JPH0134327Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a coil device, and particularly to a magnetically shielded coil device.

For example, VTR (video tape recorder)
2. Description of the Related Art Conventionally, there are coil devices shown in FIGS. 1 and 2 that are used in areas such as CTVs (color televisions) where electromagnetic interference is undesirable or where installation space is narrow.

In the coil device shown in FIG. 1, a conductive wire is connected to a hollow cylindrical body 4 inside a synthetic resin bobbin 3, which has a flange 2 and a flange 1 having a wall thickness larger than the flange 2 at both ends. The conductive wire is wound to form a coil 5, and each end of the conductive wire is tied around the bases of two lead terminals 6 and 7 driven into the outer end surface of the collar 1, and the lead terminals 6 and 7 are connected by soldering or the like. A bottomed cylindrical ferromagnetic pot core 9 with a cylindrical core 8 erected at the center of the inner bottom surface is electrically connected to the end of the conductive wire, and is inserted into the hollow interior of the cylindrical body 4 from the flange 2 side. The cylindrical core 8 is inserted to cover the entire synthetic resin bobbin 3 having the coil 5, and the synthetic resin bobbin 3 and the ferromagnetic pot core 9 are mechanically bonded with adhesive or the like. .

However, in the coil device having the above configuration, the ends of the conductive wires are tied and fixed to the bases of the lead terminals 6, 7, so when the lead terminals 6, 7 are bent at their bases, the lead terminals 6, 7 The conductive wire end may break due to the inability of the conductive wire end to follow the bending. Also,
The lead terminals 6 and 7 driven into the flange 1 are made so that they do not easily come out from the flange 1, that is, the lead terminals 6 and 7 have sufficient tensile strength against the flange 1. To prevent the flange 2 from being damaged by external stress applied to the terminals 6 and 7,
The flange portion 2 is formed to have a large wall thickness. Therefore, the height dimension H of the coil device increases, making it impossible to achieve a reduction in size and weight. Furthermore, in manufacturing the coil device having the above-mentioned structure, a conductive wire end is tied several turns around one lead terminal 6 driven into the thick flange 1 of the synthetic resin bobbin 3, and then the synthetic resin bobbin 3 After winding a conductive wire around the cylindrical body 4 to form a coil 5, the end of the wound conductive wire is connected to the other lead terminal 7.
The entirety of the synthetic resin bobbin 3 with the coil 5 formed in this way is covered with a ferromagnetic pot core 9, and both are integrated with adhesive or the like, and then,
This process consists of electrically connecting the ends of the conductive wires and the lead terminals 6 and 7 by immersing the integrated product as described above in a solder bath or the like. Therefore, in order to tape the coil device so that it can be automatically inserted into a board, etc., it is necessary to add a taping process after manufacturing the coil device, and the manufacturing process of the taped coil device requires additional steps. , problems arise such as high costs and increased manufacturing man-hours.

The coil device shown in FIG. 2 has a cylindrical body 14 of a ferromagnetic or paramagnetic drum core 13 having a flange 12 and a flange 11 having a wall thickness larger than or the same as that of the flange 12 at both ends. A conductive wire is wound to form a coil 15, and each end of the conductive wire is tied around the bases of two lead terminals 16 and 17 driven into the outer end surface of the flange 11, and the lead terminals 16 are connected by soldering or the like. , 17 and the end of the conductive wire, a bottomed cylindrical ferromagnetic pot core 19 is used to electrically connect the bottomed cylindrical spacer 1 made of synthetic resin.
8, a drum core 13 with a coil 15
The opening of a ferromagnetic pot core 19 that covers the whole body and houses the drum core 13 is sealed with a synthetic resin casting agent.

However, the coil device shown in FIG. 2 cannot be made smaller and lighter due to the same reasons as the coil device shown in FIG.
There are problems of high costs and increased manufacturing man-hours.

Further, in both the coil devices shown in FIGS. 1 and 2, lead terminals 6, 7, 16, 1
The work of tying the end of the conductive wire to 7 is complicated and is not suitable for production by automatic machinery.

This invention was made in view of the above-mentioned circumstances, and specifically aims to provide a small and lightweight coil device that can be taped without adding a taping process and is less prone to disconnection accidents.

Next, an embodiment of this invention will be described with reference to the drawings. FIG. 3 is a sectional view showing a magnetically shielded coil device which is an embodiment of this invention.

In FIG. 3, 30 indicates the inner bottom surface 3.
0A is a ferromagnetic pot core in the shape of a cylinder with a quadrilateral bottom. Moreover, what is shown by 23 has flanges 21 and 22 at both ends of the cylindrical body part 24, and
It is a ferromagnetic or paramagnetic drum core in which electrodes 25, 25 are formed by spraying silver liquid or pasting metal foil into recesses formed in the outer end surfaces of the flanges 21, 22, respectively. A coil 26 formed by winding a conductive wire is formed on the outer periphery of the cylindrical body 24,
The ends of the conductive wires are electrically connected to one ends of lead terminals 27, 28 at the electrodes 25, 25 by solder 29 or the like. In this way, the drum core 23 with the lead terminals 27 and 28 having the coil 26 is inserted through the bottomed cylindrical synthetic resin spacer 31 for reducing variations in inductance value, and the bottom surface 30A of the pot core 30
The axis of the cylindrical body 24 is parallel to the
The lead terminal 2 is disposed within the pot core 30.
The gap in the pot core 30 is filled with a synthetic resin casting agent 32 so that the other ends of the pot core 30 protrude from the opening of the pot core 30 and the arrangement of the drum core 23 is fixed, thereby forming a magnetically shielded coil. The device is configured.

The details of the structure of the device shown in FIG. 3 will now be explained. The pot core 30 has a bottom surface 30A.
Its width is larger than its height. Further, the drum core 23 has a structure in which the axial direction is the longitudinal direction, and the recesses formed in the outer end surfaces of the flanges 21 and 22 at both ends are shallow, and a metal foil is pasted there. The ends of the led conductive wires are sandwiched between lead terminals 27 and 28 and connected by solder 29 (hereinafter, this structure will be referred to as a coil device main body). Lead terminal 27, 2
8 extends in a direction perpendicular to the axis of the drum core.

As is clear from the drawings, the outermost end of the solder 29 is formed to protrude beyond the lead-out portion of the conductive wire terminal and lead terminal.
A cap-shaped synthetic resin spacer 3 is placed in contact with the inner bottom wall and inner wall of the pot core 30.
1 is installed. The coil device main body is placed horizontally so as to be completely housed within the spacer 31. In this state, the outermost protruding surfaces of the solder 29 formed on the outer end surfaces of the flanges 21 and 22 at both ends of the drum core come into contact with the inner wall of the spacer 31, thereby determining the position. Therefore, when inserting the coil device main body into the spacer 31, the conductive wire ends and lead terminals do not come into contact with the corners of the inner wall of the spacer, and no wire breakage or the like occurs. Further, the coil device main body is housed in a position offset toward the bottom surface 30A in the pot core 30, and the casting agent 32 is filled in this state, so that the coil device main body is exposed from the opening surface of the pot core. Therefore, a high magnetic shielding effect can be obtained.

Next, a method of manufacturing the magnetically shielded coil device having the above configuration will be described. FIG. 4 is an explanatory diagram showing one step in the one manufacturing method.

First, the flanges 2 located at both ends of the drum core 23
Electrodes 25, 25 are formed in the recesses bored in the outer end surfaces of the electrodes 1, 22 by, for example, spraying silver liquid or pasting metal foil, and then, with one end of the conductive wire fixed to one electrode 25, a cylindrical shape is formed. A coil 26 is formed by winding a conductive wire around the outer periphery of the body 24, and the end of the wound conductive wire is connected to the other electrode 25.
I will guide you to. Note that if there is still a surplus after leading the end of the conductive wire to the other electrode 25, cut off the excess conductive wire portion. On the other hand, as shown in FIG.
The other end is fixed to tape 33. Note that the tips of the lead terminals 27 and 28 are connected to the flanges 21 and 2.
If the drum core 23 is curved to match the shape of the recess formed in the drum core 2, the drum core 23 can be easily positioned and held, as will be described later. Next, as shown in FIG. 4, the drum core 23 with the coil 26 formed thereon is inserted between the lead terminals 27 and 28 fixed to the tape 33, and the curved tips of the lead terminals 27 and 28 and the electrodes 25 and 25 are inserted.
The drum core 23 is held between the two lead terminals 27 and 28 so that the end of the conductive wire is held between the two lead terminals 27 and 28. Thereafter, the entire drum core 23 held between the lead terminals 27 and 28 is immersed in a solder bath, or by flowing molten solder onto the outer end surfaces of the flanges 21 and 22, the lead terminals 27 and 25 are connected to the electrodes 25 and 25. 28 and the conductive wire terminal are electrically connected. After that, a synthetic resin spacer 31 is placed over the drum core 23 with the lead terminals 27 and 28 forming the coil 26, and the pot core 3
0, the drum core 23 is placed with the axis of the cylindrical body 24 parallel to the bottom surface 30A of the pot core 30, and then a synthetic resin casting agent 32 is poured into the gap in the pot core 30. When the poured casting agent 32 is solidified using a dryer or the like, a so-called taped magnetically shielded coil device shown in FIG.

In the magnetically shielded coil device having the above configuration, the cylindrical body 24 is connected to the bottom surface 30A of the pot core 30.
Since the drum core 23 is arranged within the pot core 30 so that the axes of the drum core 23 are parallel to each other, the height of the drum core 23 can be reduced, and the overall size can be reduced. In addition, the lead terminal 27,
28 is electrically connected to the conductive wire ends at the electrodes of the flanges 21 and 22, so unlike the flanges in conventional coil devices, there is no need to increase the wall thickness so that lead terminals can be driven into the flanges.
By reducing the thickness of the flange, the weight of the magnetically shielded coil device can be reduced. In addition, the conductive wire ends are sandwiched between the lead terminals 27, 28 and the electrodes 25, 25 without being tied around the conductive wire ends 27, 28, so that the conductive wire ends and the lead terminals 27, 28 are electrically connected. Since the lead terminals 27 and 28 are hardened with a casting agent to prevent them from wobbling, the structure is such that the conductive wires are difficult to break. moreover,
Since the magnetically shielded coil device can be manufactured with the lead terminals 27 and 28 taped, the taped magnetically shielded coil device can be easily manufactured using an automatic machine, and manufacturing costs can be reduced. . Moreover, the third
A taped magnetically shielded coil device can be manufactured without further adding a taping step to the manufacturing process of the magnetically shielded coil device shown in the figure.

Although one embodiment of this invention has been described in detail above, this invention is not limited to the above-mentioned embodiment, and can be implemented with appropriate modifications within the scope of not changing the gist of this invention. Needless to say.

Instead of the pot core 30 in the above embodiment, it may be a bottomed cylindrical pot core whose inner bottom surface is circular. Further, instead of the drum core 23 in the above embodiment, the cylindrical body has a total of three flanges at the center and both ends, and a coil can be formed in the body between the flanges. A drum core may also be used. Further, instead of the drum core having a cylindrical body in the above embodiment, a drum core having a prismatic body and rectangular plate-shaped flanges at both ends thereof may be used.

The drum core 23 having the coil 26 may be coated if necessary. Furthermore, the third
The coil device shown in the figure may be provided with a tube exterior if necessary, and when an exterior tube or tube exterior is not provided, it is convenient for use to display an inductance value or the like on the surface of the pot core 30.

According to the invention described in detail above, it is possible to provide a small and lightweight coil device that can be manufactured easily and at low cost using an automatic machine. Furthermore, by taping the lead terminals during manufacture, it is possible to provide a taped coil device that is easy to arrange on a board. In particular, this invention has the remarkable effect that when obtaining the same coil inductance, the height dimension can be reduced to less than half that of the conventional device.

[Brief explanation of the drawing]

1 and 2 are sectional views showing a conventional coil device, FIG. 3 is a sectional view showing a magnetically shielded coil device which is an embodiment of this invention, and FIG. 4 is a sectional view showing the magnetically shielded coil device. It is an explanatory view showing one process in one manufacturing method of the device. 21, 22...Trim part, 23...Drum core, 2
4... Cylindrical body, 25... Electrode, 26... Coil, 27, 28... Lead terminal, 30... Pot core.

Claims (1)

[Scope of utility model registration request] A conductive wire is wound around a bottomed cylindrical pot core and a drum core having flanges at both ends and whose longitudinal direction is in the axial direction, and the ends of the conductive wire are pulled out into recesses formed on the outer end surfaces of the flanges at both ends, and the lead a coil device main body which is soldered together with a terminal and whose outermost soldered end protrudes beyond the conductive wire draw-out portion and the lead terminal; and a cap-shaped spacer which is arranged in contact with most of the inner wall surface of the pot core. The coil device main body is positioned and housed in the cap-shaped spacer in a horizontal state with the solder outermost end of the coil device as the abutting part, and the coil device main body is housed in the pot core and the coil device main body is placed in the pot core. A magnetically shielded coil device characterized in that a pot core is filled with a potting agent in a position close to the bottom side.