CN112389119A - Plate embossing forming method and device based on single pulse power supply - Google Patents

Abstract

The invention provides a method and a device for embossing and forming a plate based on a single pulse power supply, which solve the problems of low efficiency, high cost and the like of the conventional method for embossing and forming the metal plate. The coil is discharged by using short-pulse-width power supply equipment to generate current with required waveform, concave deformation is completed on the first part of the plate, and then specific constraints are added at the two ends and below the forming area of the second part of the plate, so that the plate is subjected to convex deformation under the assistance of part of upward Lorentz force and upward inertia force. The metal plate is regularly deformed in an embossing manner by moving the coil to discharge for many times.

Description

Plate embossing forming method and device based on single pulse power supply

Technical Field

The invention belongs to the field of metal forming and manufacturing, and particularly relates to a method and a device for embossing and forming a plate based on a single pulse power supply, which are mainly used for forming grooves, laces and the like of metal materials.

Background

In the conventional embossing of metal materials, a press forming technique is mostly adopted, and the press forming technique uses an upper punch and a lower forming die to perform impact forming by mechanical force at a moment. According to the scheme, the cost of the die required for forming the metal workpiece is high, the surface quality is poor due to the existence of the punch, the service life of the workpiece is influenced, and even the metal workpiece is cracked. The electromagnetic force belongs to non-contact force, the surface quality problem caused by the punch can be directly avoided, the forming limit of the metal material can be effectively improved by utilizing the pulse electromagnetic force, and wrinkling is reduced.

The existing plate forming technology mainly adopts the traditional stamping forming, and the method is single. The conventional press forming technology or the technology combined with the pulse electromagnetic force has the following defects: 1. in the current actual process manufacturing technology, stamping and other means are adopted, although the forming quality is high, stamping equipment is large, the requirements on designers and manufacturers are high, and the defects that the plate is wrinkled, the stress distribution is not uniform, the wall thickness reduction amount of the plate is inconsistent and the like exist; 2. the scheme of combining a small amount of electromagnetic force with pulse has the defects of higher cost, higher manufacturing difficulty, longer period, higher requirement on manufacturers and the like. 3. One workpiece corresponds to one die, and the high die opening cost has great limitation on the production of single pieces and small batches. 4. Some existing technical schemes mainly adopt one-step forming, so that the forming effect is uneven, the qualification rate is low, and the economic benefit is low. In the electromagnetic forming scheme, the single-coil single-power scheme effectively avoids the problem of coil overheating caused by multi-stage pulse current, and simultaneously avoids forming defects caused by eddy current competition on a plate by applying a plurality of coils.

Disclosure of Invention

Aiming at the defects or the improvement requirements of the prior art, the invention provides a method and a device for embossing and forming a plate based on a single pulse power supply.

In order to achieve the above object, according to one aspect of the present invention, there is provided a sheet metal member embossing and forming device based on a single pulse power supply.

A metal plate embossing and forming device based on a single pulse power supply comprises a single pulse power supply discharging system, a forming coil, a metal plate, a blank pressing module and a constraint module; the single-pulse power supply discharge system discharges the forming coil, the forming coil is arranged above a region to be formed of the metal plate and can move parallel to the upper portion of the metal workpiece, the blank pressing module fixes two ends of the metal workpiece, and the restraint module restrains the upper end and the lower end of the region to be formed of the metal plate and assists the metal plate to deform specifically.

The device places the discharge coil above a region to be formed of a metal plate, and discharges the forming coil by adopting a required single-pulse power supply discharge system; the whole wave-shaped fluctuation is regarded as one-time complete forming of the metal plate, and the one-time complete forming process is divided into two forming area parts: the first part and the second part trigger short pulse width current when the first part is formed, the coil is discharged by the single pulse power supply to generate pulse current, the pulse current generates a pulse magnetic field, so that induced eddy current is generated on the plate, the eddy current and the magnetic field act together to generate downward electromagnetic force, the metal plate is enabled to deform downwards to form concave forming, after the first part is formed, the coil is moved to a region to be formed of the second part, at the moment, constraint modules are added at the upper two ends and the lower part of the region to be formed, the short pulse width current is triggered again, due to the existence of constraint conditions, the plate cannot deform downwards or the downward deformation of the plate is small, due to the constraint modules, the plate cannot deform downwards, and the plate is provided with force for resisting deformation, when the short pulse width current is at the falling edge, because of the reduction of the current, the induced eddy current on the plate is reversed, the downward force applied to the plate in the moment disappears, and a part of weak upward force is generated, so that the plate is deformed upwards, and the upward convex forming is formed. Repeating the above process, and moving the discharge coil for many times to make the metal plate generate regular embossing deformation.

Preferably, the single pulse power supply discharge system is a short pulse width current trigger circuit, and the circuit part is composed of a first resistor Rd1, a rectifier diode D1, a capacitor bank C1, a second resistor R1, an inductor L1, and a switch S1, one end of the first resistor Rd1 is connected to an anode of a diode D1, the other end of the first resistor Rd1 is connected to one end of the capacitor C1 and one end of the second resistor R1, and a cathode of the rectifier diode D1 is connected to the other end of the capacitor C1 and one end of the switch S1, the other end of the second resistor Rd is connected to one end of the inductor L1, the other end of the inductor L1 is connected to one end of the forming coil, and the other end of the switch S1 is connected to the other end of the forming coil, so as to perform pulse discharge on the forming coil.

Preferably, the shaped coil is a solenoid coil.

According to one aspect of the invention, the invention provides a metal plate embossing forming method based on a single pulse power supply.

The forming method of the embossing and forming device for the metal plate based on the single pulse power supply comprises the following steps:

step 1: annealing a piece of aluminum alloy plate;

step 2: the coil framework is matched with the geometric shape, then a coil is wound by a winding machine, and then interlayer reinforcement and external fixation are carried out by using the Kevlar fiber;

and step 3: after the metal plate is tightly pressed by the blank pressing die, the plate and the blank pressing die are fixed by hydraulic equipment, so that the flange area of the plate is ensured not to move axially;

and 4, step 4: selecting a proper number of capacitors according to the thickness of the plate and the discharge energy, and assembling and connecting the capacitors with the short pulse width capacitor bank pulse power supply generating device;

and 5: the displacement of the coil is designed through another group of computers, and the coil can be moved by different distances according to different requirements;

step 6: the discharge system discharges the forming coil to form a first set of downward embossing patterns on the first portion;

and 7: moving the forming coil for a preset distance, adding constraint modules at two ends and below the second part of the plate to be formed at the same time, triggering the discharge system again, and forming an upwards convex embossing model when the short-pulse-width current is at a falling edge, wherein the constraint modules at the lower ends are used for constraining the plate to generate downward deformation under the action of Lorentz force, and the constraint modules at the upper ends are used for preventing the plate from generating upward deformation due to incapability of downward deformation;

and 8: and after the whole group of the wavy embossing deformation is finished, moving the forming coil for a preset distance again, and repeating the process until the wavy embossing plate with the required size is obtained.

Preferably, the coil has 4 × 10 ═ 40 turns and a cross section of 1mm × 4 mm.

Preferably, the capacitor is 40-160 mu^FThe capacitor voltage of the capacitor bank of (2) is 12 kV.

Generally, compared with the prior art, the above technical solutions conceived by the present invention have the following advantages:

1. according to the invention, only one set of short pulse power supply is used, downward or upward deformation of the plate is realized by adding constraints at two ends of the forming area, wavy fluctuation can be generated on the metal plate in a multiple progressive discharge mode, and finally the whole lace forming is completed.

2. The proposal of only using a single pulse power supply fundamentally and directly avoids the problem that the coil is overheated due to multi-stage pulse current in the forming process. Particularly in the formation of multiple-shot and high-power corrugated sheet metal parts.

3. Compared with a forming scheme with multiple coils and multiple power supplies, the forming method disclosed by the invention has the advantage that the problem of forming defects caused by eddy current competition on the metal workpiece is avoided.

4. According to the method provided by the invention, only the edge pressing device is needed to fix the plate in the forming process, and a forming die is not needed, so that the cost is greatly saved, and the problem of difficulty in manufacturing the die is avoided.

Drawings

FIG. 1 is a schematic view of an overall single pulse power supply plate forming apparatus;

fig. 2 is a short pulse width current waveform diagram.

Fig. 3 is a block diagram of the first and second portion forming.

Fig. 4 is a diagram of ideal forming effect.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The invention relates to a method and a device for embossing and forming a plate based on a single pulse power supply, which are mainly used for forming concave-convex grooves, laces and the like of metal materials. The specific device diagram is shown in figure 1. The forming coil is arranged 7mm above the area to be formed, the coil is 4mm away from the left side edge pressing module during forming, and the coil is moved in a space with 4mm on both sides (as shown in figure 3) every time, so that the formed part is prevented from being influenced. The method comprises the steps of firstly charging a capacitor bank through a charging system, storing electric energy in a capacitor, then closing a discharge switch, forming an RLC oscillation circuit by the capacitor bank, a forming coil and a circuit, generating instantaneous alternating large current in the forming coil, generating a strong pulse magnetic field by the current, generating strong induced eddy current at a part of a workpiece to be formed, and generating Lorentz force to drive the workpiece to deform through the interaction of the eddy current and the magnetic field. The coil is discharged by a desired short pulse width pulse power discharge system, and the current waveform diagram is shown in fig. 2.

The whole forming process is completed by a single pulse power supply and a single coil. Placing a forming coil in a to-be-formed area of the plate, regarding a whole wave-shaped fluctuation as one-time complete forming of the plate, and dividing a one-time complete forming process into two parts: a first portion and a second portion. Short pulse width current is triggered in the first part in a shaping mode, the coil is discharged through the power supply to generate pulse current, the pulse current generates a pulse magnetic field, and therefore induced eddy current is generated on the plate, the eddy current and the magnetic field act together to generate downward electromagnetic force, and the plate is enabled to deform downward. And after the first part is formed, moving the forming coil to a second part forming area, adding constraints at two ends and below the area to be formed at the moment, and triggering short-pulse-width current. When the short-pulse-width current is at the falling edge, the induced eddy current on the plate is reversed due to the reduction of the current, a weak upward force is generated on the plate at the moment, but the plate is not deformed downwards due to the constraint, and the plate is suddenly deformed upwards by adding a part of the attraction force to an inertia force given by a part of constraint conditions. At the moment, constraints are added at the two ends and the lower part of the area to be formed of the plate, and discharge parameters are adjusted, so that the plate is formed in an upward convex mode under the inertia effect of electromagnetic force. The above process is repeated, and the metal plate can generate regular embossing type deformation through multiple movements.

We consider a full wave like relief as a full forming (120mm) of the plate and divide the full forming process into two parts: a first portion and a second portion (the present embodiment defines each portion forming area as 60 mm).

The method comprises the steps of firstly triggering short pulse width pulse current, generating induced eddy current on a first part of to-be-formed plate, generating downward electromagnetic force on the plate under the combined action of the eddy current and a magnetic field due to Lenz's law, and enabling the plate to be freely deformed under the action of the downward electromagnetic force without constraint conditions when the first part is formed.

After the first part of the concave type forming is finished, the forming coil moves 60mm to the right to the second part of the forming area for discharging. And then, adding constraint modules at two ends and below the plate to be formed at the second part to adjust discharge parameters. Triggering a short pulse width current, the eddy currents interact with the magnetic field, and the lorentz force acting on the plate can be expressed as:

F＝J_e×B

in the formula, J_eAnd B is the induced eddy current density and the magnetic flux density on the plate, respectively. The plate member is forced downward, but the plate member cannot deform downward or the deformation amount is very small and almost negligible due to the constraint condition. When the current reaches the peak and then is at the falling edge, the eddy current on the plate will be reversed, and as can be seen from the above formula, when J is reached_eWhen the plate is reversed, the Lorentz on the plate also can be reversed, and weak upward force can be generated on the plate at the moment, but the plate does not deform downwards due to constraint, and the plate can deform upwards due to the fact that part of attraction force is suddenly added with the inertia force given by a part of constraint conditions. Through discharging for many times, the metal plate generates regular embossing type deformation, so that the plate is formed in high quality under the action of electromagnetic force.

A plate embossing forming method based on a single pulse power supply comprises the following specific implementation steps:

step 1: carrying out annealing pretreatment on a common AA1060 aluminum alloy plate with the thickness of 2 mm (the thickness can be changed according to requirements) and the size;

step 2: manufacturing a coil framework which is matched with the geometric shape of the coil and is shown in fig. 3, winding the coil by using a winding machine to form the coil, wherein the coil has 4 multiplied by 10 to 40 turns (the section of 1mm multiplied by 4 mm), and then carrying out interlayer reinforcement and external fixation by using a nylon fiber;

and step 3: fixing the forming coil, the plate and the blank pressing mold according to the arrangement sequence of the figure 1 by using hydraulic equipment, and pressing by using the blank pressing mold, wherein the pressure intensity is generally set to be 1-1.5 MPa in order to ensure that the flange area of the plate does not move axially;

and 4, step 4: selecting proper number of capacitors according to thickness of plate and discharge energy, and generating short-pulse width currentThe selected capacitance is set to be smaller and is 40-160 mu^FThe capacitor bank (which can be changed according to requirements) is assembled and connected with the short pulse width capacitor bank pulse power supply generating device, and the voltage of the capacitor is 12 kV;

and 5: the displacement of the coil is designed through another group of computers, different distances can be moved according to different requirements, and the moving distance is set to be 60mm in the scheme;

step 6: the discharge system discharges the forming coil to form a first set of downward embossing patterns on the first portion;

and 7: moving the forming coil for a preset distance, adding constraint modules at two ends and below the second part of the plate to be formed at the same time, triggering the discharge system again, and forming an upwards convex embossing model when the short-pulse-width current is at a falling edge, wherein the constraint modules at the lower ends are used for constraining the plate to generate downward deformation under the action of Lorentz force, and the constraint modules at the upper ends are used for preventing the plate from generating upward deformation due to incapability of downward deformation;

and 8: and after the whole group of wavy embossing deformation is finished, moving the forming coil for 60mm again, starting to trigger the short-pulse-width power supply again, and repeating the process until the wavy embossing plate with the required size is obtained.

In the invention, a metal plate is taken as an object, and verification is carried out through theory and simulation; the device for realizing the method comprises a discharge circuit, a forming coil, the metal plate, a blank pressing module, a movement control device and the like, realizes high-quality controllable incremental forming of the plate under the movable forming coil, widens the forming mode of embossing and forming the metal plate, improves the forming quality and meets the use requirement.

Compared with the forming scheme of a single-power-supply single coil, the forming scheme of the single-pulse power-supply single coil avoids the problem that the coil is overheated due to multi-stage pulse current in the forming process; compared with a forming scheme with multiple coils and multiple power supplies, the forming defect problem caused by eddy current competition on the metal workpiece is avoided. The embossing die is very suitable for embossing and forming the plate with complex shape, non-batch, single piece and individuation; meanwhile, the forming limit of the material can be improved by adopting electromagnetic force, so that the forming range and the forming quality of the plate can be obviously improved; in addition, the plate is fixed only by the edge pressing device in the forming process, a forming die is not needed, and the cost is greatly saved.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (8)

1. A metal plate embossing and forming device based on a single pulse power supply is characterized by comprising a single pulse power supply discharging system, a forming coil, a metal plate, a blank pressing module and a constraint module; the single-pulse power supply discharge system discharges the forming coil, the forming coil is arranged above a region to be formed of the metal plate and can move parallel to the upper portion of the metal workpiece, the blank pressing module fixes two ends of the metal workpiece, and the restraint module restrains the upper end and the lower end of the region to be formed of the metal plate and assists the metal plate to deform specifically.

2. The sheet metal embossing and forming device based on a single pulse power supply of claim 1, wherein: the single-pulse power supply discharging system is a short-pulse-width current trigger circuit, and the circuit part comprises a first resistor Rd1, a rectifier diode D1, a capacitor bank C1, a second resistor R1, an inductor L1 and a switch S1, wherein one end of the first resistor Rd1 is connected with the anode of a diode D1, the other end of the first resistor Rd is connected with one end of a capacitor C1 and one end of a second resistor R1, the cathode of the rectifier diode D1 is connected with the other end of a capacitor C1 and one end of the switch S1, the other end of the second resistor is connected with one end of the inductor L1, the other end of the inductor L1 is connected with one end of the forming coil, and the other end of the switch S1 is connected with the other end of the forming coil to perform pulse discharging on the forming coil.

3. The sheet metal embossing and forming device based on a single pulse power supply of claim 2, wherein: the shaped coil is a solenoid coil.

4. The sheet metal embossing and forming device based on the single pulse power supply as claimed in claim 2, wherein: the device places the forming coil above a region to be formed of a metal plate, and discharges the discharge coil by adopting a required single-pulse power supply discharge system; the whole wave-shaped fluctuation is regarded as one-time complete forming of the metal plate, and the one-time complete forming process is divided into two forming area parts: the first part and the second part trigger short pulse width current when the first part is formed, the coil is discharged by the single pulse power supply to generate pulse current, the pulse current generates a pulse magnetic field, so that induced eddy current is generated on the plate, the eddy current and the magnetic field act together to generate downward electromagnetic force, the metal plate is enabled to deform downwards to form concave forming, after the first part is formed, the coil is moved to a region to be formed of the second part, at the moment, constraint modules are added at the upper two ends and the lower part of the region to be formed, the short pulse width current is triggered again, due to the existence of constraint conditions, the plate cannot deform downwards or the downward deformation of the plate is small, due to the constraint modules, the plate cannot deform downwards, and the plate is provided with force for resisting deformation, when the short pulse width current is at the falling edge, because of the reduction of the current, the induced eddy current on the plate is reversed, the downward force applied to the plate in the moment disappears, and a part of weak upward force is generated, so that the plate is deformed upwards, and the upward convex forming is formed.

5. The single pulse power supply-based metal workpiece embossing and forming device as claimed in claim 4, wherein: repeating the above process, and moving the discharge coil for many times to make the metal plate generate regular embossing deformation.

6. The method for forming a sheet metal member embossing and forming device based on a single pulse power supply as claimed in claim 1, comprising the steps of:

step 1: annealing a piece of aluminum alloy plate;

step 2: the coil framework is matched with the geometric shape, then a coil is wound by a winding machine, and then interlayer reinforcement and external fixation are carried out by using the Kevlar fiber;

and step 3: after the metal plate is tightly pressed by the blank pressing die, the plate and the blank pressing die are fixed by hydraulic equipment, so that the flange area of the plate is ensured not to move axially;

and 4, step 4: selecting a proper number of capacitors according to the thickness of the plate and the discharge energy, and assembling and connecting the capacitors with the short pulse width capacitor bank pulse power supply generating device;

and 5: the displacement of the coil is designed through another group of computers, and the coil can be moved by different distances according to different requirements;

step 6: the discharge system discharges the forming coil to form a first set of downward embossing patterns on the first portion;

and 7: moving the forming coil for a preset distance, adding constraint modules at two ends and below the second part of the plate to be formed at the same time, triggering the discharge system again, and forming an upwards convex embossing model when the short-pulse-width current is at a falling edge, wherein the constraint modules at the lower ends are used for constraining the plate to generate downward deformation under the action of Lorentz force, and the constraint modules at the upper ends are used for preventing the plate from generating upward deformation due to incapability of downward deformation;

and 8: and after the whole group of the wavy embossing deformation is finished, moving the forming coil for a preset distance again, and repeating the process until the wavy embossing plate with the required size is obtained.

7. The method of claim 6, wherein the coil has 4 x 10-40 turns and a cross-section of 1mm x 4 mm.

8. The method of claim 6, wherein the capacitor is a 40-160 μ F capacitor bank and the capacitor voltage is 12 kV.

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