High-frequency pulse current plastic thermal connection device

Abstract

The invention relates to a high-frequency pulse current plastic thermal connection device which comprises an electric cabinet and a thermal connection assembly, a control circuit, a relay and a high-frequency pulse power supply are arranged in the electric cabinet, and an output transformer is arranged in the high-frequency pulse power supply. The thermal connection assembly comprises a moving device, a framework, a converter transformer and a heating head. The converter transformer is arranged in the framework and is connected with the output transformer through a low-current cable; and the heating head is arranged at the other end of the framework, is connected with the converter transformer and realizes a thermal connection function by heating the converter transformer. According to the invention, the high-frequency pulse power supply is used, so that the time required for raising the temperature of the same heating head by 200 DEG C and stabilizing the temperature is greatly shortened; a transformer for outputting large current is not needed in the electric control box, so that the weight of the electric control box can be greatly reduced; during transmission, the power line does not need large current and is transmitted to the thermal connection assembly at the rear end to be converted, so that a thinner small-current power line can be selected, and meanwhile, the power loss of the cable is greatly reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of plastic thermal connection machines, and in particular relates to a high-frequency pulse current plastic thermal connection device. Background Art

[0002] Currently, commonly used plastic thermal joining methods include hot plate welding, hot air welding, ultrasonic welding, and medium-high frequency welding. Specifically, hot plate welding is the simplest plastic welding method and is suitable for large plastic parts with large weld surfaces. However, the heat generated by the hot plate softens the part, leading to a long cycle time. Molten resin can adhere to the hot plate and be difficult to clean. Over time, impurities form, affecting bond strength. The pressure and time must be strictly controlled to ensure the proper melt volume. Furthermore, insufficient strength can occur when joining dissimilar resins or metals. Hot air welding involves directing hot air onto the joint, melting the joint area and the filler wire, which is made of the same material as the parent material. The weld is then formed by fusing the filler material with the plastic being joined. This welding method requires relatively high welding skills. Generally speaking, all these plastic thermal joining methods require heating a hot rivet head or similar heater, which then indirectly heats the plastic joint, causing it to melt and then cool to complete the joint.

[0003] Prior art, such as patent CN2915478Y, discloses a pulse current plastic riveting device that uses pulse current for rapid heat melting and air cooling to achieve plastic hot riveting. This type of device typically uses a power frequency pulse (50Hz) to directly output a high current to heat the heating head. Each startup generates a high instantaneous current, which can significantly impact the power grid and reduce power distribution efficiency. Furthermore, to transmit the excessive current, the transmission cable has a large cross-section and high losses, resulting in high wiring costs and complex wiring. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a high-frequency pulse current plastic thermal connection device, which reduces the current required for transmission and increases the transmission voltage.

[0005] The technical solution adopted by the present invention to solve its technical problems is: to provide a high-frequency pulse current plastic thermal connection device, including an electrical control box and a thermal connection component, the electrical control box is provided with a control circuit, a relay and a high-frequency pulse power supply, and the high-frequency pulse power supply is provided with an output transformer; the thermal connection component includes: a moving device for controlling the movement of the thermal connection component toward the plastic part to be connected; a frame, one end of which is connected to the moving device and is used to support the thermal connection component; a converter transformer, which is provided in the frame and is connected to the output transformer through a low-current cable; a heating head, which is provided at the other end of the frame, is connected to the converter transformer and realizes the thermal connection function by heating it.

[0006] Preferably, the power supply frequency range of the high-frequency pulse power supply and the output transformer is 20KHZ to 1GHZ, the output form is an AC sine wave, and the output voltage range of the high-voltage high-frequency transformer is 4VRMS to 48VRMS.

[0007] Preferably, the low current cable carries a current less than 20 ARMS.

[0008] Preferably, the high-frequency pulse power supply is a high-frequency AC power supply, a radio frequency power supply or a resonant power supply.

[0009] Preferably, the converter transformer includes: a through slot, arranged in the middle of the skeleton; a magnetic core, arranged around the outer periphery of the skeleton and with a main magnetic circuit passing through the through slot at the center; a secondary coil, arranged around the main magnetic circuit, with at least 1 turn; and a primary coil winding, arranged around the main magnetic circuit and provided on at least one side of the secondary coil, with a number of turns greater than the number of turns of the secondary coil.

[0010] Preferably, the skeleton is made of copper, the secondary coil is a single U-shaped plate, both ends of the single U-shaped plate are connected to the heating head 4 to form a loop, and the secondary coil and the skeleton are integrally formed.

[0011] Preferably, the output transformer is connected to the converter transformer via a quick-connect connector.

[0012] Preferably, a cooling device for cooling the heating head is provided in the thermal connection assembly.

[0013] Preferably, the cooling device is an air cooling device, one end of the skeleton is provided with a guide shaft connecting block connected to the moving device, and the other end is provided with a gas guide block, the air cooling device includes a cooling air duct arranged in the skeleton, passing through the converter transformer and reaching one end of the heating head, the head end of the cooling air duct is arranged in the guide shaft connecting block and connected to the air source, and the other end is connected to the air duct in the gas guide block, and the air outlet of the gas guide block is arranged toward the heating head.

[0014] Compared with the prior art, when the same heating head is used and the same temperature rise is set, the present invention has the following beneficial effects: 1. By using a high-frequency pulse power supply, the time required for the same heating head to rise in temperature by 200 degrees and stabilize is greatly shortened; 2. The high-frequency power supply eliminates the need for a silicon steel transformer that outputs large current in the electrical control box, and the weight of the electrical control box can be greatly reduced; 3. By setting a high-frequency pulse power supply at the front end, the power cord does not need a large current during transmission, and the current is output to the thermal connection component at the back end for conversion, so a thinner low-current power cord can be selected, and the power loss of the cable can be greatly reduced; 4. After the transmission cable becomes thinner, multiple devices can be connected through a quick plug, and the specifications and costs of mass production can also be greatly reduced; 5. By setting a high-frequency pulse power supply at the front end, the maximum current of the power supply line is greatly reduced, and there is no input impact current several times that when the industrial frequency transformer is turned on, which can reduce the capacity of the power distribution switch; 6. The power module is reduced in size, and the overall installation space can also be reduced, saving materials and reducing costs.

[0015] In addition, the present invention also has the following beneficial effects: 1. The skeleton and the secondary coil are integrally formed, so that the skeleton plays the role of replacing the secondary coil of the converter transformer, and realizes the conversion from small current and high voltage to large current and low voltage through the coupling of the magnetic core and the primary coil; 2. The cooling air duct flowing through the skeleton can cool the skeleton and the heating head at the same time, further improving the working stability of the converter transformer and the heating head. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A three-dimensional diagram of a high-frequency pulse current plastic thermal connection device.

[0017] Figure 2 for Figure 1 Enlarged main view of the thermal connection assembly.

[0018] Figure 3 for Figure 2 Enlarged exploded view of the mid-skeleton.

[0019] Figure 4 The following is a circuit diagram of a high-frequency pulse current plastic thermal connection device.

[0020] Among them, 1-guide mechanism; 101-guide shaft; 2-skeleton; 201-cooling air duct; 202-process hole plug; 203-gas guide block; 204-guide shaft connecting block; 3-converter transformer; 301-secondary coil; 302-magnetic core; 303-low current cable; 304-primary coil winding; 305-main magnetic circuit; 306-through slot; 4-heating head; 5-output transformer; 6-quick plug connector; 7-high-frequency pulse power supply.

[0021] The same reference numerals in the various drawings represent the same components. DETAILED DESCRIPTION

[0022] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0023] like Figure 1 、 2 As shown in Figures 4 and 5, the present invention provides a high-frequency pulse current plastic thermal connection device, including an electric control box and a thermal connection component. The electric control box is provided with a control circuit, a relay and a high-frequency pulse power supply 7. The high-frequency pulse power supply 7 is provided with an output transformer 5. The relay is used to control the on and off of the power supply, the high-frequency pulse power supply 7 is used to output pulse current, and the output transformer 5 is used to convert the output voltage. The thermal connection component includes a moving device, a skeleton 2, a converter transformer 3 and a heating head 4. The moving device is used to control the movement of the thermal connection component toward the plastic part to be connected; the skeleton 2 is used to support the thermal connection component, and one end of the skeleton is connected to the moving device; the converter transformer 3 is provided in the skeleton 2 and is connected to the output transformer 5 via a low-current cable 303; the heating head 4 is provided at the other end of the skeleton 2, is connected to the converter transformer 3 and realizes the thermal connection function by heating it.

[0024] The high-frequency pulse power supply 7 can be a high-frequency sinusoidal power supply, radio frequency power supply, or resonant power supply. These power supplies are capable of outputting high power within a compact size, meeting the present invention's requirements for miniaturization and high efficiency. The power supply frequency range of the high-frequency pulse power supply 7 and the output transformer 5 is 20 kHz to 1 GHz, and the output is an AC sinusoidal wave. To ensure safe operation, the output voltage range of the high-voltage high-frequency transformer is 4 VRMS to 48 VRMS. Therefore, the low-current cable 303 can transmit less than 20 ARMS of current.

[0025] In one specific embodiment, the converter transformer 3 includes a magnetic core 302, a primary coil winding 304, and a secondary coil 301. The magnetic core 302 is typically made of a high-permeability material, such as ferrite. A through slot 306 is provided in the middle of the frame 2. The magnetic core 302 is arranged around the periphery of the frame 2, with a main magnetic path 305 at its center passing through the through slot 306. The primary coil winding 304 and the secondary coil 301 are wound around the main magnetic path 305 of the magnetic core 302. The secondary coil 301 has at least one turn, and the primary coil winding 304 is provided on at least one side of the secondary coil 301. The operating principle of the converter transformer 3 is based on the law of electromagnetic induction, similar to that of a conventional transformer, but its primary function is current conversion rather than voltage conversion. The primary coil winding 304 is connected to the output end of the high-voltage, high-frequency transformer 5 via the low-current cable 303. The secondary coil 301 is connected to the heating head 4 to transmit current, which generates heat through the tip of the heating head 4. The current conversion relationship of the converter transformer 3 is determined by the winding turns ratio. Therefore, in order to amplify the current and increase the heating speed of the heating head 4, the number of turns of the primary coil winding 304 should be greater than the number of turns of the secondary coil 301.

[0026] In a Figure 3 In the illustrated embodiment, the skeleton 2 is made of copper, the secondary coil 301 is a single U-shaped plate, and the heater head 4 is also U-shaped. The two ends of the single U-shaped plate are connected to the two ends of the heater head 4 to form a loop. The secondary coil 301 is integrally formed with the skeleton 2, and the number of turns of the secondary coil 301 is considered to be one. The primary coil winding 304 includes two sets of windings, one wound on each side of the secondary coil 301. Coil supports extending outward along the length of the main magnetic circuit 305 are provided on both sides of the through slot 306.

[0027] In one embodiment, the moving device includes a guide mechanism 1, which includes a guide shaft 101. One end of the guide shaft 101 is connected to the frame 2, and the other end of the guide shaft 101 is connected to the robotic arm. The guide mechanism 1 is used to stabilize the orientation of the heating head 4 so that the heating head 4 is aligned with the plastic part to be connected.

[0028] In a Figure 4In the illustrated embodiment, the output transformer 5 is connected to the converter transformer 3 via a commercially available quick-connect connector 6. Suitable quick-connect connectors 6 for use with the output transformer 5 and converter transformer 3 require insulation, high-frequency transmission, fast connection, and environmental adaptability, making them suitable for use in rapidly switching environments. Compared to existing technologies, the present invention utilizes lower currents during current transmission, allowing a similarly sized quick-connect base to accommodate more connectors. This quick-connect connector 6 is primarily used to connect the output transformers 5 within multiple electrical control boxes to the converter transformers 3 of multiple devices, effectively reducing connection costs.

[0029] In a specific embodiment, the low-current cable 303 adopts a commercially available shielded cable. The shielded cable is a specially designed cable that adds a metal braided layer, aluminum foil layer or other shielding materials around the cable to ensure insulation and reduce the impact of electromagnetic interference on signal transmission.

[0030] The thermal connection assembly is provided with a cooling device for cooling the heating head 4. In a specific embodiment, one end of the skeleton 2 is provided with a guide shaft connection block 204 connected to the moving device, and the other end is provided with a gas guide block 203. The cooling device is an air cooling device, which includes a cooling air duct 201 provided in the skeleton 2, passing through the converter transformer 3 and reaching one end of the heating head 4. The head end of the cooling air duct 201 is provided in the guide shaft connection block 204, and the surface of the guide shaft connection block 204 is provided with a quick interface for connecting to an air source. The other end of the cooling air duct 201 is connected to the air duct provided in the gas guide block 203, and the air outlet of the air duct in the gas guide block 203 is arranged toward the heating head 4. After completing a thermal connection, the skeleton 2, converter transformer 3 and heating head 4 are simultaneously cooled by blowing air.

[0031] In other embodiments, such as in hot plate welding or hot air welding, the air outlet of the cooling device is directed toward the contact surface between the heating head and the plastic part, thereby increasing the separation speed between the heating head and the plastic part, reducing the probability of molten plastic adhering to the heating head, and ensuring the service life of the heating head.

[0032] In a specific embodiment, the high-frequency pulse power supply 7 uses a high-frequency AC power supply, the output frequency of the high-frequency AC power supply and the output transformer 5 is 120KHz, the output voltage of the high-voltage high-frequency transformer is 48VRMS, and the ratio of the number of turns of the primary coil 304 to the number of turns of the secondary coil 301 is 8:1. Therefore, the transmission current of the low-current cable 303 is 16ARMS, and a coaxial cable with an outer diameter of 3MM and a conductor cross-sectional area of 1.5MM can be used. 2, low current cable 303. By adopting the above parameters, the present invention is compared with the traditional pulse current riveting device as follows (using the same heating head and setting the same temperature rise): 1. The time to reach the stable temperature is shortened by 50% with the same riveting head temperature rise of 200 degrees; 2. The maximum current of the power supply line is reduced by 25%; 3. The overall weight of the device is reduced by 80%; 4. The cross-sectional area of the transmission cable is reduced from 10MM 2 Down to 1.5MM 2 ; Cable power loss is reduced by 90%; 5. Since there is no input surge current several times that when the power frequency transformer is turned on, the capacity of the power distribution switch is reduced by 50%. As the transmission cable becomes thinner, the cost of the quick-plug connector 6 is greatly reduced; 6. The size of the power module is reduced by more than 60%, and the installation space is reduced by more than 80%.

Claims

1. A high-frequency pulse current plastic thermal connection device, comprising an electric control box and a thermal connection component, characterized in that: The electric control box is provided with a control circuit, a relay and a high-frequency pulse power supply, and the high-frequency pulse power supply is provided with an output transformer; The thermal connection assembly includes: a moving device for controlling the movement of the thermal connection assembly toward the plastic piece to be connected; a frame, one end of which is connected to the moving device and is used to support the thermal connection assembly; a current transformer, disposed in the frame and connected to the output transformer via a low-current cable; The heating head is arranged at the other end of the frame, is connected to the converter transformer and realizes a thermal connection function by heating the converter transformer.

2. A high-frequency pulse current plastic thermal connection device according to claim 1, characterized in that: The power supply frequency range of the high-frequency pulse power supply and the output transformer is 20KHZ to 1GHZ, the output form is an AC sine wave, and the output voltage range of the high-voltage high-frequency transformer is 4VRMS to 48VRMS.

3. The high-frequency pulse current plastic thermal connection device according to claim 1, characterized in that: The low current cable carries a current of less than 20 ARMS.

4. The high-frequency pulse current plastic thermal connection device according to claim 1, characterized in that: The high-frequency pulse power supply is a high-frequency AC power supply, a radio frequency power supply or a resonant power supply.

5. The high-frequency pulse current plastic thermal connection device according to claim 1, characterized in that: The converter transformer comprises: A through slot is provided in the middle of the frame; a magnetic core arranged around the periphery of the frame and having a main magnetic circuit passing through the through slot at its center; A secondary coil is arranged around the main magnetic circuit and has at least one turn; The primary coil winding is arranged around the main magnetic circuit and is provided on at least one side of the secondary coil, and the number of turns is greater than the number of turns of the secondary coil.

6. The high-frequency pulse current plastic thermal connection device according to claim 5, characterized in that: The skeleton is made of copper, the secondary coil is a single U-shaped plate, both ends of the single U-shaped plate are connected to the heating head 4 to form a loop, and the secondary coil and the skeleton are formed in one piece.

7. The high-frequency pulse current plastic thermal connection device according to claim 1, characterized in that: The output transformer is connected to the converter transformer via a quick-connect connector.

8. The high-frequency pulse current plastic thermal connection device according to claim 1, characterized in that: A cooling device for cooling the heating head is provided in the thermal connection assembly.

9. The high-frequency pulse current plastic thermal connection device according to claim 8, characterized in that: The cooling device is an air cooling device, one end of the skeleton is provided with a guide shaft connecting block connected to the moving device, and the other end is provided with a gas guide block. The air cooling device includes a cooling air duct arranged in the skeleton, passing through the converter transformer and reaching one end of the heating head. The head end of the cooling air duct is arranged in the guide shaft connecting block and connected to the air source, and the other end is connected to the air duct in the gas guide block. The air outlet of the gas guide block is arranged toward the heating head.

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