Scroll tube cooling module and friction riveting connection system thereof

Abstract

A kind of scroll tube cooling module and its friction riveting connection system, comprising: scroll tube, cold air throttle valve, warm air flow regulating valve and gas nozzle, cold air throttle valve and warm air flow regulating valve are respectively arranged at the two sides of scroll tube and coaxially placed, gas nozzle is arranged at close to cold air throttle valve and is arranged with throttle valve crossing, gas nozzle is connected with compressed air source, cold air throttle valve is connected with friction riveting connection system, warm air flow regulating valve is connected with external environment, scroll tube is used for the flow of compressed gas, injected compressed air rotates under the action of centrifugal field with approximately same angular velocity, the gas moving in the inner circle of scroll tube passes kinetic energy to outer circle gas and temperature drops.The cooperation of scroll tube cooler and connection system can reduce the range of joint part heat affected zone, weaken the degree of material softening, so as to improve the mechanical properties of connection joint, ensure the reliability of self-punching friction riveting process.

Description

Technical Field

[0001] This invention relates to a technology in the field of plate welding, specifically a friction riveting and welding connection system that utilizes vortex tube cooling. Background Technology

[0002] For non-metallic materials such as carbon fiber composites, the heat input during friction riveting can easily cause the resin matrix of the composite material around the rivet to burn off, forming voids during subsequent cooling and severely affecting the joint's load-bearing capacity. Current industrial production typically uses pre-drilled through-holes to avoid frictional contact between the composite material and the rivet. However, pre-drilling through-holes increases the number of process steps, making it difficult to meet the demands of high-efficiency industrial production. Summary of the Invention

[0003] This invention addresses the problems of poor cooling effect and complex cooling mechanism in various existing technologies by proposing a vortex tube cooling module and its friction riveting and welding connection system. By using the vortex tube cooler in conjunction with the connection system, the range of the heat-affected zone at the joint can be reduced, the degree of material softening can be weakened, thereby improving the mechanical properties of the joint and ensuring the reliability of the self-piercing friction riveting and welding process.

[0004] This invention is achieved through the following technical solution:

[0005] This invention relates to a vortex tube cooling module, comprising: a vortex tube, a cold air throttling valve, a heating air flow regulating valve, and a gas nozzle. The cold air throttling valve and the heating air flow regulating valve are respectively located on both sides of the vortex tube and placed coaxially. The gas nozzle is located near the cold air throttling valve and is arranged intersecting the throttling valve. The gas nozzle is connected to a compressed air source. The cold air throttling valve is connected to a friction-welded connection system. The heating air flow regulating valve is connected to the outside environment to discharge hot gas. The vortex tube is used for the flow of compressed gas. The injected compressed air rotates at approximately the same angular velocity under the action of a centrifugal force field. The gas moving in the inner circle of the vortex tube transfers kinetic energy to the outer circle gas, causing its temperature to drop.

[0006] The inner wall of the gas nozzle is provided with a tapered pipe thread.

[0007] The aforementioned heating flow regulating valve is used to control the discharge flow rate of high-temperature gas from the outer ring of the vortex tube. It includes a valve body and a conical valve core disposed therein; the valve body serves as the gas flow channel, and the valve core controls the gas flow rate. The temperature drop of the obtained cooling gas can be controlled by adjusting the opening degree of the valve core.

[0008] The valve core of the heating flow regulating valve obstructs the flow of cooling gas in the inner ring, causing the cooling gas to move towards the cold air throttle valve.

[0009] The aforementioned cold air throttling valve is used to control the discharge flow rate of the cooling gas inside the vortex tube, and includes: a valve body and a conical valve core disposed therein; the valve body serves as the gas flow channel, and the valve core is used to control the gas flow rate. By controlling the opening degree of the valve core, the temperature drop of the obtained cooling gas can be controlled.

[0010] The outlet end of the aforementioned air throttle valve is provided with a tapered pipe thread.

[0011] This invention relates to a friction riveting and welding connection system with a vortex tube cooling module, comprising: a pressure ring and a mold arranged opposite to each other, and a drive rod disposed within the pressure ring, wherein: the drive rod is provided with a sealing sleeve connected to the vortex tube cooling module, and a rivet is provided at the end of the drive rod, and two plates to be fixed are respectively disposed between the pressure ring and the mold.

[0012] The drive rod and / or the mold are provided with a cold air delivery pipe that is connected to the sealing sleeve. The inlet end of the cold air delivery pipe is connected to the cold air throttle valve of the vortex tube cooling module, and the outlet end is led out to the friction riveting welding working area.

[0013] The outlet end can be one or a combination of the following:

[0014] ① The outlet end is located at the end of the drive rod, and the distance from the center line of the drive rod is greater than or equal to the radius of the rivet head;

[0015] ② The outlet end is located at the end of the drive rod, and the distance from the center line of the drive rod is less than the radius of the rivet head;

[0016] ③ The outlet end is located inside the mold, and the distance from the upper surface of the mold is greater than or equal to the radius of the rivet head;

[0017] The combination of the aforementioned methods includes: designing multiple cold air delivery pipes inside the drive rod or diverting cooling gas to the drive rod and the mold interior through cooling delivery pipes.

[0018] The drive rod is equipped with a cooling pipe inside its body, and the pipe can be configured in various ways, including but not limited to coaxial, off-axis, and ring-axis configurations.

[0019] The sealing sleeve is located around the drive rod, and an air intake valve is provided on its outer side.

[0020] The intake valve is connected to the outlet end of the cold air throttle valve of the vortex tube cooling module via a cold air delivery pipe.

[0021] The pressure ring is a cylindrical structure, coaxially positioned on the outside of the riveting gun, used to restrict the flow of surrounding material during the riveting process. The inner diameter of the pressure ring... satisfy: >2 ,in: The radius of the rivet head.

[0022] The end of the drive rod is provided with a structure to guide the deformation of the rivet, which includes, but is not limited to, a flat-bottomed die, a flat-bottomed concave die, a convex die, or a special-shaped concave die.

[0023] This invention relates to a coordinated control method for the above-mentioned friction riveting and welding connection system, comprising:

[0024] Step 1: Compressed air is input into the scroll tube cooling system, and cooling gas begins to be discharged. Adjust the opening of the cooling gas throttle valve until the gas reaches the required cooling temperature.

[0025] Step 2: Circulate cooling gas symmetrically along the center of the drive shaft.

[0026] Step 3: Read the temperature sensor data of the upper surface of the workpiece to be fixed. After the temperature sensor data stabilizes, the rivet suction structure will activate, adsorbing and fixing the rivet to the head of the welding gun. The welding gun and the rivet will then be fed downwards in a fast, linear motion until the tip of the rivet contacts the upper surface of the workpiece to be fixed.

[0027] A temperature sensor is installed in the non-working area of ​​the upper surface of the plate to be fixed to record the temperature change at that location over time. The distance D between the sensor and the friction riveting center is set to satisfy the following: <D< ,in: This refers to the outer diameter of the rivet leg.

[0028] Step 4: The welding gun and the rivet move together axially and circumferentially to the parameters required for the self-piercing friction riveting process, thus completing the self-piercing friction riveting process. During the process, the performance of the vortex tube cooling system is adjusted to ensure that the peak temperature of the sensor is within a suitable range during the riveting process.

[0029] The aforementioned suitable range Middle and lower limit temperatures The lowest temperature corresponding to a material elongation greater than or equal to 10%, and the upper limit temperature for light alloy materials. To enhance the phase dissolution temperature, for composite materials, the upper limit temperature is... This is the melting point of the resin material.

[0030] Step 5: The vortex tube cooling system continues to output cooling gas until the temperature sensor data on the upper surface stabilizes.

[0031] The required cooling temperature T is obtained by using <T< Calculation, where At room temperature This is the maximum cooling temperature of the vortex tube cooling module.

[0032] Technical effect

[0033] This invention combines a vortex tube cooling system with a self-piercing friction riveting process, achieving rapid cooling of the friction riveting area through coordinated control of the two systems. Compared to existing technologies, this invention effectively reduces material softening caused by frictional heat and minimizes the area of ​​softened material. The increased joint material strength and reduced heat-affected zone effectively enhance the mechanical properties of the friction-riveted joint. For non-metallic materials such as carbon brazed composites, it effectively prevents material burn-off at high temperatures, ensuring the integrity of the joint structure. Attached Figure Description

[0034] Figure 1 (a)~(b) are schematic diagrams of two setup methods for a friction riveting system based on a vortex tube cooler;

[0035] In the diagram: a) shows the arrangement of cooling gas being delivered to the riveting area via the drive rod; b) shows the arrangement of cooling gas being delivered to the riveting area via the bottom mold. The components include: 1. vortex tube cooling system; 2. rivet; 3. mold; 4. drive rod; 5. pressure ring; 6. protrusion; 7. plate to be fixed; 8. temperature sensor; 9. sealing sleeve; 401. pipe; 101. cold air throttling valve core; 102. gas nozzle; 103. vortex tube; 104. heating air flow regulating valve core; 105. inner ring cooling gas; 106. outer ring hot gas; 107. cold air throttling valve body; 108. heating air flow regulating valve body.

[0036] Figure 2 This is a schematic diagram of the heat-affected zone in Example 1;

[0037] In the figure: HAZ is the average diameter of the heat-affected zone; the top figure is a partial cross-sectional view of the joint from the main perspective; the bottom figure is a top view of the joint and the heat-affected zone.

[0038] Figure 3 (a)~(d) are schematic diagrams of Example 1;

[0039] In the figure: a shows the meshing process between the rivet and the drive system in the vortex cooling assisted friction riveting process using a concave die; b shows the friction riveting stage; c shows the relative positional relationship between the rivet and the drive rod after the vortex cooling assisted friction riveting process is completed; d shows the final joint obtained; cooling gas is introduced from the air inlet valve of the sealing sleeve and runs through the entire process.

[0040] Figure 4 (a)~(d) are schematic diagrams of Example 2;

[0041] In the figure: a) shows the meshing process of the rivet and the drive system in the vortex cooling assisted friction riveting process using a flat mold; b) shows the friction riveting stage; c) shows the relative positional relationship between the rivet and the drive rod after the vortex cooling assisted friction riveting process is completed; d) shows the final joint obtained; the cooling gas is introduced through the air inlet valve of the bottom mold and runs through the entire process.

[0042] Figure 5 (a)~(d) are schematic diagrams of Example 3;

[0043] In the figure: a shows the meshing process between the rivet and the drive system in the vortex cooling assisted friction riveting process using a flat die; b shows the friction riveting stage; c shows the relative positional relationship between the rivet and the drive rod after the vortex cooling assisted friction riveting process is completed; d shows the final joint obtained; cooling gas is introduced from the air inlet valve of the sealing sleeve and runs through the entire process. Detailed Implementation

[0044] Example

[0045] like Figure 1 As shown, this embodiment relates to a vortex tube cooling system 1, including: a cold air throttle valve core 101, a cold air throttle valve body 107, a gas nozzle 102, a vortex tube 103, a heating air flow regulating valve core 104, a heating air flow regulating valve body 108, an outer ring of hot air 106, and an inner ring of cooling gas 105.

[0046] The vortex tube 103 has a length of 106 mm and an outer diameter of 17 mm.

[0047] The gas nozzle 102 is located 21 mm to the right of the outlet of the cold air throttle valve body 104, and its inlet inner wall has a 60° tapered pipe thread of type [missing information]. .

[0048] The outer diameter of the valve body 107 of the aforementioned air conditioning throttle valve is 28mm, and the model of the 60° tapered pipe thread on its outlet inner wall is [model number missing]. .

[0049] The outer diameter of the valve body 108 of the heating flow regulating valve is 19mm.

[0050] The output airflow temperature of the vortex tube cooling system 1 is -46℃ to +127℃; the cooling capacity is 34Kcal / hr to 2570Kcal / hr.

[0051] Figure 3 (d) The heat-affected zone of the formed joint, such as Figure 2 As shown, in this embodiment, the heat-affected zone diameter D of the self-piercing friction riveting welded joint is... HAZ To quantitatively characterize the size of the area softened by heat.

[0052] The heat-affected zone diameter HAZ is the diameter of the heat-affected zone in the plane between the upper and lower plates. The size of the heat-affected zone is obtained by measuring the hardness of the joint cross-section.

[0053] like Figure 3 As shown in (a)-(d), this embodiment relates to a self-piercing friction riveting system with a vortex tube cooling module, which includes: a drive rod 4, a rivet 2, a pressure ring 5, two plates to be fixed 7 stacked in sequence, a temperature sensor 8, a sealing sleeve 9, and a mold 3, wherein a cold air pipe 401 for conveying cooling gas is provided in the drive rod body.

[0054] like Figure 3 As shown in (a), the internal cooling air pipe 401 of the drive rod 4 is mounted on both sides of the rotating shaft; its outer side is surrounded by a sealing sleeve, and the air inlet valve of the sealing sleeve is connected to the cooling air throttle valve of the vortex tube cooling system.

[0055] like Figure 3 As shown in (a), the plate to be fixed in this embodiment is: aluminum alloy AA6061-T6 + aluminum alloy AA6061-T6; the thickness of the plate is matched as 2.0mm + 2.0mm.

[0056] like Figure 3 As shown in (a), the rivet 2 used in this embodiment is: alloy structural steel 40Cr; the length of the rivet body is 3.5mm, the outer diameter of the rivet body is 6mm, the inner diameter is 4mm, the inner wall of the rivet body is provided with an M4.5 thread, the thread length is 2.5mm, and the vertex of the wedge-shaped cone at the bottom of the rivet coincides with the outer wall.

[0057] like Figure 3 As shown in (a)-(d), this embodiment relates to a coordinated control method for the self-piercing friction riveting system and the vortex tube cooling system of the above system, specifically including the following steps:

[0058] Step 1: Introduce gas into the gas nozzle 102 of the vortex tube cooling system 1, and adjust the heating flow regulating valve body 108 and the cold air throttling valve body 107 until the cooling gas with a temperature drop of 46°C is obtained, and deliver the cooling gas into the cold air pipe 401 in the drive rod 4.

[0059] Step 2: The rivet 2 is coaxially mounted on the head of the drive rod 4, and damping is applied to restrict the axial movement and circumferential rotation of the rivet 2;

[0060] Step 3: Control the drive rod 4 to feed axially downwards in a linear speed of 50 mm / s until the bottom of the rivet leg contacts the upper surface of the plate 7 to be fixed;

[0061] Step 4: Continuously collect data from temperature sensor 8 until the temperature change rate is less than 1℃ / min.

[0062] Step 5: Control the drive rod 4 to feed axially downwards at a linear speed of 2 mm / s, while rotating at a speed of 3600 r / min, driving the rivet to feed at the same speed to the parameters required for the friction riveting process. During this process, record the temperature change of the temperature sensor, and the peak temperature during the process is within a suitable range.

[0063] Step 6: Control the drive rod 4 to retract axially upward at a linear speed of 50 mm / s, leaving the rivet 2 inside the plate to be fixed 7. During this process, the vortex tube cooling system continuously introduces cooling gas until the temperature change rate of the material near the joint is less than 1℃ / min.

[0064] In this embodiment, after the self-piercing friction riveting process is completed, the final self-piercing friction riveting joint obtained is as follows: Figure 3 As shown in (d).

[0065] Compared with existing technologies, the heat-affected zone diameter of the aluminum alloy-aluminum alloy self-piercing friction riveting welded joint after connection by this method is 16.3 mm, which is 25.9% smaller than the heat-affected zone diameter of 22 mm for self-piercing friction riveting welded joints without a cooling system. At the same time, the softening phenomenon of the material in the heat-affected zone is significantly improved, which is beneficial to improving the static strength of the joint.

[0066] Example

[0067] like Figure 4 As shown in (a)-(d), the plate to be fixed in this embodiment is: aluminum alloy AA7075-T6 + cast aluminum Aural-2; the plate thickness is matched to 2mm+2mm.

[0068] In this embodiment, the rivet 2, the drive rod 4, the pressure ring 5, and the flat bottom mold 3 together achieve the self-piercing friction riveting connection of the plate to be fixed 7.

[0069] like Figure 4 As shown in (a), the cold air pipe 301 inside the bottom mold 3 is spirally arranged at a depth of 2mm from the riveting area; its air inlet valve is connected to the cold air throttle valve of the vortex tube cooling system.

[0070] Other implementation methods in this embodiment are the same as in Example 1.

[0071] In this embodiment, after the self-piercing friction riveting process is completed, the final self-piercing friction riveting joint obtained is as follows: Figure 4 As shown in (d).

[0072] Compared with the prior art, the heat-affected zone diameter of the aluminum alloy-aluminum alloy self-piercing friction riveting weld joint after connection by this method is 18.2 mm, which is 27.2% smaller than the heat-affected zone diameter of 25 mm for the self-piercing friction riveting weld joint without a cooling system. At the same time, the softening phenomenon of the material in the heat-affected zone is significantly improved.

[0073] Example

[0074] like Figure 5 As shown in (a)-(d), the plate to be fixed in this embodiment is: aluminum alloy AA7075-T6 + aluminum alloy AA6061-T6; the plate thickness is matched to 2mm+2mm.

[0075] In this embodiment, the rivet 2, the drive rod 4, the pressure ring 5, and the flat bottom mold 3 together achieve the self-piercing friction riveting connection of the plate to be fixed 7.

[0076] like Figure 5 As shown in (a), the internal cooling air pipe 401 of the drive rod 4 is located coaxially with the rotating shaft; its outer side is surrounded by a sealing sleeve, and the air inlet valve of the sealing sleeve is connected to the cooling air throttle valve of the vortex tube cooling system.

[0077] Other implementation methods in this embodiment are the same as in Example 2.

[0078] In this embodiment, after the self-piercing friction riveting process is completed, the final self-piercing friction riveting joint obtained is as follows: Figure 5 As shown in (d).

[0079] Compared with the prior art, the heat-affected zone diameter of the aluminum alloy-aluminum alloy self-piercing friction riveting welded joint after connection by this method is 20mm, which is 18.4% smaller than the heat-affected zone diameter of 24.5mm of the self-piercing friction riveting welded joint without a cooling system. At the same time, the softening phenomenon of the material in the heat-affected zone is significantly improved.

[0080] Through specific practical experiments, under the specific environmental settings of connecting the vortex tube cooling module, and using the data collected by the temperature sensor as the standard, a collaborative control method of the vortex cooling system and the riveting and welding system was adopted. The experimental data obtained is: through hardness analysis, it was calculated that the reduction ratio of the heat-affected zone under the condition of introducing cooling gas compared with the heat-affected zone under the original process was obtained.

[0081] Compared with existing technologies, this device reduces the heat-affected zone of friction-welded metal joints and enables effective connection of easily burnable composite materials.

[0082] The above-described specific implementations can be partially adjusted by those skilled in the art in different ways without departing from the principles and purpose of the present invention. The scope of protection of the present invention is defined by the claims and is not limited to the above-described specific implementations. All implementation schemes within the scope of the claims are bound by the present invention.

Claims

1. A method of coordinated control of a friction rivet welding connection system, characterized in that, The friction riveting connection system includes: a pressure ring and a mold arranged opposite to each other, and a drive rod arranged inside the pressure ring, wherein: the drive rod is provided with a sealing sleeve connected to the vortex tube cooling module, the end of the drive rod is provided with a rivet, and an air inlet valve is provided on the outside of the sealing sleeve. The air inlet valve is connected to the outlet end of the cold air throttle valve of the vortex tube cooling module through a cold air delivery pipe. The aforementioned vortex tube cooling module includes: a vortex tube, a cold air throttling valve, a heating air flow regulating valve, and a gas nozzle. The cold air throttling valve and the heating air flow regulating valve are respectively located on both sides of the vortex tube and placed coaxially. The gas nozzle is located near the cold air throttling valve and is arranged crosswise with the throttling valve. The gas nozzle is connected to a compressed air source. The cold air throttling valve is connected to a friction riveting and welding connection system. The heating air flow regulating valve is connected to the external environment. Both the cold air throttling valve and the heating air flow regulating valve include: a valve body and a valve core with a conical structure disposed therein. The drive rod and / or the mold are provided with a cold air delivery pipe that is connected to the sealing sleeve. The inlet end of the cold air delivery pipe is connected to the cold air throttle valve of the vortex tube cooling module, and the outlet end is led out to the friction riveting welding working area. When the cold air delivery pipe is installed inside the mold, it is arranged in a spiral shape; The coordination and control method includes: Step 1: The vortex tube cooling system inputs compressed air and begins to discharge cooling gas; adjust the opening of the cold air throttle valve until the gas reaches the required cooling temperature; Step 2: symmetrically introduce cooling gas along the center of the drive shaft; Step 3: Read the temperature sensor data of the upper surface of the plate to be fixed. After the temperature sensor data stabilizes, the rivet suction structure works to attract and fix the rivet to the head of the welding gun. The welding gun and the rivet are fed downwards in a straight line until the front end of the rivet contacts the upper surface of the plate to be fixed. Step 4: The welding gun and the rivet move together axially and circumferentially to the parameters required for the self-piercing friction riveting process, and complete the self-piercing friction riveting process. During the process, the performance of the vortex tube cooling system is adjusted to ensure that the peak temperature of the sensor is within a suitable range during the riveting process. Step 5: The vortex tube cooling system continues to output cooling gas until the upper surface temperature sensor data stabilizes; A temperature sensor is installed in the non-working area of ​​the upper surface of the plate to be fixed to record the temperature change of this area over time. The distance D between the sensor and the center of the friction riveting is set to satisfy the following: <D< ,in: This refers to the outer diameter of the rivet leg.

2. The coordinated control method according to claim 1, characterized in that, The outlet end of the cold air throttle valve and the inner wall of the gas nozzle are provided with tapered pipe threads.

3. The coordinated control method according to claim 1, characterized in that, The outlet end can be one or a combination of the following: ① The outlet end is located at the end of the drive rod, and the distance from the center line of the drive rod is greater than or equal to the radius of the rivet head; ② The outlet end is located at the end of the drive rod, and the distance from the center line of the drive rod is less than the radius of the rivet head; ③ The outlet end is located inside the mold, and the distance from the upper surface of the mold is greater than or equal to the radius of the rivet head.

4. The coordinated control method according to claim 1, characterized in that, The pressure ring is a cylindrical structural component, coaxially positioned on the outside of the riveting gun, used to restrict the flow of surrounding material during the riveting process. The inner diameter of the pressure ring... satisfy: >2 ,in: The radius of the rivet head.

5. The coordinated control method according to claim 1, characterized in that, The end of the drive rod is provided with a structure to guide the deformation of the rivet, which includes a flat-bottomed die, a flat-bottomed concave die, a convex die, or a special-shaped concave die.

Images