JPS61172317A - Transformer - Google Patents

Abstract

PURPOSE:To reduce the quantity of bobbin material used as well as to prevent the bending of a pin terminal and the deformation of resin by a method wherein thermoplastic resin is used as the main material, and thermoplastic resin is used only at the part where heat resistance is necessary, thereby enabling to form a thin-walled structure. CONSTITUTION:A thermoplastic resin part 11 is formed using the thermoplastic resin same as that used in a cylindrical part 2, the lower end flange 3 and the upper end flange 4, and said resin is used for a bobbin 1 as the main material. Also, a thermo plastic resin part 12 is formed in double-layer structure with thermoplastic resin in such a manner that the buried surface of the pin terminal 9 of a terminal plate 5 and the entire surface of a lead wire lead-out groove 6 are covered by the resin part 12, and a bobbin 1 is formed by molding and fitting together. Also, a protrusion 13 is formed on the thermoplastic resin part 11 and a recess 14 is formed on the thermo plastic part 12 in such a manner that they are coupled together, and the coming off and the looseness of the thermosetting resin part 12, caused by the environmental change such as the impact of falling, thermal shock and the like, can be prevented. The pin terminal 9 is buried in such a manner that it penetrates the thermosetting resin 12 and the tip of the buried part is fully brought into the thermoplastic resin part 11.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a transformer (hereinafter referred to as a transformer) used in audio equipment, video equipment, industrial equipment, etc.

(Prior Art) Fig. 3 is a perspective view showing a conventional example of a transformer, in which 1 indicates a bobbin, which includes a cylindrical part 2, a lower end collar 3, a lower end collar 4, a terminal plate 5, and a lead wire extraction groove. A coil 7 is wound around the cylindrical part 2, and the lead wire 8 from the winding start, winding end, or intermediate tap is the lead wire. Line drawing groove 6
After.

It is wound around a pin terminal 9 embedded in the terminal board 5 and fixed with solder or the like. Further, 10 is an iron core insertion hole, into which an iron core (not shown) is inserted to complete the transformer.

(Problem to be solved by the invention) As mentioned above, in the conventional transformer, the bobbin 1 has a pin terminal 9.
Since it is integrally molded using resin with embedded materials, there are the following manufacturing problems.

(a) When molding only thermoplastic resin, the heat generated when the lead wire 8 of the coil 7 is wrapped around the pin terminal 9 and soldered may deform the pin terminal 9 or cause the lead wire 8 to melt due to the heat. Even a slight impact after the resin is embedded and the transformer is completed can cause the lead wire 8 to break.

(b) In a bobbin made only of thermosetting resin, the strength of the resin against impact is weak, so it is necessary to form the cylindrical part 2, the lower end flange 3, the lower end flange 4, etc. thickly. Since the line space is reduced, there are disadvantages such as a narrowing of the degree of freedom in selecting electrical performance requirements for the transformer. In addition, the tensile strength of the pin terminal 9 after completion of the transformer is very weak, so the implanted portion of the pin terminal 9 may be deformed by crushing or otherwise to provide tensile resistance.
The number of manufacturing processes that increase the implant size increases.

(Means for Solving the Problems) In order to solve the problems in the conventional transformers described above, the present invention provides a cylindrical portion 2, a lower end collar 3. Most of the lower end flange 4, etc. are made of thermoplastic resin, and the terminal plate 5, especially the implantation surface of the pin terminal 9, and the surface portion of the lead wire pull-out groove 6 are made of thermosetting resin. 1 is used to construct a transformer.

(Function) The coil 7 is wound around the bobbin 1 formed as described above.
When the lead wire 8 is wrapped around the pin terminal 9 and connected by soldering, the pin terminal 9 may be deformed due to the solder temperature, and the lead wire 8 may be deformed due to the solder temperature.
Problems caused by heat such as biting into the resin can be prevented because a highly heat-resistant thermosetting resin is used in those positions. Even if the soldering heat is applied, the pin terminal 9 is more firmly implanted due to welding, and the tensile strength of the pin terminal 9 is increased.

In addition, the coil winding portion is made of thermoplastic resin with good moldability and high impact resistance.

Thin-walled molding is possible, allowing more space for the windings, and greater flexibility in selecting electrical performance requirements.

(Example) The present invention will be explained below using an example.

FIG. 1 is a perspective view showing an embodiment of the present invention.

In the figure, 2 is the cylindrical part of the bobbin 1, the upper end of which has a lower end collar 4 on the outer periphery, and the lower end collar 3 on the opposite lower end outer periphery.
is the provision. The terminal plate 5 integrated with the lower end collar 3 has a lead wire pull-out groove 6, and a pin terminal 9 is embedded in the lowermost surface of the terminal plate 5.

FIG. 2 is an enlarged cross-sectional view of the terminal plate 5 taken along line A-A' in FIG. Thermoplastic resin such as PB
It is made of T or modified PPO, and is the main material of the bobbin 1. The thermosetting resin portion 12 is formed by two-layer molding or molding of a thermosetting resin, such as phenol or sialphthalate, so that the surface where the pin terminal 9 of the terminal board 5 is embedded and the entire surface of the lead wire pull-out groove 6 are blue. The bobbin 1 is made by fitting together after separate molding. In addition, the thermoplastic resin part 11
By forming the convex portion 13 on the thermosetting resin portion 12 and the recessed portion 14 on the thermosetting resin portion 12 so as to fit with each other, the thermosetting resin portion 12 is prevented from coming off or loosening due to environmental changes such as drop impact or thermal shock. ing. The pin terminal 9 is implanted by penetrating the thermosetting resin part 12 and being press-fitted so that the tip of the implanted part fully enters the thermoplastic resin part 11.

In such a bobbin 1, the steel wire forming the coil 7 is wound around the cylindrical part 2, and the lead 1!8 is passed between the lead wire extraction grooves 6 and the lead wire of the pin terminal 9 is wound around the part 15. After that, the thermoplastic resin part 11 and the thermosetting resin part 1 are joined by soldering using a solder dip, and a magnetic material is incorporated into the thermoplastic resin part 11 and the thermosetting resin part 1.
A transformer is constructed using a bobbin made of a material different from that of 2.

(Effects of the Invention) Since the transformer of the present invention uses a bobbin whose main material is thermoplastic resin and thermosetting resin is used only in the parts that require heat resistance, it is resistant to soldering heat during assembly, etc. Furthermore, since a large amount of thermoplastic resin can be used, a thin wall structure is possible and the amount of bobbin material used can be reduced. Furthermore, by increasing the tensile strength of the pin terminals and preventing the terminals from becoming flattened and deforming the resin during soldering, it is possible to prevent wire breakage, resulting in a significant improvement in product quality and a highly reliable transformer. .

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a bobbin according to an embodiment of the present invention, and FIG.
The figure is an enlarged cross-sectional view of the terminal plate in FIG. 1, and FIG. 3 is a perspective view showing a conventional bobbin. DESCRIPTION OF SYMBOLS 1... Bobbin, 2... Cylindrical part, 3... Lower end flange, 4... Lower end flange, 5... Terminal board, 6... Lead wire pull-out groove, 7... Coil, 8... Lead wire, 9... Pin terminal, 10... Iron core insertion hole,
11... Thermoplastic resin part, 12... Thermosetting resin part, 15... Lead wire winding part. Patent applicant: Matsushita Electric Industrial Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] In a transformer in which a coil is wound around a resin-molded bobbin, the bobbin is made of thermoplastic resin, and in particular, the surface layer portion where the lead wire from the coil contacts and the pin terminal to which the lead wire is fixed are buried. Only the surface layer part to be planted is
A transformer characterized in that the transformer is made of a thermosetting resin, and the pin terminal is embedded in the thermoplastic resin.