JPS5963705A - Transformer core - Google Patents

Abstract

PURPOSE:To contrive to reduce the loss of a transformer core by setting the rate of vacancies of the sintered body less than a specific ratio in an Mn-Zn series ferrite. CONSTITUTION:In the Mn-Zn ferrite for a transformer wherein an additive such as CaO, V2O5, or SiO2 is added according to desire to a composition of Fe2O3: 48-56, MnO: 32-40, and ZnO: 8-13mol%, the rate of vacancies of the sintered body is set less than 3.5%. Thereby, the loss of the transformer core can be reduced by reducing the hysteresis loss.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a low-loss 1-lance powder in which the porosity of the sintered body is reduced to 3.5% or less.

In general, Mn-2n type 71-i-i- is mainly used as a material for the core.The characteristics required for the core in this case are reduction of electromagnetic loss, and in particular, Transformer cores for switching power supplies have high frequencies, and reduction of loss is a critical issue.

Generally, transformer core loss is determined by the sum of eddy current loss, hysteresis loss, and residual loss. , among these losses Jn, eddy current losses are mainly caused by additives, such as ca, v, s
The reduction is reduced by increasing the Lee electrical resistance in addition to adding i, etc., and the hysteresis loss in the second term is
It is known that the porosity, crystal grain size, and different phases of the fired body vary depending on the J value. Therefore, in order to reduce hysteresis loss, it is necessary to take into consideration the manufacturing method. It's important.

Therefore, the present invention aims to reduce the porosity of Mn-Zn ferrite (by taking into consideration its manufacturing method), and by reducing the hysteresis loss. is divided by .

For example, in the M++ Zn-based ferrite, there is a magnetic head mill 1 which improves the addi- tivity or wear resistance by reducing the porosity of the fired body.However, the porosity and The relationship between loss at high frequencies has not been clarified.Roughly speaking, the major difference from the transformer 1 of the present invention is that the secondary peak temperature of magnetic permeability is raised. While the room temperature is close to 1, the operating temperature of the transformer (approximately 80°C) is approximately 80°C.

This is generally close to the second peak of magnetic permeability.'
This is due to the fact that the loss of is minimized: )'s (・There is.Furthermore, the magnetic head edition records the Buddhist name of ・ at high frequency.

Because it needs to be regenerated, high magnetic permeability is required at high frequencies. On the other hand, the 1-lance of the present invention] 77 does not require high magnetic permeability, for example, λ to 0.1 48 Z
'C-1,500 to 2,500 (there are some, but as mentioned above, the composition ranges of the two countries are of course different from each other due to the differences in the various characteristics ↑j1).

The present invention will be explained in detail below using examples.

Example 1 1 (: 2 Q 3 : 53.5'[%, M
nO: 36.01. le%.

/nQ: 10.5% and 0.1% CaO
Fa203, MnO, Zn so that wt%
O, Ca and CO3 were weighed and mixed. After that 700-1
Pre-calcined at 200℃, finely pulverized and compression molded to 1300~1
It was fired at 450°C.

Table 1 shows the results of measuring the properties of the fired body samples.

As is clear from the examples shown in Table 1-1, the transformer 1a of the present invention can reduce loss by reducing the porosity. In addition, when there is more than 3.5% of C, the loss of 1-lance-'a is not reduced, so the porosity is: 3.5
Ideally, it should be more than %.

Example 2 [0203: 52.5 mol%, M ++ Q:
37.0'Ele%.

Z ++ O: 10.5 mol% and CaO g, i
A sample was prepared in the same manner as in Example 1 in a bucket containing wt%.

11? Table 2 shows the properties of the samples obtained.

As is clear from Example J in Table 2 and above, similar to Example 1,
It can be seen that by decreasing the porosity, the loss of J:su1 to lance-1jv is reduced.

Example 3 1Te203: 53.5 mol%, MllO
: 34.5 mol%.

lnO: 12.0-El% and CaO to O,1
Samples were prepared in the same manner as in Example 1, and their properties were measured so as to achieve the same wt%. The measurement results are shown in Table 3.

As shown in Table 3 and above, it can be seen that by reducing the porosity as in Example 1, the J firing of the transformer core is reduced.

Example 4 For test #1 of A and C obtained earlier in Example 1, the loss value (loss) of transformer A versus frequency was measured. The results are shown in FIG.

From the figure, we can find out whether the intercept on the vertical axis corresponds to the hysteresis loss or not, by converting the value to n. i70 mw/C11
It can be seen that compared to the loss value of 13, the decrease in the porosity of the Sapota try-on IC results in a very small loss of about 280 mw/cm.

Furthermore, Figure 2 shows the results of measuring the temperature rise in both test slopes. As is clear from the figure, sample C with reduced porosity can avoid lowering the temperature Pi of i to lance nia 1 as much as possible compared to sample Δ.

As described above in Examples 1 to 4, when Mll-Z n-based No. 1 Lie 1- is used as a 1-lance core, low loss can be achieved by setting the porosity of the fired body to 3.5% or more. 1-
You can get a run score.

[Brief explanation of the drawing]

Figure 1 is!・The frequency reception ↑z1 of the loss of the Lance score is shown, and Figure 2 shows the temperature of the temperature of the 1~Lance 11A single unit. 7dQ(l
ap) 118=shi7g<t/z−$f;tr:→
(ζC (procedural amendment (voluntary) 11ii 1+'681i21^411111゛1 indication Showf, 1157?l"1. Purport'I Application No. 170549
'/; name of the invention Trans Core Ura 1
If you do 1, you get R+1・50B1 l'l +”/Josei Co., Ltd. J
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li, ,), day fko person i,...: place east μ; part charge 111 ku maru no 1 no da 1゛10 total 2 shi; ll+'/haku t1, ceremony and 1 phone Tokyo 284-4642 ``Detailed Description of the Invention'' column of the Lunar Elephant Specification by Hoichi. Contents of Supplement iE 1: All statements in the "Detailed Description of the Invention" column of the specification are corrected as follows. (1) In the first line of page 2 of the specification, "in the loss term" is corrected to "of the loss term." (2) Insert "ke" after "magnetic permeability" on page 3, line 8 of the same book. (3) On page 4, line 10 of the same book, "loss wo" is corrected to "loss wa."that's all

Claims (1)

[Claims] lc 203: to 48! 16. M II O:
32-40. ZnO: 8 to 13% of the composition, and the desired (trans IT with additives such as CaO, V2'Os, Si02, etc.) Mn-7n fly I-. and a low loss 1 to thin core, characterized in that the porosity of the sintered body is 3.j)% or less.