JPH03218002A - How to install reactor transformer - Google Patents

Abstract

PURPOSE:To reduce the electromagnetic sound of a reactor transformer by making an I-type iron core be the lower side, making an E-type iron core be the upper side, and fixing the outside surface of the I-type iron core on the fixing part of a reactor transformer. CONSTITUTION:A base board 27 is fixed to the outside surface of an I-type iron core 26 by welding or the like. The base board 27 is fixed to a bottom plate of an outdoor main apparatus via fixing holes 28, and a reactor transformer 21 is fixed. Thereby the I-type iron core 26, which vibrates more easily than the E-type iron core 22, can be fixed to the outdoor main apparatus, so that the resonance of the I-type iron core 26 caused by the change of magnetic flux can be reduced. As a result, the electromagnetic sound of the reactor transformer can be reduced without increasing manhours and cost.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> QB8 No. 2 relates to a method of installing a reactor transformer that can sufficiently suppress thunder-magnetic noise.

Conventionally, there is a reactor transformer mounting device for improving the power factor of an inverter in an inverter air conditioner as shown in FIGS.
34). This reactor transformer l is roughly composed of an iron core part 2, a coil part 3, and a mounting bracket 4. When attaching this reactor transformer l to the board 7, a highly elastic bumping 5 is installed at the tip of the mounting bracket 4, and the reactor transformer 1 is indirectly connected to the board 7 via the mounting screw 6 through the bumping 5. I am trying to attach it to the target.

Therefore, even if the coil portion 3 in the reactor transformer 1 is energized and the iron core 2 undergoes electromagnetic vibration, the vibration of the iron core 2 is absorbed by the bushing 5 and is not transmitted to the substrate 7. Therefore, vibration and vibration noise of the air conditioner main body are reduced.

<Problems to be Solved by the Invention> As mentioned above, in a conventional installation with a glue reactor transformer, the reactor transformer l is indirectly attached to the substrate 7 via the elastic spring 5. Therefore, the vibrations and vibration noise of the air conditioner main body due to the vibrations of the iron core 2 are certainly reduced. However, since no measures have been taken to prevent vibrations occurring in the iron core 2,
There is a problem in that electromagnetic noise from the iron core 2 cannot be prevented when electricity is applied. Further, there is a problem in that attempting to block electromagnetic noise from the iron core portion 2 increases the number of man-hours, leading to an increase in cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for attaching a reactor transformer that can reduce electromagnetic noise of the reactor transformer without increasing man-hours or costs.

Here, the mechanism of electromagnetic sound generation in the reactor transformer will be described with reference to FIG.

In FIG. 3, 12 is an E-type iron core, and 16 is an I-type iron core. The E-shaped iron core 12 having an E-shaped vertical cross section has a central portion l4 around which a winding is wound at the center of the base portion 13. Furthermore, the base l3 has arms l5.15 extending along the central axis l4 at both ends. At the tips of the arm bodies 15, 15 of the E-type iron core l2, there is a center line l4 of the E-type iron core l2.
The I-type iron core l6 is arranged and attached so as to face the tip of the iron core l6. At that time, the tip of the central part l4 of the E-type iron core I2 and
A gap is provided between the mold iron core l6.

In this way, by providing a gap between the coil part of the E-type iron core 12 and the ■-type iron core l6, when the magnetic flux reaches a saturated state, the magnetic flux leaks from the gap part and the inductance of the reactor transformer is reduced. It can be kept constant.

When the coil section is energized, the vector of the generated magnetic flux changes its magnitude and direction depending on the higher-order harmonic components of the current while keeping its direction constant, as shown in FIG. Then, as shown in FIG.
As shown in the figure, resonance occurs in the I-type iron core l3 due to the secondary mode of the support beams at both ends, causing electromagnetic vibration. As a result, as shown in the acoustic intensity analysis results of FIG. 6, electromagnetic sound is radiated upward from the I-type iron core l3. At this time, the level of radiated sound accompanying vibration (resonance) becomes extremely high, especially near the resonance frequency of the ■-shaped iron core 13 (near 7.3 KHz).

<Means for Solving the Problems> In order to achieve the above object, the present invention has arm bodies 23, 23 on both sides of the central part 24 around which the coil 25 is wound, as illustrated in FIG. an E-shaped iron core 22 having an E-shaped vertical cross section; and the central portion 2 of the E-shaped iron core (22).
Both arm bodies 23 are arranged so as to face the tips of 4 with a gap in between.
．． 23 and an I-shaped iron core 26 having an I-shaped longitudinal section attached to the tip of the reactor transformer, the I-shaped iron core 26 is placed on the lower side, while the E-shaped iron core 22 is on the upper side, and the outer surface of the I-type iron core 26 is fixed to the attachment part of the reactor transformer 21.

<Function> Compared to the E-type iron core 22, the I-type iron core 26 is weaker in rigidity7, but when the I-type iron core 26 is placed on the lower side, the outer surface of the ■-type iron core 26 is attached to the mounting part. Because of the attachment, the rigidity of the I-type iron core 26 is increased, and as a result, the electromagnetic vibration of the I-type iron core 26 is reduced.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 is a diagram showing the appearance of a reactor transformer attached to an outdoor unit of an air conditioner according to the present invention in order to improve the power factor of the inverter in the inverter air conditioner. This reactor transformer 21 is roughly constituted by an E-shaped iron core 22 having an E-shaped vertical cross section and an I-shaped iron core 26 having a ■-shaped vertical cross-section. The central portion 24 protrudes from the center of the base 29 of the E-shaped iron core 22, while the arms 23.
23 will be provided. A coil 25 is then wound around the center wI24. Furthermore, a ■-shaped iron core 26 is attached to the tips of both arms 23.23 of the E-shaped iron core 22 by welding or the like, facing the tip end surface of the central portion 24. At that time, the central part 2
A gap is provided between the tip of 4 and the side surface of the ■-shaped iron core 26.

A substrate 27 is attached to the outer surface (lower surface in FIG. 1) of the I-type iron core 26 by welding or the like, and a mounting hole 28 is provided in the substrate 27. Then, the reactor transformer 21 is attached to the outdoor unit main body by temporarily fixing the board 27 to the bottom of the outdoor unit main body with bolts or the like through the mounting holes 28.

That is, the method of attaching the reactor transformer in the present invention is to reverse the conventional method of attaching the E-type iron core 22 to the outdoor unit body and attach the I-type iron core 26 to the outdoor unit body.

By doing this, the I-type iron core 26, which is less susceptible to vibration than the E-type iron core 22, can be fixed to the outdoor unit body via the board 27, and the resonance of the I-type iron core 26 due to changes in magnetic flux density can be suppressed. It can be reduced.

At that time, the base 29 of the E-shaped iron core 22 due to changes in magnetic flux density.
However, due to the longitudinal cross-sectional shape of the E-type iron core 22, the rigidity of the base portion 29 is high and resonance is difficult to occur.

FIG. 2 shows the sound pressure level frequency characteristics of noise when the reactor transformer 21 is attached to the outdoor unit main body by the method described above. In FIG. 2, the thick solid line is the sound pressure level frequency characteristic in this embodiment, and the broken line is the sound pressure level frequency characteristic in the conventional reactor transformer mounting method. Note that the measurement of the sound pressure level was carried out by installing a microphone at a position 50n++n above the center of the E-type iron core 22. From Figure 2, it shows that ■
The sound pressure level near the resonant frequency of the molded iron core 26 (near 7.3K}12) was reduced by about 7 dB, proving that the reactor transformer mounting method in this example is effective.

As described above, in this embodiment, when attaching the reactor transformer 21 to the outdoor unit body of the air conditioner, the E-type iron core 22 constituting the reactor transformer 21 is placed on the upper side, and the ■-type iron core 26 is placed on the lower side. A square iron core 26 forming a gap with the tip of the coil 25 in the E-shaped iron core 22 is fixed to the outdoor unit body. Therefore, electromagnetic noise can be reduced by eliminating electromagnetic vibration of the l-shaped iron core 26 due to changes in magnetic flux density due to higher-order harmonic components of the current.

In the embodiments described above, a method for installing a reactor transformer in an inverter air conditioner is explained as an example, but the reactor transformer according to the present invention is not limited to a reactor transformer in an inverter air conditioner.

<Effects of the Invention> As is clear from the above, the reactor transformer mounting method of the present invention is applicable to the reactor transformer described above, which is composed of an E-shaped iron core and a ■-shaped iron core, each having a central portion around which a coil is wound. The E-type iron core is on the upper side, while the I-type iron core is on the lower side, and the outer surface of the I-type iron core, which is less likely to vibrate than the E-type iron core, is fixed to the attachment part of the reactor transformer. ,
It is possible to prevent electromagnetic vibrations caused by changes in magnetic flux caused by higher-order harmonic components of current, and it is possible to reduce electromagnetic noise from reactor transformers without increasing man-hours or costs.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of the appearance of a reactor transformer installed by the reactor transformer installation method of the present invention, Fig. 2 is a sound pressure level frequency characteristic diagram of the reactor transformer shown in Fig. 1, and Fig. 3 is a diagram showing the reactor transformer. A magnetic flux vector diagram in a transformer, FIG. 4 is an explanatory diagram of electromagnetic excitation force according to FIG. 3, FIG. 5 is an explanatory diagram of electromagnetic vibration according to FIG. 4, and FIG. 6 is an explanatory diagram of electromagnetic vibration according to FIG.
This figure is a diagram showing an example of the sound intensity analysis result according to FIG. 5, and FIGS. 7 and 8 are explanatory diagrams of a conventional method of attaching a reactor transformer. 21...Reactor transformer, 22...E-type iron core, 23...Arm body, 24
...Central part, 25...Coil, 26.
... I-type iron core, 27... Board.

Claims (1)

[Claims] (1) An E-shaped iron core (22) having arms (23, 23) on both sides of the central part (24) around which the coil (25) is wound and an E-shaped longitudinal section; I attached to the tips of the arms (23, 23) so as to face the tips of the central portion (24) of the iron core (22) with a gap therebetween;
A method of installing a reactor transformer constituted by an I-shaped iron core (26) having a vertical cross section of
A method for attaching a reactor transformer, characterized in that the outer surface of the I-type iron core (26) is fixed to the attaching part of the reactor transformer (21) with 22) facing upward.