Air bearing foil stamping auxiliary device capable of intelligently controlling blank holder force

Abstract

The invention provides an air bearing foil stamping auxiliary device. Each pressing plate is fixedly provided with a display spring guide column. Each display spring guide column is sleeved with a display spring. Guide holes of the stamping plate penetrate through the upper ends of the corresponding display spring guide columns and are pressed on the display springs; the stamping plate limiting piece limits the height position of the stamping plate; the upper die assembly is arranged on the lower die and matched with the lower die to form a stamping model. The blank holder force intelligent control assembly collects the pressure of each display bullet on the pressing plate, and when the sum of the pressure is larger than or equal to the set standard punching force, the punching force is stopped from being increased; and when the sum of the pressure is smaller than the set standard stamping force, the stamping force is stopped from being increased. The stamping die has the advantages that main body stamping and edge pressing force of four edges are achieved at the same time through one stamping force, and the edge pressing force can be accurately controlled; and the rebound rate of the foil after punch forming is reduced, the uniform wave height is ensured, and the manufacturing requirement of the air bearing foil is met.

Description

Technical Field

[0001] This invention relates to the field of air bearing foil stamping manufacturing, and in particular to an air bearing foil stamping auxiliary device with intelligent control of blanking force. Background Technology

[0002] Air bearings are support components that use gas as a lubricating medium. They rely on a pressurized air film formed within a tiny gap between the journal and the bearing surface to support rotating components, thus offering advantages such as virtually no friction, no wear, and no environmental pollution. Air bearings are increasingly used in this environment because their lubricating medium, air, can be recycled from the working environment, aligning with the concept of green, environmentally friendly, and harmonious development. Among them, the flexible corrugated foil gas bearing is considered one of the most effective and successful types of air bearings.

[0003] Air bearing foil is not a simple stamped part; it is a precision elastic element requiring extremely high accuracy and consistency. Manufacturing defects can directly lead to a sharp decline in bearing performance. Currently, domestic manufacturers still have many shortcomings in the stamping of corrugated foil. After the metal sheet is stamped and demolded, elastic rebound inevitably occurs, resulting in a mismatch between the final shape and the die surface. This is one of the biggest technical challenges in foil stamping. Inaccurate springback control means that the stamped foil is not in the desired shape, causing all performance expectations based on that design to fail to be achieved. Since air bearing foil stamping requires the application of a main stamping force and a certain blank holder force, the two stamping processes are implemented using different stamping techniques. Existing foil stamping manufacturing technology does not control the blank holder force appropriately, resulting in a high foil springback rate and a decline in bearing performance. Summary of the Invention

[0004] The present invention provides an air bearing foil stamping auxiliary device with intelligent control of blanking force. One stamping force can simultaneously realize the stamping of the main body and the blanking force of the four sides, and can achieve precise control of blanking force; reduce the springback rate after foil stamping and ensure uniform wave height, thereby meeting the manufacturing requirements of air bearing foil and overcoming the defects of the prior art.

[0005] This invention provides an air bearing foil stamping auxiliary device with intelligent control of blank holder force, comprising a lower mold 10, an upper mold assembly 6, a stamping plate 4, at least one pressure plate, at least one array spring guide post 2, at least one array spring 5, and a stamping plate limiting member 3; at least one array spring guide post 2 is fixed on each pressure plate; an array spring 5 is fitted on each array spring guide post 2; the stamping plate 4 has guide holes that match the array spring guide posts 2; the guide holes of the stamping plate 4 pass through the upper ends of the corresponding array spring guide posts 2, press on the array spring 5, and the stamping plate 4 can move up and down on the array spring guide posts 2; the stamping plate limiting member 3 restricts the height position of the stamping plate 4; the upper mold assembly 6 is set on the lower mold 10, and the two are matched to form a stamping model; the intelligent blank holder force control component collects the pressure of each array spring 5 on the pressure plate, and stops increasing the stamping force when the total pressure of the array springs is greater than or equal to the set standard stamping force; and stops increasing the stamping force when the total pressure of the array springs is less than the set standard stamping force.

[0006] Furthermore, the present invention provides an air bearing foil stamping auxiliary device with intelligent control of pressing force, which also includes the following features: the number of pressing plates is four, divided into two pairs, namely two long side pressing plates 9 and two short side pressing plates 7 symmetrically arranged; the two long side pressing plates 9 and the two short side pressing plates 7 press on the four sides of the foil 8 respectively.

[0007] Furthermore, the present invention provides an air bearing foil stamping auxiliary device with intelligent control of blanking force, which also includes the following features: two array spring guide posts 2 are fixed on the long side pressure plate 9; the lower ends of the two array spring guide posts 2 are respectively fixed at both ends of the long side pressure plate 9; one array spring guide post 2 is fixed on the short side pressure plate 7; the lower end of the one array spring guide post 2 is fixed at the middle position of the short side pressure plate 7.

[0008] Furthermore, the present invention provides an air bearing foil stamping auxiliary device with intelligent control of blanking force, which also includes the following features: the stamping plate limiting member 3 consists of at least two bolts; the stamping plate 4 has limiting holes that match the bolts; the lower die 10 has internal threads that match the bolts; the threaded end of the bolt passes through the limiting hole of the stamping plate 4 and engages with the internal thread of the lower die 10, and the bolt head is pressed on the stamping plate 4.

[0009] Furthermore, the present invention provides an air bearing foil stamping auxiliary device with intelligent control of blank holder force, which also includes the following features: the upper die assembly 6 includes an upper pressure plate and an upper die; the upper die has an upper die structure; the upper die presses on the stamped part, and the upper pressure plate presses on the upper die; the upper die is made of polytetrafluoroethylene sheet.

[0010] Furthermore, the present invention provides an air bearing foil stamping auxiliary device with intelligent control of blanking force, which also includes the following features: it further includes a linear bearing 1; the linear bearing 1 is disposed between the guide hole on the array spring guide post 2 and the stamping plate 4.

[0011] Furthermore, the present invention provides an air bearing foil stamping auxiliary device with intelligent control of blanking force, which also includes the following features: the intelligent control component for blanking force includes a blanking force sensor 12; a blanking force sensor 12 is provided between each array spring 5 and the pressure plate to collect the pressure applied by each array spring 5 to the pressure plate.

[0012] Furthermore, the present invention provides an air bearing foil stamping auxiliary device with intelligent control of blanking force, which also includes the following features: the intelligent control component for blanking force further includes a blanking force controller 13 and a hydraulic pump 14; the blanking force controller 13 calculates the sum of the pressures from the blanking force sensors 12, and then determines whether the sum of the pressures is greater than the set standard stamping pressure; when the sum of the pressures is less than or equal to the set standard stamping pressure, the hydraulic pump 14 increases the stamping pressure; when the sum of the pressures is greater than the set standard stamping pressure, the hydraulic pump 14 stops increasing the stamping pressure and maintains the current stamping pressure.

[0013] Furthermore, the present invention provides an air bearing foil stamping auxiliary device with intelligent control of blanking force, which also includes the following features: the intelligent control component for blanking force further includes a blanking force data collector 15; the blanking force data collector 15 is connected to each blanking force sensor 12 via a data line to obtain the pressure applied by each array spring 5 to the pressure plate; the blanking force data collector 15 is also connected to the blanking force controller 3 via a data line to transmit the obtained pressure data to the blanking force controller 13. Attached Figure Description

[0014] Figure 1 This is a perspective view of the air bearing foil stamping auxiliary device with intelligent control of blank holder force in the embodiment.

[0015] Figure 2 This is a force diagram of the array spring in the embodiment.

[0016] Figure 3 This is a flowchart of the stamping process in the embodiment. Detailed Implementation

[0017] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0018] Example

[0019] In this embodiment, the air bearing foil stamping auxiliary device with intelligent control of blank holder force includes: a lower mold 10, an upper mold assembly 6, four pressure plates, six arrayed spring guide pillars 2, six arrayed springs 5, a stamping plate 4, a stamping plate limiting component 3, and an intelligent control component for blank holder force.

[0020] Figure 1 The lower die 10 shown also has structures such as holes for fixed connection with the stamping machine platform, which are existing technologies and will not be described in detail. During stamping, the lower die 10 is fixed on the stamping machine platform. The lower die 10 is fixed by the locking device of the stamping machine, and leveling is performed during fixing to keep the lower die 10 in a horizontal position, ensuring the reliability of the stamping result. Of course, the lower die 10 has a lower mold structure in the middle, where the foil 8 is placed during stamping.

[0021] The upper die assembly 6 is mounted on the lower die 10, and the two fit together to form a stamping mold. In this embodiment, the upper die assembly 6 includes an upper pressure plate and an upper mold. The upper mold is made of polytetrafluoroethylene (PTFE) sheet, on which the upper mold structure is fabricated. The upper pressure plate is made of metal and has a certain weight. During stamping, the upper mold is placed on the foil sheet 8, and the upper pressure plate is placed on the upper mold. Of course, the upper pressure plate and the upper mold can be fixed together as a whole.

[0022] In this embodiment, the four pressure plates are arranged in two pairs: two symmetrically arranged long-side pressure plates 9 and two stacked short-side pressure plates 7. The two long-side pressure plates 9 and the two short-side pressure plates 7 press down on the four sides of the foil 8. Here, the long-side pressure plates 9 and the short-side pressure plates 7 correspond to the length and width directions of the foil 8, respectively. If a square foil 8 is encountered, the lengths of both sides are the same.

[0023] In this embodiment, each long side pressure plate 9 is equipped with two array spring guide posts 2. The lower ends of the two array spring guide posts 2 are fixed to both ends of the long side pressure plate 9 to prevent uneven pressure that may be caused by applying pressure only in the middle of the long side pressure plate 9. On the two long side pressure plates 9, a total of four array spring guide posts 2 are fitted with one array spring 5. Each short side pressure plate 7 is relatively short and is equipped with one array spring guide post 2.

[0024] In this embodiment, the stamping plate 4 has six guide holes that match the position and shape of the array spring guide posts 2. The guide holes of the stamping plate 4 pass through the upper ends of the corresponding array spring guide posts 2, press against the six array springs 5, and the stamping plate 4 can move up and down on the array spring guide posts 2. To improve the smoothness of the movement of the stamping plate 4 on the array spring guide posts 2, a linear bearing 1 is provided between the guide holes on the array spring guide posts 2 and the stamping plate 4. The linear bearing 1 is made of plastic, which provides wear resistance and makes the blank holder force more precise during stamping.

[0025] In this embodiment, the stamping plate limiting component 3 consists of four bolts, located at the four corners of the stamping plate 4. The stamping plate 4 has four limiting holes at corresponding positions, each slightly larger than the outer diameter of the bolt threads; the lower die 10 has four internal threads at corresponding positions that mate with the bolts. The threaded ends of the bolts pass through the limiting holes of the stamping plate 4, engage with the internal threads of the lower die 10, and the bolt heads press against the stamping plate 4, limiting the height of the stamping plate 4. The four bolts fixation makes the entire auxiliary device easy to assemble and disassemble, adaptable to different working environments.

[0026] The edge-pressing force intelligent control component collects the pressure of each stack spring (5) on the pressure plate. When the total pressure of the stack springs is greater than the set standard punching force, the punching force is stopped from increasing. In this embodiment, the edge-pressing force intelligent control component includes: 6 edge-pressing force sensors 12, edge-pressing force controller 13, hydraulic pump 14 and edge-pressing force data collector 15.

[0027] A pressure sensor 12 is installed between each display spring 5 and the pressure plate to obtain the pressure value applied by each display spring 5 to the pressure plate. The pressure force data collector (15) is connected to each pressure force sensor (12) via a data line to obtain the pressure applied by each display spring (5) to the pressure plate; the pressure force data collector (15) is also connected to the pressure force controller (13) via a data line to transmit the obtained pressure data to the pressure force controller (13). The pressure force controller (13) calculates the sum of the pressures from the pressure force sensors (12) and then determines whether the sum of the pressures is greater than the set standard punching pressure. When the sum of the pressures is less than or equal to the set standard punching pressure, the hydraulic pump (14) continues to increase the punching pressure; when the sum of the pressures is greater than the set standard punching pressure, the hydraulic pump (14) stops increasing the punching pressure. The hydraulic pump 14 controls the pressure by providing pressure force feedback to the punch head of the stamping press to achieve intelligent control of the pressure force, so that the actual punching pressure is consistent with the ideal pressure force.

[0028] Working process of the air bearing foil stamping auxiliary device with intelligent control of blank holder force:

[0029] Preparation:

[0030] The lower die 10 is fixed on the press table and secured by the press's locking device. Leveling is performed during fixing to ensure the lower die 10 remains horizontal, guaranteeing the reliability of the stamping results. The bearing foil 8 to be stamped is then placed on the lower die structure of the lower die 10. The upper die assembly 6 is then placed on the bearing foil 8, ensuring that the upper die structure matches the lower die structure.

[0031] Two long-side pressure plates 9 and two short-side pressure plates 7 are then pressed onto the four sides of the bearing foil 8. The guide hole of the stamping plate 4 passes through the upper end of the corresponding array spring guide post 2 and presses onto the array spring 5. Then, the threaded end of the bolt passes through the limiting hole of the stamping plate 4 and engages with the internal thread of the lower die 10, with the bolt head pressing on the stamping plate 4. The stamping plate 4 is then leveled, completing the preparatory work before stamping.

[0032] Stamping process:

[0033] The stamping press applies a stamping force f to the stamping plate 4, which moves downward along the array spring guide post 2, applying stamping force to the upper die assembly 6 and pressure to the array springs 5. The upper die assembly 6 presses against the lower die 10, and the two together form a stamping mold to stamp the main body of the bearing foil 8. The pressure of the array springs 5 ​​is applied to the two long-side pressure plates 9 and the two short-side pressure plates 7, realizing the edge forming of the four sides of the bearing foil 8. During the stamping process, the edge force sensor 12 can collect the pressure applied by the array springs 5 ​​to the pressure plates.

[0034] The strength coefficients of the six stacking springs A, B, C, D, E, and F are k1, k2, k3, k4, k5, and k6, respectively, taking into account the required clamping force during device operation. The stacking springs 5 ​​are arranged in parallel between the upper and lower pressure plates, therefore the equivalent stiffness coefficient of the six stacking springs 5 ​​is K. e = k1 + k2 + k3 + k4 + k5 + k6. The force applied by a single stacked spring 5 is F. (n) =k (n) x, (x is the deformation of the spring; n is the serial number of the corresponding spring).

[0035] The force exerted by the stacking spring 5 acts on the stamping plate, and the equivalent pressure of the stacking spring 5 is F. e F e =K e x = (k1 + k2 + k3 + k4 + k5 + k6)x. The pressure sensor 12 detects the blank holder force for each press, and the equivalent pressure of the stacking springs is controlled by the press or control components, based on the standard stamping force F set before each press. standard The equivalent pressure is controlled. When the equivalent pressure of the stacked spring exceeds the standard stamping pressure during stamping, the hydraulic pump 14 will provide feedback to the stamping punch, preventing the blank holder force from increasing further. To prevent excessive pressing force from breaking the foil to be stamped. (n) The stiffness coefficient of the display springs used. (n is the serial number of the corresponding spring), the unit is N / mm or N / m, and the stiffness k can be seen from the formula. (n) With wire diameter d (n)It is proportional to the fourth power, and the median diameter D (n) The force required to produce a unit deformation of the array spring 5 is inversely proportional to the cube of the force, inversely proportional to the effective number of coils N, and directly proportional to the shear modulus G. In this invention, the force is the blank-pressing force of the foil to be stamped. The required stiffness coefficient of the array spring 5 is determined by the required blank-pressing force, and then the various parameters of the array spring 5 are determined by the formula for calculating the stiffness coefficient. The required blank-pressing force is obtained by summing the height from the bottom surface of the stamping plate 4 to the upper surface of the lower die assembly 6 and the height compressed before stamping, i.e., the total deformation of the spring. This can be used to apply blank-pressing force to metal sheets with different blank-pressing force requirements. In other words, during device design, different blank-pressing forces can be obtained with the same stamping pressure by changing the strength coefficient of the array spring 5, thereby precisely controlling the magnitude of the blank-pressing force. Alternatively, the magnitude of the blank-pressing force can be adjusted by changing the thickness of the pressure plate, thereby changing the deformation of the array spring.

[0036] Furthermore, a certain springback rate is inevitable during the stamping of thin metal sheets. This springback rate can be reduced by applying a blank holder force to the sheet to be stamped. In this invention, the radius of curvature ρ' after springback is determined by... Calculate ρ, where ρ' is the radius of curvature of the stamping punch (mm), ρ' is the radius of curvature of the workpiece after unloading (mm), M is the bending moment on the workpiece section before unloading (N·mm), E is the elastic modulus of the material (MPa), and I is the moment of inertia of the workpiece section (mm). 4 The larger the bending moment M, the larger the subtrahend on the right side of the equation, resulting in a greater curvature after springback. The smaller the value, the larger the radius of curvature ρ' after springback, resulting in a flatter part to be stamped. P represents pressure, which in this invention is the blank holder force, i.e., P = F. (n) =k (n) x (n is the serial number of the corresponding spring), L is the distance (mm) between the two support points; that is, the length of the foil.

[0037] The foil to be stamped is a rectangular cross-section foil. Where b is the foil width and t is the foil thickness. In this invention, the radius of curvature ρ' after springback can be obtained through... (n is the serial number of the corresponding spring) is used for calculation. The radius of curvature after rebound is obtained through the above formula, and the springback rate K of the foil is then calculated. When K=1, there is no springback; when K>1, there is positive springback; and when K<1, there is negative springback. This invention provides an air bearing stamping auxiliary device capable of applying blank holder force. By calculating the spring deformation x, stiffness coefficient k(n), and pressure plate length L, the smaller the springback rate K, the more effective the design can control these coefficients, thereby reducing the foil springback rate K. This improves the yield of thin metal sheets and allows for controllable blank holder force. The blank holder force is determined by the stiffness coefficient k and spring deformation x of the array springs. When different blank holder forces are required, the value of k or the height x can be changed to control the blank holder force. Furthermore, during stamping, the blank holder force sensor 12 detects the pressure feedback from the device, allowing for more precise adjustment of the array spring 5 selection and installation. This auxiliary device features high integration and can be used on existing stamping methods, applying blank holder force to the foil's perimeter while maintaining constant stamping head pressure.

[0038] The embodiments described above are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. An air bearing foil stamping auxiliary device with intelligent control of blank holder force, characterized in that: It includes a lower mold (10), an upper mold assembly (6), a stamping plate (4), at least one pressure plate, at least one array spring guide post (2), at least one array spring (5), a stamping plate limiting component (3), and a blank holder force intelligent control component; Each of the pressure plates is fixed with at least one array spring guide post (2); each of the array spring guide posts (2) is fitted with an array spring (5); The stamping plate (4) has a guide hole that matches the array spring guide post (2); the guide hole of the stamping plate (4) passes through the upper end of the corresponding array spring guide post (2) and presses on the array spring (5); and the stamping plate (4) can move up and down on the array spring guide post (2). The stamping plate limiting member (3) will limit the height position of the stamping plate (4); The upper die assembly (6) is disposed on the lower die (10), and the two are matched to form a stamping pattern; The intelligent pressure control component collects the pressure of each display spring (5) on the pressure plate. When the total pressure of the display springs is greater than or equal to the set standard pressure, the pressure is stopped from increasing; when the total pressure of the display springs is less than the set standard pressure, the pressure is stopped from increasing.

2. The air bearing foil stamping auxiliary device with intelligent control of blank holder force as described in claim 1, characterized in that: in, The number of pressure plates is four, divided into two pairs: two long-side pressure plates (9) and two short-side pressure plates (7) arranged symmetrically; the two long-side pressure plates (9) and the two short-side pressure plates (7) press on the four sides of the foil (8) respectively.

3. The air bearing foil stamping auxiliary device with intelligent control of blank holder force as described in claim 2, characterized in that: in, Two array spring guide posts (2) are fixed on the long side pressure plate (9); The lower ends of the two array spring guide posts (2) are respectively fixed to both ends of the long side pressure plate (9); A spring guide post (2) is fixed on the short side pressure plate (7); The lower end of one of the array spring guide posts (2) is fixed at the middle position of the short side pressure plate (7).

4. The air bearing foil stamping auxiliary device with intelligent control of blank holder force as described in claim 1, characterized in that: in, The stamping plate limiting component (3) consists of at least two bolts; The stamping plate (4) has a limiting hole that matches the bolt; The lower mold (10) has an internal thread that matches the bolt; The threaded end of the bolt passes through the limiting hole of the stamping plate (4) and engages with the internal thread of the lower die (10), and the bolt head presses on the stamping plate (4).

5. The air bearing foil stamping auxiliary device with intelligent control of blank holder force as described in claim 1, characterized in that: in, The upper mold assembly (6) includes: an upper pressure plate and an upper mold; the upper mold has an upper mold structure; The upper mold presses onto the stamped part, and the upper pressure plate presses onto the upper mold; The model described above is made of polytetrafluoroethylene (PTFE) sheet.

6. The air bearing foil stamping auxiliary device with intelligent control of blank holder force as described in claim 1, characterized in that: It also includes linear bearings (1); The linear bearing (1) is disposed between the guide hole on the array spring guide post (2) and the stamping plate (4).

7. The air bearing foil stamping auxiliary device with intelligent control of blank holder force as described in any one of claims 1 to 6, characterized in that: in, The intelligent control component for blank holder force includes a blank holder force sensor (12); A pressure sensor (12) is provided between each of the display springs (5) and the pressure plate to collect the pressure exerted by each display spring (5) on the pressure plate.

8. The air bearing foil stamping auxiliary device with intelligent control of blank holder force as described in claim 7, Its features are: The intelligent control component for blank holder force also includes a blank holder force controller (13) and a hydraulic pump (14); The blank holder force controller (13) calculates the sum of the pressures from the blank holder force sensor (12) and then determines whether the sum of the pressures is greater than the set standard punching force. When the total pressure is less than or equal to the set standard punching pressure, the hydraulic pump (14) increases the punching pressure; When the total pressure exceeds the set standard pressure, the hydraulic pump (14) stops increasing the pressure and maintains the current pressure.

9. The air bearing foil stamping auxiliary device with intelligent control of blank holder force as described in claim 8, characterized in that: in, The intelligent control component for blank holder force also includes a blank holder force data collector (15); The edge pressure data collector (15) is connected to each of the edge pressure sensors (12) via a data line to obtain the pressure exerted by each array spring (5) on the pressure plate; The blank holder force data collector (15) is also connected to the blank holder force controller (13) via a data line to transmit the acquired pressure data to the blank holder force controller (13).

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