transformer

Abstract

The overall size of the transformer is reduced, resulting in a smaller and lighter design, while also improving overall heat dissipation and enhancing the ease of assembly. [Solution] The coil unit 2 comprises another coil 4 arranged between sheet coils 3u and 3d, a coil insulating part 5 that insulates the entire coil unit 2, a core part 6 that is attached to the coil unit 2, and a core insulating part that insulates the core part 6 and the coil unit 2. The coil insulating part is formed in a U-shape that contacts the upper surface 2u, lower surface 2d and side surface 2s of the coil unit 2 and grips the coil unit 2, thereby insulating the core part 6 and the coil unit 2. The intermediate parts of the core insulating parts 7p and 7q are formed in a notched shape, and the insulation between the core part 6 and the coil unit 2 in the formed through spaces 7ps and 7qs is shared by the coil insulating part 5.

Description

Technical Field

[0001] The present invention relates to a transformer including a coil insulating portion for insulating a coil unit, a core portion attached to the coil unit, and a core insulating portion for insulating between the core portion and the coil unit.

Background Art

[0002] Conventionally, as a transformer including a coil unit in which sheet coils are arranged on upper and lower surfaces and another coil is arranged between the sheet coils, a coil insulating portion for insulating the coil unit, a core portion attached to the coil unit, and a core insulating portion for insulating between the core portion and the coil unit, a transformer described in Patent Document 1 proposed by the present applicant is already known.

[0003] The transformer described in the same Document 1 aims to reduce manufacturing costs associated with reducing the number of manufacturing steps, enhance manufacturing ease including ease of automation, and in addition, contribute to improving the performance and quality of the entire transformer by eliminating variations during manufacturing with an integrated coil portion. Specifically, one of the coil portions in the primary coil portion or the secondary coil portion is integrally formed by a first coil half portion and a second coil half portion that are continuous via an intermediate sheet portion, and by bending the intermediate sheet portion, the coil half portions are formed in a U shape facing each other with a predetermined interval therebetween, and the other coil portion is configured to be arranged between the coil half portions. Further, insulating spacers are interposed between the coil members including the coil half portions.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the transformer described in Patent Document 1 mentioned above still had the following issues that needed to be resolved.

[0006] Figure 10 shows a typical structure of this type of transformer in the past. This transformer 50 has a primary coil section 51 and a secondary coil section 52, and has the function of converting high voltage to low voltage. The secondary coil section 52 uses a sheet coil (2 turns) with a curved shape made from flat rectangular conductors, while the primary coil section 51 uses a sheet coil or a coil section with a large number of turns using magnet wire with a circular cross-section.

[0007] Therefore, the device has an insulating structure that provides insulation between the primary coil section 51 and the secondary coil section 52, and includes a coil insulating section 61 that takes into account heat dissipation from the coil sections 51 and 52, as well as core insulating sections (separators) 62p and 62q that insulate the core section 71 mounted on the coil sections 51 and 52.

[0008] As a result, in the conventional transformer 50, there are insulating parts with different insulating properties and shapes in the coil insulating part 61 and the core insulating parts 62p and 62q, which leads to an increase in the overall size of the transformer 50. This limits the possibility of making the transformer 50 smaller and lighter, and there is room for further improvement in terms of ensuring the overall heat dissipation of the transformer 50 and further improving the ease of assembly of the transformer 50.

[0009] The present invention aims to provide a transformer that solves the problems present in the background technology described above. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems, the transformer 1 according to the present invention comprises a coil unit 2 having sheet coils 3u and 3d arranged on an upper surface 2u and a lower surface 2d, and another coil 4 arranged between the sheet coils 3u and 3d, a coil insulating part 5 that insulates the entire coil unit 2, a core part 6 that is mounted on the coil unit 2, and a core insulating part that insulates the core part 6 and the coil unit 2. The transformer is characterized in that it is provided with a pair of left and right core insulating parts 7p and 7q that are formed in a U-shape to contact the upper surface 2u, lower surface 2d and side surface 2s of the coil unit 2 and grip the coil unit 2, thereby insulating the core part 6 and the coil unit 2, and the intermediate parts of these core insulating parts 7p and 7q are formed in a notched shape, and the insulation between the core part 6 and the coil unit 2 in the formed through space 7ps... is also provided by the coil insulating part 5.

[0011] In this case, according to a preferred embodiment of the invention, the sheet coils 3u and 3d can be applied to the secondary coil section C2, and the other coil 4 can be applied to the primary coil section C1. Furthermore, the core insulating section 7p... can be integrally formed from an elastic synthetic resin material and has an upper plate section 7pu... and a lower plate section 7pd... that grips the space between the upper surface section 2u and the lower surface section 2d. By inclining at least one of the upper plate section 7pu... and the lower plate section 7pd... with respect to the upper surface section 2u and the lower surface section 2d, the space between the tip 7pus... of the upper plate section 7pu... and the tip 7pds... of the lower plate section 7pd... can be narrowed, and the upper plate section 7pu... and the lower plate section 7pd... can be pressed against the coil unit 2. Furthermore, the core insulating portion 7p... connects the ends 7puf..., 7pur... in the front-rear direction Fs of the upper plate portion 7pu... and the lower plate portion 7pd..., and protrudes outward from the coil unit 2, thereby providing a pair of connecting plate portions 7pf..., 7pr... that grip the end faces 6f, 6r of the core portion 6 in the front-rear direction Fs. Additionally, by forming one or both of the upper plate portion 7pu... and the lower plate portion 7pd... wider in the front-rear direction Fs relative to the connecting plate portions 7pf..., 7pr..., and integrally forming a pair of auxiliary plate portions 7pfs..., 7prs... outward from the ends in the front-rear direction Fs, the auxiliary plate portions 7pfs..., 7pr... and the connecting plate portions 7pf..., 7pr... can be formed in a continuous manner at a right angle. In addition, locking edge portions 7px… can be integrally formed on the core insulating portion 7p… at the outer position of one or both of the upper plate portion 7pu… and the lower plate portion 7pd… to restrict the position of the side surface of the coil unit 2. [Effects of the Invention]

[0012] The transformer 1 according to the present invention, having such a configuration, produces the following remarkable effects.

[0013] (1) The transformer is provided with a pair of left and right core insulating parts 7p and 7q that are formed in a U-shape to grip the coil unit 2 by contacting the upper surface 2u, lower surface 2d and side surface 2s of the coil unit 2, thereby insulating the core part 6 from the coil unit 2. Furthermore, the intermediate parts of these core insulating parts 7p and 7q are notched, and the insulation between the core part 6 and the coil unit 2 in the notched through space 7ps... is also provided by the coil insulating part 5, which allows for a reduction in the overall size of the transformer 1, making it smaller and lighter. In addition, the overall heat dissipation can be improved, and the assembly of the transformer 1 can be further improved.

[0014] (2) In a preferred embodiment, if the sheet coils 3u and 3d are applied to the secondary coil section C2 and the other coil 4 is applied to the primary coil section C1, it can be used in a planar transformer, etc., and is therefore ideal for use in equipment such as DC-DC converters.

[0015] (3) In a preferred embodiment, if the core insulating portion 7p... is integrally formed from an elastic synthetic resin material, it can be integrally molded by injection molding or the like, and can therefore be implemented easily and at low cost.

[0016] (4) In a preferred embodiment, upper plate portions 7pu… and lower plate portions 7pd… are provided to grip the space between the upper surface portion 2u and the lower surface portion 2d, and at least one of these upper plate portions 7pu… and lower plate portions 7pd… is inclined with respect to the upper surface portion 2u and the lower surface portion 2d, so that the space between the tip 7pus… of the upper plate portion 7pu… and the tip 7pds… of the lower plate portion 7pd… is narrowed, and the upper plate portions 7pu… and lower plate portions 7pd… are pressed against the coil unit 2, so that the coil unit 2 can be stably held by the core insulating portions 7p, 7q, thereby preventing unnecessary rattling during the manufacturing process, contributing to quality improvement, and further enhancing heat dissipation (heat transfer).

[0017] (5) In a preferred embodiment, the core insulating portion 7p... connects the ends 7puf..., 7pur... in the front-rear direction Fs of the upper plate portion 7pu... and the lower plate portion 7pd... and protrudes outward from the coil unit 2, thereby providing a pair of connecting plate portions 7pf..., 7pr... that grip the end faces 6f, 6r of the core portion 6 in the front-rear direction Fs. This ensures reliable positioning between the core insulating portion 7p... and the core portion 6, thereby increasing the strength and rigidity of the core insulating portion 7p... and improving the reliability and stability of the transformer 1.

[0018] (6) In a preferred embodiment, one or both of the upper plate portion 7pu... and the lower plate portion 7pd... are formed wider in the front-rear direction Fs relative to the connecting plate portion 7pf..., 7pr..., and a pair of auxiliary plate portions 7pfs..., 7prs... are integrally formed outward from the end in the front-rear direction Fs, so that the auxiliary plate portions 7pfs..., 7prs... and the connecting plate portions 7pf..., 7pr... are formed in a continuous manner at a right angle, the strength and rigidity between the upper plate portion 7pu... and the lower plate portion 7pd... in the core insulating portion 7p..., and between the upper plate portion 7pu..., the lower plate portion 7pd... and the connecting plate portions 7pf..., 7pr... can be further increased by the rib effect.

[0019] (7) In a preferred embodiment, if locking edge portions 7px... are integrally formed on the core insulating portion 7p... at an outer position on one or both of the upper plate portion 7pu... and the lower plate portion 7pd..., the positioning between the coil unit 2 and the core insulating portion 7p... can be controlled, and the coil unit 2 can be stably held in a fixed position. [Brief explanation of the drawing]

[0020] [Figure 1] Cross-sectional front view of a transformer according to a preferred embodiment of the present invention. [Figure 2] Plan view of the coil unit and core insulation section that constitute the transformer. [Figure 3] Perspective view of the core insulation section of the transformer. [Figure 4] A partially broken plan view of the core insulation section of the transformer. [Figure 5]Side view of the core insulation part provided in the same transformer, [Figure 6] Front view of the core insulation part provided in the same transformer, [Figure 7] Cross-sectional front view of the state where each part of the same transformer is disassembled, [Figure 8] Explanation diagram of the operation of the core insulation part provided in the same transformer, [Figure 9] External perspective view showing the whole of the same transformer, [Figure 10] Cross-sectional front view of a transformer according to the prior art,

Modes for Carrying Out the Invention

[0021] Next, preferred embodiments according to the present invention will be given and described in detail based on the drawings.

[0022] First, the main components and basic structure of the transformer 1 according to the present embodiment will be described with reference to FIGS. 1 to 9.

[0023] The exemplary transformer 1 is a planar transformer used in a DC-DC converter, and converts a high voltage of about 400 [V] applied to the primary coil part C1 into a low voltage of about 12 [V] by the secondary coil part C2 and outputs it. For this reason, a high current of about 100 [A] flows through the secondary coil part C2 of the transformer 1.

[0024] The transformer 1 includes, as basic main components, a coil unit 2, a coil insulation part 5, a core part 6, and core insulation parts 7p and 7q.

[0025] In this case, the coil insulation part 5 includes a housing part that entirely covers with an insulating synthetic resin material. Note that this coil insulation part 5 also serves as a coil bobbin around which another coil 4 (primary coil part C1) described later is wound.

[0026] As shown in Figure 1, the example coil insulation portion 5 comprises a first housing portion 11 in which an outer peripheral surface portion 11o, an inner peripheral surface portion 11i, and a bottom surface portion 11m provided between the outer peripheral surface portion 11o and the inner peripheral surface portion 11i are integrally formed, and a second housing portion 12 in which a bobbin body portion 12s overlapping the outer peripheral surface of the inner peripheral surface portion 11i and a top surface portion 12u facing the aforementioned bottom surface portion 11m and covering the upper opening of the first housing portion 11 are integrally formed.

[0027] As shown in Figure 7, the coil unit 2 comprises a pair of single-turn sheet coils 3u and 3d, which are arranged in overlapping positions on the lower surface 2d of the bottom surface 11m of the first housing portion 11 and the upper surface 2u of the top surface 12u of the second housing portion 12.

[0028] As shown in Figures 1 and 2, these sheet coils 3u and 3d are rectangular conductors formed by punching out copper plates of a certain thickness (for example, about 1 mm), and constitute the secondary coil section C2 described above.

[0029] Furthermore, another coil 4 is arranged between the sheet coils 3u and 3d on the outer surface of the bobbin body 12s. The other coil 4 shown is a typical coil made by winding magnet wire (copper wire) multiple times, and constitutes the primary coil section C1 described above. Thus, the coil unit 2 is composed of the sheet coils 3u and 3d (secondary coil section C2) and the other coil 4 (primary coil section C1).

[0030] In this way, by applying the sheet coils 3u and 3d to the secondary coil section C2 and the other coil 4 to the primary coil section C1, a planar transformer and the like can be constructed, making it ideal for use in equipment such as DC-DC converters.

[0031] As shown in Figure 7, the core portion 6 is composed of an upper core half 6u and a lower core half 6d formed in an E shape from ferrite material or the like. When assembling to the coil unit 2, the upper core half 6u is attached from the direction of the arrow F3a, and the lower core half 6d is attached from the direction of the arrow F3d. As a result, the tips of the upper core half 6u and the lower core half 6d come into contact with each other, and a continuous magnetic path is formed by the upper core half 6u and the lower core half 6u.

[0032] The core insulating parts 7p and 7q constitute the essential parts of the present invention. As shown in Figures 3-6, the core insulating parts 7p and 7q are integrally molded from an insulating material using an elastic synthetic resin, and each is configured as a single component.

[0033] Since the core insulation parts 7p and 7q have the same shape, they can be manufactured as the same component, with one (left) used as core insulation part 7p and the other (right) as core insulation part 7q.

[0034] Thus, by integrally forming the core insulating portion 7p from an elastic synthetic resin material, it can be integrally molded by injection molding or the like, making it easy and low-cost to implement.

[0035] The core insulating portion 7p (and the core insulating portion 7q) are positioned opposite each other vertically and, as shown in Figures 1, 2, and 7, comprise an upper plate portion 7pu and a lower plate portion 7pd that grip the entire coil unit 2, including the aforementioned coil insulating portion 5, i.e., between the upper surface portion 2u and the lower surface portion 2d.

[0036] In this case, as shown in Figure 8, at least one (both in the example) of the upper plate portion 7pu and the lower plate portion 7pd is inclined with respect to the upper surface portion 2u and the lower surface portion 2d, so that the space between the tip 7pus of the upper plate portion 7pu and the tip 7pds of the lower plate portion 7pd is narrowed. The example shows a state inclined by a predetermined angle Qs. That is, the upper plate portion 7p and the lower plate portion 7d are not parallel surfaces, but are formed so that the tips 7pus and 7pds located on the coil unit 2 side are narrowed. If the upper plate portion 7pu and the lower plate portion 7pd are parallel surfaces, the position will be that of the dashed line in Figure 8, but by giving them a predetermined angle Qs, they will be that of the position shown by the solid line. Also, in Figure 8, the direction of the arrow F2a indicates the mounting direction of the core insulating portion 7p.

[0037] By providing an upper plate portion 7pu and a lower plate portion 7pd on the core insulating portion 7p, which grip the space between the upper surface portion 2u and the lower surface portion 2d, and by inclining at least one of the upper plate portion 7pu and the lower plate portion 7pd with respect to the upper surface portion 2u and the lower surface portion 2d, the space between the tip 7pus of the upper plate portion 7pu and the tip 7pds of the lower plate portion 7pd is narrowed, and the upper plate portion 7pu and the lower plate portion 7pd are pressed against the coil unit 2, the coil unit 2 can be stably held by the core insulating portions 7p and 7q, thereby preventing unnecessary rattling during the manufacturing process, contributing to improved quality, and further enhancing heat dissipation (heat transfer).

[0038] Furthermore, the core insulating portion 7p is provided with a pair of connecting plate portions 7pf and 7pr that connect the ends 7puf and 7pur in the front-rear direction Fs of the upper plate portion 7pu and the ends 7pdf and 7pdr in the front-rear direction Fs of the lower plate portion 7pd, respectively.

[0039] In this case, each connecting plate portion 7pf, 7pr is formed to protrude from the upper plate portion 7pu and the lower plate portion 7pd so as to be on the outside of the coil unit 2. As a result, as shown in Figures 2 and 9, the pair of connecting plate portions 7pf, 7pr can grip the end faces 6f, 6r of the core portion 6 in the front-rear direction Fs, respectively. By providing such connecting plate portions 7pf, 7pr, the positioning between the core insulating portion 7p and the core portion 6 can be reliably ensured, thereby increasing the strength and rigidity of the core insulating portion 7p and improving the reliability and stability of the transformer 1. In Figure 9, reference numeral 7qf indicates the connecting plate portion on the core insulating portion 7q side.

[0040] With the above configuration, the upper plate portion 7pu, the lower plate portion 7pd, and the connecting plate portions 7pf and 7pr form a frame-shaped core insulating portion 7p, and a notched through-space 7ps is formed in the middle of the core insulating portion 7p. In Figure 1, 7qs indicates the through-space on the core insulating portion 7q side.

[0041] Furthermore, as shown in Figure 3, one or both of the upper plate portion 7pu and the lower plate portion 7pd (the upper plate portion 7pu is an example) are formed wider in the front-rear direction Fs relative to the connecting plate portions 7pf and 7pr, and a pair of auxiliary plate portions 7pfs and 7prs are integrally formed from the ends in the front-rear direction Fs outward relative to the coil unit 2, and these auxiliary plate portions 7pfs and 7prs are formed continuously so as to be perpendicular to the connecting plate portions 7pf and 7pr.

[0042] By providing such auxiliary plate sections 7pfs and 7prs, the rib effect can further increase the strength and rigidity between the upper plate section 7pu and the lower plate section 7pd in the core insulating section 7p, and between the upper plate section 7pu, the lower plate section 7pd, etc., and the connecting plate sections 7pf and 7pr.

[0043] In addition, as shown in Figure 3, the core insulating portion 7p has a locking edge portion 7px integrally formed on one or both of the upper plate portion 7pu and the lower plate portion 7pd at a position on the outside relative to the coil unit 2, which restricts the position of the side surface of the coil unit 2.

[0044] By providing this locking edge portion 7px, positioning (position control) between the coil unit 2 and the core insulating portion 7p... can be performed, thereby stably holding the coil unit 2 in a fixed position.

[0045] Thus, the core insulating portion 7p is configured as a core insulating portion 7p that in contact with the upper surface 2u, lower surface 2d, and side surface 2s of the coil unit 2 and is formed in a U-shape to grip the coil unit 2, thereby insulating the inner surface of the core portion 6. In this case, by forming a notch in the middle of the core insulating portion 7p, the insulation between the core portion 6 and the coil unit 2 in the formed through space 7ps is also provided by the coil insulating portion 5 described above.

[0046] Furthermore, as shown in Figure 2, when the core insulating portion 7p is attached to the coil unit 2, the side portion 2s of the coil unit 2 is restricted by the locking edge portion 7px.

[0047] The above describes one core insulating section 7p in detail, but the other core insulating section 7q is used in the same way as the other core insulating section 7p, except that it is arranged symmetrically.

[0048] Next, the manufacturing method of the transformer 1 according to this embodiment will be described with reference to Figures 1-9.

[0049] First, the primary coil section C1 is manufactured. In this case, it can be manufactured by winding a magnet wire (copper wire) with a circular cross-section around the bobbin body section 12s of the second housing section 12. The second housing section 12 with the magnet wire wound around it is then housed in the first housing section 11, as shown in Figure 7.

[0050] Furthermore, one sheet coil 3u, which will become the secondary coil section C2, is assembled to the upper surface of the top surface 12u of the second housing section 12, i.e., the upper surface section 2u, and the other sheet coil 3d, which will become the secondary coil section C2, is assembled to the lower surface of the bottom surface 11m of the first housing section 11, i.e., the lower surface section 2d. This makes it possible to obtain the coil unit 2 shown in Figure 7, which is insulated by the coil insulation section 5.

[0051] Next, as shown in Figure 7, one core insulating part 7p is attached to the coil unit 2 from the direction of the arrow F2a, and the other core insulating part 7q is attached to the coil unit 2 from the direction of the arrow F2b. At this time, the coil unit 2 is sandwiched between the upper plate portion 7pu and the lower plate portion 7pd of the core insulating part 7p (and the same applies to the core insulating part 7q). As a result, after attachment, the upper plate portion 7pu and the lower plate portion 7p press against the upper surface portion 2u and the lower surface portion 2d of the coil unit 2, and the side portion 2s of the coil unit 2 faces the through space 7ps of the core insulating part 7p and is positioned by the locking edge portion 7px.

[0052] In this case, the positional relationship between the coil unit 2 and the core insulating part 7p is as shown in Figure 2. The arrow direction F1 indicates the mounting direction of the core insulating part 7p. The core insulating part 7p is formed as a frame by the through space 7ps, but the insulation of this part is also provided by the coil insulating part 5.

[0053] Next, as shown in Figure 7, the upper core half 6u is attached to the coil unit 2 from the direction of the arrow F3a, and the lower core half 6d is attached to the coil unit 2 from the direction of the arrow F3b. As a result, the tips of the upper core half 6u and the lower core half 6d come into contact with each other, forming a continuous magnetic path, and the end faces 6f and 6r of the upper core half 6u and the lower core half 6d are held between the connecting plate portions 7pf and 7pr, as shown in Figure 9, etc.

[0054] Next, the upper core half 6u and the lower core half 6d are fixed together by taping as shown in Figure 9. This allows the desired transformer 1 to be manufactured. In Figure 9, reference numeral 31 indicates the tape after taping.

[0055] Although preferred embodiments have been described in detail above, the present invention is not limited to these embodiments, and the details of the configuration, shape, materials, quantity, etc., can be arbitrarily changed, added, or deleted without departing from the spirit of the present invention.

[0056] For example, in this embodiment, the secondary coil section C2 is one coil section and the primary coil section C1 is the other coil section, but the primary coil section C1 may be one coil section and the secondary coil section C2 may be the other coil section. Furthermore, the embodiment has an upper plate section 7pu... and a lower plate section 7pd... that grips the space between the upper surface section 2u and the lower surface section 2d, and it is desirable to form the upper plate section 7pu... and the lower plate section 7pd... so that the space between the tip 7pus... of the upper plate section 7pu... and the tip 7pds... of the lower plate section 7pd... becomes narrow by inclining at least one of these upper plate section 7pu... and lower plate section 7pd... with respect to the upper surface section 2u and the lower surface section 2d, thereby pressing the upper plate section 7pu... and the lower plate section 7pd... against the coil unit 2, but this is not an essential component. Furthermore, although the example given illustrates a case where the core insulating portion 7p... connects the ends 7puf..., 7pur... in the front-rear direction Fs of the upper plate portion 7pu... and the lower plate portion 7pd... and protrudes outward from the coil unit 2, thereby providing a pair of connecting plate portions 7pf..., 7pr... that grip the end faces 6f, 6r in the front-rear direction Fs of the core portion 6, this can be replaced by other configurations having a similar function. On the other hand, the example given shows a case where one of the upper plate portion 7pu... and the lower plate portion 7pd... is formed wider in the front-rear direction Fs relative to the connecting plate portions 7pf..., 7pr..., and a pair of auxiliary plate portions 7pfs..., 7prs... are integrally formed outward from the end in the front-rear direction Fs, so that the auxiliary plate portions 7pfs..., 7prs... and the connecting plate portions 7pf..., 7pr... are formed in a continuous manner at a right angle. However, the auxiliary plate portions 7pfs..., 7prs... may be provided on both the upper plate portion 7pu... and the lower plate portion 7pd..., and are not necessarily essential components. In addition, the example given shows a case where a locking edge portion 7px... that restricts the position of the side surface of the coil unit 2 is integrally formed on the core insulating portion 7p... at an outer position on one of the upper plate portion 7pu... and the lower plate portion 7pd..., but the locking edge portion 7px... may be provided on both the upper plate portion 7pu... and the lower plate portion 7pd..., and are not necessarily required. In addition, although the primary coil section C1 is shown as being composed of two coil members, it may be one or three or more. In other words, it is generally applicable to various transformers having a primary coil section C1 having one or more coil members formed in a sheet shape and a secondary coil section C2 having one or more coil members formed in a sheet shape.Furthermore, this does not preclude the case where the coil insulation section 5 is insulated by other insulation methods, such as integrally insert-molding the entire structure with a synthetic resin material. [Industrial applicability]

[0057] This invention can be used in transformers for various applications, including planar transformers with a stacked primary and secondary coil configuration used in DC-DC converters and the like. [Explanation of Symbols]

[0058] 1: Transformer, 2: Coil unit, 2u: Top surface of coil unit, 2d: Bottom surface of coil unit, 2s: Side surface of coil unit, 3u: Sheet coil, 3d: Sheet coil, 4: Other coils, 5: Coil insulation, 6: Core, 6f: (Front) end face of core, 6r: (Rear) end face of core, 7p: Core insulation, 7q: Core insulation, 7ps...: Through space, 7pu …: Upper plate section, 7pd…: Lower plate section, 7pus…: Tip of upper plate section, 7pus…, 7pds…: Tip of lower plate section, 7pds…, 7pf…: Connecting plate section, 7pr…: Connecting plate section, 7pfs…: Auxiliary plate section, 7prs…: Auxiliary plate section, 7puf…: (Front) end of upper plate section, 7pur…: (Rear) end of upper plate section, 7px…: Locking edge section, C1: Primary coil section, C2: Secondary coil section, Fs: Front-rear direction

Claims

1. A transformer comprising a coil unit having sheet coils arranged on its upper and lower surfaces and other coils arranged between the sheet coils, a coil insulating part that insulates the entire coil unit, a core part that is mounted on the coil unit, and a core insulating part that insulates the core part and the coil unit, wherein the transformer comprises a pair of left and right core insulating parts formed in a U-shape that contacts the upper, lower and side surfaces of the coil unit and grips the coil unit, thereby insulating the core part and the coil unit, and the intermediate part of the core insulating part is formed in a notch shape, so that the insulation between the core part and the coil unit in the formed through space is also provided by the coil insulating part.

2. The transformer according to claim 1, characterized in that the sheet coil is applied to the secondary coil section and the other coil is applied to the primary coil section.

3. The transformer according to claim 1, characterized in that the core insulating portion is integrally formed from an elastic synthetic resin material.

4. The transformer according to claim 1, wherein the core insulating portion has an upper plate portion and a lower plate portion that grip the upper surface portion and the lower surface portion, and at least one of the upper plate portion and the lower plate portion is inclined with respect to the upper surface portion and the lower surface portion so that the distance between the tip of the upper plate portion and the tip of the lower plate portion is narrowed, and the upper plate portion and the lower plate portion are pressed against the coil unit.

5. The transformer according to claim 4, characterized in that the core insulating portion has a pair of connecting plate portions that connect the ends of the upper plate portion and the lower plate portion in the front-rear direction and protrude outward from the coil unit, thereby gripping the front-rear end faces of the core portion.

6. The transformer according to claim 4, characterized in that the core insulating portion is formed such that one or both of the upper plate portion and the lower plate portion are widened in the front-rear direction relative to the connecting plate portion, and a pair of auxiliary plate portions are integrally formed outward from the ends in the front-rear direction, so that the auxiliary plate portions and the connecting plate portion are formed in a continuous manner at a right angle.

7. The transformer according to claim 1, characterized in that the core insulating portion has a locking edge integrally formed on the outer position of one or both of the upper plate portion and the lower plate portion, which restricts the position of the side surface of the coil unit.

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