Plate connecting device and method based on heat assistance

Abstract

The invention discloses a plate connecting device and method based on heat assistance. The plate connecting device comprises a supporting base, a connecting piece and a connecting piece, the C-shaped frame is mounted on the supporting seat; the self-piercing riveting mechanism is used for riveting the plates to be connected; the gas-liquid pressure cylinder is used for providing riveting power for the self-piercing riveting mechanism; the high-frequency induction heating mechanism is used for heating the to-be-connected plate; the mechanical arm is used for conveying plates; the rivet supply mechanism is used for providing rivets; according to the device, gas-liquid pressurization, automatic rivet supply, high-frequency induction heating and circulating water cooling cooperative control are integrated, and riveting of ultrahigh-strength plates can be completed by locally softening a riveting area; local rapid heating is carried out on a plate riveting area through high-frequency induction heating, different heating temperatures are set for dissimilar plates, single-side stress concentration can be eliminated, plate deformation is avoided, the riveting quality is improved, and the device is particularly suitable for ultrahigh-strength steel and other materials difficult to machine.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical manufacturing and material connection, and particularly to a sheet material connection device and method based on thermal assistance. Background Art

[0002] Self-piercing riveting is a cold connection technology that does not require pre-drilling and is widely used in fields such as automotive manufacturing and aerospace, especially suitable for connecting lightweight materials (such as aluminum alloys, magnesium alloys or dissimilar material combinations). Its core principle is that the rivet directly pierces the upper layer material and plastically expands in the lower layer material to form a mechanical interlock, achieving high-strength connection, and having advantages such as low heat input, no smoke and dust pollution, and high fatigue performance.

[0003] In order to meet the high safety and lightweight requirements of automobiles and aerospace vehicles, ultra-high-strength steel is widely used in the fuselage. Due to the characteristics of ultra-high-strength steel such as high strength, high hardness and low ductility, existing self-piercing riveting machines are prone to technical problems such as stress concentration, inability to pierce through, and difficult bearing and deformation of rivets during the riveting process of ultra-high-strength steel, making it difficult to achieve effective connection and being unfavorable for the popularization and application of self-piercing riveting technology. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a sheet material connection device and method based on thermal assistance, aiming to solve the problems in the background art.

[0005] To achieve the above object, the present invention provides the following technical solution: A sheet material connection device based on thermal assistance, comprising: A support base; A C-shaped frame, which is installed on the support base; A self-piercing riveting mechanism, which is arranged inside the opening of the C-shaped frame and is used for riveting the sheet materials to be connected; A gas-liquid intensifying cylinder, which is arranged on the top of the C-shaped frame and is used for providing riveting power to the self-piercing riveting mechanism; A high-frequency induction heating mechanism, which is arranged on the support base and is used for heating the sheet materials to be connected; A robotic arm, which is arranged on the support base and is used for transporting the sheet materials; A rivet supply mechanism, which is arranged on the C-shaped frame and is used for automatically supplying rivets to the self-piercing riveting mechanism.

[0006] Furthermore, the pneumatic-hydraulic intensifying cylinder includes a hydraulic cylinder front cover disposed at the top of the opening of the C-shaped frame. The top of the hydraulic cylinder front cover is connected to the hydraulic cylinder. The top of the hydraulic cylinder is connected to the middle cover. The top of the middle cover is connected to the pneumatic cylinder. The top of the pneumatic cylinder is connected to the pneumatic cylinder rear cover. One side of the middle cover is connected to the oil barrel front cover. The top of the oil barrel front cover is connected to the oil storage barrel. The top of the oil storage barrel is connected to the oil barrel rear cover. A third channel is provided on the hydraulic cylinder front cover. A hydraulic piston is disposed in the hydraulic cylinder. The bottom of the hydraulic piston is connected to the front rod. The front rod reciprocates through the third channel. A first channel is provided on the middle cover. A pneumatic pressure increasing piston is disposed in the pneumatic cylinder. The bottom of the pneumatic pressure increasing piston is connected to the pressure increasing rod. The pressure increasing rod reciprocates through the first channel. An oil barrel piston for pushing hydraulic oil is disposed in the oil storage barrel. A first air vent is provided on the hydraulic cylinder front cover. The first air vent communicates with the inner cavity of the hydraulic cylinder. A second air vent is provided on the middle cover. The second air vent communicates with the inner cavity of the pneumatic cylinder. A third air vent is provided on the pneumatic cylinder rear cover. The third air vent communicates with the inner cavity of the pneumatic cylinder. A fourth air vent is provided on the oil barrel rear cover. The fourth air vent communicates with the inner cavity of the oil storage barrel. A second channel is provided in the oil barrel front cover. One end of the second channel is connected to the inner cavity of the oil storage barrel, and the other end of the second channel is connected to the first channel. When the pneumatic pressure increasing piston drives the pressure increasing rod to the topmost position in the inner cavity of the pneumatic cylinder, the inner cavity of the oil storage barrel and the inner cavity of the hydraulic cylinder are communicated through the first channel and the second channel.

[0007] Furthermore, the initial state of the pneumatic-hydraulic intensifying cylinder is as follows: the oil barrel piston is at the top end of the inner cavity of the oil storage barrel, and the inner cavity of the oil storage barrel is filled with hydraulic oil in the cavity below the oil barrel piston; the pneumatic pressure increasing piston is at the topmost position in the inner cavity of the pneumatic cylinder, the pressure increasing rod rises, and the inner cavity of the oil storage barrel and the inner cavity of the hydraulic cylinder are communicated through the first channel and the second channel; the hydraulic piston is at the top of the inner cavity of the hydraulic cylinder.

[0008] Furthermore, the self-piercing riveting mechanism includes a conduit and a lower punch respectively disposed at the upper and lower ends of the opening of the C-shaped frame. A mold is provided on the top of the lower punch. An upper punch is movably disposed in the conduit. The upper punch, the mold, and the lower punch are on the same axis. The top of the upper punch is connected to the front rod. The front rod and the upper punch are on the same axis. A groove is provided at the bottom of the upper punch. A through hole is provided on the conduit. The specific connection relationship between the rivet supply mechanism and the self-piercing riveting mechanism is as follows: the movable end of the rivet feeding track passes through the through hole on the conduit.

[0009] Furthermore, the high-frequency induction heating mechanism includes a high-frequency induction heating main unit, a coil, and a magnetic core. Two sets of high-frequency induction heating main units are provided on the support base. The high-frequency induction heating main units are both connected to the coil. The coil is arranged in a surrounding manner. The coil is wound around the magnetic core and supports the magnetic core. The magnetic cores of the two sets of high-frequency induction heating main units are vertically arranged and on the same axis. A preset distance is provided between the magnetic cores of the two sets of high-frequency induction heating main units. The coil is connected to the high-frequency induction heating main unit.

[0010] Furthermore, a cooling fan is provided on the high-frequency induction heating main unit; the coil is a hollow copper tube and is connected to an external water cooling system.

[0011] A sheet metal connection method based on thermal assistance, which is applied to a sheet metal connection device based on thermal assistance, includes the following steps: Step S1: Clamp the sheet metal to be connected by a robotic arm and transfer the sheet metal to be connected between two magnetic cores of the high-frequency induction heating mechanism; Step S2: Heat the sheet metal to be connected to a preset temperature by two magnetic cores of the high-frequency induction heating mechanism; Step S3: Transfer the heated sheet metal to between the upper punch and the lower punch of the self-piercing riveting mechanism by the robotic arm; Step S4: Start the gas-liquid intensifying cylinder. Drive the front rod to press down through the preloading stroke. The front rod drives the upper punch to press down, so that the rivet on the rivet feeding belt falls off and is pressed onto the heated sheet metal by the upper punch. Drive the upper punch to press down further through the boosting stroke. Under the combined action of the lower punch and the die, the plastic deformation of the rivet is completed, and the connection between the sheet metals is completed; drive the upper punch to reset through the reset stroke to perform subsequent sheet metal connections.

[0012] Furthermore, the specific process of the preloading stroke is as follows: The fourth air inlet admits air, the first air outlet exhausts air, the oil barrel piston inputs hydraulic oil into the hydraulic cylinder through the second channel and the first channel. At the same time, the first air outlet exhausts air, and the hydraulic piston drives the front rod to press down under the push of the hydraulic oil to complete the preloading; the specific process of the boosting stroke is as follows: The third air inlet admits air, the second air outlet exhausts air, the pneumatic boosting piston drives the boosting rod to press down, closes the connection between the second channel and the first channel, the boosting rod enters the inner cavity of the hydraulic cylinder, and squeezes the hydraulic oil in the cavity, thereby realizing the boosting of the hydraulic piston and the front rod; the specific process of the reset stroke is as follows: The second air inlet admits air, the third air outlet exhausts air, the pneumatic boosting piston drives the boosting rod to rise and withdraws from the inner cavity of the hydraulic cylinder. At this time, the inner cavity of the oil storage barrel and the inner cavity of the hydraulic cylinder are connected through the first channel and the second channel. The first air inlet admits air, the fourth air outlet exhausts air, the hydraulic piston pushes the hydraulic oil in the inner cavity of the hydraulic cylinder back to the oil storage barrel, and at the same time the front rod is also driven by the hydraulic piston to reset.

[0013] Compared with the existing technologies, the present invention has the following beneficial effects: The present invention integrates gas-liquid supercharging, automatic nail feeding, high-frequency induction heating and circulating water cooling collaborative control, and can complete the riveting of ultra-high-strength sheet materials through local softening of the riveting area. A stable and controllable punching force output is provided by a gas-liquid supercharging cylinder, the automatic nail feeding mechanism realizes accurate and continuous supply of rivets, the high-frequency induction heating mechanism realizes local softening regulation of materials, and cooperates with the circulating water cooling system to synchronously manage the temperature field, improving the riveting efficiency and overcoming the technical problems such as stress concentration, non-penetration during riveting, and difficult load-bearing deformation of rivets in the process of riveting difficult-to-process materials such as ultra-high-strength steel. Moreover, by locally and rapidly heating the riveting area of the sheet material through high-frequency induction heating and setting different heating temperatures for dissimilar sheet materials, unilateral stress concentration can be eliminated, sheet material deformation can be avoided, and the riveting quality can be improved, which is especially suitable for difficult-to-process materials such as ultra-high-strength steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0015] Figure 2 It is a schematic diagram of the structure of the gas-liquid supercharging cylinder of the present invention.

[0016] Figure 3 It is a schematic diagram of the internal structure of the gas-liquid supercharging cylinder of the present invention.

[0017] Figure 4 It is a sectional view of the gas-liquid supercharging cylinder of the present invention.

[0018] Figure 5 It is a schematic diagram of the structure of the rivet supply mechanism of the present invention.

[0019] Figure 6 It is a schematic diagram of the structure of the self-piercing riveting mechanism of the present invention.

[0020] Figure 7 It is a schematic diagram of the connection of the conduit, the upper punch and the nail feeding track of the present invention.

[0021] Figure 8 It is a schematic diagram of the structure of the high-frequency induction heating mechanism and the robotic arm of the present invention.

[0022] In the figure, 1 is a support base; 2 is a C-shaped frame; 3 is a gas-liquid booster cylinder; 31 is the front cover of the hydraulic cylinder; 32 is the hydraulic cylinder; 33 is the middle cover; 34 is the pneumatic cylinder; 35 is the rear cover of the pneumatic cylinder; 36 is the front cover of the oil barrel; 37 is the oil storage barrel; 38 is the rear cover of the oil barrel; 39 is the pneumatic booster piston; 310 is the hydraulic piston; 311 is the front rod; 312 is the pressure gauge; 313 is the booster rod; 314 is the oil barrel piston; 315 is the first channel; 316 is the second channel; 317 is the third channel; 4 is the nail supply and transmission bin; 5 is the collection bin; 6 is the high-frequency induction heating mechanism; 61 is the high-frequency induction heating main unit; 62 is the coil; 63 is the magnetic core; 64 is the cooling fan; 7 is the robotic arm; 8 is the upper punch; 9 is the lower punch; 10 is the mold; 11 is the conduit; 12 is the through port; 13 is the nail-sending track; 14 is the sheet metal; P1 is the first ventilation port; P2 is the second ventilation port; P3 is the third ventilation port; P4 is the fourth ventilation port. Detailed implementation manner

[0023] As Figure 1 shown, the present invention provides a technical solution: a sheet metal connection device based on thermal assistance, comprising:

[0024] A support base 1.

[0025] A C-shaped frame 2, and the C-shaped frame 2 is installed on the support base 1.

[0026] A self-piercing riveting mechanism, which is arranged inside the opening of the C-shaped frame 2 and is used for riveting the to-be-connected sheet metal 14.

[0027] A gas-liquid booster cylinder 3, which is arranged on the top of the C-shaped frame 2 and is used for providing riveting power for the self-piercing riveting mechanism.

[0028] A high-frequency induction heating mechanism 6, which is arranged on the support base 1 and is used for heating the to-be-connected sheet metal 14.

[0029] A robotic arm 7, which is arranged on the support base 1 and is used for transporting the sheet metal 14.

[0030] A rivet supply mechanism, which is arranged on the C-shaped frame 2 and is used for automatically supplying rivets to the self-piercing riveting mechanism.

[0031] As Figures 2 - 4As shown in the figure, the air-liquid intensifying cylinder 3 includes a hydraulic cylinder front cover 31 disposed at the top of the opening of the C-shaped frame 2. The top of the hydraulic cylinder front cover 31 is connected to the hydraulic cylinder 32. The top of the hydraulic cylinder 32 is connected to the middle cover 33. The top of the middle cover 33 is connected to the air cylinder 34. The top of the air cylinder 34 is connected to the air cylinder rear cover 35. One side of the middle cover 33 is connected to the oil barrel front cover 36. The top of the oil barrel front cover 36 is connected to the oil storage barrel 37. The top of the oil storage barrel 37 is connected to the oil barrel rear cover 38. A third channel 317 is provided on the hydraulic cylinder front cover 31. A hydraulic piston 310 is disposed inside the hydraulic cylinder 32. The bottom of the hydraulic piston 310 is connected to the front rod 311. The front rod 311 reciprocates through the third channel 317. A first channel 315 is provided on the middle cover 33. An air pressure intensifying piston 39 is disposed inside the air cylinder 34. The bottom of the air pressure intensifying piston 39 is connected to the intensifying rod 313. The intensifying rod 313 reciprocates through the first channel 315. An oil barrel piston 314 for pushing hydraulic oil is disposed inside the oil storage barrel 37. A first air vent P1 is provided on the hydraulic cylinder front cover 31. The first air vent P1 communicates with the inner cavity of the hydraulic cylinder 32. A second air vent P2 is provided on the middle cover 33. The second air vent P2 communicates with the inner cavity of the air cylinder 34. A third air vent P3 is provided on the air cylinder rear cover 35. The third air vent P3 communicates with the inner cavity of the air cylinder 34. A fourth air vent P4 is provided on the oil barrel rear cover 38. The fourth air vent P4 communicates with the inner cavity of the oil storage barrel 37. A second channel 316 is provided inside the oil barrel front cover 36. One end of the second channel 316 is connected to the inner cavity of the oil storage barrel 37, and the other end of the second channel 316 is connected to the first channel 315. When the air pressure intensifying piston 39 drives the intensifying rod 313 to the topmost position inside the air cylinder 34, the inner cavity of the oil storage barrel 37 and the inner cavity of the hydraulic cylinder 32 are connected through the first channel 315 and the second channel 316.

[0032] The initial state of the air-liquid intensifying cylinder 3 is as follows: The oil barrel piston 314 is at the top of the inner cavity of the oil storage barrel 37. The inner cavity of the oil storage barrel 37 is filled with hydraulic oil in the cavity below the oil barrel piston 314. The air pressure intensifying piston 39 is at the topmost position inside the air cylinder 34. The intensifying rod 313 rises. The inner cavity of the oil storage barrel 37 and the inner cavity of the hydraulic cylinder 32 are connected through the first channel 315 and the second channel 316. The hydraulic piston 310 is at the top of the inner cavity of the hydraulic cylinder 32.

[0033] The working principle of the air-liquid intensifying cylinder 3 is as follows:

[0034] Preloading stroke: The fourth air vent P4 intakes air, and the first air vent P1 exhausts air. The oil barrel piston 314 inputs hydraulic oil into the hydraulic cylinder 32 through the second channel 316 and the first channel 315. At the same time, the first air vent P1 exhausts air. The hydraulic piston 310 drives the front rod 311 to press down under the push of the hydraulic oil, completing the preloading.

[0035] Boosting stroke: The third vent port P3 intakes air, the second vent port P2 exhausts air. The pneumatic boosting piston 39 drives the boosting rod 313 to press downwards, closing the connection between the second channel 316 and the first channel 315. The boosting rod 313 enters the inner cavity of the hydraulic cylinder 32, squeezing the hydraulic oil in the cavity, and thus realizing the pressurization (boosting) of the hydraulic piston 310 and the front rod 311.

[0036] Reset stroke: The second vent port P2 intakes air, the third vent port P3 exhausts air. The pneumatic boosting piston 39 drives the boosting rod 313 to rise and withdraw from the inner cavity of the hydraulic cylinder 32. At this time, the inner cavity of the oil storage barrel 37 and the inner cavity of the hydraulic cylinder 32 are connected through the first channel 315 and the second channel 316. The first vent port P1 intakes air, the fourth vent port P4 exhausts air. The hydraulic piston 310 pushes the hydraulic oil in the inner cavity of the hydraulic cylinder 32 back into the oil storage barrel 37, and at the same time, the front rod 311 is also reset under the drive of the hydraulic piston 310.

[0037] Among them, the intake and exhaust of the first vent port P1, the second vent port P2, the third vent port P3, and the fourth vent port P4 can be realized through an external gas compression source and an action controller.

[0038] As Figure 5 shown, the rivet supply mechanism includes a rivet supply transfer bin 4, a rivet feeding track 13, and a collection bin 5. The rivet supply transfer bin 4 and the collection bin 5 are respectively arranged on both sides of the top of the C-shaped frame 2. The rivet supply transfer bin 4 is used to carry and output the rivet feeding track 13, and cooperate with the collection bin 5 to supply rivets to the self-piercing riveting mechanism. The movable end of the rivet feeding track 13 passes through between the self-piercing riveting mechanisms and enters the collection bin 5 to be collected; a number of evenly arranged rivets are arranged on the rivet feeding track 13; the rivet feeding track 13 enters from the top feeding port of the rivet supply transfer bin 4, discharges from the bottom discharge port of the rivet supply transfer bin 4, passes through between the self-piercing riveting mechanisms, and enters the collection bin 5 to be collected; a motor-driven roller can be used to collect the rivet feeding track 13 and drive the rivet feeding track 13 to transmit; the rivet feeding track 13 is made of a flexible material.

[0039] As Figures 6 - 7As shown in the figure, the self-piercing riveting mechanism includes a conduit 11 and a lower punch 9 respectively arranged at the upper and lower ends of the opening of the C-shaped frame 2. A die 10 is arranged on the top of the lower punch 9. An upper punch 8 is movably arranged in the conduit 11. The upper punch 8 can slide up and down in the conduit 11. The upper punch 8, the die 10 and the lower punch 9 are on the same axis. The top of the upper punch 8 is connected to the front rod 311, and the front rod 311 and the upper punch 8 are on the same axis. A groove for clamping the rivet head is arranged at the bottom of the upper punch 8. A through port 12 is arranged on the conduit 11. The inner diameter of the conduit 11 is slightly larger than the diameter of the rivet. During actual use, when the upper punch 8 presses down, the rivet on the nail feeding track 13 will be pressed out. When pressing down, the groove at the bottom of the upper punch 8 will clamp the rivet head, so that the rivet will not fall when it detaches from the nail feeding track 13. At the same time, the inner diameter of the conduit 11 that is slightly larger than the diameter of the rivet also makes it difficult for the rivet to fall out easily.

[0040] Among them, the specific connection relationship between the rivet supply mechanism and the self-piercing riveting mechanism is that the movable end of the nail feeding track 13 passes through the through port 12 on the conduit 11.

[0041] The nail supply transmission bin 4 cooperates with the collection bin 5, as well as the motor and the roller to transmit the nail feeding track 13. When the rivet on the nail feeding track 13 moves into the conduit 11 and is at the bottom of the upper punch 8, the front rod 311 is driven by the pneumatic-hydraulic intensifying cylinder 3 to press down the upper punch 8.

[0042] As Figure 8 shown in the figure, the high-frequency induction heating mechanism 6 includes a high-frequency induction heating main unit 61, a coil 62, and a magnetic core 63. Two sets of high-frequency induction heating main units 61 are arranged on the support base 1. The high-frequency induction heating main units 61 are both connected to a coil 62. The coil 62 is arranged in a surrounding manner. The coil 62 is wound around the magnetic core 63 and supports the magnetic core 63. The magnetic cores 63 of the two sets of high-frequency induction heating main units 61 are arranged vertically and on the same axis. A preset distance is provided between the magnetic cores 63 of the two sets of high-frequency induction heating main units 61 for heating the to-be-connected sheet metal 14. The coil 62 is connected to the high-frequency induction heating main unit 61.

[0043] Among them, a cooling fan 64 is arranged on the high-frequency induction heating main unit 61 for dissipating heat from the high-frequency induction heating main unit 61 to ensure that the equipment temperature is controlled within a safe range.

[0044] Among them, the coil 62 is a hollow copper tube and is connected to an external water cooling system. By passing circulating cooling water into the coil 62 through the external water conservancy system, its stability and service life in a high-temperature and high-current working environment can be ensured.

[0045] Among them, a pressure gauge 312 for detecting hydraulic pressure is also arranged on the middle cover 33.

[0046] A sheet metal connection method based on thermal assistance includes the following steps:

[0047] Step S1: Clamp the to-be-connected sheet material 14 by the robotic arm 7 and transfer the to-be-connected sheet material 14 between the two magnetic cores 63 of the high-frequency induction heating mechanism 6.

[0048] Step S2: Heat the to-be-connected sheet material 14 to a preset temperature (the temperature can be adjusted according to sheet materials of different materials) by the two magnetic cores 63 of the high-frequency induction heating mechanism 6.

[0049] Step S3: Transfer the heated sheet material 14 between the upper punch 8 and the lower punch 9 of the self-piercing riveting mechanism by the robotic arm 7.

[0050] Step S4: Start the gas-liquid intensifying cylinder 3. Drive the front rod 311 to press down through the preloading stroke. The front rod 311 drives the upper punch 8 to press down, so that the rivets on the nail feeding track 13 fall off and are pressed onto the heated sheet material 14 by the upper punch 8. Drive the upper punch 8 to press down further through the boosting stroke. Complete the plastic deformation of the rivets under the cooperative action of the lower punch 9 and the die 10 to complete the connection between the sheet materials 14; drive the upper punch 8 to reset through the reset stroke to perform the subsequent connection of the sheet materials 14.

[0051] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood 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 heat-assisted sheet metal connection device, characterized in that: include: Support seat; A C-shaped frame, wherein the C-shaped frame is mounted on a support seat; A self-piercing riveting mechanism, which is arranged in the opening of the C-shaped frame and is used for riveting the sheets to be connected; A gas-liquid booster cylinder, which is arranged on the top of the C-shaped frame and is used to provide riveting power to the self-piercing riveting mechanism; A high-frequency induction heating mechanism, which is arranged on the support seat and is used to heat the sheets to be connected; A mechanical arm, which is arranged on a support base and is used for conveying sheet materials; The rivet supply mechanism is arranged on the C-shaped frame and is used for automatically supplying rivets to the self-piercing riveting mechanism.

2. A heat-assisted sheet metal connection device according to claim 1, characterized in that: The gas-liquid booster cylinder comprises a hydraulic cylinder front cover arranged at the top of the C-shaped frame opening, the top of the hydraulic cylinder front cover is connected to the hydraulic cylinder, the top of the hydraulic cylinder is connected to the middle cover, the top of the middle cover is connected to the pneumatic cylinder, the top of the pneumatic cylinder is connected to the pneumatic cylinder rear cover, one side of the middle cover is connected to the oil barrel front cover, the top of the oil barrel front cover is connected to the oil storage barrel, and the top of the oil storage barrel is connected to the oil barrel rear cover; a third channel is arranged on the hydraulic cylinder front cover, a hydraulic piston is arranged in the hydraulic cylinder, the bottom of the hydraulic piston is connected to the front rod, and the front rod reciprocates through the third channel, a first channel is arranged on the middle cover, a gas pressure booster piston is arranged in the pneumatic cylinder, the bottom of the gas pressure booster piston is connected to the booster rod, and the booster rod reciprocates through the first channel; a pressure booster piston for pushing the liquid is arranged in the oil storage barrel an oil barrel piston for pressurizing oil; a first air vent is arranged on the front cover of the hydraulic cylinder, the first air vent is communicated with the inner cavity of the hydraulic cylinder, a second air vent is arranged on the middle cover, the second air vent is communicated with the inner cavity of the pneumatic cylinder, a third air vent is arranged on the rear cover of the pneumatic cylinder, the third air vent is communicated with the inner cavity of the pneumatic cylinder, a fourth air vent is arranged on the rear cover of the oil barrel, the fourth air vent is communicated with the inner cavity of the oil storage barrel; a second channel is arranged in the front cover of the oil barrel, one end of the second channel is connected to the inner cavity of the oil storage barrel, and the other end of the second channel is connected to the first channel; when the pneumatic booster piston drives the booster rod to be at the top end of the inner cavity of the pneumatic cylinder, the inner cavity of the oil storage barrel and the inner cavity of the hydraulic cylinder are communicated through the first channel and the second channel.

3. A heat-assisted plate connection device according to claim 2, characterized in that: The initial state of the gas-liquid booster cylinder is: the oil barrel piston is at the top of the oil barrel inner cavity, the oil barrel inner cavity is below the oil barrel piston and is full of hydraulic oil; the air pressure booster piston is at the top of the air cylinder inner cavity, the booster rod rises, the oil barrel inner cavity and the hydraulic cylinder inner cavity are connected through the first channel and the second channel; the hydraulic piston is at the top of the hydraulic cylinder inner cavity.

4. A heat-assisted plate connection device according to claim 3, characterized in that: The self-piercing riveting mechanism comprises a guide tube and a lower punch respectively arranged on the upper and lower ends of the C-shaped frame opening, a die is arranged on the top of the lower punch, an upper punch is movably arranged in the guide tube, and the upper punch, the die and the lower punch are on the same axis; the top of the upper punch is connected to the front rod, and the front rod and the upper punch are on the same axis; a groove is arranged at the bottom of the upper punch; and a through hole is arranged on the guide tube; The specific connection relationship between the rivet supply mechanism and the self-piercing riveting mechanism is that the movable end of the rivet feeding track passes through the through opening on the guide tube.

5. The heat-assisted plate connection device according to claim 4, characterized in that: The high-frequency induction heating mechanism includes a high-frequency induction heating host, a coil, and a magnetic core; two sets of high-frequency induction heating hosts are arranged on the support seat, and the high-frequency induction heating hosts are both connected to the coils, which are arranged in a surrounding manner and wound on the magnetic cores to support the magnetic cores; the magnetic cores of the two sets of high-frequency induction heating hosts are arranged vertically and are on the same axis; a preset distance is set between the magnetic cores of the two sets of high-frequency induction heating hosts; the coils are connected to the high-frequency induction heating hosts.

6. The heat-assisted plate connection device according to claim 5, characterized in that: The high-frequency induction heating host is provided with a heat dissipation fan; the coil is a hollow copper tube connected to an external water cooling system.

7. A heat-assisted sheet metal connection method, applied to a heat-assisted sheet metal connection device according to any one of claims 1 to 6, characterized in that: The steps include: Step S1: clamping the sheet materials to be connected by a robotic arm and transferring the sheet materials to be connected between two magnetic cores of a high-frequency induction heating mechanism; Step S2: heating the plates to be connected to a preset temperature by two magnetic cores of the high-frequency induction heating mechanism; Step S3: The heated sheet material is transferred to between the upper punch and the lower punch of the self-piercing riveting mechanism by a robotic arm; Step S4: Start the gas-liquid booster cylinder, and drive the front rod to press down through the pre-pressing stroke, and the front rod drives the upper punch to press down, so that the rivets on the nail feeding track fall off and are pressed onto the heated sheet by the upper punch, and the upper punch is driven to press further downward through the boosting stroke, and the rivet is plastically deformed under the coordinated action of the lower punch and the mold to complete the connection between the sheets; the upper punch is driven to reset through the reset stroke to perform subsequent sheet connection.

8. The heat-assisted sheet metal joining method according to claim 7, characterized in that: The specific process of the pre-stressing stroke is as follows: air is taken in through the fourth air vent and exhausted through the first air vent, and the oil barrel piston inputs the hydraulic oil into the hydraulic cylinder through the second channel and the first channel. At the same time, exhaust is conducted through the first air vent, and the hydraulic piston drives the front rod downward under the push of the hydraulic oil to complete the pre-stressing; the specific process of the boosting stroke is as follows: air is taken in through the third air vent and exhausted through the second air vent, and the air pressure boosting piston drives the boosting rod downward, closing the connection between the second channel and the first channel, and the boosting rod enters the inner cavity of the hydraulic cylinder to squeeze the hydraulic oil in the cavity, thereby achieving the boosting of the hydraulic piston and the front rod; the specific process of the reset stroke is as follows: air is taken in through the second air vent and exhausted through the third air vent, and the air pressure boosting piston drives the boosting rod to rise and withdraw from the inner cavity of the hydraulic cylinder. At this time, the inner cavity of the oil storage barrel and the inner cavity of the hydraulic cylinder are connected through the first channel and the second channel, air is taken in through the first air vent and exhausted through the fourth air vent, and the hydraulic piston pushes the hydraulic oil in the inner cavity of the hydraulic cylinder back into the oil storage barrel, and at the same time, the front rod is reset under the drive of the hydraulic piston.

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