JPH0341445Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a small transformer, and in particular to an EI type small transformer used in audio equipment and the like.

Prior Art FIG. 4 is an exploded perspective view showing a conventional EI type small transformer.

100 is a roughly Oji-shaped foot metal made by carefully carving a single iron plate.

The foot plate 100 has four bending protrusions 101.
A, 101B, 101c and 101D, two bent side plates 102A and 102B, and reinforcing ribs 103A and 103B are formed. Furthermore, mounting holes 104 and 105 are formed at both ends of the foot 100, through which screws (not shown) are passed through for mounting a small transformer (described later) to an audio device or the like (not shown).

200 is the transformer body, 211 and 22
Reference numeral 1 denotes an E-type core and an I-type core formed by laminating silicon steel plates. 212 is the central leg of the E-type iron core. 230 is a coil section, and a bobbin 231
and a terminal case 235 are attached as one body. That is, the bobbin 231 is a hollow rectangular prism-shaped bobbin integrally formed of plastic or the like, and the outer periphery of the bobbin 231 is provided with partition walls 232A, 2.
32B and 232C are formed. Partition wall 23
A primary coil (not shown) is wound between 2A and 232B, and a secondary coil (not shown) is wound between partition walls 232B and 232C. Reference numeral 235 is a box-shaped terminal case integrally formed of plastic or the like, and is provided with primary and secondary terminals (described later).

The central leg 212 of the E-shaped core 211 is inserted into the bobbin 231 from the direction of arrow A. Bobbin 2
Two protrusions 233A and 233B each having a triangular cross section are formed on the inner bottom surface 234 of 31. By providing these protrusions 233A and 233B, even if the number of silicon steel plates constituting the E-type core 211 is one more than the predetermined number, the central leg 212 of the E-type core 211 can be connected to the bobbin 231. It is empirically known that it can be inserted inside the In addition, the inserted central leg 2
12 is held by the upper ends of the protrusions 233A and 233B and the inner upper surface and side surface of the bobbin 231.

FIG. 5 shows that the center leg 212 of the E-type core 211 is inserted inside the bobbin 231, and the E-type core 211 is inserted into the bobbin 231.
A partially cutaway perspective view of an E-type core assembly 210 in which a coil portion 230 and a coil portion 230 are integrated, and an I-type core 22
1 to the bent protrusions 101A, 101 of the footing 100
B, 101C, 101D and bent side plate 102
102B is a perspective view of an I-type core assembly 220 obtained by fitting into the space formed by A and 102B. In the same figure, the thickness a and the width b of the E-type core 211 are equal to the width c and the length d of the I-type core 221, respectively. The dimensions are set.

FIG. 6 is a perspective view of a small transformer 300 obtained by moving the I-type core assembly 220 in the direction of arrow B in FIG. 5 and integrating it with the E-type core assembly 210. The state is shown with 100 at the top. In FIG. 6, a plurality of primary terminals 237 are provided on the upper part of a terminal side plate 236, which is a side surface of the terminal section 235, to which the starting end, terminal end, and intermediate tap of the primary coil are connected. Further, inside a rectangular opening 239 formed in the lower part of the terminal side plate 236, a plurality of secondary terminals 238 connected to the secondary coil are provided.

Figure 7 shows the small transformer 300 shown in Figure 6.
FIG. E-type core assembly 210 and I-type core assembly 220 are fixed by welding a core joining line 230, which is the outer circumferential line of the joint between E-type core 211 and I-type core 221. W indicates the welding trace described above.

FIG. 8 shows a plan view of the welded small transformer 300 attached to a printed circuit board 400 of an audio device or the like (not shown). The distances g and h represent the distances from the centers of the mounting holes 104 and 105 of the foot 100 to the printed circuit board 400, respectively.

Problems to be solved by the invention As mentioned above, the dimensions a, b,
Since the relationships a=c and b=d are established between c and d, it should be possible to place the I-type core 221 on the E-type core 211 without shifting the joint surfaces. However, in reality, when the I-type core assembly 220 is placed on the E-type core assembly 210 by human work, as shown in FIG. It is inevitable that discrepancies will occur. That is, the type I core assembly 220 is moved to
It is extremely difficult to place on top of the mold core assembly 210.

On the other hand, the dimensions g and h explained in FIG. 8 are required to have considerably high accuracy, and therefore the dimension e is necessarily required to be as small as possible. In addition, the distance f is also made extremely small, and the iron core weld line 23
It is required to be able to easily perform welding for 0 minutes.

The present invention was devised in view of the above-mentioned circumstances, and aims to provide a small transformer in which the displacement between the joint surfaces of the E-type core assembly 210 and the I-type core assembly 220 is as small as possible. Furthermore, another purpose is to improve the efficiency of positioning work when placing the I-type core assembly 220 on the E-type core assembly 210.

Means for Solving the Problems The small transformer of the present invention includes a cylindrical bobbin with a rectangular cross section, a central leg with a rectangular cross section inserted into the bobbin, and a central leg opposite to the central leg on both sides of the central leg. an E-type iron core having a pair of identical outer legs having a rectangular cross-section and arranged to a rectangular parallelepiped-shaped I-shaped core having one surface; a pair of identical ridges formed in the longitudinal direction on the inner surface of the bobbin and having a tip contacting the central leg; A pair of side plates that are joined to the surface and sandwich one pair of opposing side surfaces between the one surface and the other surface, and one or more pairs of protrusions that sandwich the other pair of opposing side surfaces are formed. A foot plate, and a protrusion protruding from the one side plate of the foot plate and inserted between the protrusions, the width of the protrusion being equal to the distance between the protrusions,
The thickness of the protrusion is equal to the height of the protrusion, and the distance between one end of the protrusion in the width direction and the one protrusion is the distance between the outer surface of the one outer leg and the one protrusion. The distance between the one outer leg and the opposite end is equal to the distance between the other end of the protruding piece in the width direction and the other protrusion. The distance is made equal to the distance between the other outer leg and the opposite end of the vein.

Function The I-type core is placed on the end face of the E-type core so that the protrusions are inserted between the protrusions.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1a is a perspective view of the foot plate according to the present invention. In the same figure, a foot pad 150 is the same as the foot pad 100 explained in FIG. 4 except for the following points, so only the different points will be described. That is, the foot metal 150 has a rectangular protruding piece 106 projecting from the upper surface of the center portion of the bent side plate 102B of the foot metal 110. Note that 213 is a pair of identical outer legs 213 with a rectangular cross section, which are disposed on both sides of the central leg 212 with a rectangular cross section of the E-type core 211 so as to face the central leg 212; , 213A are the central legs 21, respectively.
2. The end surfaces of the outer legs 213, and these end surfaces 21
2A, 213A, these end surfaces 212A, 213
Said one side 2 of a rectangular parallelepiped-shaped I-type core 221 having one side 221A of the same shape as the rectangle formed by A.
21A is joined. In the figure, dimensions l and m are
The width and thickness of each protruding piece 106 are shown.
FIG. 1b is a sectional view taken along line CC in FIG. 1a. Dimension p1 indicates the horizontal distance between the right end surface of the bending protrusion 101B and the left end surface of the protruding piece 106, and the dimension
p2 is the left end surface of the bending protrusion 101D and the protrusion 1
The position of the protruding piece 106 is set so that the horizontal distance from the right end surface of the protruding piece 106 is equal to the dimension p1 and the dimension p2.

FIG. 2 shows a front view of the E-type core assembly 210 described in FIG. 5. In FIG. 2, dimensions j and k are ridges 233A and 233B, respectively.
, and the distance between the two ridges from the bottom surface 234. The dimensions j and k are set to be equal to the dimensions m and l explained in FIG. 1, respectively. In addition, the dimension q1 represents the distance between the left end surface of the E-shaped core 211 (the outer surface of one outer leg 213) and the right end of the bottom of the protrusion 233A, and the dimension q2 represents the E
It represents the distance between the right end surface of the type iron core 211 (the outer surface of the other outer leg 213) and the left end of the bottom of the protrusion 233B, and the positions of the protrusion 233A and 233B are determined so that q1 and q2 are equal. is set. Furthermore, the dimension p1 explained in FIG. 1 is set to be equal to the dimension q1.

FIG. 3 shows a perspective view of the E-type core assembly explained in FIG. 2, and a perspective view of an I-type core assembly using a foot metal used in a small transformer according to the present invention. Type I core assembly 250 shown in FIG.
In this case, the I-type core 221 is attached to the space formed by the bent protrusions 101A, 101B, 101C, 101D and the bent side plates 102A, 102B of the foot plate 150 explained in FIG. The other side (not shown) facing the side plate 102A, 1 is bent.
02B holds one pair of opposing side plates (the side surfaces between one side 221A and the other side) of the I-type core 221, and also bends the protrusions 101A, 101.
Type I core 221 by B, 101C, 101D
The other opposing side of the two is held in between.

As explained in Fig. 1 and Fig. 2, between the dimensions l, m, j, k, p1, p2, q1, q2, k
=l, j=m, p1=p2=q1=q2.

Furthermore, as explained in FIG. 5, a=c, b
= d, b=p1+l+p2, d=q1
+k+q2. Therefore, after moving the I-type core assembly 250 in the direction of arrow D, the projecting piece 10
6 is inserted between the protrusions 233A and 233B and the E-type core assembly 210 is placed on top.
It is possible to eliminate misalignment of the bonding surfaces between the type iron core 211 and the I type iron core 221. In this state, both core assemblies are fixed to each other using a clamp or the like (not shown), and the core joining line portion explained in FIG. 7 is welded. Therefore, the above-mentioned distances g and h can also maintain high accuracy.

Effects of the Invention As explained above, according to the present invention, a protrusion is formed on the foot plate, and the I-type iron core is inserted by inserting the protrusion between the two protrusions formed on the inner bottom surface of the bobbin. If it is placed on the end face of the E-type core, it is possible to eliminate the occurrence of misalignment of the joint surfaces between the E-type core and the I-type core. Therefore, the accuracy of the distance between the mounting hole provided in the foot plate and the printed circuit board on which the small transformer according to the present invention is mounted can be maintained extremely well. Furthermore, the efficiency of positioning work when placing the I-type core assembly on the E-type core assembly can be improved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a foot according to the present invention, FIG. 2 is a front view of an E-type core assembly, and FIG. 3 is a perspective view of an E-type core assembly and an I-type core assembly using a foot according to the present invention. The perspective view and Figure 4 are of the conventional
FIG. 5 is a partially cutaway perspective view of an E-type core assembly and a conventional I-type core assembly. FIG. 6 is a perspective view of a small transformer. FIG. FIG. 8 is a perspective view of a portion of the small transformer, and FIG. 8 is a plan view of the small transformer attached to a printed circuit board. 100,105...Ashikin, 104,105...
Mounting hole, 106... protrusion, 200... transformer body, 210... E type core assembly, 211...
E type iron core, 212...center leg, 213...outer leg,
212A, 213A... end surface, 220, 250...
...I-type core assembly, 221...I-type core, 2
21A...One side, 230...Coil part, 231...
...Bobbin, 233A, 233B...Ring, 235
...Terminal case, 300 ...Small transformer, 40
0...Printed circuit board.

Claims (1)

[Claims for Utility Model Registration] A cylindrical bobbin with a rectangular cross section, a central leg with a rectangular cross section inserted into the inside of the bobbin, and disposed on both sides of the central leg so as to face the central leg. an E-type iron core having a pair of identical outer legs having a rectangular cross section; and a rectangular parallelepiped core having one side having the same shape as the rectangle that is joined to the end faces of the central leg and the outer leg and formed by these three end faces. an I-type iron core; a pair of identical ridges formed in the longitudinal direction on the inner surface of the bobbin and whose tips are in contact with the central leg; and a pair of protrusions that are joined to one surface of the I-type iron core and opposite to the other surface of the I-type iron core, a pair of side plates that sandwich one pair of opposing side surfaces between and the other surface, and one or more pairs of protrusions that sandwich the other pair of opposing side surfaces; a protrusion protruding from the one side plate and inserted between the protrusions, the width of the protrusion is equal to the distance between the protrusions, and the thickness of the protrusion is equal to the height of the protrusions. The distance between one end of the protruding piece in the width direction and the one protrusion is equal to the distance between the outer surface of the one outer leg and the end of the one protrusion opposite to the one outer leg. The distance between the other end of the protruding piece in the width direction and the other protrusion is equal to the distance between the outer surface of the other outer leg and the end of the other protrusion opposite to the other outer leg. A small transformer characterized by a distance equal to the distance between the two parts.