, and a positioner side plate. The front end of the front side plate is connected to the positioner lower base plate. The positioner lower base plate is provided with a tooth groove. The positioner upper cover plate is provided with corresponding teeth on the bottom. The positioner lower base plate and the positioner upper cover plate are adjusted by meshing at different positions and are fixed by bolts.

[0015] An ultrasonic copper tube sealing and welding method using electric servo closed-loop control includes the following steps: Step 1: Assemble the ultrasonic copper tube sealing and welding device based on closed-loop servo control, and confirm that all electrical connections between it and the control box are correct and reliable. Step 2: Fine-tune the minimum safe distance between the bottom mold and the welding tool head by screwing in the spacing adjustment screw; Step 3: Select the calibration mode, insert the feeler gauge between the bottom mold and the welding tool head in sequence, and press the start button; the welding base will automatically rise, the displacement sensor will record the corresponding position value, and the calibration will be completed. Step 4: Adjust the position of the locator side plate and select the welding area to be used on the welding tool head; Step 5: Set the welding parameters and welding mode for the copper tube of the corresponding specification; place the copper tube to be welded between the bottom mold and the welding tool head, and keep it close to the side plate of the locator; the servo motor drives the push rod to push the bottom mold to rise, and the height sensor monitors the rise height of the bottom mold in real time; after compressing the copper tube to the starting welding height, the welding sound component starts ultrasonic vibration to complete the welding and reach the preset final welding height; the servo motor reverses, and the spring causes the bottom mold support frame to quickly reset.

[0016] The present invention has the following beneficial effects: The ultrasonic copper tube sealing and welding device with electric servo closed-loop control proposed in this invention replaces traditional pneumatic components with servo motor components, fundamentally avoiding pressure and height fluctuations caused by the compressibility of air in the pneumatic system, and realizing precise control and active adjustment of pressure and height during the welding process. This invention establishes a closed-loop process based on the target height by feeding back real-time welding height information to the servo system. This effectively solves the industry problem of difficulty in actively adjusting welding height and improving welding consistency caused by insufficient thrust and stroke control precision in pneumatic systems.

[0017] This invention utilizes 26-pin terminals arranged on the first and second terminal boards to achieve rapid disconnection of electrical connections when the rear cover is removed, facilitating maintenance and debugging. This invention, based on a combination structure of cylindrical pins and clamping set screws, enables convenient clamping and quick replacement of welding sound components, improving equipment maintainability; and through the integrated bearing mounting component, it realizes torque transmission between the servo motor and the lead screw, axial fixation of the lead screw, and installation of tapered roller bearings, significantly reducing the axial dimension. This invention can significantly improve the control accuracy of welding pressure and height, realizing a fundamental shift from passive monitoring to active control of welding height, and providing the refrigeration industry with a copper pipe sealing solution that can achieve high consistency and high reliability welding. Attached Figure Description

[0018] Figure 1 An isometric view of an ultrasonic copper tube sealing and welding device based on closed-loop servo control.

[0019] Figure 2 This is an isometric drawing of the fuselage components.

[0020] Figure 3 This is an isometric view of the interior of the fuselage components.

[0021] Figure 4 This is an isometric view of the welding acoustic assembly.

[0022] Figure 5Isometric view of the servo clamping assembly.

[0023] Figure 6 A front sectional view of the servo mold clamping assembly.

[0024] Figure 7 This is a top sectional view of the servo mold clamping assembly.

[0025] Figure 8 This is a sectional view of the servo mold clamping component along direction A. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0027] Specific implementation method one: Combining Figure 1-8 This embodiment describes an ultrasonic copper tube sealing and welding device with electric servo closed-loop control, comprising: a body assembly 1, a welding acoustic component 2, and a mold closing assembly 3. The welding acoustic component 2 is a welding acoustic component. The welding acoustic component 2 and the mold closing assembly 3 are disposed inside the body assembly 1, and the welding acoustic component 2 and the mold closing assembly 3 cooperate to perform welding at the ends of the body assembly that extend out of it. The mold clamping assembly 3 includes: a drive structure, a bottom mold support frame 3-4, a spring 3-6, a force-increasing block 3-10, a roller 3-8, and a displacement sensor 3-11. The drive structure is connected to the machine body assembly 1, and its output end is connected to the force-increasing block 3-10. The rear end of the bottom mold support frame 3-4 is rotatably connected to the machine body assembly via a rotating shaft and is positioned between the welding acoustic assembly 2 and the mold clamping assembly 3. The front side of the bottom mold support frame 3-4 is sequentially equipped with a spring 3-6, a roller 3-8, and a bottom mold 3-9 from back to front. The upper end of the spring 3-6 presses against the outer wall of the welding acoustic assembly 2, and the lower end of the spring 3-6 is fixedly connected to the bottom mold support frame 3-4. The force-increasing block 3-10 has a force-increasing ramp that cooperates with the roller 3-8. The roller 3-8 uses a needle roller bearing. The inner ring of wheel 3-8 is rotatably connected to the bottom mold support frame 3-4 via cylindrical pin 3-7. The bottom mold 3-9 at the front end of the bottom mold support frame 3-4 is correspondingly set with the welding sound component 2. A displacement sensor 3-11 is set below the force-enhancing block 3-10. The driving device can drive the force-enhancing block 3-10 to move forward in a straight line. The force-enhancing ramp of the force-enhancing block 3-10 pushes the roller 3-8 used for friction reduction to rotate and drive the bottom mold 3-9 at the front end of the bottom mold support frame 3-4 to move upward. Compared with parallel mold closing, the rotary mold closing of the present invention requires the addition of four guide columns, which makes the structure complex. In addition, the bottom mold support is not ideal in terms of force, and the bending moment it bears is large, resulting in large deformation. The present invention is reasonably designed based on portability and lightweight, and is more economical and convenient to use.

[0028] Specific Implementation Method Two: Combining Figure 1-8 This embodiment describes an ultrasonic copper tube sealing and welding device with electric servo closed-loop control. The drive structure includes: a servo motor 3-1, a lead screw end housing 3-3, a push rod 3-13, a lead screw 3-20, a lead screw nut 3-21, and a sensor trigger rod 3-23. The servo motor 3-1 is bolted to the rear end of the machine body assembly 1. The output end of the servo motor 3-1 is connected to the lead screw 3-20. The lead screw nut 3-21 is fitted onto the lead screw 3-20 and bolted to it. The front end of the lead screw nut 3-21 is bolted to one end of the push rod 3-13. The lead screw nut 3-21 is located inside the lead screw end housing 3-3. The lower side of the lead screw nut 3-21 or the push rod 3-13... The lower side is fixedly connected to one end (upper) of the sensor trigger rod 3-23. A linear slide is provided on the lower side of the lead screw end housing 3-3. The other end of the sensor trigger rod 3-23 passes through the linear slide on the lower side of the lead screw end housing 3-3 and is set to correspond to the detection end of the displacement sensor 3-11. This can prevent the rotation of the lead screw nut from causing motion deviation, and detect the movement distance of the bottom mold by moving the trigger rod. The other end of the push rod 3-13 is threaded to the rear side of the force-increasing block 3-10. The front end of the force-increasing block 3-10 is provided with an opening, which can avoid the spacing adjustment screw 3-24 while reducing weight and not affecting rigidity. It is a reserved working position for the hexagonal wrench to adjust the spacing adjustment screw 3-24, making adjustment convenient. Specific implementation method three: Combining Figure 1-8This embodiment describes an ultrasonic copper tube sealing and welding device with electric servo closed-loop control. The drive structure further includes: a motor end housing 3-2, a front end cover 3-5, a first flat key 3-15, a stop washer and locking nut 3-16, a tapered roller bearing 3-17, a bearing mounting component 3-18, a second flat key 3-19, a copper bushing 3-22, a lead screw fixing screw 3-25, and a slider 3-26. The servo motor 3-1, motor end housing 3-2, lead screw end housing 3-3, and front end cover 3-5 are sequentially bolted from back to front. The bearing mounting component 3-18 is connected to the outer motor end housing 3-2 via the tapered roller bearing 3-17 sleeved on the outer side. The rear side of the bearing mounting component 3-18 is threaded with a stop washer and locking nut 3-16 for stopping. The washer lock nut 3-16 presses against the inner ring of the tapered roller bearing 3-17. One end of the bearing mounting part 3-18 is connected to the output end of the servo motor 3-1 through the first flat key 3-15, and the other end of the bearing mounting part 3-18 is connected to the rear end of the lead screw 3-20 through the second flat key 3-19. The center of the front end cover 3-5 is machined with a through hole, and a copper bushing 3-22 is set in the through hole. The front end of the push rod 3-13 passes through the copper bushing 3-22 to achieve a sliding connection. The inner wall of the lead screw end housing 3-3 is provided with a linear groove. A slider 3-26 (anti-rotation clip) is fixedly set on the outside of the lead screw nut 3-21. The slider 3-26 is slidably connected to the linear groove. The lead screw fixing screw 3-25 passes through the radial hole of the bearing mounting part 3-18 and is threadedly connected to the lead screw nut 3-21.

[0029] Specific implementation method four: Combination Figure 1-8 This embodiment describes an ultrasonic copper tube sealing and welding device with electric servo closed-loop control. The mold closing assembly 3 is a servo mold closing assembly, which also includes: a flat round head screw 3-12, a sensor mounting base 3-14, and a spacing adjustment screw 3-24. The lower front side of the lead screw end housing 3-3 is bolted to the sensor mounting base 3-14. The sensor mounting base 3-14 is connected to the displacement sensor 3-11 through the flat round head screw 3-12. The spacing adjustment screw 3-24 is threadedly connected to an inclined threaded hole. The extension length of the end of the spacing adjustment screw 3-24 is used to adjust the minimum distance between the mold closing assembly 3 and the welding acoustic assembly 2, ensuring that a certain safe distance is maintained between the bottom mold and the welding tool head. The safe distance is less than the distance required for copper tube welding, which is used to ensure that the bottom mold will not directly contact the welding tool head in the absence of copper tube, effectively preventing the tool head and bottom mold from being scrapped.

[0030] Specific Implementation Method Five: Combining Figure 1-8This embodiment describes an ultrasonic copper tube sealing and welding device with electric servo closed-loop control. The welding acoustic component 2 includes: a transducer bracket 2-1, a piezoelectric transducer 2-2, an amplitude transformer 2-3, and a welding tool head 2-4. The piezoelectric transducer 2-2, amplitude transformer 2-3, and welding tool head 2-4 are connected sequentially from back to front. The transducer bracket 2-1 is detachably fitted onto the outside of the piezoelectric transducer 2-2 to accommodate the dimensions of the inner cavity of the machine body component 1. Different inner diameter transducer brackets 2-1 can be used to achieve this. It can be adapted to various piezoelectric transducer models. The connection between the piezoelectric transducer 2-2, the amplitude rod 2-3, and the welding tool head 2-4 is provided with a threaded countersunk hole at the center. The two ends of the first screw are threaded to the piezoelectric transducer 2-2 and the amplitude rod 2-3 respectively, and the two ends of the second screw are threaded to the amplitude rod 2-3 and the welding tool head 2-4 respectively. This makes the relative positions of the assembled piezoelectric transducer 2-2, the amplitude rod 2-3, and the welding tool head 2-4 fixed, and facilitates disassembly, replacement, and maintenance.

[0031] Specific Implementation Method Six: Combination Figure 1-8 This embodiment describes an ultrasonic copper tube sealing and welding device with electric servo closed-loop control. The bottom mold 3-9 is connected to the front end of the bottom mold support frame 3-4 by bolts. The bottom mold 3-9 and the front end of the welding tool head 2-4 can be set parallel to each other. This invention ensures that the upper and lower molds are parallel at the position where the copper tube sealing is completed, and ensures that the bottom mold 3-9 and the front end of the welding tool head 2-4 correspond accurately.

[0032] Specific implementation method seven: Combining Figure 1-8 This embodiment describes an ultrasonic copper tube sealing and welding device with electric servo closed-loop control. The body assembly 1 includes: a first retaining ring hinge pin 1-15, a clamping set screw 1-16, a first cylindrical pin 1-17, a second retaining ring hinge pin 1-19, and a first needle roller bearing 1-26. The clamping set screw 1-16 connects to an inclined threaded hole in the body. The protruding ends of the two symmetrically arranged clamping set screws 1-16 press against the lower part of the stepped section in the middle of the welding tool head 2-4. The upper part of the stepped section in the middle of the welding tool head 2-4 is provided with a first cylindrical pin 1-17 detachably connected to the body assembly. -17 has a stop sleeve 1-18 installed in the annular notch at the end. Stable clamping at the joint of the welding acoustic component is achieved by adjusting the clamping set screw 1-16. The first needle roller bearing 1-26 is connected to the machine body assembly through the first snap ring hinge pin 1-15. A copper washer 1-25 is provided on the side of the first needle roller bearing 1-26. Bushings 1-14 are installed at both ends of the first snap ring hinge pin 1-15 and are connected to the machine body through the bushings 1-14. The bottom mold support frame 3-4 is rotatably connected to the machine body assembly through the second snap ring hinge pin 1-19. The bottom of the force-increasing block 3-10 contacts the two first needle roller bearings 1-26 to achieve guiding and friction reduction.

[0033] Specific implementation method eight: Combination Figure 1-8 This embodiment describes an ultrasonic copper tube sealing and welding device with electric servo closed-loop control. The body assembly 1 includes: a rear cover 1-2, a cable cover 1-3, a left housing 1-4, a right housing 1-6, a handle base 1-9, a front side plate 1-10, and a bottom cover 1-23. The rear cover 1-2 and the front side plate 1-10 are symmetrically arranged on the rear and front sides of the left housing 1-4 and right housing 1-6, respectively. -6 has a cable cover plate 1-3 and a handle base 1-9 arranged from back to front on the upper side. The left housing 1-4 and the right housing 1-6 are symmetrically arranged with a bottom cover plate 1-23 on the upper side. The left and right ends of the first buckle hinge pin 1-15, the first cylindrical pin 1-17, and the second buckle hinge pin 1-19 are connected to the left housing 1-4 and the right housing 1-6 respectively. The left housing 1-4 and the right housing 1-6 are respectively machined with inclined machine body threaded holes for installing clamping set screws 1-16.

[0034] Specific Implementation Method Nine: Combining Figure 1-8 This embodiment describes an ultrasonic copper tube sealing and welding device with electric servo closed-loop control. The body assembly 1 further includes: a rear interface plate 1-1, a handle 1-5, a switch button 1-7, a lifting lug 1-8, a positioner upper cover plate 1-11, a positioner lower base plate 1-12, a positioner side plate 1-13, a first wiring plate 1-21, a second wiring plate 1-22, and an inner nut pin 1-24. The left and right sides of the rear cover 1-2 are connected to the left housing 1-4 and the right housing 1-6 respectively via a connector 1-20. The connector 1-20 includes a connecting piece with two through holes and a small screw passing through the through holes. The two small screws are detachably connected to the left / right housing and the rear cover 1-2 respectively. The rear side of the rear cover 1-2 has a rear interface plate 1-1. The first wiring plate 1-21 and the second wiring plate 1-22 are disposed inside the rear cover 1-2. The welding acoustic assembly 2... The first wiring plate 1-21 is electrically connected to the rear interface plate 1-1. The mold closing assembly 3 is electrically connected to the rear interface plate 1-1 through the second wiring plate 1-22. The handle 1-5 is inserted into the rear side of the handle base 1-9 and bolted to it. The handle base 1-9 is provided with a switch button 1-7 electrically connected to the wiring plate. The handle base 1-9 is provided with a lifting lug 1-8. The pin passes through the left / right housing and is connected to the inner nut pin hole 1-24 on the bottom cover plate 1-23. The annular groove at the end of the pin is provided with a retaining ring for fixation. The front ends of the two front side plates 1-10 are fixedly connected to the lower base plate 1-12 of the locator. The lower base plate 1-12 of the locator is provided with a toothed groove. The lower cover plate 1-11 of the locator is provided with a corresponding tooth. The lower base plate 1-12 of the locator and the upper cover plate 1-11 of the locator achieve position adjustment through meshing at different positions and are fixed by bolts. This invention replaces traditional pneumatic components with servo motor assemblies, fundamentally avoiding pressure and height fluctuations caused by the compressibility of air in pneumatic systems, and achieving precise control and active adjustment of pressure and height during the welding process. By feeding real-time welding height information back to the servo system, a closed-loop process based on the target height is established, effectively solving the industry problem of insufficient thrust and stroke control precision in pneumatic systems, which makes it difficult to actively adjust welding height and improve welding consistency. The innovation of this invention lies in its deep integration of high-precision electromechanical transmission technology, real-time feedback-based closed-loop control technology, and convenient maintenance structure design, which can significantly improve the control precision of welding pressure and height, realizing a fundamental shift from passive monitoring to active control of welding height. Compared with traditional pneumatically driven ultrasonic sealing devices, this device has significant advantages in control precision and welding consistency, providing the refrigeration industry with a copper pipe sealing solution that can achieve high consistency and high reliability welding.

[0035] Specific Implementation Method Ten: Combining Figure 1-8 This embodiment describes an ultrasonic copper tube sealing and welding method with electric servo closed-loop control, which includes the following steps: Step 1: Assemble the ultrasonic copper tube sealing and welding device based on closed-loop servo control, and confirm that all electrical connections between it and the control box are correct and reliable. Step 2: Fine-tune the minimum safe distance between the bottom mold 3-9 and the welding tool head 2-4 by screwing in the spacing adjustment screw 3-24; this distance can prevent the two from being damaged by rigid collision when the equipment is accidentally started without copper pipe. Step 3: After replacing the welding head / welding base (bottom mold) or adjusting the spacing, height calibration must be performed; select calibration mode on the controller, insert 1 mm and 2 mm feeler gauges between the bottom mold 3-9 and the welding tool head 2-4 in sequence, and press the start button respectively; the device will automatically drive the welding base to rise, and the displacement sensor 3-11 will record the corresponding position values ​​to complete the calibration. Step 4: Adjust the position of the locator side plate 1-13 and select the welding area to be used on the welding tool head 2-4; Step 5: Set the welding parameters and welding mode for the corresponding copper tube specifications in the controller; place the copper tube to be welded between the bottom mold 3-9 and the welding tool head 2-4, and keep it close to the side plate 1-13 of the locator; press the start button, the servo motor 3-1 drives the push rod 3-13 to push the bottom mold 3-9 to rise, the height sensor 3-11 monitors the rise height of the bottom mold in real time, and feeds back the welding height information to the servo system to establish a closed-loop process based on the target height; after compressing the copper tube to the starting welding height, the welding acoustic component 2 starts ultrasonic vibration for about 0.4 seconds to complete the welding and reach the preset final welding height; then the servo motor 3-1 reverses, and the spring 3-6 causes the bottom mold support frame 3-4 to quickly reset; Step 6: After the current welding area is worn to a certain extent, adjust the positioner to activate the new area; if all three areas on one side are worn, the back cover 1-2 can be removed, the clamping set screws 1-16 can be loosened, the entire welding sound assembly 2 can be pulled out backward, flipped to the other unworn side and reinstalled; if both working surfaces are worn, a new welding tool head needs to be replaced. Step 7: After the copper pipe sealing operation is completed, turn off the power, and the device operation will end.

[0036] Example 1: Combination Figure 1-8 This invention innovatively proposes an ultrasonic copper pipe sealing welding device with electric servo closed-loop control of welding height. An example is the sealing welding of copper pipes for a household refrigerator using this device.

[0037] This device employs a highly integrated design, replacing traditional pneumatic components with servo motor assemblies. This fundamentally avoids pressure and height fluctuations caused by the compressibility of air in pneumatic systems, enabling precise control and active adjustment of pressure and height during the welding process. By feeding real-time welding height information back to the servo system, a closed-loop process based on the target height is established, effectively solving the industry problem of insufficient thrust and stroke control precision in pneumatic systems, which hinders active adjustment of welding height and makes it difficult to improve welding consistency. This device significantly improves the control precision of welding pressure and height, achieving a fundamental shift from passive monitoring to active control of welding height. It provides the refrigeration industry with a copper tube sealing solution capable of achieving high consistency and high reliability welding. Specifically, it includes: The internal wiring of the housing assembly 1 is integrated into a DB15 socket, which is mounted on a first junction box 1-21. The first junction box 1-21 is fixed to the left housing 1-4 and the right housing 1-6 of the front housing. A DB15 plug is mounted on a second junction box 1-22, which connects to an external control box. The second junction box 1-22 is fixed to the rear cover 1-2. The connecting cables are protected by cable conduits mounted on the rear interface plate 1-1. After releasing the fasteners 1-20, the rear cover 1-2 can be completely removed, allowing the DB15 plug to be separated from the socket, enabling quick disconnection of most electrical connections.

[0038] The handle base 1-9, left housing 1-4, and right housing 1-6 are all equipped with threaded mounting holes for lifting lugs, enabling the device to be lifted from multiple directions to accommodate the sealing operations of different production lines. Simultaneously, the device integrates switch buttons 1-7 at each of the three operating positions, significantly improving ease of operation. All signal wires for the switch buttons are concealed within the cable tray cover 1-3, effectively preventing exposed wiring and eliminating safety hazards.

[0039] Both the lower base plate 1-12 and the upper cover plate 1-11 of the locator are machined with toothed scales. Through the meshing of these teeth, the axial position of the side plate 1-13 of the locator can be precisely adjusted. When sealing the copper tube, the copper tube to be sealed is placed tightly against the side plate of the locator. Using this as a reference, the width of the welding area on the copper tube by the welding tool head 2-4 can be indirectly limited. Based on this, the working end face of the welding tool head 2-4 can be conceptually divided into three areas. When a certain area is worn due to welding operations of the corresponding width, by adjusting the position of the side plate of the locator to change the positioning reference of the copper tube, the new area of ​​the tool head can participate in welding, thereby achieving efficient utilization and extended service life.

[0040] The first needle roller bearing 1-26 is mounted on the first retaining ring hinge pin 1-15, with copper washers 1-25 and bushings 1-14 on its two sides. The two ends of the first retaining ring hinge pin 1-15 are axially limited by snap rings to prevent the bushings 1-14 and bearings from falling off. The core function of the first needle roller bearing 1-26 is to withstand the vertical load generated by the force-increasing ramp 3-10 during the sealing process, while ensuring low-friction rotational engagement of the force-increasing ramp 3-10 during operation.

[0041] The welding tool head 2-4 is clamped using the following structure: its arc surface at the joint is tangent to the cylindrical pin 11-17 for radial positioning; the first cylindrical pin 1-17 is wrapped by a flexible stop sleeve 1-18 to provide a small elastic compensation range. Simultaneously, a clamping set screw 1-16 is provided on both the left housing 1-4 and the right housing 1-6, acting together on the joint surface of the welding tool head 2-4 to achieve reliable axial and circumferential fastening. The transducer bracket 2-1 is fixed by the cylindrical cavity formed by the rear ends of the left housing 1-4 and the right housing 1-6. These structures together provide stable support for the entire welding acoustic assembly 2, completing its clamping. When the welding acoustic assembly 2 needs to be replaced, simply loosen the two clamping set screws 1-16 to pull the entire assembly backward, making the operation convenient.

[0042] The left housing 1-4 and the right housing 1-6 are reliably connected in the following ways: at the front end, they are connected by three hexagon socket screws; on the upper side, they are connected to the cable cover 1-3 and the handle base 1-9; in the lower middle part, they are fastened and positioned by one hexagon socket pin 1-24 and two hexagon socket screws; and at the lower rear part, they are connected and sealed by the bottom cover 1-23. This multi-directional, multi-point connection structure ensures the rigidity and stability of the connection between the left and right housings.

[0043] The upper and lower parts of the welding tool head 2-4 are provided with working surfaces for welding. To further improve utilization, each working surface can be conceptually divided into three specific welding areas for rotation after wear.

[0044] The bottom mold support frame 3-4 has a mounting cavity at its front for mounting the cylindrical pin 3-7 and the second needle roller bearing 3-8. When the push rod 3-13 pushes the force-enhancing ramp 3-10 forward, the second needle roller bearing 3-8 will roll on the ramp surface. The resulting force drives the bottom mold support frame 3-4 to rotate around the second snap ring hinge pin 1-19, thereby driving the bottom mold 3-9 and the welding tool head 2-4 to complete the mold closing action, so as to realize the shearing and sealing of the copper tube.

[0045] The bottom mold support frame 3-4 is machined with spring mounting holes for installing spring 3-6. The function of spring 3-6 is to provide a reset driving force for the bottom mold support frame 3-4 after the sealing operation is completed and the push rod 3-13 retracts, so that it can quickly leave the welding position, thereby improving the production efficiency of the equipment.

[0046] The displacement sensor 3-11 is installed inside the sensor mounting base 3-14 and is axially limited by a flat-head screw 3-12 to prevent it from coming out. The sensor trigger rod 3-23 is threadedly connected to the threaded hole of the push rod 3-13. When the push rod 3-13 moves forward, it drives the sensor trigger rod 3-23 to move synchronously, thereby pressing the probe of the displacement sensor 3-11, monitoring the linear displacement of the push rod in real time, and using this displacement signal to realize closed-loop servo control of the push rod stroke.

[0047] The motor end housing 3-2 is machined with a set of threaded holes and a set of countersunk screw holes. The threaded holes are used to install screws to connect and fix the servo motor 3-1; the countersunk screw holes are used to mate and fasten with the lead screw end housing 3-3.

[0048] A pair of tapered roller bearings 3-17 are mounted back-to-back to withstand the shaft reaction force, primarily axial. Their axial limiting structure is as follows: the outer ring of the left bearing is limited by the boss on the motor end housing 3-2, and the inner ring is locked by a locking washer and nut 3-16; the outer ring of the right bearing is limited by the boss on the screw end housing 3-3, and the inner ring is limited by the shoulder of the bearing mounting piece 3-18. This shaft system primarily bears leftward axial force, which is transmitted through the screw 3-20 to the bearing mounting piece 3-18, then via the tapered roller bearings 3-17, and finally to the motor end housing 3-2, thus ensuring that this axial force does not act on the output shaft of the servo motor 3-1.

[0049] The torque transmission path of the device is as follows: the output torque of the servo motor 3-1 is transmitted to the bearing mounting part 3-18 through the flat key 13-15, and then to the lead screw 3-20 through the flat key 23-19. This rotational motion is converted into the axial linear motion of the lead screw nut 3-21 by the lead screw pair, and then finally drives the bottom mold support frame 3-4 to achieve the mold closing action through components such as the push rod 3-13.

[0050] The lead screw 3-20 withstands bidirectional axial force and torque during operation. The torque is transmitted and borne through the keyway of the flat key 23-19 and the bearing mount 3-18. During mold closing, the main leftward axial force on the lead screw is borne by the mating end face between the lead screw shoulder and the bearing mount 3-18. During retraction, the smaller rightward axial force on the lead screw is borne by the threaded connection between the lead screw 3-20 and the bearing mount 3-18. Because the axial force is small during retraction, and there is a gap between the threaded mounting hole on the bearing mount 3-18 and the hex socket screw, this screw connection mainly relies on friction to offset the small rightward axial force to prevent circumferential movement of the lead screw, and does not bear the working torque or the main leftward axial force during mold closing.

[0051] The spacing adjustment screw 3-24 is used to set and fine-tune the minimum safe distance between the bottom mold 3-9 and the welding tool head 2-4. By screwing in this screw, the bottom mold can be forced to maintain a preset gap with the welding tool head when returning to its original position. This design effectively avoids direct rigid contact between the bottom mold and the welding tool head due to accidental equipment startup when no copper tube is placed, thereby preventing damage to both due to collision.

[0052] Two anti-rotation clips 3-26 are clamped between the lead screw nut 3-21 and the push rod 3-13. An axial groove is machined on the inner wall of the lead screw end housing 3-3, and the protruding portion of the anti-rotation clip 3-26 is embedded in this groove, forming a sliding fit. This structure effectively restricts the circumferential rotation of the lead screw nut 3-21, ensuring that it can only move axially in a linear fashion along the groove direction, thereby accurately converting the rotational motion of the lead screw 3-20 into the linear motion of the push rod 3-13.

[0053] The front cover 3-5 has a copper bushing 3-22 inside. The copper bushing 3-22 acts as a sliding bearing to support the push rod 3-13 and reduce friction and wear during its reciprocating motion.

[0054] The bottom mold support frame 3-4 adopts a bifurcated structure, which allows the servo mold clamping assembly 3 to be moved forward, effectively reducing the axial dimension of the device and achieving a miniaturized design. At the same time, connecting material is retained between the ends of the bifurcated structure to form an integral frame, which enhances the structural rigidity and effectively suppresses deformation that may occur during machining.

[0055] The ultrasonic copper tube sealing and welding device based on closed-loop servo control is assembled, and all electrical connections between it and the control box are confirmed to be correct and reliable. The device is suspended using lifting lugs for easy operator access. The minimum safe distance between the bottom mold 3-9 and the welding tool head 2-4 is fine-tuned by screwing in the spacing adjustment screw 3-24. This clearance prevents damage from rigid collisions when the device is accidentally started without copper tubes. Height calibration is necessary after changing the welding head / welding seat or adjusting the spacing. Select the calibration mode on the controller, insert 1 mm or 2 mm feeler gauges between the bottom mold and the welding tool head, and press the start button. The device will automatically drive the welding seat upwards, and the displacement sensor 3-11 will record the corresponding position values, completing the calibration. Adjust the position of the positioner side plate 1-13 to select the welding area to be used on the welding tool head 2-4. Set the welding parameters and welding mode for the corresponding copper tube specifications in the controller. Place the copper tube to be welded between the bottom mold 3-9 and the welding tool head 2-4, ensuring it is flush against the positioner side plate 1-13. Press the start button. Servo motor 3-1 drives push rod 3-13 to lift bottom mold 3-9, compressing the copper tube to the starting welding height. Welding acoustic assembly 2 then initiates ultrasonic vibration for approximately 0.4 seconds to complete welding and reach the preset final welding height. Subsequently, servo motor 3-1 reverses, and spring 3-6 causes bottom mold support frame 3-4 to quickly return to its original position. Once the current welding area is worn to a certain extent, adjust the positioner to activate a new area. If all three areas on one side are worn, remove the rear cover 1-2, loosen the clamping screw 1-16, pull the entire welding acoustic assembly 2 backward, flip it to the other unworn side, and reinstall it. If both working surfaces are worn, a new welding tool head must be replaced. After the copper tube sealing operation is completed, turn off the power; the device operation ends.

[0056] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be permuted and combined. Those skilled in the art can exhaust all possibilities based on the mathematical knowledge of permutation and combination. Therefore, the present invention will not describe the technical solutions after permutation and combination one by one, but it should be understood that the technical solutions after permutation and combination have been disclosed by the present invention.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An ultrasonic copper tube sealing and welding device with electric servo closed-loop control, characterized in that: include: The body assembly (1) is equipped with a welding sound assembly (2) and a mold closing assembly (3); The mold closing assembly (3) includes: a drive structure connected to the body assembly (1), the output end of the drive structure connected to the force-increasing block (3-10), the rear end of the bottom mold support frame (3-4) rotatably set between the welding sound assembly (2) and the mold closing assembly (3), the front side of the bottom mold support frame (3-4) is provided with a spring (3-6), a roller (3-8) and a bottom mold (3-9), the force-increasing block (3-10) has a force-increasing ramp that cooperates with the roller (3-8), the bottom mold (3-9) at the front end of the bottom mold support frame (3-4) is correspondingly set with the welding sound assembly (2), and a displacement sensor (3-11) is set below the force-increasing block (3-10).

2. The ultrasonic copper tube sealing and welding device with electric servo closed-loop control according to claim 1, characterized in that: The drive structure includes: the output end of the servo motor (3-1) is connected to the lead screw (3-20), the lead screw nut (3-21) is fitted on the lead screw (3-20), the front end of the lead screw nut (3-21) is connected to one end of the push rod (3-13), the lead screw nut (3-21) is set inside the lead screw end housing (3-3), the lower side of the push rod (3-13) is connected to one end of the sensor trigger rod (3-23), the other end of the sensor trigger rod (3-23) passes through the linear slide on the lower side of the lead screw end housing (3-3) and is set to correspond to the detection end of the displacement sensor (3-11), and the other end of the push rod (3-13) is threadedly connected to the rear side of the force booster block (3-10).

3. The ultrasonic copper tube sealing and welding device with electric servo closed-loop control according to claim 2, characterized in that: The drive structure also includes: a servo motor (3-1), a motor end housing (3-2), a lead screw end housing (3-3), and a front cover (3-5) connected sequentially from back to front. A bearing mounting component (3-18) is connected to the outer motor end housing (3-2) via a tapered roller bearing (3-17). One end of the bearing mounting component (3-18) is connected to the output end of the servo motor (3-1) via a first flat key (3-15), and the other end of the bearing mounting component (3-18) is connected via a second flat key (3-17). -19) is connected to the lead screw (3-20). The center of the front cover (3-5) is machined with a through hole. A copper bushing (3-22) is installed in the through hole. The front end of the push rod (3-13) passes through the copper bushing (3-22). A linear groove is provided on the inner wall of the lead screw end housing (3-3). A slider (3-26) is provided on the outer side of the lead screw nut (3-21). The slider (3-26) is slidably connected to the linear groove. The servo motor (3-1) is connected to the machine body assembly (1) through the motor end housing (3-2).

4. The ultrasonic copper tube sealing and welding device with electric servo closed-loop control according to claim 3, characterized in that: The mold assembly (3) further includes: the lead screw end housing (3-3) is connected to the sensor mounting base (3-14), the sensor mounting base (3-14) is connected to the displacement sensor (3-11) through a flat round head screw (3-12), and the spacing adjustment screw (3-24) is threadedly connected to the inclined threaded hole.

5. The ultrasonic copper tube sealing and welding device with electric servo closed-loop control according to claim 4, characterized in that: The welding acoustic assembly (2) includes: a transducer bracket (2-1), a piezoelectric transducer (2-2), an amplitude transformer (2-3), and a welding tool head (2-4). The piezoelectric transducer (2-2), the amplitude transformer (2-3), and the welding tool head (2-4) are connected sequentially from back to front. The transducer bracket (2-1) is detachably mounted on the outside of the piezoelectric transducer (2-2).

6. The ultrasonic copper tube sealing and welding device with electric servo closed-loop control according to claim 5, characterized in that: The bottom mold (3-9) is connected to the front end of the bottom mold support frame (3-4) by bolts, and the bottom mold (3-9) is set parallel to the front end of the welding tool head (2-4).

7. The ultrasonic copper tube sealing and welding device with electric servo closed-loop control according to claim 6, characterized in that: The body assembly (1) includes: a clamping set screw (1-16) connected to an inclined machine body threaded hole; the protruding ends of two symmetrically arranged clamping set screws (1-16) press against the lower part of the stepped section in the middle of the welding tool head (2-4); the upper part of the stepped section in the middle of the welding tool head (2-4) is provided with a first cylindrical pin (1-17) detachably connected to the machine body; the first needle roller bearing (1-26) is connected to the machine body through a first snap ring hinge pin (1-15); the bottom mold support frame (3-4) is rotatably connected to the machine body through a second snap ring hinge pin (1-19); and the lower part of the force-increasing block (3-10) contacts the two first needle roller bearings (1-26).

8. The ultrasonic copper tube sealing and welding device with electric servo closed-loop control according to claim 6, characterized in that: The body of the fuselage assembly (1) includes: a rear cover (1-2) and a front side plate (1-10) respectively provided on the rear and front sides of the symmetrically arranged left housing (1-4) and right housing (1-6); a cable cover plate (1-3) and a handle base (1-9) are provided on the upper side of the symmetrically arranged left housing (1-4) and right housing (1-6) from back to front; a bottom cover plate (1-23) is provided on the upper side of the symmetrically arranged left housing (1-4) and right housing (1-6); the left and right ends of the first buckle hinge pin (1-15), the first cylindrical pin (1-17), and the second buckle hinge pin (1-19) are respectively connected to the left housing (1-4) and right housing (1-6); and inclined fuselage threaded holes for installing clamping set screws (1-16) are respectively machined on the left housing (1-4) and right housing (1-6).

9. The ultrasonic copper tube sealing and welding device with electric servo closed-loop control according to claim 8, characterized in that: The left and right sides of the rear cover (1-2) are connected to the left housing (1-4) and the right housing (1-6) respectively via a connector (1-20). The connector (1-20) includes a connecting piece with two through holes and a small screw passing through the through holes. The two small screws are detachably connected to the housing and the rear cover (1-2) respectively. The rear side of the rear cover (1-2) has a rear interface plate (1-1). A first wiring board (1-21) and a second wiring board (1-22) are located inside the rear cover (1-2). The welding acoustic assembly (2) is electrically connected to the rear interface plate (1-1) via the first wiring board (1-21). The mold closing assembly (3) is electrically connected to the rear interface plate (1-1) via the second wiring board (1-22). The handle (1-5) is inserted into the back of the handle base (1-9) and bolted to it. The handle base (1-9) is equipped with a switch button (1-7) that is electrically connected to the terminal block. The handle base (1-9) is equipped with a lifting lug (1-8). The pin passes through the housing and is connected to the inner nut pin hole (1-24) on the bottom cover plate (1-23). ​​The front end of the front side plate (1-10) is connected to the lower base plate (1-12) of the positioner. The lower base plate (1-12) of the positioner is equipped with a toothed groove. The lower cover plate (1-11) of the positioner is equipped with corresponding teeth. The lower base plate (1-12) of the positioner and the upper cover plate (1-11) of the positioner achieve position adjustment through meshing at different positions and are fixed by bolts.

10. An ultrasonic copper tube sealing and welding method with electric servo closed-loop control, characterized in that: The ultrasonic copper tube sealing and welding device with electric servo closed-loop control as described in any one of claims 1-9 includes the following steps: Step 1: Assemble the ultrasonic copper tube sealing and welding device based on closed-loop servo control, and confirm that all electrical connections between it and the control box are correct and reliable. Step 2: Fine-tune the minimum safe distance between the bottom mold (3-9) and the welding tool head (2-4) by screwing in the spacing adjustment screw (3-24); Step 3: Select the calibration mode and insert the feeler gauge between the bottom mold (3-9) and the welding tool head (2-4) in sequence; the welding base will be automatically driven to rise, and the displacement sensor (3-11) will record the corresponding position value to complete the calibration; Step 4: Adjust the position of the locator side plate (1-13) and select the welding area to be used on the welding tool head (2-4); Step 5: Set the welding parameters and welding mode for the copper tube of the corresponding specification; place the copper tube to be welded between the bottom mold (3-9) and the welding tool head (2-4), and keep it close to the side plate (1-13) of the locator; the servo motor (3-1) drives the push rod (3-13) to push the bottom mold (3-9) to rise, and the height sensor (3-11) monitors the height of the bottom mold in real time; after compressing the copper tube to the starting welding height, the welding sound component (2) starts ultrasonic vibration to complete the welding and reaches the preset final welding height; the servo motor (3-1) reverses, and the spring (3-6) causes the bottom mold support frame (3-4) to quickly reset.

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