JPH02138712A - Transformer - Google Patents

Abstract

PURPOSE:To make it possible to assemble without using gap paper by a method wherein an E-type laminated iron core, on which a coil is wound on the center magnetic leg, and an I-type laminated iron core provided with a recessed part larger than the center magnetic leg are butted together. CONSTITUTION:When an E-type laminated iron core laminated plate 2, on which a coil 1 is wound on the center magnetic leg 3, and an I-type laminated iron core laminated plate, provided in the center part with the recessed parts 6 and 7 which are larger than the magnetic leg 3, are butted together, a transformer, having the self-inductance and self-impedance same as the one obtained when gap paper is used, can be assembled easily and reliably, and also the transformer can be assembled automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a transformer used in various audio equipment, video equipment, industrial equipment, and the like.

BACKGROUND OF THE INVENTION FIG. 6 shows an assembled diagram of a laminated core of a conventional transformer, and FIG. 7 shows a cross-sectional view of a transformer using a conventional laminated core as seen from the side. Also, Figures 8 and -6 show reference examples of conventional ferrite core assembly methods, and Figures 9a and -a
1 shows an example of a conventional method for assembling a laminated iron core.

Furthermore, FIG. 10 shows a change curve of self-impedance and self-inductance when direct current is passed through the transformer.

Transformers are used in a wide variety of ways, depending on their use and purpose. - For example, a commercial power transformer for converting commercial power, an impedance matching transformer for transmitting signals between circuits, or a low frequency transformer for direct current separation of circuits and for converting voltage and current; The reality is that switching transformers that convert high-frequency pulsed power are used in so many ways that it is impossible to list them all.

Naturally, the required electrical performance varies depending on the purpose of use, and among these, the core material and core assembly method have the greatest effect on electrical performance. In the power supply transformer, silicon steel having a high magnetic flux saturation density is used, and the E-type iron core 2 and the working-type iron core 5 are alternately inserted and assembled as shown in FIG. 9a. Furthermore, many of the impedance matching transformers are mainly used in the audio frequency band of 20 to 20 KHz and superimpose a direct current on the primary side.

For this reason, silicon steel, permalloy, etc. are often used as core materials, and the core is assembled with E-type core laminates 2 and I as shown in Figure 9.
A method of inserting and assembling the molded iron core laminate 5 in abutment manner is employed. The one on which even larger direct currents are superimposed is assembled by inserting a gap paper 9 between the E-type core laminate 2 and the working-type core laminate 5, as shown in FIG. 9C.

In addition, for switching transformers that convert high frequency pulse power from several KHz to several hundred KHz, a ferrite core with low high frequency loss is used as the iron core material.The method for assembling the core will be explained using Figures 8a-e. .

8a shows a structure in which a gap paper 9 is sandwiched between the E-type core 11 and the 1-type core 12, and FIG. 8a shows the E-type core 12.
The central magnetic leg 3 is polished to form a gap 13 and is butted against the type 1 core 11. Further, FIG. 8C shows a structure in which a gap 13 is provided in the central magnetic leg 3 of one of a pair of E-shaped cores 110, and the E-shaped core 11' of the other one is butted. Furthermore, the eighth
FIG. d shows a structure in which steps 14 and 14' are provided on both sides of the 1-type core 12 to form gaps 13 and 13', which abut against the E-type core 11. FIG. 8 θ shows that a step 14 is provided on one side of the 1-type core 12 to form a gap 13, and the E-type core 11 is
The structure is a combination of the two. These methods are selected based on the voltage, current value, and waveform applied to the primary side of the transformer, electrical performance such as leakage to the circuit, equipment for assembling the iron core, cost of core parts, etc. This is common. However, Fig. 8b, c, d, θ
Regarding the method of creating the gap 13 by polishing the E-type core 11 or I-type core 12, it is difficult to ensure the dimensional accuracy of the gap due to variations in polishing equipment and polishing materials, and the size of the gap size is Our current ability is to guarantee a minimum value of 200 microns or more and a tolerance of ±20 microns or more. Therefore, products that require performance with a gap size of several tens of microns have large tolerances, so the gap size is several hundreds of microfrons ± 2 microns, resulting in large variations in self-inductance, and is used as a transformer. It turns out you can't do it. Also, the ones shown in Fig. 8 b, c, d, and θ require a step of polishing the abutting surfaces of the cores and then polishing them again to provide the gap 13. Because of the structure in which the gaps 13 and 13' are provided, three polishing and reversing steps are required: polishing the step 14, then turning it over again and polishing the step 14'. Therefore, as described above, the polishing process requires a lot of time, resulting in an increase in the cost of the core. As a method for solving the above-mentioned problems in electrical performance and cost, the method shown in FIG. 8b is as shown in FIG.
c, d.

Currently, a method is employed in which a gap is provided by sandwiching gap paper 9 having a thickness corresponding to the gap dimension 13 of θ.

The above describes the general characteristics of various transformers and the method of inserting the core. Among these, the transformer of the present invention is applied to a low frequency transformer in which a direct current is superimposed on the primary winding and is used in a low frequency band for the purpose of impedance matching. This section explains the electrical performance required. The purpose of this type of transformer is to efficiently convert primary input to secondary output within the frequency band used, and its efficiency is greatly affected by the primary side impedance.
The higher the value, the more advantageous it becomes. Therefore, as the magnetic material, a laminated plate of silicon steel with high magnetic flux saturation density or permalloy with high magnetic permeability is used. The self-impedance will be explained using the core insertion method shown in FIG. 9 and the graph of the self-impedance or self-intersoton DC current curve shown in FIG. 10. If a DC current is superimposed on the primary side of the transformer due to the circuit conditions of the temporary hook set, and a sufficient self-impedance J is required to satisfy the efficiency of the transformer at that time, the DC current is At the time of construction, only the self-impedance value of J& can be obtained. As shown in Fig. 9, the method of assembling the E-type bond, soundboard 2, and construction-type laminate 6 is based on Ja (direct). If a gear paper 9 thickness b is provided between them, the value of JbO will be determined by the curve of Hb, and similarly, if the thickness of the gap is C, the impedance will be determined by the curve of Ha.
cO value.

With the above method, the desired self-impedance J cannot be obtained. Therefore, if the thickness of the gap paper shown in Figure 9C is further increased and the gap dimension is d, the self-impedance at the point of DC current I will be the curve Hd, and the impedance value will be Jd, which can satisfy the required value J. . The thickness of this gap paper varies depending on the number of primary turns of the transformer, the value of the superimposed DC current, and the material of the iron core, and the optimum gap size is set to a value that ensures the maximum self-impedance.

Next, an outline of the method for assembling the transformer will be explained using FIGS. 6 and 7. A coil 1 is formed by winding a primary winding and a secondary winding around a bobbin 10. Such a coil 1 is E
Insert into the central magnetic leg 3 of the type iron core laminate 2. Then, the gap paper 9 having the optimum gap thickness determined based on the required electrical performance is applied to the central magnetic leg 3 of the E-type core laminate 2 and the outer magnetic films 4 at both ends.
Place it in the center of the top. The width dimension is set to be slightly larger than the dimension in the stacking thickness direction of the core, and the shape is approximately U-shaped so that the working-type core 5' and the E-type core 2' on the end face do not come into direct contact. Next, the specified number of laminated steel core laminates 5 are gently placed on the gap paper 9 so that the gap paper 9 does not move, and the gap paper 9 is stacked on the E-type core laminated board 2 and the steel core laminate 2. Sandwiched between plates 5. The outer periphery of such an assembled iron core is tightly bound and fixed with insulating tape. Alternatively, the E-type core laminate 2 and the engineered core laminate 6 are pressed down and fixed using metal fittings or the like. Furthermore, this transformer is completed by applying moisture-proofing treatment such as wax. As shown in FIG. 7, in this transformer, the magnetic flux 8 generated by passing a current through the primary winding of the coil 1 is interposed between the E-shaped core laminates 2, the working-type core laminates 6, and the front core. gap paper 9
It passes through a magnetic circuit constructed by That is, the self-impedance curve Hd for direct current shown in FIG. 10 can be obtained, and the self-impedance J at the time of direct current work, which is the required performance, can be satisfied.

Problems to be Solved by the Invention This transformer satisfies electrical performance by inserting gap paper between the E-type core laminate and the engineering-type core laminate to provide a gap in the magnetic circuit. be.

The core assembly method is as shown in FIG. It has a structure in which a substantially U-shaped gap paper 9 is placed on top of the gap paper 9, and then the engineered iron core laminate 5 is placed and sandwiched thereon. Therefore, E type iron core laminate 2
Even if the gap paper 9 is placed on top, the gap paper 9 is thin and light, so it may move due to a slight impact, and it takes time to align the center of the gap paper 9. Furthermore, even when placing the single core laminate 5 on the gap paper 9, the gap paper 9 moves and it takes time to align it with the E-type core laminate 2.

Furthermore, the gear paper 9 itself has a thickness of several microns to several tens of microns and is light in shape, so it is difficult to take out one sheet at a time during the gap paper insertion operation, and two or three sheets are taken out stuck together, and it is difficult to tear them off into one sheet. It took a lot of time to do the work. As mentioned above, it is difficult to automate the assembly because the work can only be done manually, and the process is mainly done by hand, resulting in a long assembly time and high cost.

Moreover, the work itself tends to vary easily and gap paper 9 is E.
The gap size between the E-type core laminate 2 and the engineering-type core laminate 5 may be caused by protruding from the central magnetic leg 3 or outer magnetic film 4 of the E-type core laminate 2 or by overlapping the gap paper 9 and inserting it. This has many drawbacks, such as variations in the self-impedance of the transformer, resulting in variations in the self-impedance value of the transformer, which is said to be the cause of a high self-impedance failure rate.

Means for Solving the Problems The technical means of the present invention for solving the problems described above is such that when the E-type core laminate and the engineered core laminate are butted, the E-type core is opposite to the central magnetic leg of the laminate and the center A magnetic path is formed by abutting an I-type core laminate with a recessed portion having an opening width larger than the width of the magnetic leg against the type-II core laminate.

Effect The effect of this technical means is to provide four parts of the E-type core laminate facing the abutting portions of the central magnetic legs of the E-type core laminate.
By creating a structure in which an appropriate gap is provided between the central magnetic leg of the molded iron core laminate and the molded iron core laminate, it is possible to obtain the same self-impedance as in the conventional method of inserting gap paper.

Embodiment As described in the section of the prior art, the present invention is applied to a low frequency transformer or the like in which a direct current is superimposed on the primary winding and is used in a low frequency band for the purpose of impedance matching. Therefore, the magnetic materials used are silicon steel with a high magnetic flux saturation density and permalloy laminates with a high magnetic permeability. The present invention and a substantially concave-shaped ferrite core are shown in Figure 8 d and e, but when used in this transformer, the ferrite core has a magnetic flux saturation density that is almost the same as that of silicon steel, so it is low in the low frequency band. The magnetic flux density saturates, making it impossible to satisfy the specified self-impedance.

The minimum value of the gap dimension 13 is 200 microns, and the minimum accuracy is ±20 microns.

This transformer is a small-capacity, low-frequency transformer that has a direct current superimposed current of less than 100 epsilon amperes and a gap size of 10 to 100 epsilon. In terms of dimensions and accuracy, the values themselves are small and the variations are large, making it impossible to satisfy electrical performance.

In the present invention, an EI-shaped iron core made of silicon steel, permalloy iron core, and aluminum plate has a recessed portion for providing a gap, and is produced by punching with a press die.

An embodiment of the present invention will be described below.

FIG. 1 is an assembled diagram of a laminated core of a transformer according to the present invention, and FIG. 2 is a cross-sectional view of a transformer using a laminated core of a transformer according to the present invention, viewed from the side.

Further, FIG. 3 shows the shape of the iron core of the present invention.

First, the shape of the iron core will be explained using FIG. 3. The E-shaped core 2 is a generally well-known E-shaped core having a central magnetic leg 3 at the center and a pair of outer magnetic legs 4 at both ends. At the tips of both rows of magnetic legs 4 and the center magnetic leg 3, there are recesses 6 and 7 on both sides.
A magnetic path is constructed by abutting air-shaped iron cores 5 having . Next, to describe the shape of the D-shaped core 5, one side of the D-type core 5 is provided with four parts 6 corresponding to the central magnetic leg 3 of the E-shaped core 2, and the dimensions of the opening are the i of the central magnetic leg 3. It is set slightly larger than the depression a, and the dimension g to the end face is E.
The width is set larger than the width of the outer magnetic leg 4 of the type iron core 2. Further, the depth dimension 13d is set to an appropriate gap dimension that satisfies electrical performance.

Furthermore, a recess 7 is provided on the back side of the D-shaped core 6, and the dimensions such as the opening width and depth of the six recesses are exactly the same, so that the configuration can be made such that either the four parts 6 or the four parts A can be used, or the recess 7 The depth 1315 of the recess 6 is different from the depth 13d of the recess 6, so that different requirements for self-impedance performance can be satisfied with the same D-shaped core 6. In this case, the opening width C of the recess 7 is set to be a different dimension from the opening width of the recess 6 so that the direction can be visually determined.

Next, the manufacturing method will be explained with reference to FIG. 4. The laminated core is created by punching out a portion of a magnetic steel plate using a press die. Ushizu recess 6, 7. 6, 7
'Punch the metal-plated knife-shaped core 5, 5' to make a knife-shaped core 5,
Create 5'. Furthermore, in the next step, window portion 1 of iron cores 2 and 2'
5, punch out 15'. In the next step, the legs 3 and 4 of the connected cores 2 and 2' and the backs of the cores 2 and 2' are cut to create separate E-shaped cores 2 and 2'. E-type cores 2, 2' and I-type cores 6, 6' are then pressed.
is stored in a box and further annealed under high temperature conditions to complete the E-shaped core 2 and the D-shaped core 5. Note that the shape of the D-shaped core of the present invention also applies to FIGS. 5a, b, c, d, and e.

Next, a method for assembling a transformer according to the present invention will be outlined with reference to FIGS. 1 and 2. The winding process is exactly the same as the conventional one, and the secondary winding and secondary winding are wound around the pobbin 10 to form the coil 1.
, and such a coil 1 is inserted into the central magnetic leg 3 of the E-type core laminate 2.

Then, the engineered core laminate 6 having the recesses 6 and 7 is butted and joined to the central magnetic leg 3 of the E-type core laminate 2 and the pair of outer magnetic films 4 at both ends. After that 1. The outer periphery of the assembled core 2 is tightly bound and fixed with insulating tape, or the E-type core laminate 2 and the I-type core laminate 5 are pressed and fixed from above and below with metal fittings or the like.

Then, apply moisture-proofing treatment such as wax to complete the transformer. As shown in the cross-sectional view of the transformer in Figure 2, one core laminate plate 6
A gap dimension 13 is set between the E-type iron core 2 and the central magnetic leg 3 by the recess 6 provided in the E-shaped core 2, and the magnetic flux 8 passes through this gap. In other words, by creating a gap using a steel core with a recessed part, it is possible to satisfy the same performance as the conventional method of inserting gap paper, and the curve Hd of self-impedance and self-inductance for direct current shown in Fig. 10 is obtained. is obtained and the impedance is Jd
The value becomes O, which is equivalent to the conventional value.

DETAILED DESCRIPTION OF THE INVENTION As described in detail, the present invention provides a recessed portion having an opening slightly wider than the width of the central magnetic leg in the engineered core laminate corresponding to the central magnetic leg of the E-type core laminate, and butts and joins the respective core laminates. In particular, it is characterized by providing an appropriate gap between the central magnetic leg of the E-type core laminate and the engineering-type core laminate. By adopting the above shape, the gap paper that was conventionally used becomes unnecessary, and the time required for taking out the gap paper, sorting the number of sheets, and aligning when inserting the gap paper is completely unnecessary. Electrical performance can be satisfied simply by butt-joining the engineered core laminates to the laminates, leading to reductions in assembly work time and ease of assembly automation. In addition, because the gap at the depth of the concave part of the molded iron core is formed by punching out with a press die that is integrated with the molded iron core, the accuracy of the gap dimension is extremely high and the variation in electrical performance is small. Furthermore, the electrical performance defects caused by the misalignment of the gap paper and the insertion of two to three gear papers, which occurred in the past, are completely eliminated, and great improvements can be made in terms of quality.

[Brief explanation of the drawing]

Fig. 1 is an assembly diagram of a laminated core in an embodiment of the transformer of the present invention, Fig. 2 is a sectional view from the side of a transformer using the laminated core of the present invention, and Fig. 3 is the shape of the core of the present invention. Figure 4 is a press process diagram for creating the same laminated iron core.
Figures 5a-d are top views showing other examples of engineered core laminates, Figure 6 is an assembly diagram of the core in a conventional transformer, Figure 7 is a sectional view of the conventional transformer seen from the side, Figures 8a-0 are diagrams showing a reference example of a conventional ferrite core assembly method, Figures 9a-c are diagrams showing an example of a conventional laminate core assembly method, and Figure 10 is a diagram showing a reference example of a conventional ferrite core assembly method. It is a figure which shows the change curve of self-impedance or self-inductance when flowing. 1... Coil, 2... E-type iron core laminate, 3... Central magnetic leg, 4... External magnetic leg,
6... Engineered iron core laminate, e... Concavity,
7... Concavity. Name of agent Patent attorney Shigetaka Awano and one other person Return map Funeral map Figure 10 ■ Procedural amendment (method) % formula % Case indication 1988 Patent application No. 292746 Q 2 Name change of invention Fy , Relationship with the case of a person who makes device corrections Patent application Colonel Address 1006 Kadoma, Kadoma City, Osaka Prefecture Name
(582) Matsushita Electric Industrial Co., Ltd. Representative Tani
Akio I

Claims (2)

[Claims] (1) A laminated core is constructed by an E-type laminated core and an I-type laminated core, and a coil is wound around the central magnetic leg of the E-type laminated core, and is placed at a position opposite to the central magnetic leg of the E-type laminated core. A transformer in which an I-type laminated core provided with a recessed portion having an opening larger than the central magnetic leg is butt-joined to the E-type laminated core. (2) The transformer according to claim 1, wherein the I-type laminate core is provided with a recess having the same shape as the abutting surface or a recess having a different shape on the back side facing the abutting surface.