JPH051049Y2 - - Google Patents

Description

Claim 1: A chiyoke coil for fixing on an electronic circuit board, comprising a coil member having at least one winding and an opening passing through the center of the winding, the coil comprising: an elongated central post 22; and first and second outer legs 18, 20, the first and second outer legs being parallel to and spaced apart from the central post 22;
It is further joined at one end to the center post by a base portion 16 integral with the center post, the center post being disposed within the coil member aperture 28, and said outer legs extending outside the windings 54,56. are located adjacent to the outer legs and the central post extend beyond either winding at their free ends a distance of approximately 30% of their length, thereby A chiyoke coil characterized by the E-shaped core member made of ferrite, which provides magnetic field coupling between the ferrite and the central post.

2 The coil member has two end flanges 3 provided with a central opening for receiving the central post 22.
2. A bobbin according to claim 1, characterized in that it comprises a bobbin 26 having 2, 34 and a cylindrical hollow central part 36, said winding being supported between the flanges and around the hollow central part. Chiyoke coil.

3. At least one locking tab 52 extends from one face of the flanges 32, 34 of the bobbin to engage an outer edge of the base, thereby retaining the bobbin in place on the central post 22. A chiyoke coil according to any one of the ranges 1 and 2.

4. Two pairs of opposing locking tabs 52 extend from the flanges 32, 34 of the bobbin to either side of the center post and to the base portion 1 of the core member 14.
4. The chain yoke coil according to claim 3, wherein the chain yoke coil is engaged with the edge of the flange in a locking manner from the flange.

5. A chiyoke coil according to claim 4, wherein the base portion, the legs, and the central post of the core member all have a generally rectangular cross section.

6 The bobbin has a partition 3 spaced between the flanges.
8. A coil according to claim 5, characterized in that it carries two windings 54, 56, one on each side of the partition.

7. Each of the flanges 32, 34 of said bobbin has at least one hole extending through the flange in the plane of the flange and is provided with a terminal pin 44 inserted through said hole, one end of said pin Claim 6, characterized in that the portion (46) is curved at right angles and couples the winding to the pin, the other end (48) extending from the bobbin and being secured to the circuit board. Chiyoke coil.

8. 2 of the central post 22 at its free end.
8. A chain yoke coil according to claim 7, characterized in that the two opposing edges (24) are chamfered to facilitate insertion of the central post into the bobbin opening.

9. The opposing inner edges of the flange opening 28 through which the tab 52 extends are chamfered to facilitate insertion of the center post 22 into the bobbin opening. Chiyoke coil.

10. A chain yoke coil according to claim 9, characterized in that a pair of opposing tongue-like lead-in members are provided and flare outwardly from the bobbin between locking tabs on each side of the core.

TECHNICAL FIELD This invention relates generally to inductance elements for electronic circuits, and more particularly to a chiyoke coil suitable for mounting on an electronic circuit board.

BACKGROUND OF THE INVENTION Many electronic circuits commonly include an inductance element that performs some wave function as one of their components.
I need it as one. One such example is the circuitry used in telephone handsets. These circuits are subject to various electromagnetic noises, which are optimally wavered by inductance.

Inductance elements commonly used for noise suppression in electronic circuits are commonly known as "chiyoke coils." These coils are preferably designed so that they can be quickly attached to the circuit board along with other circuit elements on the board. Since this mounting procedure is done separately from the fabrication of other circuit parts on the circuit board, it is important to minimize the complexity involved in the assembly process. Also, most of the other components of the circuit are printed on circuit boards or provided as relatively small integrated circuits.
Furthermore, since space and volume tend to be at a premium for this type of device, it is desirable to minimize the distance that the chiyoak coil projects from the substrate surface.

SUMMARY OF THE INVENTION A novel chiyoke coil according to the present invention has an E-shaped core with a coil member on its central leg. The legs and center post of this E-shaped core extend beyond the ends of the coil member, which provides sufficient magnetic flux coupling between the legs and posts to greatly reduce the number of windings of the coil member. It becomes possible. This also reduces the thickness of the coil member and therefore the thickness of the entire York coil element.
This configuration also provides a particularly quick and reliable assembly of coil members with E-shaped cores.

The coil member has one or more coils wound on a bobbin that slides over the central post of the core. The bobbin has a locking tab which locks the core in its installed position. The coil members are asymmetrically configured to allow orientation by automated assembly equipment.

[Brief explanation of the drawing]

1 is a front perspective view of the yoke coil assembly of FIG. 1 according to a preferred embodiment of the present invention, FIG. 2 is a front view of the yoke coil assembly of FIG. FIG. 4 is a front perspective view showing the core of the coil assembly removed from the assembly; FIG.
FIG. 3 is a front perspective view of the bobbin of the yoke coil of FIGS. DETAILED DESCRIPTION FIGS. 1 and 2 illustrate a chiyoke coil assembly 10 that includes a core member 1.
4, the bobbin assembly 12 is fixed to the bobbin assembly 12. Core member 14 is shown removed from bobbin assembly 12 in FIG. For example, the core 14 is
In 1983, Western Electric Co., North Andover, Mass.
LRM382 manufactured by Eiectric Company
- An E-shaped core made of a ferrite ceramic material, such as a material called L1, is used. This core 14 has a base part 16, two outer legs 18, 2
0, and a central post 22. The vertical edges 24 at the ends of the central post 22 are beveled. The bobbin assembly 12 includes a bobbin 26 molded from a thermoplastic resin material. Bobbin 26 has a central guide opening 28 for receiving central post 22 of core 14 . The outer vertical edge 30 of the guide opening 28 is chamfered and the bobbin assembly 12
facilitates horizontal alignment when receiving the center post. Vertical alignment is achieved through guide opening 2.
8 and are provided by a pair of tongue-shaped introduction members 31 which extend outwardly a short distance from the opening and are flared as they move away from the opening. A pair of axially spaced end flanges 32, 34 define a central cylindrical portion 3 of rectangular cross section.
It is fixed at 6. The intermediate portion spaced between the flanges 32, 34 constitutes a partition 38 which axially divides the bobbin 26 into two winding spools. Each of the flanges 32, 34 has in its plane,
Two holes 40 are provided, each receiving a terminal pin 44. This terminal pin has a leg section 46 for short coil winding turns at right angles.
and a fixing stem section 48. The locking stem section 48 has a swage segment or swage portion 50 that deforms the inner wall of the receiving bore 40 to securely hold the pin 44 in place after it has been installed in the bobbin 26. ing. Four locking tongue tabs 52 extend from one flange 32. These tabs are located at the base 16 of the bobbin assembly.
The core 14 is designed to engage the outer edge surface of the base 16 of the core 14 when pressed against the core 14 and secure the core 14 in position. Returning to FIG. 2, bobbin assembly 12 is shown with terminal pin 44 in place and each of the winding spools is wound with a copper winding 54,56. The completed assembly of FIGS. 1 and 2 consists of a winding 5 with wire wrapped around the terminal leg 46.
4,56. A fixation stem 48 extends from the bottom of the assembly and is designed for quick attachment to a circuit board. Legs 18, 20 of core 14 and central post 22
are considerably longer than the length of the guide opening 28 of the bobbin 26, so that these members have approximately their total length.
It extends beyond the end of the outer winding 56 by a distance of 30%. This provides magnetic flux coupling through the air gap between the outer legs 18, 20 and the center post 22, which significantly increases the inductance value of the York coil assembly 10. If there is no such feature, to obtain a similar inductance value,
The number of turns of the windings 54, 56 must be increased, which increases the diameter of the windings 54, 56 and correspondingly increases the overall thickness of the York coil assembly. This thickness dimension is undesirable in many applications where space is at a premium since it is the dimension that determines how much the assembly 10 protrudes above the level of the circuit board to which it is secured. Another feature of this Chiyoke coil assembly 10 is that the copper wire forming the windings 54 and 56 has a thickness such that the copper wire is used as a fuse link for the circuit in which the Chiyoke coil assembly 10 is used. One example is that. The asymmetrical configuration of bobbin 26 is an advantageous feature. This feature allows the bobbin to be quickly manipulated by automated assembly equipment. It is well known that automated assembly equipment is more easily designed to manipulate asymmetrical pieces than symmetrical pieces, due to the ease of orientation and alignment of such pieces. The same can be said about the core 14. central post 22 and outer legs 18 of core 14;
The distance d that 20 extends beyond the end of outer winding 56 may vary within the ranges possible for the particular application.
Further, even if the distance d is made significantly greater than about 30% of the total length of the legs 18, 20 and post 22, no appreciable inductance will be added to the structure, and the core 14 will not be damaged during operation. It becomes easier to receive. The coil assembly 10 has two windings 54, 56.
However, as will be apparent to those skilled in the art, the bobbin 26 may be wound with a single winding or with more than one winding. Furthermore, the assembly can be readily modified to be specifically designed for a single winding. The core 14 of the coil assembly 10 may also have a U-shaped core with only two outer legs, if the outer legs and the center post extend far enough beyond the outer windings that magnetic flux will be present in the air gap between them. It is possible to provide a bond. This is another structure suitable for certain purposes. A single locking tab can also hold the bobbin in place on the core. However, structures with two opposing locking tabs, or preferably four as in assembly 10 above, are preferred.
The structure with two tabs is highly reliable and allows for secure fixation. From the standpoint of shaping the bobbin 26, it is more advantageous to use two diagonally opposed locking tabs than the four locking tabs of the assembly 12.