Nanocrystalline annular cutting air gap-added iron core for welding machine and finished iron core

Abstract

The utility model provides a nanocrystalline annular cutting air gap-added iron core and a finished iron core for a welding machine, and relates to the technical field of soft magnetic materials, the iron core comprises two C-shaped semicircular iron cores, a single binder layer for bonding the end faces of the two C-shaped semicircular iron cores, and a combined bonding layer; the first end faces of the two C-shaped semicircular iron cores are oppositely arranged, and a single binder layer used for bonding the two first end faces is arranged between the two first end faces to form a first air gap; the second end faces of the two C-shaped semicircular iron cores are oppositely arranged, and a combined bonding layer used for bonding the two second end faces is arranged between the two second end faces to form a second air gap; the air gap width of the first air gap is smaller than the air gap width of the second air gap. The problems that an existing nanocrystalline annular iron core is poor in anti-saturation capacity, the inductance value and the loss value cannot be adjusted at will, and when the air gap width is smaller than or equal to 0.5 mm, cutting is difficult, and cost is increased are solved.

Description

Technical Field

[0001] This utility model relates to the field of soft magnetic materials technology, and in particular to a nanocrystalline ring-cut iron core with air gap for welding machines and a finished iron core. Background Technology

[0002] Nanocrystalline cores used in inverter welding machines typically have their saturation resistance improved by adjusting the heat treatment process. This approach has two main drawbacks: 1) The improvement in saturation resistance through heat treatment is very limited. Heat treatment improves magnetic properties by adjusting grain orientation and residual stress, but the amorphous / nanocrystalline dual-phase structure of nanocrystalline materials is extremely sensitive to heat treatment. Slight deviations in temperature or time can easily lead to grain coarsening or grain boundary oxidation, which in turn reduces permeability and saturation flux density. Therefore, the improvement in saturation flux density through heat treatment is usually less than 5%, which is insufficient to meet the saturation resistance requirements under dynamic loads in welding machines. 2) The inductance and loss values ​​of the core cannot be arbitrarily adjusted after heat treatment. If different welding processes are required, the core must be redesigned or the material changed, leading to increased inventory management and production costs.

[0003] To overcome the limitations of heat treatment, existing technologies typically employ cutting the toroidal core to improve its anti-saturation capability. However, this often involves single-sided cutting, which presents two main problems: Firstly, due to the arc of the toroidal core, the air gap width becomes unstable and losses are high after cutting, leading to overheating and potential burn-out during use. Secondly, the blade thickness of conventional cutting dies is usually around 2mm. When single-sided cutting requires a small air gap width (≤0.5mm), the processing of the air gap becomes very difficult and increases processing costs. Furthermore, the fixed cut width after single-sided cutting prevents flexible adjustment of the air gap size, thus hindering the arbitrary adjustment of inductance and loss values. In addition, the cut edge cannot be polished or repaired after single-sided cutting, preventing further optimization of inductance and loss values ​​after cutting, further limiting the flexible adjustment of inductance and loss values. Utility Model Content

[0004] The purpose of this invention is to provide a nanocrystalline ring-cut core with air gap for welding machines and a finished core, which solves the problems of poor anti-saturation ability of existing nanocrystalline ring cores (without cutting), the inductance and loss value of nanocrystalline ring cores (with single-sided cutting and air gap) cannot be adjusted arbitrarily, and the difficulty and cost increase brought by cutting when the air gap width is ≤0.5mm.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This utility model provides a nanocrystalline ring-cut iron core with air gap for welding machines. The iron core includes two C-shaped semi-circular iron cores, a single adhesive layer for bonding the end faces of the two C-shaped semi-circular iron cores, and a combined adhesive layer.

[0007] The first end faces of the two C-shaped semicircular iron cores are arranged opposite each other, and a single adhesive layer for bonding the two first end faces is provided between the two first end faces to form a first air gap;

[0008] The second end faces of the two C-shaped semicircular iron cores are arranged opposite to each other, and a combined adhesive layer for bonding the two second end faces is provided between the two second end faces to form a second air gap;

[0009] The width of the first air gap is smaller than the width of the second air gap.

[0010] Furthermore, based on the above technical solution, the air gap width of the first air gap is 0.1-0.3mm; and the air gap width of the second air gap is 0.3-1mm.

[0011] Furthermore, based on the above technical solution, the combined adhesive layer includes an insulating gasket and a first adhesive layer disposed on both sides of the insulating gasket for bonding the two second end faces.

[0012] Furthermore, based on the above technical solution, the insulating gasket includes aramid paper or Nomex paper.

[0013] Furthermore, based on the above technical solution, the thickness of the insulating gasket is 0.18-0.76 mm.

[0014] Furthermore, based on the above technical solution, the first adhesive layer used to bond the two second end faces is an organic silicone adhesive layer or an epoxy adhesive layer.

[0015] Furthermore, based on the above technical solution, the single adhesive layer is an organosilicone single adhesive layer or an epoxy single adhesive layer.

[0016] This utility model also provides a finished iron core, which is provided from top to bottom as follows: a protective box cover, multiple stacked welding machine nanocrystalline ring-cut iron cores with air gap as described above, and a protective box cover.

[0017] A second adhesive layer is provided between the upper cover of the protective box and the welding machine nanocrystalline annular cut and air gap iron core adjacent to the upper cover of the protective box, and a third adhesive layer is provided between the lower cover of the protective box and the welding machine nanocrystalline annular cut and air gap iron core adjacent to the lower cover of the protective box.

[0018] Furthermore, based on the above technical solution, the outer ring of the multiple stacked welding machine nanocrystalline annular cut and air gap iron cores described above is provided with insulating tape for fixing.

[0019] Furthermore, based on the above technical solution, the adhesives in the second and third adhesive layers are both silicone adhesive layers or epoxy adhesive layers.

[0020] This utility model provides a nanocrystalline ring-cutting core with air gap for welding machines and a finished core, which have the following advantages:

[0021] 1. The nanocrystalline ring-cut iron core with air gap provided by this utility model can effectively prevent magnetic saturation. The large air gap makes it less likely for the iron core to reach saturation under high current or strong magnetic field, while the small air gap can help adjust the magnetic flux distribution to a certain extent, thus optimizing the overall magnetic saturation characteristics of the iron core. This combination of large and small air gaps allows the iron core to maintain good linear magnetic properties under different working conditions, improving circuit stability.

[0022] 2. The nanocrystalline ring-cutting and air-gap iron core for welding machines provided by this utility model is a ring-shaped iron core composed of two C-shaped semi-circular iron cores. It can not only grind the cut, but also flexibly adjust the air gap width according to actual needs, effectively improving the consistency of the nanocrystalline ring-cutting and air-gap iron core for welding machines in the production process. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the structure of the nanocrystalline ring-cut and air-gap iron core for welding machines provided by this utility model;

[0025] Figure 2 A schematic diagram of the structure of the finished iron core provided by this utility model;

[0026] icon:

[0027] 1. C-shaped semi-circular iron core; 2. Single adhesive layer; 3. Insulating gasket; 4. Top cover of protective box; 5. Insulating tape; 6. Bottom cover of protective box; 7. First adhesive layer; 8. Second adhesive layer; 9. Third adhesive layer. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below in conjunction with the embodiments of this utility model. Those skilled in the art should understand that the embodiments described are merely to help understand this utility model and should not be considered as specific limitations on this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. Process parameters in the following embodiments that do not specify specific conditions are generally based on conventional conditions.

[0029] The endpoints and any values ​​of the ranges disclosed in this utility model are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this utility model.

[0030] According to the first aspect of this utility model, as Figure 1 As shown, a nanocrystalline annular cut and air gap iron core for welding machines is provided. The iron core includes two C-shaped semi-circular iron cores 1, a single adhesive layer 2 for bonding the end faces of the two C-shaped semi-circular iron cores 1, and a combined adhesive layer.

[0031] The first end faces of the two C-shaped semicircular iron cores 1 are arranged opposite each other, and a single adhesive layer for bonding the two first end faces is provided between the two first end faces to form a first air gap;

[0032] The second end faces of the two C-shaped semi-circular iron cores 1 are arranged opposite to each other, and a combined adhesive layer for bonding the two second end faces is provided between the two second end faces to form a second air gap;

[0033] The width of the first air gap is smaller than the width of the second air gap.

[0034] Specifically, the air gap width of the first air gap refers to the thickness of the single adhesive layer 2, and the air gap width of the second air gap is the thickness of the combined adhesive layer.

[0035] Specifically, at the first end face joint, the two C-shaped semi-circular iron cores 1 are bonded together by a single adhesive 2. The adhesive can fill the tiny gaps, playing a certain role in sealing and initial fixation. However, due to the influence of the bonding process and the type of adhesive, it is impossible to guarantee that the joint will remain completely sealed, so there is a tiny air gap, which is the first air gap.

[0036] As an optional embodiment of this utility model, the air gap width of the first air gap is 0.1-0.3mm (e.g., 0.15mm, 0.2mm, 0.25mm, etc.); the air gap width of the second air gap is 0.3-1mm (e.g., 0.5mm, 0.7mm, 0.9mm, etc.).

[0037] As an optional embodiment of the present invention, the combined adhesive layer includes an insulating gasket 3 and a first adhesive layer 7 disposed on both sides of the insulating gasket 3 for bonding the two second end faces.

[0038] Specifically, the first air gap is a tiny air gap formed by a single adhesive 2, and the second air gap is a large air gap formed by the insulating gasket 3 and the first adhesive layer 7. This invention, by setting the first and second air gaps, has the following advantages:

[0039] (1) Effectively prevent magnetic saturation. A large air gap makes it less likely for the iron core to reach saturation under high current or strong magnetic field, while a small air gap can help adjust the magnetic flux distribution to a certain extent, thus optimizing the overall magnetic saturation characteristics of the iron core. This combination of large and small air gaps allows the iron core to maintain good linear magnetic properties under different working conditions, improving circuit stability.

[0040] (2) Nanocrystalline materials are sensitive to high-frequency eddy current loss. If the air gap is too small (such as only the first air gap exists), the magnetic field distortion at the edge of the magnetic core may cause local eddy current loss. Through the synergistic effect of the first air gap and the second air gap, the magnetic circuit path can be stabilized and the high-frequency magnetic field distortion can be reduced. The distributed air gap formed by the first air gap and the second air gap can reduce the "steepness" of the hysteresis loop, alleviate the hysteresis effect of magnetic domain flipping at high frequency, and further reduce hysteresis loss.

[0041] (3) The air gap width of the first air gap is small, which allows the core to deform slightly when heated or stressed, and avoids the air gap size from going out of control due to processing errors or assembly stress. If only the second air gap exists, the second air gap may close or expand due to deformation.

[0042] (4) The thickness of the insulating pad 3 in the second air gap can be precisely controlled to control the width of the second air gap, ensuring the repeatability of the magnetic circuit design. After the adhesive cures, the insulating pad 3 can be firmly bonded to the C-shaped semi-circular iron core 1, preventing the insulating pad 3 from shifting during vibration or impact, and ensuring the long-term stability of the second air gap;

[0043] (5) By replacing the insulating pads 3 of different thicknesses, the width of the second air gap can be quickly adjusted to adapt to different inductance or saturation current requirements without reprocessing the core. The first air gap can compensate for the tolerance of the pad thickness and improve the consistency of mass production.

[0044] (6) The double air gap structure with one large and one small can disperse the edge effect of the magnetic field, reduce the leakage of magnetic lines of force from the iron core cut, reduce electromagnetic interference to external circuits, and also adjust the ratio of equivalent inductance and parasitic capacitance of the magnetic circuit, suppress high frequency resonance peaks, and improve the stability of the welding machine power supply.

[0045] As an optional embodiment of this utility model, the insulating gasket 3 includes aramid paper or Nomex paper.

[0046] As an optional embodiment of this utility model, the thickness of the insulating pad 3 is 0.18-0.76mm (e.g., 0.3mm, 0.4mm, 0.5mm, 0.6mm, etc.).

[0047] As an optional embodiment of this utility model, the first adhesive layer 7 used to bond the two second end faces is an organic silicone adhesive layer or an epoxy adhesive layer.

[0048] As an optional embodiment of this utility model, the single adhesive layer 2 is an organosilicone single adhesive layer or an epoxy single adhesive layer.

[0049] The preparation method of the nanocrystalline annular cut and air gap iron core for welding machines described in this utility model includes the following steps:

[0050] S1: The toroidal core is wound according to the preset size. The preset size of the winding is the inner and outer diameters of the winding inner and outer diameters designed based on the maximum inner diameter (i.e., minimum wall thickness) and minimum outer diameter (i.e., maximum wall thickness) of the protective box for the required nanocrystalline toroidal cut and air gap core, as well as the thickness of the cutting die blade.

[0051] S2: The wound toroidal core is subjected to heat treatment. The heat treatment temperature is 555-565℃, the holding time is 90-120min, and the magnetic field time is 400-500min.

[0052] S3: The heat-treated toroidal core is immersed in the varnish for 5 to 90 seconds. Typically, without limitation, the varnish is a commercially available conventional varnish. Cutting the nanocrystalline toroidal core after varnishing can enhance the core's anti-saturation ability and allow it to withstand a larger excitation current.

[0053] After impregnation, the toroidal core is left to air dry for 1-1.5 hours, and then baked and cured at 80-150℃ for 180-240 minutes.

[0054] S4: The cured annular core is cut bilaterally at its two diametrical points (two points corresponding to the center axis are called diametrical points; when the line segment connecting them passes through the center of the annulus, its length is equal to the diameter of the annulus, and the two are symmetrically distributed at 180 degrees on the annulus) to obtain two C-shaped semi-circular cores 1; typically, but not limited to, the cutting method can be any one of abrasive wheel cutting, diamond wire cutting, or milling machine cutting; after cutting, the cut surfaces of the two C-shaped semi-circular cores 1 need to be polished. Since this invention bonds the two C-shaped semi-circular cores 1 together through a single adhesive layer 2 and a combined adhesive layer, this invention does not need to consider the face angle of the cut surface when polishing the cut surface; it only needs to ensure the bonding strength between the cut surface and the adhesive, which reduces the production difficulty and is suitable for mass production.

[0055] S5: Two C-shaped semi-circular iron cores 1 are bonded together at one end by a single adhesive layer 2 to form a first air gap, and the other end is bonded together by a combination of the first adhesive layer 7, the insulating gasket 3 and the first adhesive layer 7 to form a second air gap. The two bonded C-shaped semi-circular iron cores 1 are then fixed to obtain a nanocrystalline ring-cut iron core with an air gap for welding machines.

[0056] Specifically, this utility model selects a double-sided cutting method to cut the nanocrystalline ring core into two C-shaped semi-circular cores 1. The two C-shaped semi-circular cores 1 are bonded together with a single adhesive layer 2 and a combined adhesive layer. This not only allows for the grinding of the cut but also enables flexible adjustment of the air gap width according to actual needs, effectively improving the consistency of nanocrystalline ring-cut and air gap-added cores for welding machines during the production process.

[0057] According to a second aspect of this utility model, such as Figure 2 As shown, a finished iron core is provided, which is provided from top to bottom as follows: a protective box upper cover 4, multiple stacked welding machine nanocrystalline ring-cut iron cores with air gap as described above, and a protective box lower cover 6;

[0058] A second adhesive layer 8 is provided between the upper cover 4 of the protective box and the welding machine nanocrystalline ring-cut and air-gap iron core adjacent to the upper cover 4 of the protective box, and a third adhesive layer 9 is provided between the lower cover 6 of the protective box and the welding machine nanocrystalline ring-cut and air-gap iron core adjacent to the lower cover 6 of the protective box.

[0059] As an optional embodiment of this utility model, such as Figure 2 As shown, the outer ring of the multiple stacked welding machine nanocrystalline annular cut and air gap iron cores is provided with insulating tape 5 for fixing.

[0060] As an optional embodiment of this utility model, the second adhesive layer 8 and the third adhesive layer 9 are both silicone adhesive layers or epoxy adhesive layers.

[0061] The present invention will now be described in further detail with reference to specific embodiments and comparative examples.

[0062] Example 1

[0063] S1: Based on the maximum inner diameter of 60mm, the minimum inner outer diameter of 120mm, and the thickness of 2mm of the grinding wheel cutting disc of the required nanocrystalline annular cut and air gap iron core protective box upper cover 4 and protective box lower cover 6, the winding inner diameter is designed to be 63.5mm and the winding outer diameter is 119mm. The annular iron core is wound to obtain an annular iron core with an outer diameter of 120mm, an inner diameter of 60mm, and a thickness of 30mm.

[0064] S2: The wound toroidal core is heat-treated at a temperature of 560℃ for 120 minutes and with a magnetic field applied for 500 minutes.

[0065] S3: Immerse the heat-treated toroidal core in the varnish solution for 5 seconds, then let it air dry for 1 hour, and bake it at 125℃ for 180 minutes to cure it.

[0066] S4: The cured annular core is cut on both sides using a grinding wheel to obtain two C-shaped semi-circular cores 1;

[0067] S5: The first end faces of the two C-shaped semi-circular iron cores 1 are arranged opposite each other, and an organic silicone single adhesive layer for bonding the two first end faces is provided between the two first end faces to form a first air gap with a width of 0.14mm;

[0068] The second end faces of the two C-shaped semicircular iron cores are arranged opposite each other, and a combined adhesive layer for bonding the two second end faces is provided between the two second end faces to form a second air gap with a width of 0.32mm;

[0069] The combined adhesive layer includes aramid paper and an organic silicone adhesive layer disposed on both sides of the aramid paper; the two bonded C-shaped semi-circular iron cores 1 are fixed by wrapping the outer ring with insulating tape 5 to obtain a nanocrystalline ring-cut iron core with air gap for welding machine.

[0070] S6: An organic silicone adhesive layer is provided between the upper cover 4 of the protective box and the welding machine nanocrystalline ring-cut and air-gap iron core adjacent to the upper cover 4 of the protective box, and an organic silicone adhesive layer is provided between the lower cover 6 of the protective box and the welding machine nanocrystalline ring-cut and air-gap iron core adjacent to the lower cover 6 of the protective box, to obtain the finished iron core.

[0071] Example 2

[0072] The difference between this embodiment and Embodiment 1 is that the width of the first air gap is 0.14 mm and the width of the second air gap is 0.65 mm. The remaining steps and technical parameters are the same as in Embodiment 1.

[0073] Comparative Example 1

[0074] The main difference between this comparative example and Example 1 is that the performance test was conducted directly using the cured toroidal core obtained in step S3.

[0075] Performance testing

[0076] Anti-saturation capability: Hysteresis loop test (test instrument model: Lianzhong MATS-2010SD) was performed on the finished iron cores prepared in the examples and comparative examples to obtain BH curves. The anti-saturation capability of the finished iron cores prepared in the examples and comparative examples was calculated by observing the position of the saturation point through the BH curves.

[0077] Results data

[0078] Table 1

[0079]

[0080] In summary, the nanocrystalline ring-cut iron core with air gap provided by this invention can effectively prevent magnetic saturation. The large air gap makes it less likely for the iron core to reach saturation under high current or strong magnetic field, while the small air gap can, to some extent, help adjust the magnetic flux distribution, thus optimizing the overall magnetic saturation characteristics of the iron core. This combination of large and small air gaps allows the iron core to maintain good linear magnetic properties under different operating conditions, improving circuit stability.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A nanocrystalline ring-cut iron core with air gap for welding machines, characterized in that, The core includes two C-shaped semicircular cores, a single adhesive layer for bonding the end faces of the two C-shaped semicircular cores, and a combined adhesive layer. The first end faces of the two C-shaped semicircular iron cores are arranged opposite each other, and a single adhesive layer for bonding the two first end faces is provided between the two first end faces to form a first air gap; The second end faces of the two C-shaped semicircular iron cores are arranged opposite to each other, and a combined adhesive layer for bonding the two second end faces is provided between the two second end faces to form a second air gap; The width of the first air gap is smaller than the width of the second air gap.

2. The nanocrystalline annular cut and air-gap iron core for welding machines according to claim 1, characterized in that, The width of the first air gap is 0.1-0.3 mm; the width of the second air gap is 0.3-1 mm.

3. The nanocrystalline annular cut and air-gap iron core for welding machines according to claim 1, characterized in that, The combined adhesive layer includes an insulating gasket and a first adhesive layer disposed on both sides of the insulating gasket for bonding the two second end faces.

4. The nanocrystalline annular cut and air-gap iron core for welding machines according to claim 3, characterized in that, The insulating pad includes aramid paper or Nomex paper.

5. The nanocrystalline annular cut and air-gap iron core for welding machines according to claim 3, characterized in that, The thickness of the insulating gasket is 0.18-0.76 mm.

6. The nanocrystalline annular cut and air-gap iron core for welding machines according to claim 3, characterized in that, The first adhesive layer used to bond the two second end faces is an organic silicone adhesive layer or an epoxy adhesive layer.

7. The nanocrystalline annular cut and air-gap iron core for welding machines according to any one of claims 1-6, characterized in that, The single adhesive layer is either an organosilicone adhesive layer or an epoxy adhesive layer.

8. A finished iron core, characterized in that, From top to bottom, the assembly consists of a protective box top cover, multiple stacked welding machine nanocrystalline ring-cut and air-gap iron cores as described in any one of claims 1-7, and a protective box bottom cover. A second adhesive layer is provided between the upper cover of the protective box and the welding machine nanocrystalline annular cut and air gap iron core adjacent to the upper cover of the protective box, and a third adhesive layer is provided between the lower cover of the protective box and the welding machine nanocrystalline annular cut and air gap iron core adjacent to the lower cover of the protective box.

9. The finished iron core according to claim 8, characterized in that, The outer ring of the plurality of stacked nanocrystalline annular cut and air gap iron cores for welding machines as described in any one of claims 1-7 is provided with insulating tape for fixing.

10. The finished iron core according to claim 8, characterized in that, Both the second and third adhesive layers are silicone adhesive layers or epoxy adhesive layers.

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