Vacuum-pumping sealing equipment and method for heat-insulating vessel

Abstract

The invention discloses vacuumizing sealing equipment and method for a heat insulation vessel. The vacuumizing sealing equipment comprises a rack, a vacuum pump, a control system, a jig jacking device, a positioning jig, an ultrasonic device, an infrared radiator, a vacuum machining head and a visual positioning and laser welding assembly. Vacuum pumping is accelerated through cooperation of an ultrasonic device and an infrared radiator, an air exhaust hole is accurately positioned through a visual positioning assembly, and a laser welding assembly seals the heat insulation vessel through the material of the laser melting heat insulation vessel. The method comprises the steps of vessel placing, jacking and sealing, vacuumizing, positioning, welding and material taking. The method solves the problems of long working procedure, high reject ratio, lead content, high energy consumption and the like of the traditional process, realizes lead-free production, improves the processing efficiency, reduces the cost and the energy consumption, and is suitable for small-batch rapid production.

Description

Technical Field

[0001] The present invention relates to the technical field of processing vacuum insulation containers, and particularly to a vacuum pumping and sealing device and method for insulation containers. Background Art

[0002] A vacuum insulation container is made of double-layer metal materials. A vacuum environment is formed between the double-layer metal materials through vacuum pumping, thereby reducing heat conduction and realizing the heat insulation function. Among them, the vacuum pumping and sealing process is particularly important.

[0003] The commonly used existing vacuum pumping and sealing process methods are: pressure sealing method, spinning sealing method, fusion sealing method (also known as tailless fusion sealing method). Currently, the tailless vacuum fusion sealing method is commonly used for vacuum pumping and sealing the bottom of vacuum insulation containers in the market. The tailless vacuum fusion sealing method is to place a spherical glass-based brazing flux on the air extraction hole. During the air extraction process, the glass-based brazing flux is in a solid state and will not block the air extraction hole. After the air extraction is completed, the container and the glass-based brazing flux are heated together at a high temperature above 500 °C to melt the glass-based brazing flux, thereby blocking the air extraction hole.

[0004] The disadvantages of this method are as follows: 1. The process time is long, and a single cycle is about 4 - 6 hours; 2. Due to the use of a large-volume vacuum chamber, usually multiple (more than 1000 pieces) insulation containers are processed at one time. The brazing flux is manually placed on a single container, and then multiple containers are centrally placed in a metal material frame. During the transportation process of the metal material frame to the vacuum chamber, the vibration generated will cause the glass-based brazing flux to shift, ultimately resulting in an increase in the defective rate; 3. The cost of the glass-based brazing flux is relatively high; 4. The glass-based brazing flux contains lead, and there are already customers in the market requiring that the insulation container itself and the production process should not contain lead; 5. The energy consumption is high. In order to heat a small amount of the glass-based brazing flux locally, the entire cavity is heated to 500 °C, resulting in a large waste of energy consumption.

[0005] Therefore, developing a new type of vacuum pumping and sealing device and method for insulation containers has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of the present invention is to provide a vacuum pumping and sealing device and method for insulation containers, to solve the problems existing in the existing vacuum pumping and sealing process, such as long process time, high defective rate, high cost, containing lead, and high energy consumption, to realize the lead-free of the product, improve the processing efficiency, and meet the requirements of small-batch and rapid production.

[0007] The above object of the present invention is achieved by the following technical solutions: A vacuum pumping and sealing device for heat-insulating vessels, comprising a frame, a vacuum pump and a control system. A fixture lifting device is provided on the frame. A positioning fixture is fixed on the lifting seat of the fixture lifting device. An ultrasonic device and an infrared radiator are provided on the positioning fixture. The vacuum pump is connected with a vacuum pipeline, and the end is connected with a vacuum processing head. A vision positioning and laser welding assembly is provided above the vacuum processing head.

[0008] Further, the ultrasonic device includes an ultrasonic generator and an ultrasonic transducer, which are connected by a cable. That is, the ultrasonic generator transmits high-frequency electrical signals to the ultrasonic transducer through the cable, driving the transducer to convert the electrical signals into mechanical vibrations. Among them, the output frequency range of the ultrasonic generator is 15 - 40 kHz, and the output power range is 30 - 1000 W.

[0009] Further, the vacuum processing head is of a small vacuum cavity structure, and the optical glass on the top is light-transmissive, facilitating the implementation of the functions of the vision positioning and laser welding assembly. A through hole is provided at the bottom of the vacuum processing head, and a sealing ring for vacuum pumping after sealing is provided around the through hole.

[0010] Further, the vision positioning and laser welding assembly includes a laser welding head and a vision positioning camera. The output power range of the laser welding head is 100 - 3000 W, and the wavelength is 800 - 1550 nm. Further, there is at least one vacuum processing head. When there are two or more, the vacuum pump is equipped with a three-way pipeline and a valve. By controlling the on-off of the three-way pipeline and the valve through the control system, sequential vacuum pumping of two vacuum processing heads can be achieved. The predetermined vacuum degree is set according to the usage requirements of the heat-insulating vessel, and usually the value range is 1×10 -3 Pa - 1×10 -4 Pa.

[0011] Further, the vacuum pumping and sealing device for heat-insulating vessels further includes a water chiller. A water tank and a circulation pump are provided inside the water chiller. The water outlet of the water chiller is connected to the water inlet of the vacuum pump through a water pipe, and then connected back to the water inlet of the water chiller from the water outlet of the vacuum pump to form a cooling water circulation loop.

[0012] During operation, at least one air extraction hole is reserved at the bottom of the heat-insulating vessel to be processed. The number and aperture of the air extraction holes can be adjusted according to the vacuum pumping efficiency, and the risk of being blocked by foreign objects can also be reduced.

[0013] The steps of the vacuum pumping and sealing method for heat-insulating vessels based on the above device are as follows: S1: Place the heat-insulating vessel with the reserved air extraction hole on the fixture. The fixture lifting device drives the heat-insulating vessel and pushes the side with the reserved air extraction hole to be pressed tightly against the vacuum processing head. S2: After the bottom sealing ring of the vacuum processing head is sealed with the end face of the heat insulation vessel, the ultrasonic device and the infrared radiator operate, and then the vacuum pump evacuates through the vacuum pipeline. S3: The vision positioning and laser welding assembly operates. The vision positioning camera of the laser welding assembly locates the position of the air extraction holes on the surface of the heat insulation vessel and transmits the positioning data to the laser welding head of the laser welding assembly. S4: When the vacuum reaches the predetermined vacuum degree, the laser welding assembly performs laser beam emission welding on the air extraction holes according to the positioning data. S5: After welding is completed, stop evacuating, reset the jig, and take the material.

[0014] The vacuum evacuation and sealing equipment and method for the heat insulation vessel of the present invention achieve efficient and environmentally friendly vacuum evacuation and sealing based on multi-technology integration. During operation, first place the heat insulation vessel on the jig assembly, and the jig lifting device drives the heat insulation vessel to rise, so that the side with the reserved air extraction holes is in close contact with the bottom of the vacuum processing head assembly, and the sealing ring at the bottom of the vacuum processing head assembly realizes sealing. Subsequently, the ultrasonic transducer and ultrasonic generator connected to the jig are started, and high-frequency electrical signals are transmitted through the cable, enabling the transducer to convert the electrical signals into mechanical vibrations. At the same time, the infrared radiator at the top performs infrared radiation heating on the heat insulation vessel. The two work together to accelerate the movement of gas molecules inside the heat insulation vessel and shorten the vacuum evacuation time.

[0015] Then, the vacuum pump assembly is connected to the vacuum processing head assembly through the vacuum pipeline, and the vacuum evacuation operation is started. During the air extraction process, the camera of the vision positioning assembly takes pictures of the positions of the air extraction holes on the surface of the heat insulation vessel, obtains image information using the optical imaging principle, and transmits the positioning data of the air extraction holes to the laser welding assembly after algorithm processing. When the vacuum reaches the predetermined vacuum degree, the laser welding head generates a high-energy laser beam, and the laser beam quickly scans in the two-dimensional plane to locate the position of the air extraction holes. The laser welding assembly controls the laser welding head to emit light according to the positioning data, so that the material of the heat insulation vessel itself melts under the action of the high heat of the laser, and the welding and sealing of the air extraction holes are completed. After welding is completed, stop evacuating, reset the jig, and the processed heat insulation vessel is taken away by manual or robotic means. The whole process integrates laser technology, vision positioning technology, vacuum technology, local infrared heating technology, and ultrasonic technology, replacing traditional glass-based brazing and realizing lead-free and high-efficiency production.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. Lead-free: The present invention does not use lead-containing glass-based brazing flux, and realizes sealing by melting the material of the heat insulation vessel itself, achieving lead-free for both the product itself and the processing process, and meeting the market demand for lead-free products.

[0017] 2. Efficiency improvement: Integrating multiple technologies, using ultrasonic and infrared radiation heating to accelerate the movement of gas molecules inside the heat-insulating container, shortening the vacuum pumping time; Laser welding is fast, accurate, and the equipment can be configured with multiple vacuum processing heads and cavities, suitable for small-batch rapid production, significantly shortening the process time compared to traditional processes.

[0018] 3. Cost reduction: Avoid using expensive glass-based brazing fluxes, reducing the loss of defective products caused by the displacement of glass-based brazing fluxes, etc., and reducing production costs.

[0019] 4. Energy consumption reduction: Laser welding has less energy loss and does not need to heat the entire large-volume cavity like traditional processes, effectively reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of one side structure of the device of the present invention.

[0021] Figure 2 It is a schematic diagram of the other side structure of the device of the present invention.

[0022] Figure 3 It is a schematic diagram of one side structure of a part of the device of the present invention.

[0023] Figure 4 It is a schematic diagram of the other side structure of a part of the device of the present invention.

[0024] Figure 5 It is a schematic diagram of the structure of the air extraction hole reserved on the heat-insulating container to be evacuated.

[0025] Figure 6 It is a process flow chart of the method of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention will be further described in detail below with reference to the accompanying drawings.

[0027] Example 1: As Figures 1 to 6 shown, in this embodiment, the heat-insulating container evacuation and sealing device for processing a vacuum-insulated stainless steel water cup is composed of a frame 1, a vacuum pump 2, a control system, a fixture lifting device 3, a positioning fixture 4, an ultrasonic device 5, an infrared radiator 6, a vacuum processing head 7, and a vision positioning and laser welding assembly 8 as a whole.

[0028] The frame 1 serves as the supporting body of the equipment, carrying and fixing other components; the jig lifting device 3 is installed on the frame 1, and the positioning jig 4 is fixed on its lifting seat; the positioning jig 4 is provided with an ultrasonic device 5 and an infrared radiator 6, wherein the ultrasonic device 5 includes an ultrasonic generator and an ultrasonic transducer connected by a cable, the ultrasonic generator has an output frequency of 15kHz and an output power of 50W, and can transmit a high-frequency electrical signal to the ultrasonic transducer, driving the transducer to convert the electrical signal into mechanical vibration, and the infrared radiator 6 is used to heat the insulation vessel; the vacuum pump 2 is connected to the vacuum pipe 9, and the end of the pipe is connected to the vacuum processing head 7, which is a small vacuum chamber The body structure is provided with a light-transmissive optical glass 12 on the top to facilitate the implementation of the functions of the visual positioning and laser welding components. A through hole 14 and a sealing ring 13 for vacuuming after sealing are provided at the bottom; a visual positioning and laser welding component is arranged above the vacuum processing head 7, and the visual positioning and laser welding component includes a laser welding head (with an output power of 2000W and a wavelength of 1080nm) placed in the frame 1 component. The laser welding head welds the surface of the workpiece. The visual positioning camera is integrated in the laser welding head to locate the position of the exhaust hole on the surface of the insulation container, and transmits the positioning data to the control system through a signal line. The control system controls the light emission of the laser welding head according to the positioning data.

[0029] In order to prevent the vacuum pump from overheating and affecting the pumping efficiency, the heat-insulating container vacuum sealing device also includes a water cooler 15, which is provided with a water tank and a circulating pump. The water outlet of the water cooler is connected to the water inlet of the vacuum pump 2 through a water pipe, and then the water outlet of the vacuum pump 2 is connected to the water return port of the water cooler 15 to form a cooling water circulation loop. The specific functions are as follows: (1) Prevent overheating: When the vacuum pump is working, the impeller and other components rotate at high speed, and the gas compression process will generate a lot of heat. If the heat cannot be dissipated in time, the temperature of the pump body will continue to rise, which will cause the components to expand and deform, affecting the accuracy and stability of the pump, and even causing component damage. The water cooler takes away the heat through the circulating cooling water, maintains the pump body temperature within a suitable range, and ensures the normal operation of the vacuum pump. For example, when a water-cooled Roots vacuum pump is working, the air in the air chamber is thin and the heat conduction is poor, so a water cooler is needed to control the temperature so that it can work stably for a long time. (2) Improve the pumping efficiency: Too high a temperature will intensify the thermal motion of the gas molecules in the pump, increase the gas back diffusion, and reduce the pumping efficiency. After the water cooler lowers the temperature of the pump body, it can reduce gas back diffusion and improve the pumping efficiency and vacuum degree.

[0030] Based on the above equipment, the vacuum sealing method of the insulated container is as follows: First, place the stainless steel heat-insulated water cup 10 with several air extraction holes 11 reserved at the bottom (for example, three air extraction holes are reserved, and the aperture is set to 0.2 mm according to the vacuum pumping efficiency) on the positioning fixture 4 through a manipulator. Subsequently, the fixture lifting device 3 drives the heat-insulated water cup to rise, so that one side of the bottom of the water cup with the reserved air extraction holes is in close contact with the bottom of the vacuum processing head 7, and the sealing ring 13 at the bottom of the vacuum processing head 7 realizes sealing.

[0031] Next, start the ultrasonic generator and the infrared radiator 6. At this time, the ultrasonic transducer converts the electrical signal into mechanical vibration, and the infrared radiator 6 heats the water cup. The two work together to accelerate the movement of gas molecules inside the water cup.

[0032] Immediately afterwards, the vacuum pump 2 starts the vacuum pumping operation through the vacuum pipeline. During the air extraction process, the camera of the visual positioning component takes pictures and locates the positions of the air extraction holes on the surface of the water cup, obtains image information using the optical imaging principle, and transmits the positioning data of the air extraction holes to the laser welding component after algorithm processing.

[0033] When the vacuum reaches the predetermined vacuum degree of 4*10 -3 Pa, the laser beam generated by the laser welding head passes through the optical glass 12 at the top of the vacuum processing head 7. After the beam passes through the glass, it reaches the position of the air extraction hole. The laser welding component controls the laser welding head to emit light according to the positioning data, so that the stainless steel material melts under the action of high laser heat, and the welding and sealing of the air extraction hole are completed.

[0034] After the welding is completed, stop the vacuum pumping, reset the fixture, and the manipulator takes away the processed heat-insulated water cup to complete the entire processing process.

[0035] Embodiment 2: As Figures 1 to 6 shown, this embodiment is for the processing of a stainless steel vacuum insulation bucket. The overall structure of the equipment is similar to that of Embodiment 1, but two vacuum processing heads 7 are configured to improve the efficiency. The equipment also includes a frame 1, a vacuum pump 2, a control system, a fixture lifting device 3, a positioning fixture 4, an ultrasonic device 5, an infrared radiator 6, a vacuum processing head 7, and a visual positioning and laser welding component 8.

[0036] The frame 1 provides stable support for the equipment. The fixture lifting device 3 is installed on the frame 1, and its lifting seat bears the positioning fixture 4. The positioning fixture 4 is equipped with an ultrasonic device 5 and an infrared radiator 6. The ultrasonic generator and ultrasonic transducer of the ultrasonic device 5 are connected by a cable and are used to generate mechanical vibrations. The infrared radiator 6 is used to heat the insulation bucket. The vacuum pump 2 is connected to a vacuum pipeline, and the end of the pipeline is connected to two vacuum processing heads 7. Each vacuum processing head 7 is a small vacuum cavity, with a light-transmitting optical glass 12 at the top and a through hole 14 and a sealing ring 13 at the bottom. The vision positioning and laser welding assembly is located above the vacuum processing head 7. Its composition and working principle are the same as those in Embodiment 1, including a laser welding head and a vision positioning camera. Laser welding is achieved through coordinated work. At the same time, the vision positioning camera is responsible for the positioning of the air extraction holes, transmits the data to the control system to control the welding process. In addition, the vacuum pump 2 is equipped with a three-way pipeline and a valve, which is controlled by the control system and can achieve the sequential vacuum pumping of the two vacuum processing heads 7.

[0037] The specific processing method is as follows: First step, place the stainless steel vacuum insulation bucket with 4 air extraction holes reserved at the bottom on the positioning fixture 4. The fixture lifting device 3 jacks up the insulation bucket, making the side with the reserved air extraction holes at the bottom closely fit with the bottom of the first vacuum processing head 7. The sealing ring 13 at the bottom of the first vacuum processing head 7 completes the sealing.

[0038] Second step, start the ultrasonic device 5 and the infrared radiator 6, so that the ultrasonic transducer generates mechanical vibrations, and the infrared radiator 6 heats the insulation bucket to accelerate the movement of internal gas molecules.

[0039] Third step, the vacuum pump 2 starts to perform vacuum pumping on the first vacuum processing head 7. During this process, the vision positioning component takes pictures and locates the positions of the air extraction holes on the surface of the insulation bucket, and transmits the positioning data to the laser welding component.

[0040] Fourth step, when the first vacuum processing head 7 reaches the predetermined vacuum degree, the laser welding component controls the laser welding head to emit light and completes the welding work of the corresponding air extraction holes.

[0041] Fifth step, after the welding is completed, the control system controls the switching of the three-way pipeline and the valve, so that the second vacuum processing head 7 is connected to the insulation bucket and starts to pump vacuum. At the same time, the vision positioning component locates the remaining air extraction holes. When the second vacuum processing head 7 reaches the predetermined vacuum degree, the laser welding component completes the welding of the remaining air extraction holes.

[0042] Sixth step, after all the air extraction holes are welded, stop vacuum pumping, reset the fixture, and remove the processed insulation bucket. The two vacuum processing heads 7 work alternately, further improving the processing efficiency and meeting the small-batch and rapid production requirements of large-scale heat-insulating utensils.

[0043] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art will appreciate that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A vacuum pumping and sealing device for heat-insulating utensils, characterized in that: It includes a frame, a vacuum pump and a control system. A fixture lifting device is provided on the frame. A positioning fixture is fixed on the lifting seat of the fixture lifting device. An ultrasonic device and an infrared radiator are provided on the positioning fixture. The vacuum pump is connected with a vacuum pipeline, and the end is connected with a vacuum processing head. The vacuum processing head is of a small vacuum cavity structure. An optical glass that can transmit light is provided at the top, and a through hole and a sealing ring for vacuum pumping after sealing are provided at the bottom. A vision positioning and laser welding assembly is provided above the vacuum processing head.

2. The vacuum pumping and sealing device for a heat-insulating container according to claim 1, characterized in that: The ultrasonic device includes an ultrasonic generator and an ultrasonic transducer, which are connected by a cable. The output frequency range of the ultrasonic generator is 15 - 40 kHz, and the output power range is 30 - 1000 W.

3. A vacuum pumping and sealing device for a heat-insulating vessel according to claim 1, characterized in that: The vision positioning and laser welding assembly includes a laser welding head and a vision positioning camera.

4. A vacuum pumping and sealing device for a heat-insulating vessel according to claim 3, characterized in that: The output power range of the laser welding head is 100 - 3000 W, and the wavelength is 800 - 1550 nm.

5. A vacuum pumping and sealing device for a heat-insulating vessel according to claim 1, characterized in that: There is at least one vacuum processing head.

6. The vacuum packaging device for heat-insulating containers according to claim 1, characterized in that: At least one air extraction hole is reserved at the bottom of the heat insulation vessel to be processed.

7. A vacuum pumping and sealing device for heat-insulating containers according to claim 1, characterized in that: The heat insulation vessel vacuumizing and sealing device further includes a water chiller. A water tank and a circulation pump are provided inside the water chiller. The water outlet of the water chiller is connected to the water inlet of the vacuum pump through a water pipe, and then connected back to the water inlet of the water chiller from the water outlet of the vacuum pump to form a cooling water circulation loop.

8. A method for evacuating and sealing a heat-insulating container based on the device according to any one of claims 1-7, characterized in that: It includes the following steps: S1: Place the heat insulation vessel with the reserved air extraction hole on the fixture. The fixture lifting device drives the heat insulation vessel and pushes the side with the reserved air extraction hole to be tightly pressed against the vacuum processing head. S2: After the sealing ring at the bottom of the vacuum processing head is sealed with the end face of the heat insulation vessel, the ultrasonic device and the infrared radiator work, and then the vacuum pump evacuates through the vacuum pipeline. S3: The vision positioning and laser welding assembly works. The vision positioning camera of the laser welding assembly locates the position of the air extraction hole on the surface of the heat insulation vessel and transmits the positioning data to the laser welding head of the laser welding assembly. S4: When the vacuum pumping reaches the predetermined vacuum degree, the laser welding assembly performs laser beam output welding on the air extraction hole according to the positioning data. S5: After welding is completed, stop vacuum pumping, reset the fixture, and take the material.

9. The method for evacuating and sealing a heat-insulating container according to claim 8, characterized in that: The value range of the predetermined vacuum degree is 1×10 -3 Pa - 1×10 -4 Pa.

Images