Iron core and inductor

Abstract

The present invention provides an iron core and an inductor including the same. The iron core is wound by an amorphous / nanocrystalline ribbon, and the unrolled amorphous / nanocrystalline ribbon includes n winding sections, where n≥3; wherein, when n is an odd number, the winding section of the (n+1) / 2th section is a rectangle, and the rest are right-angled trapezoids. When n is an even number, each winding section is a right-angled trapezoid. Since the winding section is a right-angled trapezoid with one side being an oblique line, the cross section of the formed iron core along the direction perpendicular to the magnetic circuit is approximately a regular polygon, which effectively improves the space utilization rate compared to the iron core with a square cross section along the direction perpendicular to the magnetic circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of iron cores, and in particular to an amorphous / nanocrystalline ribbon iron core and an inductor. Background Art

[0002] Amorphous / nanocrystalline ribbon wound cores are generally made of amorphous / nanocrystalline thin ribbons. The core shape is a closed ring shape such as a circular ring or a square ring. The traditional amorphous / nanocrystalline ribbon core is made of a whole strip of amorphous / nanocrystalline ribbon with equal width, which is neatly wound layer by layer, so the cross section of the core ring is rectangular. This method is prone to waste space and leads to a larger inductor size. Summary of the invention

[0003] In order to solve the above problems, the main purpose of the present application is to provide an iron core with high space utilization.

[0004] The present application provides an iron core, which is wound by an amorphous / nanocrystalline ribbon, characterized in that the amorphous / nanocrystalline ribbon after unfolding includes n winding parts, n≥3; wherein, when n is an odd number, the winding part of the (n+1) / 2th section is a rectangle, and the rest are right-angled trapezoids. The angle between the oblique waist and the straight waist of the winding parts from the 1st section to the (n-1) / 2nd section decreases successively, and the angle between the oblique waist and the straight waist of the winding parts from the (n+3) / 2nd section to the nth section increases successively. When n is an even number, each winding part is a right-angled trapezoid. wherein, the angle between the oblique waist and the straight waist of the winding parts from the 1st section to the n / 2nd section decreases successively, and the angle between the oblique waist and the straight waist of the winding parts from the 1+n / 2nd section to the nth section increases successively.

[0005] Preferably, the angle between the oblique waist and the straight waist of the winding portion is less than or equal to 10 degrees.

[0006] Preferably, when n is an odd number, the angle between the slant waist and the straight waist of the winding part from the 1st section to the (n-1) / 2th section decreases by less than or equal to 3 degrees, and the angle between the slant waist and the straight waist of the winding part from the (n+3) / 2th section to the nth section increases by; when n is an even number, the angle between the slant waist and the straight waist of the winding part from the 1st section to the n / 2th section decreases by, and the angle between the slant waist and the straight waist of the winding part from the 1+n / 2th section to the nth section increases by less than or equal to 3 degrees.

[0007] Preferably, when n is an odd number, the lengths of the upper bases of the winding portions from the 1st to the (n-1) / 2nd sections increase successively, the lengths of the upper bases of the winding portions from the (n+3) / 2nd to the nth sections decrease successively, and the length of the lower base of the winding portion from the (n-1) / 2nd section, the width of the winding portion from the (n+1) / 2nd section, and the length of the lower base of the winding portion from the (n+3) / 2nd section are equal.

[0008] Preferably, assuming that the inner core circumference of the core is L, the thickness of the winding portion is t, the winding coefficient is η, and the length of the straight waist of the winding portion of the nth section is l n The number of winding turns of the winding portion of the nth section is s n , then it satisfies the following formula:

[0009]

[0010] Among them, when n=1, l0=L, k is a constant, 0<k≤8.

[0011] The present application also provides an inductor, which includes the above-mentioned iron core.

[0012] Preferably, the inductor further comprises a flat coil wound on the iron core.

[0013] The above-mentioned amorphous / nanocrystalline ribbon winding of the present application is adopted. Since the winding portion is a right-angled trapezoid (only when n is an odd number, the (n+1) / 2nd winding portion 11 is a rectangle), one side of which is an oblique line, the cross section of the formed iron core along the direction perpendicular to the magnetic circuit is approximately a regular 2m-gon, m≥4, m∈N, n=m-1. When forming the inductor, the coil is wound on the iron core, and the gap between the coil and the iron core 100 is small, which effectively improves the space utilization rate compared with the iron core with a square cross section along the direction perpendicular to the magnetic circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 is a three-dimensional schematic diagram of an iron core provided in an embodiment of the present invention;

[0016] Figure 2 yes Figure 1 A cross-sectional view of the core shown along its magnetic path direction;

[0017] Figure 3 yes Figure 1 A three-dimensional cross-sectional view of the core shown along a direction perpendicular to its magnetic circuit;

[0018] Figure 4 yes Figure 1 A schematic plan view of the amorphous / nanocrystalline ribbon of the iron core after unfolding;

[0019] Figure 5 is a plan view schematically showing an unfolded amorphous / nanocrystalline ribbon of an iron core according to another embodiment of the present invention;

[0020] Figure 6 is a plan view schematically showing an unfolded amorphous / nanocrystalline ribbon of an iron core according to yet another embodiment of the present invention;

[0021] Figure 7 It is a schematic diagram of a coil wound on an iron core with a square cross section along the direction perpendicular to the magnetic circuit;

[0022] Figure 8 is a three-dimensional schematic diagram of an inductor provided in an embodiment of the present invention;

[0023] Fig. 9 is a schematic diagram of a prefabricated iron core according to an embodiment of the present invention;

[0024] Fig.10 is a schematic diagram of shaping the prefabricated core; and

[0025] Fig.11 Schematic diagram of cutting amorphous / nanocrystalline ribbons. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0027] In the description of this application, unless otherwise clearly specified and limited, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; unless otherwise specified or explained, the term "plurality" refers to two or more; the terms "connected" and "fixed" should be understood in a broad sense, for example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the description of this specification, it should be understood that the directional words such as "upper" and "lower" described in the embodiments of the present application are described at the angles shown in the accompanying drawings and should not be understood as limiting the embodiments of the present application. In addition, in the context, it should also be understood that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element.

[0029] The embodiment of the present invention provides an iron core, which is formed by winding an amorphous / nanocrystalline ribbon, and its cross section along the direction perpendicular to the magnetic circuit is approximately a regular polygon, and steps are formed on the edge. Figure 1-3, taking the iron core whose cross section along the direction perpendicular to the magnetic circuit is approximately a regular octagon as an example, Figure 1 is a three-dimensional schematic diagram of the iron core 100, Figure 2 is a cross-sectional view of the core 100 along its magnetic circuit direction, Figure 3 1 is a cross-sectional perspective view of the core 100 along the direction perpendicular to its magnetic path. The core 100 is formed by winding an amorphous / nanocrystalline ribbon 10. In this embodiment, the amorphous / nanocrystalline ribbon 10 is formed around a cylindrical mandrel (not shown). Figure 2 As shown, the core 100 has a multi-layer structure, and its cross section along the magnetic circuit direction is annular as a whole, and the middle hollow part is a cylindrical core shaft. After winding, the core shaft is removed. The core 100 has a multi-layer structure. The actual design is determined by the magnetic flux and volume requirements. It can be understood that the cross section of the core 100 along the magnetic circuit direction can also be in other shapes, which depends on the magnetic circuit direction and the shape of the core 100, and the present invention does not limit it.

[0030] Assuming that the number of sides of the approximate polygon is 2m, m≥4, m∈N, the unrolled amorphous / nanocrystalline ribbon 10 includes n winding sections, n=m-1.

[0031] When n is an odd number, the (n+1) / 2nd winding section is a rectangle, and the rest are right-angled trapezoids. The angle θ between the oblique waist and the straight waist of the winding section 1 to the (n-1) / 2nd winding section decreases successively, and the angle θ between the oblique waist and the straight waist of the winding section (n+3) / 2 to the nth winding section increases successively.

[0032] Please also see Figure 4 In this embodiment, the cross section of the core 100 along the direction perpendicular to the magnetic circuit is approximately a regular octagon, and n is 3. The amorphous / nanocrystalline ribbon 10 includes three winding sections 11 .

[0033] See also Figure 5 In this embodiment, the cross section of the core 100 along the direction perpendicular to the magnetic circuit is approximately a regular dodecagon, and n is 5. The amorphous / nanocrystalline ribbon 10 includes 5 winding sections 11. The angle θ1 between the oblique waist 112 and the straight waist 114 of the first winding section 11 is greater than the angle θ2 of the second winding section 11. The first winding section 11 is rectangular, and the angle θ3 of the fourth winding section 11 is less than the angle θ4 of the fifth winding section 11.

[0034] When n is an even number, each winding portion is a right-angled trapezoid, wherein the angle θ between the oblique waist and the straight waist of the 1st to n / 2nd winding portions decreases successively, and the angle between the oblique waist and the straight waist of the 1st+n / 2nd to nth winding portions 11 increases successively.

[0035] Please also see Figure 6In this embodiment, the cross section of the core 100 along the direction perpendicular to the magnetic circuit is approximately a regular decagon, and n is 4. The amorphous / nanocrystalline ribbon 10 includes four winding portions 11 in the form of right-angled trapezoids. Among them, the angle θ1 of the first winding portion 11 is greater than the angle θ2 of the second winding portion 11, the first winding portion 11 is rectangular, and the angle θ3 of the third winding portion 11 is less than the angle θ4 of the fourth winding portion 11.

[0036] The amorphous / nanocrystalline ribbon 10 of the above structure is wound, and since the winding portion 11 is a right-angled trapezoid (only when n is an odd number, the (n+1) / 2nd winding portion 11 is a rectangle), one side of which is an oblique line, the cross section of the formed iron core 100 along the direction perpendicular to the magnetic circuit is approximately a regular 2m-gon, m≥4, m∈N. When forming an inductor, the coil is wound on the iron core 100, and the gap between the coil and the iron core 100 is small, which effectively improves the space utilization rate compared to the iron core with a square cross section along the direction perpendicular to the magnetic circuit.

[0037] See also Figure 7 and Figure 8 , Figure 7 It is a schematic diagram of a coil wound on an iron core with a square cross section in the direction perpendicular to the magnetic circuit. Figure 8 is a three-dimensional schematic diagram of an inductor provided in an embodiment of the present invention, wherein the coil is wound around an iron core 100 having a cross section approximately in the shape of a regular octagon in an embodiment of the present invention. After calculation, Figure 7 The winding cross-section utilization of the inductor shown is only 63.7%, while Figure 8 The winding cross-sectional utilization rate of the inductor is shown to be about 95.5%. That is, the use of the iron core 100 according to the embodiment of the present invention can greatly improve the winding cross-sectional utilization rate of the inductor, thereby improving the space utilization rate of the iron core 100.

[0038] Since amorphous / nanocrystalline ribbons are very flexible and difficult to cut, if the edges of the amorphous / nanocrystalline ribbons are curved, the processing is difficult and the processing cost is high; in addition, the scraps generated when processing the curved edges are difficult to reuse, resulting in material waste. The core 100 of the embodiment of the present invention has a straight edge, not a curved edge, and is easy to process.

[0039] It should be noted that the plurality of winding parts 11 can be integrated or two parts that are independent and connected together, which can be adjusted according to actual conditions. When the plurality of winding parts 11 are connected, they can be connected end to end or the end to end can overlap, which can be adjusted according to actual conditions.

[0040] In a specific embodiment, the angle θ between the oblique waist 112 and the straight waist 114 of the winding portion 11 is less than or equal to 10 degrees.

[0041] In a specific embodiment, when n is an odd number, the angle θ between the oblique waist 112 and the straight waist 114 of the winding portion 11 from the 1st section to the (n-1) / 2nd section decreases by less than or equal to 3 degrees, and the angle θ between the oblique waist 112 and the straight waist 114 of the winding portion 11 from the (n+3) / 2nd section to the nth section increases by less than or equal to 3 degrees.

[0042] In a specific embodiment, when n is an even number, the angle θ between the oblique waist 112 and the straight waist 114 of the winding portion 11 from the 1st section to the n / 2nd section decreases by less than or equal to 3 degrees, and the angle θ between the oblique waist 112 and the straight waist 114 of the winding portion 11 from the 1+n / 2th section to the nth section increases by less than or equal to 3 degrees.

[0043] In one specific embodiment, see Figure 4 When n is an odd number, the lengths of the upper bases 116 of the 1st to (n-1) / 2nd winding portions 11 increase successively, the lengths of the upper bases 116 of the (n+3) / 2nd to nth winding portions 11 decrease successively, and the length of the lower base 118 of the (n-1) / 2nd winding portion 11, the width 110 of the (n+1) / 2nd winding portion, and the length of the lower base 118 of the (n+3) / 2nd winding portion 11 are equal.

[0044] In a specific embodiment, the inner core circumference of the core 100 is L, the thickness of the winding portion 11 is t, the winding coefficient is η, and the length of the straight waist of the winding portion of the nth segment is l n The number of winding turns of the winding portion of the nth section is s n , then it satisfies the following formula:

[0045]

[0046] Among them, when n=1, l0=l, k is a constant, 0<k≤8.

[0047] Among them, the inner core circumference refers to the circumference of the middle hollow part of the iron core 100. If the middle hollow part of the iron core 100 is circular, the inner core circumference is the circumference of the circle; if the middle hollow part of the iron core 100 is square, the inner core circumference is the circumference of the square; if the middle hollow part of the iron core 100 is other irregular shapes, the inner core circumference is the circumference of the irregular shape. The thickness of the winding part 11 refers to the single layer thickness of the amorphous / nanocrystalline 10. The winding coefficient refers to the ratio of the number of turns of the winding part 11 that can actually be accommodated within a certain thickness to the number of turns of the winding part 11 that can be accommodated theoretically. The thickness of the winding portion 11 is 0.025 mm. If the iron core 100 with a thickness of 10 mm needs to be wound, theoretically, 10 mm / 0.025 mm=400 turns need to be wound. However, since it is impossible to completely fit the core 100 in practice, only 320 turns can be wound. The winding coefficient is 320 / (10 / 0.025)=0.8. The number of winding turns refers to the number of turns wound by a certain winding portion.

[0048] When the length and shape of the winding inner core are certain, and the inner diameter of the coil wound thereon is certain, in order to achieve a higher effective area, the more sides the cross-section approximates to a regular polygon, the more the cross-section approximates to a circle, and the higher the effective area. However, when the number of sides is large, the length of each winding portion is short, the number of winding portions n is large, and the winding cost is high. Therefore, when the length of the winding portion is more economical, the angle θ between the oblique waist 112 and the straight waist 114 of the winding portion 11 should be appropriately small. In one embodiment of the present application, the angle θ between the oblique waist 112 and the straight waist 114 is less than or equal to 10 degrees. Within this range, the effective area and the winding cost are better balanced.

[0049] See also Figure 7 , Figure 7 Schematic diagram of cutting amorphous / nanocrystalline strips. Since the amorphous / nanocrystalline strips are in the shape of long strips, after the amorphous / nanocrystalline strips are cut along the cutting line II to form the amorphous / nanocrystalline strips 10, the remaining part also forms a right-angle trapezoidal structure, which can also be used to wind the iron core 100, thereby avoiding processing waste. In actual design, the sum of the length of the upper base of one winding portion 11 and the length of the lower base of another winding portion 11 can be made equal to the width of the amorphous / nanocrystalline strip, thereby forming two available winding portions 11 at the same time, further improving processing efficiency.

[0050] The manufacturing process of the iron core 100 having an approximately regular 2m-gon shape includes the following steps:

[0051] First, the first winding section 11 is wound around the mandrel, and wound S1 turns to the tail of the first winding section 11; then the second winding section 11 is wound on the coil layer formed by the first winding section 11, and wound S2 turns to the tail of the second winding section 11; and the winding is repeated in the same manner until the nth winding section 11 is wound S n Loop to obtain a prefabricated iron core 101;

[0052] The prefabricated iron core 101 is subjected to shaping treatment to obtain the iron core 100;

[0053] The final finished iron core 100 is obtained by heat treatment of the amorphous / nanocrystalline strip and post-processing method (coating, adding a plastic shell).

[0054] Preferably, one side of the prefabricated iron core 101 is flush, and the other side forms a step; the prefabricated iron core 101 is shaped so that both sides form steps and are symmetrical.

[0055] Specifically, see Fig. 9 , 10 , place the prefabricated iron core 101 into a shaping jig 30 with steps formed thereon, the bottom surface of the shaping jig 30 is formed with steps corresponding to the target cross section, the flat side of the prefabricated iron core 101 is placed toward the steps, and appropriate pressure is applied to the prefabricated iron core 101, so that steps are formed on both sides of the prefabricated iron core 101 and the prefabricated iron core 101 is symmetrical, thereby forming an iron core 100 with a cross section that is approximately a regular polygon.

[0056] The term "approximate regular polygon" in the present application means that the edge of the polygon has steps, and is not straight. This is because the winding portion 11 in the shape of a right-angled trapezoid has a straight hypotenuse, and after winding and shaping, an approximate straight edge with steps is formed.

[0057] It can be understood that when the nth winding section 11 is wound on the coil layer formed by the n-1th winding section 11, the head end of the nth winding section 11 can be connected to the tail end of the n-1th winding section 11 without overlap, or they can be partially overlapped, or they can be separated by a suitable distance. Due to the reasons of processing accuracy, the difference in the shape of the iron core 100 obtained by connecting by the above different methods is an acceptable error in the art.

[0058] It is understandable that if the winding portion adopts an arc-shaped edge, the iron core formed after winding may have a circular cross-section. However, since amorphous / nanocrystalline strips are very flexible and difficult to cut, it is difficult to process the arc-shaped edge and the processing cost is high; in addition, the scraps generated when processing the arc-shaped edge are difficult to reuse, resulting in material waste.

[0059] Since the edge of amorphous / nanocrystalline 10 is straight, not curved, the processing difficulty is low, and the low-cost rubber roller cutting method can be used to cut amorphous / nanocrystalline materials. Fig.11 , Fig.11Schematic diagram of cutting amorphous / nanocrystalline strips. Since the amorphous / nanocrystalline strips are in the shape of long strips, after cutting to form the amorphous / nanocrystalline strips 10, the remaining part also forms a right-angle trapezoidal structure, which can also be used to wind the iron core 100, thereby avoiding processing waste. In actual design, the sum of the length of the upper base of one winding portion 11 and the length of the lower base of another winding portion 11 can be made equal to the width of the amorphous / nanocrystalline strip, thereby simultaneously forming two amorphous / nanocrystalline strips 10 that can be used to wind the iron core 100, further improving processing efficiency.

[0060] Another aspect of the present invention provides an inductor, such as Figure 8 As shown, the inductor 300 includes an iron core 100 and a flat coil 200 wound on the iron core 100. The flat coil 200 is in a circular shape as a whole. Since it has a compressive elastic force, it is aligned with the iron core 400. After being released, the flat coil 200 is automatically wound on the iron core 100 under the action of the elastic force.

[0061] The winding method has high winding efficiency, strong versatility of automation equipment, and simple debugging. Since the cross section of the iron core 100 is quasi-circular, it matches the flat coil 200 and has high space utilization. Therefore, the inductor 300 of the embodiment of the present invention has low processing cost and high space utilization.

[0062] The above is only a preferred specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An iron core, which is wound by an amorphous / nanocrystalline ribbon, characterized in that: The amorphous / nanocrystalline ribbon after being unfolded comprises n winding sections; Wherein, when n is an odd number, the winding portion of the (n+1) / 2th section is a rectangle, and the rest are right-angled trapezoids, the angles between the oblique waist and the straight waist of the winding portion of the 1st section to the (n-1) / 2th section decrease successively, and the angles between the oblique waist and the straight waist of the winding portion of the (n+3) / 2th section to the nth section increase successively; When n is an even number, each winding portion is a right-angled trapezoid, wherein the angles between the oblique waist and the straight waist of the winding portion from the 1st to the n / 2nd segment decrease successively, and the angles between the oblique waist and the straight waist of the winding portion from the 1+n / 2nd to the nth segment increase successively; The cross section of the core along the direction perpendicular to the magnetic circuit is an approximate regular polygon, the number of sides of the approximate regular polygon is 2m, m≥4, m∈N, and the number of segments n of the winding portion satisfies n=m-1, n≥3.

2. An iron core as claimed in claim 1, characterized in that: The angle between the oblique waist and the straight waist of the winding portion is less than or equal to 10 degrees.

3. An iron core as claimed in claim 1, characterized in that: When n is an odd number, the angle between the oblique waist and the straight waist of the winding part from the 1st section to the (n-1) / 2nd section decreases by less than or equal to 3 degrees, and the angle between the oblique waist and the straight waist of the winding part from the (n+3) / 2nd section to the nth section increases by less than or equal to 3 degrees; when n is an even number, the angle between the oblique waist and the straight waist of the winding part from the 1st section to the n / 2nd section decreases by less than or equal to 3 degrees, and the angle between the oblique waist and the straight waist of the winding part from the 1+n / 2nd section to the nth section increases by less than or equal to 3 degrees.

4. An iron core as claimed in claim 1, characterized in that: When n is an odd number, the lengths of the upper base sides of the winding portions from the 1st section to the (n-1) / 2nd section increase successively, the lengths of the upper base sides of the winding portions from the (n+3) / 2nd section to the nth section decrease successively, and the length of the lower base side of the winding portion from the (n-1) / 2nd section, the width of the winding portion from the (n+1) / 2nd section, and the length of the lower base side of the winding portion from the (n+3) / 2nd section are equal.

5. An iron core according to any one of claims 1 to 4, characterized in that The inner core circumference of the core is L, the thickness of the winding portion is t, the winding coefficient is η, and the length of the straight waist of the winding portion of the nth section is l n The number of winding turns of the winding portion of the nth section is s n , then it satisfies the following formula: Among them, when n=1, l0=L, k is a constant, 0<k≤8.

6. An inductor, characterized in that: The inductor comprises the core according to any one of claims 1-5.

7. An inductor as claimed in claim 6, characterized in that The inductor further includes a flat coil wound around the iron core.

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