JPH0244493Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a structure for reducing the height and number of parts of a small transformer used in a switching power supply device or the like.

[Prior art and its problems]

Conventionally, this type of small transformer has a base 2 on which terminal pins 4 are implanted under the bobbin around which the coil 1 is wound, as shown in the side view of FIG. 3 is generally pulled out downward and connected to the terminal pin 4 through the side surface of the base 2. 5 is the collar of the bobbin, 6 is a core for forming a magnetic circuit, and 7 is a groove on the side surface of the base 2 through which the lead 3 is passed. In this structure, before connecting the lead 3 to the terminal pin 4, it extends from the winding part of the bobbin to the base 2, the side of the base 2, and from the base 2 to the terminal pin 4, and so on, so that the coil 1 of the small transformer The bottom part is vertically long, making it difficult to reduce the height. In recent years, there has been a demand for miniaturization of electronic components, and there is a desire for improved structures to reduce the height.

In order to solve the above problems,
In No. 137760, we proposed a structure in which the coil lead is drawn upwards, eliminating the need for a base. This structure was unsatisfactory in terms of the number of parts and assembly man-hours, as the frame consisted of side plates, partition plates, and a bottom plate, and an outer plate was required.

[Purpose of invention]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a compact transformer that can be lowered in height and the number of parts, thereby reducing assembly man-hours.

[Means for solving problems]

The present invention achieves the above object by pulling out the coil lead upward, storing the lead in a guide groove provided on the outer wall of the side plate, pulling it downward along the outer wall, and using it as a terminal. It is something.

In other words, the coil is wound around a bobbin that has two rod-like parts extending parallel to the outside of the winding part at the upper end of the coil winding part, and an engaging part formed at the lower end along the lower side of the rod-like part. In a small transformer in which the coil is housed in two frames in which both ends of the rod-shaped part are locked to the upper side of the side plate and the engaging part is locked to the bottom plate, the lead of the coil is pulled out upward. After that, it is pulled out downward through a guide groove formed on the outer wall of the side plate of the frame body and used as a terminal.This eliminates the need for a base and allows the outer plate to connect the leads. This eliminates the need to hold down.

[Example of idea]

Examples of the present invention will be described below in Figures 1 and 2.
This will be explained with reference to FIGS. FIG. 1 is an exploded perspective view, FIG. 2 is an assembled plan view, and FIG. 3 is an assembled bottom view.

In Figures 1 to 3, 10 is a bobbin;
1 is a frame, 13 is a coil, 14 is a lead, and 15 and 16 are an E-type core and an I-type core, respectively.

A bobbin 10 made of synthetic resin has a rectangular cylindrical winding portion around which a band-shaped coil 13 is wound, and a winding portion 17.
Two rod-shaped parts 18 that also serve as flanges are formed at the upper end and extend parallel to the outside along the two sides, and a protrusion 19 is formed at the lower end along the lower side of the rod-shaped part 18. Both end portions 20 of the rod-like portion 18 are bent in a crank shape within a plane, and protrusions 21 are formed on the side surfaces. Frame body 11 approximately the same height as bobbin 10
The U-shaped side plate 24 and bottom plate 29 constitute a housing portion 22 for the coil 13, and the outer wall thereof serves as a lead pull-out portion 25. Furthermore, a slit 26 for locking the end portion 20 of the rod-shaped portion 18 is provided at the upper corner of the side plate 24 from top to bottom. The width of the slit 26 is partially widened so that the end portion 20 can be locked by the projection 21. A recess 30 that widens inward is provided at the end of the bottom plate 29 in the storage section 22, and the protrusion 1 of the bobbin 10
9 is inserted. A plurality of notches 27 are formed on the upper side of the side plate 24, and a plurality of guide grooves 28 are formed in the drawer section 25. The positions of the notch 27 and the guide groove 28 correspond to each other vertically, and are used to draw out the lead 14 of the coil 13 downward as described later.

The coil 13 is a strip-shaped conductor that is wound around the winding portion 1 of the bobbin 10.
7 windings, and the lead 1 is placed at the desired location.
4 is pulled out to the top.

The E-shaped core 15 has a central vertical portion 33 and a winding portion 17.
The vertical portions 34 at both ends are positioned outside the coil 13, and the horizontal portion 35 is positioned between the rod-shaped portions 18. And the I-type core 16 is the E-type core 15
A magnetic circuit is constructed by fixing the magnetic circuit board with an adhesive or the like while in contact with the lower sides of the vertical portions 33 and 34 of the vertical portions 33 and 34.

The components of such a small transformer are assembled as shown in FIGS. 2 and 3. In addition, in FIGS. 2 and 3, E-type core 15, I-type core 1
6 are omitted from illustration.

The end 20 of the rod-shaped portion 18 of the bobbin 10 is connected to the frame 11
The protrusion 19 is fitted into the recess 30 so that the frame 11
is fixed to the opposite side of the rod-shaped portion 18 from the opposing side. The lead 14 pulled out upward from the coil 13 in the storage part 22 of the frame 11 passes through the notch 27 of the side plate 24 and is pulled out at the outside drawer part 25, and is used as a terminal as it is. lead 14
This is a guide groove that accommodates the lead 14 in order to fix the position of the lead 14. By changing the shape of the lower part as shown in FIG. 1, the lead 14 can be prevented from coming off. Figure 5 shows an enlarged view of this part.The upper part should be the same or wider than the lead width, and the lower part should be fitted with the outer width smaller than the lead width. It was designed to be fixed with. The structure of the guide groove 28 is not limited to that shown in the drawings, but it is sufficient that the guide groove 28 can fix the lead 14 at least at the lower part.

In addition, although the coil 13 used the strip-shaped conductor in the Example, it may be a normal wire. The winding portion of the bobbin may be cylindrical. Additionally, the upper side of the frame 11 is open, but this is done in consideration of the possibility of flowing synthetic resin into the frame 11 and solidifying it, if desired, in order to solidify the overall fixation after assembly. Yes, there is no need to limit it to this shape. Furthermore,
Although the end portion 20 of the bobbin 10 is bent into a crank shape, this is to facilitate engagement with the frame 11, and engagement is possible even if the end portion 20 is straight.
Alternatively, if the lower end of the bobbin 10 is also provided with the same portion as the rod-shaped portion 18 and is locked to the frame 11, the bottom plate 29 of the frame 11 becomes unnecessary.

[Effect of idea]

According to the present invention, there is no need for a base, so the height can be reduced, and the leads can be fixed to the outer wall of the side plate of the frame. Therefore, there is no need for an outer plate for holding down the leads, so the number of parts and cost can be reduced.

This also has a great advantage in that the number of assembly steps can be reduced.

[Brief explanation of the drawing]

1, 2, and 3 are an exploded perspective view, an assembled top view, and an assembled bottom view showing an embodiment of a small transformer according to the present invention, respectively. FIG. 4 is a side view of a conventional small transformer, and FIG. 5 is a side view of a conventional small transformer. 1 shows a partial plan view of a side plate of a frame body in an embodiment of the present invention. 10... Bobbin, 11... Frame body, 13... Coil, 14... Lead, 18... Rod-shaped portion, 19...
Projection, 22... Storage section, 24... Side plate, 25...
Drawer section, 28...guide groove.

Claims (1)

[Claims for Utility Model Registration] (1) Two bar-shaped parts extending in parallel to the outside of the winding part at the upper end of the winding part of the coil, and an engaging part formed at the lower end along the lower side of the bar-shaped part. A small transformer in which a coil is wound around a bobbin, and the coil is housed in two frames that lock both ends of the rod-shaped portion on the upper side of the side plate and lock the engaging portion on the bottom plate, A small transformer characterized in that the lead of the coil is drawn out upwardly and downwardly through a guide groove formed on the outer wall of the frame body to be used as a terminal. (2) The small transformer according to claim (1) of the utility model registration, characterized in that the outer width of a part of the guide groove is smaller than the inner width. (3) a notch is formed in the upper end of the side plate of the frame, and the guide groove is formed in the outer wall at a position corresponding to the notch;
A small transformer according to claim 1, wherein a lead of the coil is drawn out through the notch and the guide groove.