A magnetic core of a mutual inductor and its manufacturing process

Abstract

The present invention discloses a magnetic core of a mutual inductor and its manufacturing process, which are carried out successively through step a, step b, step c, and step d to combine L-shaped silicon steel sheets into a magnetic core finished product with a rectangular structure. Through this process, during the forming process of the silicon steel sheets, the waste of raw materials is effectively reduced, and through the quick combination of the L-shaped silicon steel sheets and riveting points, the working hours for assembling the magnetic core are reduced, the production efficiency of the magnetic core is improved, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to a magnetic core of a mutual inductor, in particular to a UU28 type silicon steel sheet magnetic core and its forming and assembling process. Background Art

[0002] At present, the magnetic core of the uu28 type mutual inductor on the market is stacked by 0.5mm silicon steel sheets. The external dimensions of such silicon steel sheets are shown in Figure 1, and Figure 2 shows the way of forming U-shaped sheets by a punching machine. As shown in Figure 2, after each U-shaped sheet is formed, a waste part in the shape of a rectangle of 12.7 * 19 = 241.3mm 2 is generated, and the area used for processing one U-shaped sheet is 28 * 17.22 = 481.6 mm 2 , 241.3 / 481.6 ≈ 50%, that is, 50% of the material is wasted for each processed U-shaped sheet. Figure 3 shows the combination method of silicon steel sheets. The U-shaped sheets are assembled by an inserting machine, and the I-shaped sheets are manually installed. This process has a relatively low efficiency, and the upper and lower I-shaped sheets are prone to falling off after assembly. Summary of the Invention

[0003] The purpose of the present invention is to provide a magnetic core of a mutual inductor and its manufacturing process, which can effectively reduce the waste of materials during the forming of silicon steel sheets and reduce the man-hours during the assembly of the magnetic core.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A magnetic core of a mutual inductor, comprising a magnetic core body formed by assembling a left U-shaped magnetic core and a right U-shaped magnetic core with the same structure. The left U-shaped magnetic core is composed of a plurality of first L-shaped silicon steel sheets and second L-shaped silicon steel sheets stacked alternately. The first L-shaped silicon steel sheet includes a first long side, a first short side, first riveting grooves symmetrically arranged on the upper sides of both ends of the first long side, and first riveting points symmetrically arranged on the lower sides of both ends of the first long side. The second L-shaped silicon steel sheet includes a second long side, a second short side, second riveting grooves symmetrically arranged on the upper sides of both ends of the second long side, and second riveting points symmetrically arranged on the lower sides of both ends of the second long side. The first long side and the second long side are alternately overlapped. A first gap is provided between adjacent first short sides, and a second gap is provided between adjacent second short sides. The widths of the first gap and the second gap are equal. The first riveting point and the second riveting groove have matching structures, the second riveting point and the first riveting groove have matching structures, and the first riveting point and the second riveting point have the same structure.

[0005] The manufacturing process of the magnetic core of the mutual inductor includes the following steps: Step a, cut a number of first L-shaped silicon steel sheets and second L-shaped silicon steel sheets from the raw material silicon steel sheet, and set riveting points and riveting grooves at both ends of the first long side and the second long side; Step b, stack the first L-shaped silicon steel sheets and the second L-shaped silicon steel sheets alternately according to the first long side and the second long side, with the first short side and the second short side facing the same side, and fix them alternately and firmly through the first riveting point and the second riveting groove and the second riveting point and the first riveting groove to form a U-shaped magnetic core; Step c, take two U-shaped magnetic cores, make the openings of the left U-shaped magnetic core face the openings of the right U-shaped magnetic core, insert the first short side of the left U-shaped magnetic core into the second gap of the right U-shaped magnetic core, and insert the second short side of the left U-shaped magnetic core into the first gap of the right U-shaped magnetic core to form a magnetic core finished product with a rectangular structure; Step d, dip the magnetic core finished product in paint and then perform a drying treatment.

[0006] Further preferably, in step a, the first long side and the second short side of the first L-shaped silicon steel sheet and the second L-shaped silicon steel sheet are joined, and the first short side and the second long side face different sides and are combined into a Z-shaped row for cutting on the raw material silicon steel sheet.

[0007] The beneficial effects of the present invention: During the forming process of the silicon steel sheet by this process, the waste of raw materials is effectively reduced, and through the quick combination of the L-shaped silicon steel sheet with the riveting points and the riveting grooves, the working hours for assembling the magnetic core are reduced, the production efficiency of the magnetic core is improved, and the production cost is reduced. Description of the Drawings

[0008] Attached Figure 1 is a schematic structural diagram of the existing such silicon steel sheet.

[0009] Attached Figure 2 is a schematic structural diagram of the existing U-shaped sheet formed by a punching machine.

[0010] Attached Figure 3 is a schematic combination diagram of the existing such silicon steel sheets.

[0011] Attached Figure 4 is a schematic diagram of the cutting and forming of the silicon steel sheet.

[0012] Attached Figure 5 is a schematic structural diagram of the first silicon steel sheet.

[0013] Attached Figure 6 is an enlarged structural diagram of A.

[0014] Attached Figure 7 is an enlarged structural diagram of B.

[0015] Attached Figure 8 is a schematic structural diagram of the U-shaped magnetic core.

[0016] Attached Figure 9 is a schematic combination diagram of the U-shaped magnetic core.

[0017] Attached Figure 10 is a schematic structural view of the finished magnetic core.

[0018] Legend: 1. Left U-shaped magnetic core; 2. Right U-shaped magnetic core; 3. Magnetic core body; 4. First L-shaped silicon steel sheet; 5. Second L-shaped silicon steel sheet; 41. First long side; 42. First short side; 43. First riveting groove; 44. First riveting point; 45. First gap; 51. Second long side; 52. Second short side; 53. Second riveting groove; 54. Second riveting point; 55. Second gap. Specific embodiments

[0019] Next, we will further illustrate the magnetic core process of an instrument transformer according to the present invention with reference to the accompanying drawings.

[0020] The magnetic core of an instrument transformer in this embodiment includes a magnetic core body 3 formed by assembling a left U-shaped magnetic core 1 and a right U-shaped magnetic core 2 with the same structure. The left U-shaped magnetic core 1 is composed of a number of alternately stacked first L-shaped silicon steel sheets 4 and second L-shaped silicon steel sheets 5. The first L-shaped silicon steel sheet 4 includes a first long side 41, a first short side 42, first riveting grooves 43 symmetrically arranged on the upper sides of both ends of the first long side, and first riveting points 44 symmetrically arranged on the lower sides of both ends of the first long side. The second L-shaped silicon steel sheet 5 includes a second long side 51, a second short side 52, second riveting grooves 53 symmetrically arranged on the upper sides of both ends of the second long side, and second riveting points 54 symmetrically arranged on the lower sides of both ends of the second long side. The first long side 41 and the second long side 51 are alternately overlapped. A first gap 45 is provided between adjacent first short sides 42, and a second gap 55 is provided between adjacent second short sides 52. The widths of the first gap 45 and the second gap 55 are equal. The first riveting point 44 and the second riveting groove 53 are matched in structure, the second riveting point 54 and the first riveting groove 43 are matched in structure, and the first riveting point 44 and the second riveting point 54 are the same in structure. Among them, the first gap is formed by the second long side provided between adjacent first long sides, so that a gap with a width equal to the second long side is formed between adjacent first L-shaped silicon steel sheets. At the same time, since the first long side and the second long side are in close contact, a first gap with a width equal to the second long side is formed between adjacent first short sides and the second long side. The formation of the second gap is the same as that of the first gap.

[0021] The manufacturing process of the magnetic core of the current transformer includes the following steps: Step a: Cut a number of first L-shaped silicon steel sheets 4 and second L-shaped silicon steel sheets 5 from the raw material silicon steel sheet, and set riveting points and riveting grooves at both ends of the first long side 41 and the second long side 51; Step b: Stack the first L-shaped silicon steel sheets 4 and the second L-shaped silicon steel sheets 5 alternately according to the first long side 41 and the second long side 51, with the first short side 42 and the second short side 52 facing the same side, and fix them alternately and firmly through the first riveting point 44 and the second riveting groove 53 and the second riveting point 54 and the first riveting groove 43 to form a U-shaped magnetic core; Step c: Take two U-shaped magnetic cores, make the openings of the left U-shaped magnetic core 1 face the openings of the right U-shaped magnetic core 2, insert the first short side of the left U-shaped magnetic core 1 into the second gap of the right U-shaped magnetic core 2, and insert the second short side of the left U-shaped magnetic core 1 into the first gap of the right U-shaped magnetic core 2 to form a magnetic core finished product with a rectangular structure; Step d: Immerse the magnetic core finished product in paint and then perform a drying treatment. Among them, in step a, the first long side 41 of the first L-shaped silicon steel sheet 4 and the second L-shaped silicon steel sheet 5 is connected to the second short side 52, and the first short side 42 and the second long side 51 face different sides and are combined into a Z-shaped row for cutting on the raw material silicon steel sheet.

[0022] As Figures 1 to 10 shown in the figure, in step a of this embodiment, assuming that the length of the raw material silicon steel sheet is 1m, the width is 62.5mm, the width of the L-shaped silicon steel sheet 1 is 5mm, the height is 0.5mm, the length of the long side is 29mm, and the length of the short side is 12.7mm; the length of the riveting point 2 is 2.3mm, the width is 0.5mm, the depth is 0.25mm, and the radius of the chamfered arc is 0.25mm. According to Figure 4 the operation, except for the head and tail, the wasted area of one formed silicon steel sheet is 5*5 / 2 = 12.5mm 2 , and the actual used area of one silicon steel sheet is 208.5mm 2 , and the material utilization rate is 94.3%, with a high material utilization rate, effectively reducing the material input cost. According to Figure 8 the stacked silicon steel sheets are firmly fixed through the riveting points and the riveting grooves to form a U-shaped magnetic core, and then the two U-shaped magnetic cores are combined according to Figure 9 the method and then immersed in paint and dried, and finally the magnetic core finished product shown in Figure 10 the figure is obtained. The whole assembly process is simple to operate and takes less time.

[0023] The protection scope of the present invention is not limited to the above embodiments and their variations. Conventional modifications and replacements made by those skilled in the art based on the content of this embodiment all fall within the protection scope of the present invention.

Claims

1. A manufacturing process for the magnetic core of a mutual inductor, characterized in that: The magnetic core is a magnetic core body formed by assembling a left U-shaped magnetic core and a right U-shaped magnetic core with the same structure. The left U-shaped magnetic core is composed of a number of first L-shaped silicon steel sheets and second L-shaped silicon steel sheets stacked alternately. The first L-shaped silicon steel sheet includes a first long side, a first short side, first riveting grooves symmetrically arranged on the upper sides of both ends of the first long side, and first riveting points symmetrically arranged on the lower sides of both ends of the first long side. The second L-shaped silicon steel sheet includes a second long side, a second short side, second riveting grooves symmetrically arranged on the upper sides of both ends of the second long side, and second riveting points symmetrically arranged on the lower sides of both ends of the second long side. The first long side and the second long side are alternately overlapped. A first gap is provided between adjacent first short sides, and a second gap is provided between adjacent second short sides. The widths of the first gap and the second gap are equal. The first riveting point and the second riveting groove are matched in structure, the second riveting point and the first riveting groove are matched in structure, and the first riveting point and the second riveting point are the same in structure. The manufacturing process includes the following steps: Step a, cut a number of first L-shaped silicon steel sheets and second L-shaped silicon steel sheets from the raw material silicon steel sheet, and set riveting points and riveting grooves at both ends of the first long side and the second long side. Step b, stack the first L-shaped silicon steel sheets and the second L-shaped silicon steel sheets alternately according to the first long side and the second long side, with the first short side and the second short side facing the same side, and fix them alternately by fitting the first riveting point with the second riveting groove and the second riveting point with the first riveting groove to form a U-shaped magnetic core. Step c, take two U-shaped magnetic cores, make the openings of the left U-shaped magnetic core face the openings of the right U-shaped magnetic core, insert the first short side of the left U-shaped magnetic core into the second gap of the right U-shaped magnetic core, and insert the second short side of the left U-shaped magnetic core into the first gap of the right U-shaped magnetic core to form a magnetic core finished product with a rectangular structure. Step d, perform dipping and drying treatment on the magnetic core finished product.

2. The manufacturing process of the magnetic core of the mutual inductor according to claim 1, characterized in that: In step a, connect the first long side of the first L-shaped silicon steel sheet and the second L-shaped silicon steel sheet to the second short side, and combine the first short side and the second long side facing different sides into a Z-shaped row for cutting on the raw material silicon steel sheet.

3. A magnetic core manufactured by using the magnetic core manufacturing process of an instrument transformer described in claim 2.

Images