A constant pressure ultrasonic-assisted roller bending forming method and apparatus

Abstract

This invention discloses a constant-pressure ultrasonic-assisted roll bending forming method and apparatus to solve the problems of uneven forming and poor precision caused by changes in the gap between the roller teeth when roll bending thin plates of varying thickness in existing methods and apparatuses. During forming, the air pressure is first adjusted according to the yield strength of the thin plate; then, power parameters are transmitted to the active roller teeth, and ultrasonic vibration parameters are applied to the driven roller teeth; finally, the thin plate is fed into the forming zone for constant-pressure ultrasonic-assisted roll bending forming. The forming apparatus includes a frame, a power system, an active roller tooth system, a driven roller tooth system, a pneumatic system, and an ultrasonic vibration system. This invention is applicable to the uniform and precise roll bending forming of thin plates of varying thickness.

Description

Technical Field

[0001] This invention belongs to the field of advanced manufacturing technology, specifically relating to a constant pressure ultrasonic-assisted roller bending forming method and apparatus. Background Technology

[0002] Corrugated sheets are crucial components in the fabrication of metal honeycomb structures. Currently, corrugated sheets are primarily manufactured using roll forming methods. However, existing methods suffer from incomplete forming and poor uniformity when roll forming thin sheets of varying thickness. This is because the gap between the driving and driven roller teeth cannot precisely adjust with the sheet thickness during roll forming. Furthermore, thin sheet roll forming is a micro-plastic forming process, subject to size effects. During the forming process, the heterogeneity of individual grains is significantly amplified, increasing the dispersion of the formed parts and severely restricting the application and development of metal honeycomb structures. Summary of the Invention

[0003] The purpose of this invention is to provide a constant pressure ultrasonic-assisted roll bending forming method and apparatus. By introducing an ultrasonic energy field into the roll bending forming process, the acoustic softening effect of the ultrasonic energy field is used to reduce the influence of individual grain heterogeneity. At the same time, a pneumatic system is introduced to maintain the adaptive fit of the ultrasonic vibration field on the variable thickness thin plate, thereby achieving uniform and precise roll bending forming of the variable thickness thin plate.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A constant-pressure ultrasonic-assisted roller bending forming method, characterized by comprising the following steps:

[0006] Step 1: Clean the driving roller teeth, driven roller teeth, and sheet metal with acetone, and let them air dry;

[0007] Step 2: Turn on the pneumatic system and adjust the pressure between the driving roller teeth and the driven roller teeth;

[0008] Step 3: Turn on the power system and send power to the drive roller teeth so that the drive and driven roller teeth rotate at a uniform speed of 6~30mm / s.

[0009] Step 4: Turn on the ultrasonic vibration system and apply ultrasonic vibration to the driven roller teeth, so that the driven roller teeth vibrate along the center line of the main and driven roller teeth axis at an ultrasonic vibration frequency of 20~50KHz and an amplitude of 2~10μm.

[0010] Step 5: Feed the sheet into the forming area for roll bending.

[0011] In step two, the method for adjusting the pressure between the active roller teeth and the driven roller teeth is as follows: turn off the power system, turn on the pneumatic system, and adjust the pneumatic control device to make the pressure of the two cylinders equal, with the pressure value being 0.8 to 1.1 times the yield strength value of the thin plate.

[0012] In step four, the method for activating the ultrasonic vibration system is as follows: during the rotation of the roller teeth, two ultrasonic generators are activated simultaneously, causing the vibration seat of the driven roller teeth system to vibrate at the same frequency and amplitude.

[0013] The ultrasonic vibration frequency and amplitude were determined based on ultrasonic-assisted thin plate tensile tests. At this vibration frequency and amplitude, the elongation of the thin plate was maximized.

[0014] The thin plate is a variable thickness thin plate, with the included angle between the upper and lower surfaces at any point on the thin plate being 0° to 60°, and the thickness being 30 to 3000 μm.

[0015] The constant pressure ultrasonic-assisted roller bending forming method is characterized by employing the following constant pressure ultrasonic-assisted roller bending forming device:

[0016] The constant pressure ultrasonic-assisted roller bending forming device includes: a frame, a power system, an active roller tooth system, a driven roller tooth system, a pneumatic system, and an ultrasonic vibration system.

[0017] The power system includes a servo motor and a power control device;

[0018] The active roller gear system includes an active shaft, active roller gears, rolling bearings, bushings, and end caps. The active roller gears are fixed to the active shaft by the bushings, and the active shaft is fixed to the frame by the rolling bearings and end caps. One end of the active shaft is connected to a servo motor.

[0019] The driven roller tooth system includes a driven shaft, driven roller teeth, a sliding bearing, a bushing, and a vibrating seat. The driven roller teeth are fixed to the driven shaft by the bushing, and the driven shaft is fixed to the vibrating seat by the sliding bearing.

[0020] The ultrasonic vibration system includes two ultrasonic generators, two transducers, and two amplitude transformers, with the amplitude transformers connected to the vibration base.

[0021] The pneumatic system includes an air compressor, a pneumatic control device, two cylinders and two sets of linear slide rails. The cylinders and transducers are fixed on the linear slide rails, the end of the cylinder is connected to the transducer, and the linear slide rails are fixed on the frame.

[0022] The vibrating seat consists of an upper vibrating seat with a semi-circular shape, a diameter of 5-80 mm, and a wall thickness of 2-4 mm, and a lower vibrating seat with a semi-circular shape, a diameter of 5-80 mm, and a wall thickness of 2-4 mm. The upper vibrating seat has a cylindrical boss with a height of 20-50 mm and an inclination of 1 / 20-1 / 30 at its top. The diameter of the top circle of the cylindrical boss is the same as the diameter of the end of the amplitude transformer. The cylindrical boss has a hollow structure inside and a countersunk hole at its top.

[0023] The tooth shape of the driving roller teeth and the driven roller teeth is triangular, rectangular, trapezoidal or circular arc.

[0024] The beneficial effects of this invention are as follows: 1. By applying a specific pressure between the driving and driven roller teeth using the method of this invention, the gap between the driving and driven roller teeth adaptively adjusts when the thickness of the thin plate changes, which is particularly beneficial for the roll bending forming of thin plates with varying thicknesses; 2. By applying the method of this invention, under the acoustic softening effect of a specific ultrasonic energy field, the influence of individual grain heterogeneity within the thin plate is weakened, the deformation distribution state undergoes uniform reconstruction, and the forming accuracy of the corrugated plate is greatly improved; 3. The forming device of this invention has a special structural design of the vibrating seat with an energy-concentrating effect. By applying the same ultrasonic vibration field to both ends of the driven shaft simultaneously through the vibrating seat, the effect of ultrasonic vibration is amplified, making it particularly easy to achieve the acoustic softening effect of the ultrasonic vibration field; 4. The device of this invention has a pneumatic system set at the front end of the ultrasonic vibration system. By applying a constant pressure ultrasonic energy field to the driven roller teeth, the subsequent corrugated plate pressure forming process is avoided, greatly improving the production efficiency of ultra-thin wall corrugated plates. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the constant pressure ultrasonic-assisted roller bending forming method described in this invention.

[0026] Figure 2 This is a schematic diagram of the constant pressure ultrasonic-assisted roller bending forming device described in this invention.

[0027] Figure 3 This is a schematic diagram of the vibration seat described in this invention.

[0028] Explanation of the numbers in the diagram: 1. Power system, 101. Servo motor, 102. Power control device, 2. Frame, 3. Active roller gear system, 301. Active shaft, 302. Bushing A, 303. Active roller gear, 304. Rolling bearing, 305. End cover, 4. Driven roller gear system, 401. Driven shaft, 402. Sliding bearing, 403. Bushing, 404. Driven roller gear, 405. Vibration seat, 405A. Upper vibration seat, 405B. Lower vibration seat, 405C. Cylindrical boss, 5. Ultrasonic vibration system, 501. Amplitude bar, 502. Transducer, 503. Ultrasonic generator, 6. Pneumatic system, 601. Air compressor, 602. Air pressure control device, 603. Cylinder, 604. Linear guide rail, 7. Thin plate. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solutions of this application, the specific embodiments proposed by the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0030] Combination Figures 1-3As shown, a constant-pressure ultrasonic-assisted roller bending forming method is characterized by comprising the following steps:

[0031] Step 1: Clean the 303 driving roller teeth, 404 driven roller teeth, and 7 thin plate with acetone, and let them air dry;

[0032] Step 2: Activate the pneumatic system and adjust the pressure between the 303 driving roller tooth and the 404 driven roller tooth;

[0033] Step 3: Turn on the power system 1 to transmit power to the 303 drive roller teeth, so that the drive and driven roller teeth rotate at a uniform speed of 6~30 mm / s.

[0034] Step 4: Turn on the ultrasonic vibration system and apply ultrasonic vibration to the 404 driven roller teeth, so that the 404 driven roller teeth vibrate along the center line of the main and driven roller teeth axis at an ultrasonic vibration frequency of 20~50KHz and an amplitude of 2~10μm.

[0035] Step 5: Feed the 7 thin plates into the forming area for ultrasonic-assisted roll bending forming.

[0036] Combination Figures 1-3 As shown, a constant-pressure ultrasonic-assisted roller bending forming method can employ the following constant-pressure ultrasonic-assisted roller bending forming device:

[0037] The constant pressure ultrasonic-assisted roller bending forming device includes: 1 power system, 2 frame, 3 active roller tooth system, 4 driven roller tooth system, 5 ultrasonic vibration system and 6 pneumatic system;

[0038] The power system 1 includes a servo motor 101 and a power control device 102;

[0039] The 3-drive roller system includes a 301 drive shaft, a 303 drive roller, a 304 rolling bearing, a 302 bushing A, and a 305 end cap. The 303 drive roller is fixed to the 301 drive shaft via the 302 bushing A. The 301 drive shaft is fixed to the 2-frame via the 304 rolling bearing and the 305 end cap. One end of the 301 drive shaft is connected to the 101 servo motor.

[0040] The four driven roller tooth system includes a driven shaft 401, a driven roller tooth 404, a sliding bearing 402, a bushing 403, and a vibrating seat 405. The driven roller tooth 404 is fixed to the driven shaft 401 through the bushing 403, and the driven shaft 401 is fixed to the vibrating seat 405 through the sliding bearing 402.

[0041] The ultrasonic vibration system includes two 503 ultrasonic generators, two 502 transducers, and two 501 amplitude transformers, with the 501 amplitude transformers connected to the 405 vibration base.

[0042] The pneumatic system includes one 601 air compressor, one 602 air pressure control device, two 603 cylinders and two sets of 604 linear slide rails. The 603 cylinders and the 502 transducer are fixed on the 604 linear slide rails. The end of the 603 cylinder is connected to the 502 transducer. The 604 linear slide rails are fixed on the two frames.

[0043] The 405 vibration seat consists of a 405A upper vibration seat with a semi-circular shape, a diameter of 5-80mm, and a wall thickness of 2-4mm, and a 405B lower vibration seat with a semi-circular shape, a diameter of 5-80mm, and a wall thickness of 2-4mm. The top of the 405A upper vibration seat is provided with a 405C cylindrical boss with a height of 20-50mm and an inclination of 1 / 20-1 / 30. The diameter of the top circle of the 405C cylindrical boss is the same as the diameter of the end of the 501 amplitude transformer. The interior of the 405C cylindrical boss is hollow, and a countersunk hole is provided at the top of the 405C cylindrical boss.

[0044] Example 1

[0045] LY12 aluminum alloy sheet with a thickness of 80~300μm and an angle between the upper and lower surfaces of 20°~50°, 500mm in length and 60mm in width. Corrugated sheet with a forming angle of 120°. Forming parameters: 50mm diameter for both driving and driven roller teeth, 120° trapezoidal tooth profile, and roller rotation speed of 1mm / s. The air pressure system is adjusted to maintain a pressure of 280MPa between the driving and driven roller teeth. Ultrasonic vibration parameters: frequency of 20 kHz and amplitude of 5μm.

[0046] Comparative Example 1

[0047] LY12 aluminum alloy sheet with a thickness of 80~300μm and an angle between the upper and lower surfaces of 20°~50°, 500mm in length and 60mm in width. Corrugated sheet with a forming angle of 120°. Forming parameters: 50mm diameter for both driving and driven roller teeth, 120° trapezoidal tooth profile, and roller rotation speed of 1mm / s. 150μm gap between driving and driven roller teeth. Ultrasonic vibration parameters: None.

[0048] Table 1 compares five randomly selected forming angles in the examples and comparative examples.

[0049] Serial Number 1 2 3 4 5 Forming error Example 1 123.3° 121.7° 116.7° 122.4° 119.8° ±3.3° Comparative Example 1 158.2° 147.8° 127.1° 102.2° 95.3° ±38.2°

[0050] Example 1 and Comparative Example 1 show the angle measurement results of corrugated sheets formed using the methods of the present invention and conventional methods. The serial numbers, from smallest to largest, indicate that the sheet thickness increases. The results show that the constant-pressure ultrasonic-assisted roller bending forming method and apparatus of the present invention produce relatively uniform forming angles and a small forming error (±3.3°), meeting the forming requirements (±5°). In contrast, corrugated sheets formed using conventional methods exhibit more dispersed forming angles and a larger forming error (±38.2°). In areas with thinner thicknesses, the springback angle is larger, while in areas with thicker thicknesses, the springback angle is very small, even exhibiting negative springback. This is because the gap between the driving and driven roller teeth cannot change with the sheet thickness. Using the method and apparatus of the present invention, corrugated sheets of varying thicknesses can be formed from thin sheets to meet the requirements.

Claims

1. A constant-pressure ultrasonic-assisted roller bending forming method, characterized in that: Includes the following steps: Step 1: Clean the driving roller teeth, driven roller teeth, and sheet metal with acetone, and let them air dry; Step 2: Turn on the pneumatic system and adjust the pressure between the driving roller teeth and the driven roller teeth; Step 3: Turn on the power system and send power to the drive roller teeth so that the drive and driven roller teeth rotate at a uniform speed of 6~30 mm / s. Step 4: Turn on the ultrasonic vibration system and apply ultrasonic vibration to the driven roller teeth, so that the driven roller teeth vibrate along the center line of the main and driven roller teeth axis at an ultrasonic vibration frequency of 20~50KHz and an amplitude of 2~10μm. Step 5: Feed the sheet into the forming area for roll bending; In step two, the method for adjusting the pressure between the active roller teeth and the driven roller teeth is as follows: turn off the power system, turn on the pneumatic system, and adjust the pneumatic control device to make the pressure of the two cylinders equal, with the pressure value being 0.8 to 1.1 times the yield strength value of the thin plate.

2. The constant pressure ultrasonic-assisted roller bending forming method according to claim 1, characterized in that: In step four, the method for activating the ultrasonic vibration system is as follows: during the rotation of the roller teeth, two ultrasonic generators are activated simultaneously, causing the vibration seat of the driven roller teeth system to vibrate at the same frequency and amplitude.

3. The constant pressure ultrasonic-assisted roller bending forming method according to claim 2, characterized in that: The ultrasonic vibration frequency and amplitude were determined based on ultrasonic-assisted thin plate tensile tests. At this vibration frequency and amplitude, the elongation of the thin plate was maximized.

4. The constant pressure ultrasonic-assisted roller bending forming method according to claim 1, characterized in that: The thin plate is a variable thickness thin plate, with the included angle between the upper and lower surfaces at any point on the thin plate being 0° to 60°, and the thickness being 30 to 3000 μm.

5. A constant-pressure ultrasonic-assisted roller bending forming device, employing the constant-pressure ultrasonic-assisted roller bending forming method according to any one of claims 1 to 4, characterized in that, The device includes: Frame, power system, driving roller system, driven roller system, pneumatic system, and ultrasonic vibration system: The power system includes a servo motor and a power control device; The active roller gear system includes an active shaft, active roller gears, rolling bearings, bushings, and end caps. The active roller gears are fixed to the active shaft by the bushings, and the active shaft is fixed to the frame by the rolling bearings and end caps. One end of the active shaft is connected to a servo motor. The driven roller tooth system includes a driven shaft, driven roller teeth, a sliding bearing, a bushing, and a vibrating seat. The driven roller teeth are fixed to the driven shaft by the bushing, and the driven shaft is fixed to the vibrating seat by the sliding bearing. The ultrasonic vibration system includes two ultrasonic generators, two transducers, and two amplitude transformers, with the amplitude transformers connected to the vibration base. The pneumatic system includes an air compressor, a pneumatic control device, two cylinders and two sets of linear slide rails. The cylinders and transducers are fixed on the linear slide rails, the end of the cylinder is connected to the transducer, and the linear slide rails are fixed on the frame.

6. The constant pressure ultrasonic-assisted roller bending forming device according to claim 5, characterized in that: The vibrating seat consists of an upper vibrating seat with a semi-circular shape, a diameter of 5-80 mm, and a wall thickness of 2-4 mm, and a lower vibrating seat with a semi-circular shape, a diameter of 5-80 mm, and a wall thickness of 2-4 mm. The upper vibrating seat has a cylindrical boss with a height of 20-50 mm and an inclination of 1 / 20-1 / 30 at its top. The diameter of the top circle of the cylindrical boss is the same as the diameter of the end of the amplitude transformer. The cylindrical boss has a hollow structure inside and a countersunk hole at its top.

7. The constant pressure ultrasonic-assisted roller bending forming device according to claim 5, characterized in that: The tooth shape of the driving roller teeth and the driven roller teeth is triangular, rectangular, trapezoidal or arc-shaped.

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