Large ferromagnetic workpiece demagnetizing coil, demagnetizing method and demagnetizing equipment

Abstract

The invention discloses a large ferromagnetic workpiece demagnetizing coil, a demagnetizing method and demagnetizing equipment. Mainly provides a demagnetization coil suitable for a large ferromagnetic workpiece, and provides a demagnetization method and demagnetization equipment based on the coil. Wherein the demagnetizing coil comprises a first winding and a second winding, and the first winding and the second winding are mutually independent, are synchronously wound in parallel and are electrified with currents in opposite directions; and the winding specifications of the first winding and the second winding are the same. According to the invention, the limitation of commercial power and power distribution capacity can be eliminated, enough magnetic induction intensity is provided, and the problem of self-loop short circuit generated during current commutation is avoided at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of workpiece demagnetization, and more particularly to a large-scale ferromagnetic workpiece demagnetization coil, a demagnetization method and a demagnetization device. Background Art

[0002] During industrial processing, ferromagnetic materials often generate residual magnetic fields in the workpiece due to magnetization. These residual magnetic fields may have an adverse effect on subsequent processing or surrounding instrument sensors. Therefore, in order to ensure processing quality and improve sensor accuracy, ferromagnetic parts must be demagnetized.

[0003] Traditional demagnetization methods usually involve the use of a demagnetization coil, placing the workpiece in the demagnetization coil, and generating an alternating magnetic field higher than the coercivity of the workpiece material by passing a current with a continuously changing direction through the coil winding to achieve demagnetization. This method includes the remote magnetic field attenuation method or the in-situ current attenuation method, which can effectively reduce the residual magnetism in the workpiece.

[0004] However, as the volume of ferromagnetic parts increases, the required diameter of the demagnetization coil also increases. When a large-diameter demagnetization coil generates the required magnetic induction intensity, its inductance has a strong inhibitory effect on the size of the alternating current. However, due to the limitations of the mains voltage (such as AC 380V 50Hz) and the power distribution capacity of general production sites (current <2000A), the traditional demagnetization coil design is difficult to meet the requirements of large-diameter parts for magnetic induction intensity; that is, the maximum voltage is limited by the mains, and the use of a boosting method not only cannot overcome this limitation, but also increases power loss.

[0005] In addition, during the demagnetization process, the current in the coil needs to be commutated multiple times in a certain period to achieve the change of the residual magnetism direction on the workpiece. The current commutation period (commutation frequency) of the workpiece away from the coil has a significant impact on the demagnetization efficiency. However, due to the large inductance of the large-diameter coil, the delay time of the self-inductance potential during current commutation is long, which is very easy to form a self-loop of the rectifier circuit and produce a short circuit, thereby limiting the increase of the current commutation frequency.

[0006] Therefore, there is a need for a method that can effectively demagnetize large-diameter ferromagnetic parts. Summary of the invention

[0007] In view of this, the present invention provides a demagnetization coil, a demagnetization method and a demagnetization device for a large ferromagnetic part, aiming to get rid of the limitation of mains power and distribution capacity, provide sufficient magnetic induction intensity, avoid the self-loop short circuit problem caused by current commutation, and improve the demagnetization efficiency and flexibility.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] In the first aspect, the present application provides a demagnetization coil for a large ferromagnetic part, the coil comprising a first winding and a second winding, the first winding and the second winding being independently and synchronously wound and passing current in opposite directions; and the winding wire specifications in the first winding and the second winding are the same.

[0010] Furthermore, the first winding and the second winding are wound together on the same coil frame.

[0011] Furthermore, the first winding and the second winding are matched with independent rectification circuits or current sources respectively.

[0012] Furthermore, the winding specifications include winding length, number of turns, cross-sectional area and material.

[0013] In a second aspect, the present application provides a method for demagnetizing a large ferromagnetic workpiece, based on a large ferromagnetic workpiece demagnetization coil as described above, the method comprising:

[0014] Place large ferromagnetic parts in the demagnetization coil or move them through the demagnetization coil;

[0015] The magnetic field strength is controlled by synchronously adjusting the current in the first winding and the second winding;

[0016] By adjusting the commutation frequency of the first winding and the second winding, the speed of change of the magnetic field is controlled to adjust the demagnetization efficiency;

[0017] The magnetic induction intensity of the coil is adjusted by synchronously adjusting the ampere-turns of the first winding and the second winding.

[0018] Furthermore, it also includes:

[0019] The demagnetization efficiency can be adjusted by adjusting the speed at which large ferromagnetic parts pass through the demagnetization coil.

[0020] In a third aspect, the present application also provides a large ferromagnetic workpiece demagnetization device, comprising a large ferromagnetic workpiece demagnetization coil as described above, and a demagnetization trolley and a guide rail device;

[0021] The demagnetization trolley is placed on the guide rail device and is used for carrying the large ferromagnetic workpiece and moving it through the coil for demagnetizing the large ferromagnetic workpiece.

[0022] Furthermore, it also includes:

[0023] Two controllable full-wave rectifier circuits are used to provide forward and reverse currents to the first winding and the second winding;

[0024] The thyristor phase-shift trigger circuit is used to control the ampere-turns of the demagnetization coil;

[0025] The PLC control system is used to generate movement instructions to control the thyristor phase-shift trigger circuit; and to generate demagnetization-related instructions to achieve intelligent demagnetization of large ferromagnetic parts.

[0026] It can be seen from the above technical solutions that the present invention discloses a large-scale ferromagnetic workpiece demagnetization coil, a demagnetization method and a demagnetization device. Compared with the prior art, the present application has the following beneficial effects:

[0027] According to the above content, the large ferromagnetic workpiece demagnetization coil, demagnetization method and demagnetization equipment provided by the present invention have the following beneficial effects:

[0028] 1. Get rid of the limitation of mains and distribution capacity: By using two full-wave rectifier circuits, the two-phase AC380V mains is rectified into two independent DC circuits, which greatly reduces the resistance of the coil inductance to the current. This design effectively solves the problem of limitation of distribution capacity on site and provides a stronger magnetic field and more flexible adjustment capability for large ferromagnetic parts demagnetization equipment.

[0029] 2. Improve demagnetization efficiency and flexibility: Adopt double coil stacking technology, design two independent windings in one coil frame, ensure that the winding length, inductance and other parameters of the two windings are equal. This design enables two DC currents to be connected to the head and tail ends of the two windings respectively, forming two independent current loops, completely solving the problem of current delay cutoff caused by coil inductance, effectively avoiding the short circuit phenomenon of the self-loop, and greatly improving the stability and safety of the equipment.

[0030] 3. Optimize the demagnetization process: Due to the use of two independent air-core coils, the mutual inductance is weak, which significantly improves the switching rate of the two coil currents. It not only meets the frequency requirements of the far-field attenuation method of demagnetization, but also broadens the adjustment range of the commutation frequency, providing more flexibility and adjustability for the demagnetization process.

[0031] The present application can accurately control the magnetic field strength, magnetic field change speed and demagnetization efficiency through two windings: thereby flexibly adapting to ferromagnetic parts of different volumes and characteristics, and improving the applicability and versatility of demagnetization. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0033] Figure 1 A schematic diagram of the structure of a double-winding coil provided by the present invention;

[0034] Figure 2 An independent full-wave rectifier circuit diagram provided by the present invention;

[0035] Figure 3 The present invention provides a control circuit diagram of the entire large-scale ferromagnetic workpiece demagnetization equipment. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] The theoretical basis of demagnetization of parts is based on the characteristic that the remanence of ferromagnetic parts after magnetization is always smaller than the magnitude of the external magnetization intensity. The difference between the two is related to the remanence coercivity of the material of the part. During the demagnetization process, the current in the coil is commutated multiple times in a certain period. After each commutation, it is necessary to ensure that the remanence direction of each part on the part is opposite to the remanence direction of the previous magnetization. Then the part is slowly moved away from the coil or the external magnetization intensity on the part is gradually reduced until it is minimum, so as to achieve the purpose of demagnetization.

[0038] Embodiment 1

[0039] This embodiment is based on the above theory and provides a demagnetization coil for demagnetizing large ferromagnetic parts to solve the problem that the inductance of large-diameter coils is large and the self-inductance potential delay time is long during current commutation. If a single coil structure is used, it will cause the rectifier circuit to form a self-loop and then cause a short circuit.

[0040] In this embodiment, Figure 1 As shown, the coil includes a first winding and a second winding, the first winding and the second winding are independent of each other and are synchronously wound, and currents in opposite directions are passed through them; and the winding wire specifications of the first winding and the second winding are the same.

[0041] Specifically, synchronous parallel winding means that two windings are synchronously and side by side wound from the same starting point, thereby forming a continuous coil together; preferably, the two windings are arranged evenly and closely, and there is no obvious gap between the windings.

[0042] The novel coil of the present application adopts a double winding design, and each winding forms an independent current loop. This design improves the flexibility of current commutation, avoids the problem of current delay cutoff caused by coil inductance, and effectively avoids the short circuit phenomenon of the self-loop when the current is quickly commutated;

[0043] Furthermore, the first winding and the second winding have the same winding specifications, which means that the winding length and inductance of the two windings are the same, which can ensure that the two windings have the same obstruction effect on the conversion current, that is, have equivalent electrical characteristics.

[0044] As a preferred solution, the winding specifications include winding length, number of turns, cross-sectional area and material, wherein the material may be copper wire, copper alloy wire or aluminum wire;

[0045] Through the design of the novel coil of the present application, the self-circuit phenomenon can be effectively overcome and short circuit can be avoided, thereby improving the stability and safety of the demagnetization equipment for large ferromagnetic parts.

[0046] To further optimize the above technical solution, the first winding and the second winding are wound together on the same coil frame to provide support for the formed coil and ensure that the two windings are concentric and the wound coils have the same radius.

[0047] Furthermore, the first winding and the second winding are respectively matched with independent full-wave rectification circuits or DC current sources to provide more flexibility and adjustability, so that the demagnetization task can be completed more efficiently and the goal of energy saving and environmental protection can be achieved.

[0048] In one embodiment, an independent full-wave rectifier circuit such as Figure 2 As shown;

[0049] In this embodiment, the rectifier circuit adopts a unidirectional controllable full-wave rectifier circuit, the input end can be directly connected to the AC power, and the output end is connected to the first winding and the second winding, which are respectively used to provide forward current and reverse current to the first winding and the second winding.

[0050] The working principle of the full-wave rectifier circuit is well known and will not be repeated here.

[0051] Embodiment 2

[0052] Based on the demagnetization coil in the first embodiment, the present application further provides a demagnetization method for a large ferromagnetic workpiece, comprising:

[0053] (1) Place the large ferromagnetic part in the demagnetization coil or move it through the demagnetization coil; that is, first, place the large ferromagnetic part inside the designed demagnetization coil and move it smoothly through the demagnetization coil. The choice of this method depends on the specific needs and operating conditions.

[0054] (2) Controlling the magnetic field strength by adjusting the current in the first winding and the second winding;

[0055] By adjusting the current in the first winding and the second winding, the magnetic field strength can be precisely controlled. The current directly affects the magnetic field strength generated by the coil. According to Ampere's law, the greater the current, the greater the magnetic field strength generated by the coil.

[0056] In practical applications, the current can be controlled by adjusting the output voltage of the current source. For example, different ferromagnetic parts may require different magnetic field strengths to achieve the best demagnetization effect. In this case, a current regulator can be set to adjust the current through a knob or touch screen interface, so as to quickly adjust the magnetic field strength to meet the demagnetization requirements of different parts. Furthermore, the current can be monitored in real time through an ammeter to ensure that the magnetic field strength meets expectations.

[0057] (3) By adjusting the commutation frequency of the first winding and the second winding, the speed of change of the magnetic field is controlled to adjust the demagnetization efficiency;

[0058] The commutation frequency refers to the number of times the current direction changes per unit time. When the commutation frequency increases, the number of times the magnetic field direction changes also increases, thereby speeding up the change speed of the magnetic field. Conversely, when the commutation frequency decreases, the number of times the magnetic field direction changes decreases, and the speed of magnetic field change also slows down.

[0059] In practical applications, the commutation frequency can be precisely controlled by adjusting the parameters of the PLC control system. And the magnitude of the commutation frequency can be displayed in real time on a display screen so that the operator can intuitively understand the current commutation frequency. In one application, for certain ferromagnetic parts, a higher commutation frequency can be used to quickly attenuate the residual magnetism, thereby achieving an ideal demagnetization effect. By adjusting the commutation frequency, this embodiment can quickly adjust the magnetic field change speed to meet the demagnetization requirements of different parts.

[0060] (4) The magnetic induction intensity of the coil is adjusted by synchronously adjusting the ampere-turns of the first winding and the second winding.

[0061] According to the calculation formula of magnetic induction intensity, the vacuum magnetic permeability is a constant value, and due to the limitation of mains electricity, the current cannot be increased blindly. Therefore, increasing the number of coil turns is a feasible way to increase the magnetic induction intensity of the coil.

[0062] The number of turns directly affects the magnetic induction intensity, thus affecting the demagnetization effect. Specifically, the number of turns of the coil refers to the number of wire turns wound on the coil frame. When the number of turns increases, the magnetic induction intensity generated by the coil also increases. Conversely, when the number of turns decreases, the magnetic induction intensity also decreases. At the same time, when the number of turns increases, the inductance will decrease accordingly, thereby reducing the coil impedance, increasing the current, and further improving the magnetic induction intensity.

[0063] In practical applications, the ampere-turns can be displayed in real time on the display screen so that the operator can intuitively understand the current ampere-turns. For different ferromagnetic parts, the magnetic induction intensity can be quickly adjusted by adjusting the ampere-turns to meet the demagnetization requirements.

[0064] The method of increasing the ampere-turns of the coil in the present invention can effectively solve the requirement of the large-caliber demagnetization coil for the required alternating magnetic field strength, and at the same time can reduce power consumption, save energy and protect the environment.

[0065] Furthermore, it also includes:

[0066] (5) Adjust the demagnetization efficiency by adjusting the speed at which large ferromagnetic parts pass through the demagnetization coil.

[0067] That is, if the speed of separation is too fast, the external magnetization intensity of each commutation is not enough to reverse the direction of the previous residual magnetism; if the speed of separation is too slow, the demagnetization time will be extended and the energy consumption will be increased.

[0068] In one embodiment, the travel speed can be precisely controlled by adjusting the speed of the demagnetization trolley. For example, the travel speed can be adjusted by adjusting the motor speed of the demagnetization trolley, and the travel speed can be displayed in real time on a display screen.

[0069] By adjusting the travel speed, the demagnetization efficiency can be flexibly controlled, thereby optimizing the demagnetization process.

[0070] Embodiment 3

[0071] This embodiment also provides an implementable large-scale ferromagnetic workpiece demagnetization device, comprising any large-scale ferromagnetic workpiece demagnetization coil as described above, and a demagnetization trolley and a guide rail device;

[0072] The demagnetization trolley is placed on a guide rail device and is used to carry large ferromagnetic parts and move through the demagnetization coils of the large ferromagnetic parts.

[0073] Among them, the demagnetization trolley is a remote 304 stainless steel demagnetization trolley.

[0074] Furthermore, it also includes a frame, a 304 stainless steel platform, a trolley electric control system, a controllable full-wave rectifier circuit, a thyristor phase-shift trigger circuit, a touch screen and a PLC control system, control software, etc. In this embodiment,

[0075] Two controllable full-wave rectifier circuits are used to provide forward and reverse currents to the first winding and the second winding;

[0076] The thyristor phase-shift trigger circuit is used to control the demagnetization trolley to move left or right;

[0077] The PLC control system is used to generate movement instructions to control the thyristor phase-shift trigger circuit; and to generate demagnetization-related instructions to achieve intelligent demagnetization of large ferromagnetic parts.

[0078] In an exemplary embodiment, the control circuit of the entire large ferromagnetic workpiece demagnetization device is as follows: Figure 3 As shown,

[0079] In summary, this application uses a dual full-wave rectifier circuit to get rid of the limitations of mains power and distribution capacity.

[0080] The two-phase AC380V mains electricity is rectified into two independent direct currents through two controllable full-wave rectifier circuits, which greatly reduces the resistance of the coil inductance to the current. The number of coil turns is increased exponentially, the input current is reduced, and the magnetic induction intensity required by the coil can be flexibly controlled, solving the limitation of the distribution capacity on site.

[0081] At the same time, two independent windings are designed in one coil frame. Through a special coil stacking process, the winding length, inductance, etc. of the two windings are equal. Then the two DC powers are connected to the head and tail ends of the two windings respectively to form two independent current loops. This completely solves the problem of delayed current cutting off due to the inductance of the coil, and the short-circuit phenomenon of the self-loop when the current is quickly reversed.

[0082] In addition, the present application can broaden the adjustment range of the commutation frequency, and has both the demagnetization functions of the distance method and the in-situ attenuation method; that is, due to the use of two independent hollow coils, their inductance effect is weak, so that the switching rate of the two coil currents is greatly improved, meeting the frequency requirements of the demagnetization method of the distance magnetic field attenuation method.

[0083] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referenced to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0084] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A demagnetization coil for large ferromagnetic parts, characterized in that: The invention comprises a first winding and a second winding, wherein the first winding and the second winding are independently and synchronously wound and are passed with currents in opposite directions; and the winding wire specifications of the first winding and the second winding are the same.

2. A large ferromagnetic workpiece demagnetization coil according to claim 1, characterized in that: The first winding and the second winding are wound together on the same coil frame.

3. A large ferromagnetic workpiece demagnetization coil according to claim 1, characterized in that: The first winding and the second winding are matched with independent rectification circuits or current sources respectively.

4. A large ferromagnetic workpiece demagnetization coil according to claim 1, characterized in that: Winding specifications include winding length, number of turns, cross-sectional area and material.

5. A method for demagnetizing a large ferromagnetic workpiece, characterized in that: A method for applying a large ferromagnetic workpiece demagnetization coil as described in any one of claims 1 to 4 comprises: Place large ferromagnetic parts in the demagnetization coil or move them through the demagnetization coil; Synchronously adjusting the current in the first winding and the second winding to control the magnetic field strength; By adjusting the commutation frequency of the first winding and the second winding, the speed of change of the magnetic field is controlled to adjust the demagnetization efficiency; The magnetic induction intensity of the coil is adjusted by synchronously adjusting the ampere-turns of the first winding and the second winding.

6. A demagnetization method for large ferromagnetic parts according to claim 5, characterized in that: Also includes: The demagnetization efficiency can be adjusted by adjusting the speed at which large ferromagnetic parts pass through the demagnetization coil.

7. A demagnetization device for large ferromagnetic parts, characterized in that: It comprises a large ferromagnetic workpiece demagnetization coil as described in any one of claims 1 to 4, as well as a demagnetization trolley and a guide rail device; The demagnetization trolley is placed on the guide rail device and is used for carrying the large ferromagnetic workpiece and moving it through the large ferromagnetic workpiece demagnetization coil.

8. A large ferromagnetic workpiece demagnetization device according to claim 7, characterized in that: Also includes: Two controllable full-wave rectifier circuits are used to provide reverse current for the first winding and the second winding; The thyristor phase-shift trigger circuit is used to control the ampere-turns of the demagnetization coil; The PLC control system is used to generate movement instructions to control the thyristor phase-shift trigger circuit; and to generate demagnetization-related instructions to achieve intelligent demagnetization of large ferromagnetic parts.

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