JPH0436088Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a transformer, and more specifically, to a transformer configured to effectively radiate heat generated by copper loss.

[Prior Art] A transformer has been put into practical use as a method of changing voltage using mutual induction.

Although this transformer has a large or small capacity, its structure has a high saturation density.The primary coil and secondary coil are wound around a core (magnetic core) made of a material with high magnetic permeability and low core loss. It is well known as a device that increases or decreases the voltage applied to the primary coil depending on the turns ratio of the secondary coil.

Since a transformer has no rotating parts, there is no mechanical loss such as friction, but there is iron loss that occurs in the iron core and copper loss that occurs due to the current flowing in the primary and secondary windings.

When the transformer is operated, the temperature of the transformer increases due to the aforementioned iron loss occurring in the iron core and copper loss occurring due to the current flowing through the primary and secondary coils. As this temperature rises, the insulation used in the transformer changes or deteriorates, resulting in a decrease in dielectric strength, viscosity, flash point, etc.

Methods for cooling the temperature that rises due to the operation of a transformer include natural cooling, air-cooled dry cooling methods, natural cooling, There are air-cooled, water-cooled, oil-filled air-cooled, oil-filled water-cooled, and gas-filled types.

[Problems to be solved by the invention] Although these cooling methods are generally applied to large-capacity transformers, they are not suitable for transformers installed in electronic devices because they do not comply with the miniaturization of devices.

A power transformer that drives a large number of ICs, such as the calculation part of a computer, generally has a low secondary voltage and supplies a large secondary current of several 100 A, so heat generation due to copper loss in the secondary winding is particularly significant. As a countermeasure, wind cooling and water cooling methods were introduced, but the structure became complicated and was not desirable.

The object of this invention is to provide a transformer configuration that efficiently dissipates heat generated by copper loss in the above-mentioned transformer with low voltage and large load current.

[Means for Solving the Problems] The purpose of this invention described above is to provide a cylindrical body formed of a metal member with good thermal conductivity and provided with a gap for preventing shot ring, and a cylindrical body integral with the cylindrical body. A thermally conductive bobbin having mounting legs for attaching the shaped body to a heat sink, etc., a secondary or primary coil wound on the cylindrical body of the bobbin, and a primary or secondary coil wound on the coil. and a core inserted into the cylindrical body.

[Function] This transformer applies, for example, 100V to the primary coil, and reduces the applied voltage by, for example, 1/
The heat generated by the copper loss caused by lowering the voltage to 40A and passing a relatively large current such as a secondary load current of about 200A can be dissipated from the cylindrical body with good thermal conductivity through the mounting leg itself. Heat can be dissipated efficiently by dissipating heat to the heat sink attached to the.

[Example] As shown in Fig. 1, the transformer of this invention uses a metal with good thermal conductivity such as aluminum or copper, and uses die casting or other methods to form a top plate 1.
From both ends of the lower plate 14 of the cylindrical body 11 having a rectangular cross section, which has a stop ring prevention gap 13 at 2, the crank is 2 to 3 times thicker than the thickness of the upper plate 12 and the side plates 15, including the lower plate. A heat-conducting bobbin 1 is produced in which shaped mounting legs 16 are integrally formed on both ends of a bottom plate, and the gap 13 is closed with an insulating spacer 17.

First, a secondary coil 2 capable of withstanding a large current with an allowable current of about 200 A is mounted on the heat-conducting bobbin 1 with a relatively small number of turns on a cylindrical body 11 with an insulating film 3 interposed between the layers, as shown in FIG. Wind.

Next, the primary coil 4 is wound around the outer surface of the secondary coil 2 with a number of turns 40 times (or 20 times) the number of turns of the secondary coil, and a band is placed over the primary coil 4 as shown in Fig. 2. Concluded in 5.

Two sets of transformer assemblies 6 constructed in this manner are prepared as shown in FIG. 2, and cut cores 7, each having a C-shape, for example, shown in FIG. As shown in the figure, a band 8 is attached and fastened around this core.

The primary coil 4 and each transformer assembly 6 may be wound separately like the secondary coil 2, or may be wound continuously as in the embodiment. Further, the core 7 may be any core that forms a closed magnetic path, such as a well-known EI core.

The transformer T thus formed is the seventh
As shown in the figure, heat generated by copper loss generated in the secondary coil 2 can be dissipated by attaching it to the heat sink 9 with the mounting legs 16. Furthermore, although two transformer assemblies 6 are used in the embodiment, only one transformer assembly 6 may be used as shown in FIG. 5, and an external iron type transformer TA may be formed using the E-E core 7A. .

The transformer of this invention is constructed as described above, and by inputting commercial power, for example, 100V (AC), 5.2A, 520W between the leads 41 and 42 of the primary winding 4, the leads of the secondary coil 2 are connected. between 23
Can obtain output of 2.5V, 200A, 500W approximately
A loss of 20W (mainly copper loss) occurs.

The Joule heat generated by this copper loss is transferred to the heat conduction bobbin 1.
The heat is radiated and cooled through the mounting leg 16 itself or the heat sink 9 which is heat-transferably attached to the mounting leg 16.

Note that the heat sink 9 is not necessarily required, and if the mounting legs 16 are made large and provided with fins, the mounting legs 16 can be
It can radiate heat by itself.

In addition, if the secondary coil 2 is a relatively high voltage transformer with a large number of turns and is designed to require a small current, the primary coil 4
may be wound first, and then the secondary coil 2 may be wound on top of this primary coil 4. In this case, the primary coil 4
Heat generation due to copper loss due to relatively large current flowing through the heat conduction bobbin 11, mounting legs 16, and heat sink 9
Heat can be radiated through the

[Effects of the invention] As mentioned above, this invention adopts a means to solve the above problems, so it is possible to use a bobbin made of a material with high thermal conductivity to radiate heat directly through the mounting legs or to the heat sink 7. By winding the secondary coil or primary coil, through which a large current flows, close to the heat conduction bobbin, the heat dissipation effect is extremely large, and the copper loss caused by outputting a large current is This has the effect of efficiently dissipating the generated heat.

[Brief explanation of drawings]

The figures all show one embodiment of this invention. Figure 1 is a perspective view of a heat conduction bobbin, Figure 2 is a perspective view of a transformer assembly, Figure 3 is a perspective view of a cut core, and Figure 4 is a perspective view of a cut core. FIG. 5 is a perspective view of the transformer, and FIG. 6 is a plan view showing another example of the transformer according to this invention.
This figure is an enlarged cross-sectional view of the device shown in FIG. 2, and FIG. 7 is a perspective view of the device attached to a heat sink. 1... Heat conduction bobbin, 11... Cylindrical body, 13...
...Gap for preventing shot ring, 16...Mounting leg, 2...Secondary coil, 3...Insulating film, 4
...Primary coil, 6...Transformer assembly, 7...
Core, 9...heat sink, 17...insulating spacer.

Claims (1)

[Scope of utility model registration request] A cylindrical body 11 made of a metal member with good thermal conductivity and having a shot ring prevention gap 13
, a thermally conductive bobbin 1 that is integral with the cylindrical body 11 and has a mounting leg 16 for attaching the cylindrical body to another member such as a heat sink 9; and a cylindrical body 11 of the bobbin 1.
Secondary coil 2 or primary coil 4 wound on top
A transformer comprising: a primary coil 4 or a secondary coil 2 wound on the coil; and a core 7 inserted into the cylindrical body 11.