WO1997009728A1

WO1997009728A1 - Encased magnetic core

Info

Publication number: WO1997009728A1
Application number: PCT/JP1996/002426
Authority: WO
Inventors: Norio Matsumoto
Original assignee: Mitsui Chemicals, Inc.
Priority date: 1995-09-01
Filing date: 1996-08-29
Publication date: 1997-03-13
Also published as: EP0848392A4; TW340946B; CA2230276A1; EP0848392A1

Abstract

An encased magnetic core (10) comprising a core (11) housed in a case (12) and powder (13) packed at least partially in the gap between the core and the case. The powder is preferably a nylon resin, or powder of silica particles coated with silicone oil.

Description

Specification

Case storage type magnetic core

The present invention relates to a case storage type magnetic core, for example, to a case storage type magnetic core used for a magnetic component used in an electronic circuit. Background art

For a magnetic component that is formed by forming a coil around a magnetic core around a wire wound wire, use a wire with an insulation coating as the coil to prevent short-circuiting of the coil during coil formation. .

The wire wound around this core has a harder core than the insulation coating applied to the wire, so if the wire is wound directly around the core, the insulation coating on the wire may be damaged during the winding, resulting in a short circuit. .

In order to prevent such insulation coating from being damaged, it is necessary to store the magnetic core in a resin case and then form a coil in that case, or to wind the coil around a resin bobbin in advance. After that, the bobbin is attached to the magnetic core.

Which of the above methods is used to protect the insulating coating is selected according to the shape of the target magnetic core.

For example, in the case of a magnetic core using a magnetic alloy ribbon, the former method is adopted because the shape of the magnetic core is substantially annular.

By the way, when storing the magnetic core in the case, unless the magnetic core is fixed to the case, the magnetic core moves in the case during transportation and collides with the case wall.

When the magnetic core collides with the case wall in this way, stress may act on the magnetic core, causing the magnetic core to break or deteriorating the magnetic properties of the magnetic core.

In addition, the impact can propagate to other components, adversely affecting that component.

Furthermore, the impact of the collision may cause the soldered part of the coil to peel off. What

Therefore, in order to form a case storage type magnetic core, it is necessary to prevent the magnetic core from moving in the case in order to ensure the reliability as a magnetic component.

Here, in order to prevent the movement of the magnetic core in the case, a method of making the dimensions of the inner wall of the case the same as the outer dimensions of the magnetic core is considered.

When a coil is formed by winding a wire around such a case storage type magnetic core, the case may be wound around the wire and deformed, and stress may be applied to the magnetic core.

In addition, since the magnetic core is in direct contact with the case, vibration of the magnetic core is easily transmitted to the case, and a large noise is generated when the magnetic core is excited.

For this reason, as a means to prevent the generation of noise, it has been customary to prepare a case with an inner diameter larger than the outer shape of the magnetic core, and then fill or apply the adhesive to the gap between the case and the magnetic core. Has been done.

On the other hand, if the case is significantly larger than the core, the magnetic flux in the gap between the core and the case must be considered.

Therefore, a case slightly larger than the magnetic core is used in the production of such a case storage type magnetic core.

As described above, in the past, the gap between the magnetic core and the case was filled or applied with an adhesive to prevent the movement of the magnetic core in the case 內 and the propagation of the vibration of the magnetic core to the case.

However, when an adhesive is used, when the temperature inside the case becomes higher than room temperature, the adhesive fixing the case and the magnetic core expands.

Therefore, depending on the filling amount or application amount of the adhesive, there is a problem that the vibration absorbing power of the adhesive is lost due to distortion caused by the volume increase due to the expansion of the adhesive.

An object of the present invention is to provide a case storage type magnetic core that has high reliability as a magnetic component and generates little noise. Disclosure of the invention

A first feature of the present invention includes (a) a magnetic core, (: b) a case for accommodating the magnetic core, and (c) a powder at least partially filled in a gap between the magnetic core and the case. It is a case storage type magnetic core.

In other words, the case and the magnetic core are fixed by filling the gap between the case and the magnetic core with powder, while preventing the loss of the vibration absorbing force due to the use of the adhesive, and the vibration of the magnetic core is transmitted to the case. To prevent or suppress.

Here, the filling rate of the powder filling the gap between the magnetic core and the case is, for example, in the range of 1% to 150%, preferably 10% to 150%, more preferably 10% to; %, Most preferably 10% to 100%.

The powder filling rate was calculated by the following equation.

Powder mass (: g

Filling factor (%) - 1 0 0 clearance volume ^[cm: '] bulk density of X powder [g / cm ^3]

Here, the bulk density [g / cm ³ ] of the powder was measured according to ASTM D1895-69.

Further, the case storage type magnetic core according to the present invention can use either magnetic or non-magnetic powder.

Next, a second feature of the present invention is that the case-containing magnetic core has a maximum value of the minor axis of the powder to be filled in a range of 5 m to 500 m.

The maximum value of the minor axis of the powder to be filled is preferably in the range of 100 m to 400;

Here, the minor axis of the powder is the diameter of a pearl-shaped (circular cross-section) powder, and the shortest diameter of an irregular-shaped powder such as an elliptical cross-section. Refers to the diameter.

Next, a third feature of the present invention is that the powder is a case storage type magnetic core having a sily force in which a nylon resin or silicone oil is adhered to the periphery thereof.

The powder used is, for example, polyolefin powder such as polyethylene, polypropylene and polymethyl ', alumina powder, silicon dioxide powder, etc. You can also.

Next, a fourth feature of the present invention is that the case is a case storage type magnetic core having a closed structure.

Therefore, in the case storage type magnetic core according to the present invention, noise caused by vibration of the magnetic core can be isolated by sealing the magnetic core with the case.

Next, a fifth feature of the present invention is that a case storage type magnetic core is used in which the magnetic core is made of an amorphous magnetic alloy ribbon.

The case storage type magnetic core is applicable to magnetic cores made of various materials such as an amorphous alloy (for example, Fe-based amorphous alloy), gay steel, ferrite, and dust. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an explanatory diagram showing the configuration of the case storage type magnetic core of the present invention.

FIG. 2 is an explanatory diagram showing an outline of a noise measurement test of a case storage type magnetic core.

FIG. 3 is a waveform diagram of the excitation signal supplied to the coil during the noise measurement test.

FIG. 4 is a diagram showing the test results for each case storage type magnetic core.

FIG. 5 is a graph in which the noise level of each case-storing magnetic core is plotted against the powder filling rate. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(Example 1)

First, an outline of a case storage type magnetic core according to the present embodiment will be described based on FIG.

Here, FIG. 1 is an explanatory diagram showing the configuration of the case storage type magnetic core of the present invention. The case storage type magnetic core 10 according to the present embodiment includes a magnetic core 11, cases 12, 12 ₂ , and powder 13 as shown in FIG.

Next, the magnetic core 11 is accommodated in the case 12 and the powder 13 is filled in the gap between the magnetic core and the case.

Hereinafter, the configuration and performance of the case storage type magnetic core according to the present embodiment will be described with reference to FIGS. g. Specific explanation based on 5.

Here, FIG. 2 is an explanatory diagram showing an outline of a noise measurement test of the case-stowed core, and FIG. 3 is a waveform diagram of an excitation signal supplied to the coil during the noise measurement test ₍ The magnetic core 11 used in this case-storing type magnetic core is an amorphous magnetic alloy ribbon that is a Fe-based amorphous alloy including Si and B (manufactured by Allied Signal Inc., product name: Metg 1 as 26 05 S—2, [Circular wound body with outer diameter 27. Omm, inner diameter 15.0 mm, height 10.0 mm formed by composition F e τ _δ ,, ₃ S i ₉ (] Used at about 470 ° C.

The case 12 has an outer diameter of 27.7 mm, an inner diameter of 14.7 mm, and a height of 10.3 mm (both inner dimensions) (manufactured by Toray Industries, trade name: 1184 G— 3 0.) is used.

The powder 13 filled into the gap between the magnetic core 11 and the case 12 is made of nylon resin powder (manufactured by Sumitomo Seika Co., Ltd., product name: Floron) whose maximum diameter is 180, Two types of powders are used, such as a powder with silicone oil attached to the periphery of a sily force with a maximum value of 300 zm (Toray Dow Corning 'Silicone, product name: Trefil).

Using these, several types of case storage cores having different powder filling rates were produced.

Next, in this case storage type core, a coil was formed by winding 31 mm of a 1. Omm0 magnetic wire around each of the case storage type cores manufactured by the above-described process to form a sample for evaluation.

For the evaluation samples, a fixed test was performed to evaluate the reliability of each sample as a magnetic component, and a noise measurement test was performed to evaluate the noise level during operation. Hereinafter, details of each test method will be described.

First, the fixing test was carried out by supporting the case-retained core by hand and shaking it strongly in a direction parallel to the laminated cross section of the core.

Next, in the noise measurement test, as shown in FIG. 2, when the excitation signal is supplied to the coil 15 wound around the case-mounted magnetic core 10, the case-mounted magnetic core 10 is generated. The noise level was measured by measuring the noise level with a microphone 21 installed at a position 200 mm away from the center of the case storage type magnetic core 10.

The sound pressure level at which the center frequency of the 1/3 octave band measured via the microphone 21 is 10 kHz is defined as the noise level, and the sound level depends on whether or not the noise level is 45.0 dB or less. The pass / fail of the noise measurement test was determined.

The target value of 45.0 dB is based on the noise level that is clearly lower than the noise level of 58.0 dB in case-mounted magnetic cores using adhesive. It is.

As the excitation signal supplied to the coil 15, a current value and a 500-20000 Hz sweeping sine wave varying between 0 and 6 A are used as shown in FIG. The evaluation of each sample was mainly performed at room temperature, and some samples were also evaluated at a high temperature of 110 ° C.

Hereinafter, the evaluation results of the case storage type magnetic cores will be described based on FIGS.

Here, Fig 4 is a diagram showing the evaluation results of each sample in a tabular format, and Fig 5 is a diagram plotting the relationship between the noise level and the filling factor of each sample by the powder used. is there.

As shown in Fig 4, Samples 1 to 3 used nylon resin powder among the 10 types of samples prepared, and Samples 4 to 10 used silicon powder with silicone oil adhered to the periphery. Using.

First, in Sample 1, the fixing test and the noise level were measured with the filling rate of the nylon resin powder calculated by the above filling rate calculation formula being 10.6%.

As a result, the fixed test passed and the noise level was 34.9 dB, meeting the target value.

Next, in Sample 2, the fixing test and the noise level were measured at room temperature and at a high temperature of 110 with the filling rate of the nylon resin powder being 24.5%.

As a result, both the room temperature and the high temperature of 110 ° C passed the fixed test, and the noise level was 35.9 dB, meeting the target value.

In sample 3, the filling rate of nylon resin powder was set to 49.7%, And noise levels were measured.

As a result, the fixed test passed and the noise level was 43.5 dB, clearing the target value.

Therefore, in the test using the nylon resin powder, all the samples fell below 45.0 dB, meeting the target value.

Next, in Sample 4, the fixing test and the noise level at room temperature and at a high temperature of 110 ° C were measured with the silica powder filling rate being 30.0%.

In sample 5, the fixing test and the noise level were measured at a silica powder filling rate of 50.0%.

As a result, the fixed test passed, and the noise level was 32.8 dB, meeting the target value.

In sample 6, the fixing test and the noise level were measured at a silica powder filling rate of 60.0%.

As a result, the fixed test passed, and the noise level was 32.9 dB, meeting the target value.

Next, for Sample 7, the fixing test and the noise level were measured with the filling rate of the powdered sily powder set to 70.0%.

As a result, the fixed test passed, and the noise level was 32.1 dB, meeting the target value.

For sample 8, the fixing test and the noise level were measured at a silica powder filling rate of 80.0%.

As a result, the fixed test passed, and the noise level was 36.2 dB, meeting the target value.

For sample 9, the fixing test and the noise level were measured with the filling ratio of the powdered silicon powder being 90.0%.

As a result, the fixed test passed and the noise level was 32.3 dB, meeting the target value. For sample 10, the fixing test and the noise level were measured at a silica powder filling rate of 100.0%.

As a result, the fixed test passed and the noise level was 34.3 dB, meeting the target value.

Therefore, in the test using silica powder, all the samples were 45.0 dB or less, meeting the target value.

That is, it was found that by filling the gap between the magnetic core and the case with the powder, the noise generated from the magnetic core and the movement of the magnetic core in the case could be effectively suppressed. As described above, if the powder is filled between the case and the magnetic core, a case storage type magnetic core having high reliability as a magnetic component and low noise is obtained. Furthermore, as is clear from the test results at 110 ° C performed on Samples 2 and 4, this case-stowed core can be used stably even at high temperatures.

From the evaluation results for each sample, the powder filling rate is preferably in the range of 1% to 150%, particularly preferably 10% to; L50% is more preferable, and 10% to 120% is more preferable. Preferably, 10% to 100% is most preferred.

The maximum value of the minor axis of the powder used in the present invention is preferably in the range of 5 to 500, particularly preferably in the range of 100 to 400 m. Industrial applicability

ADVANTAGE OF THE INVENTION Since the case storage type magnetic core of this invention can prevent or suppress both the movement of the magnetic core in a case, and the propagation of the vibration of a magnetic core to a case, the reliability as a magnetic component is high, and In addition, a case storage type magnetic core with low noise generated during use can be obtained.

Further, since the case storage type magnetic core of the present invention does not use an adhesive, the vibration absorbing force is not lost even when used at a high temperature.

Therefore, according to the present invention, a case storage core having a wider usable temperature range than the conventional case storage core can be obtained.

Claims

(A) a magnetic core;

(b) a case for storing the magnetic core,

(: C The powder is at least partially filled in the gap between the magnetic core and the case.

A case storage type magnetic core characterized by the following.

2. The case storage core according to claim 1, wherein the maximum value of the minor axis of the powder is in a range of 5 / m to 500〃m.

3. The case storage type magnetic core according to claim 1, wherein the powder is made of a nylon resin.

3. The case storage type magnetic core according to claim 1, wherein the powder is silica having silicone oil adhered to the periphery thereof. 5. The case storage type magnetic core according to claim 1, wherein the case has a closed structure.

6. The case storage type magnetic core according to claim 1, wherein the magnetic core is made of an amorphous magnetic alloy ribbon.