JPH0519940Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a small transformer used in consumer electronic equipment, such as AC adapters.

(Prior art and its problems) Generally, a small transformer has a built-in temperature fuse to ensure safety.

However, as a prior example of attaching a temperature fuse to a small transformer, there exists Publication No. 36102 of 1982. That is, in this small transformer, as shown in FIG. 4, a groove 19 for storing a temperature fuse is formed in the coil bobbin 18, and a temperature fuse 20 is housed in the groove 19.

However, in this case, since the concave groove 19 is open, there are problems in that heat during abnormal temperature rise is likely to escape, temperature sensing is poor, and the temperature fuse 20 cannot be blown out quickly.

(Means for solving the problem) The present invention was proposed in view of the above points, and its purpose is to provide a small transformer that has excellent temperature sensing and is easy to assemble. .

That is, in the present invention, in order to achieve the purpose, flanges 3 and 3 are provided at both ends of the hollow cylindrical body.
A temperature fuse insertion window 4a is formed in one flange 4, and a lead wire 7a of a temperature fuse 7 is inserted and stored in a temperature fuse storage part 2b formed on the outer periphery of the body 2. a primary coil bobbin 1 that is pulled out from the other flange 3 side, and a flange 1 that accommodates the primary coil bobbin 1 and slides into contact with the one flange 4 to close the entrance of the temperature fuse insertion window 4a.
A secondary coil bobbin 10 having a secondary coil bobbin 2 is provided.

(Function) In the present invention, the temperature fuse insertion window formed in the primary coil bobbin is closed by the secondary coil bobbin to prevent heat from escaping.

In addition, a temperature fuse is inserted from one flange side of the primary coil bobbin, and its lead wire is pulled out from the other flange side on the opposite side.
Improves ease of assembly.

(Example) An example of the present invention will be described below with reference to the drawings.

FIG. 1 shows a perspective view of a primary coil bobbin 1 used in the present invention, in which a hollow rectangular cylindrical body 2
flanges 3 and 4 are formed at both ends of the
A thick portion 3a is formed at the lower end of the flange 3 in the illustrated state, and a pair of plug blades 5 and 6 are implanted in the thick portion 3a.

In addition, in the illustrated state, the lower trunk inner surface 2a
A horizontally elongated temperature fuse insertion window 4a for inserting a temperature fuse 7 is formed in one flange 4 at a lower position of the body. It is configured to be placed in the temperature fuse storage section 2b.

FIG. 2A shows a side view of the primary coil bobbin 1 seen from the other flange 3 side, and FIG. temperature fuse 7
The lead wires 7a provided at both ends of the flange 3 are bent toward the other flange 3, and in this state, the temperature fuse 7 inserted through the temperature fuse insertion window 4a is inserted into the body 2 in the temperature fuse housing 2b.
It is inserted and stored in a direction perpendicular to the axial direction of the

Further, as each lead wire 7a is inserted, it is pulled out to the outside of the flange 3 side through the lead wire insertion hole 8 formed in the body 2 and the flange 3, as shown in FIG. The lead wire 7a is tied to a pin terminal 9 planted in the lower part of the thick part 3a, and the other lead wire 7a is tied to the connection part 5a of one of the plug blades 5.

Therefore, as shown by the imaginary line in Figure B,
A primary winding 9' is wound around the outer periphery of the body 2. In this case, the temperature fuse 7 is located approximately in the center of the primary winding 9'. Further, as shown in Figure C, a primary winding 9' is wound close to the outside of the temperature fuse 7 provided in the temperature fuse housing 2b.
Therefore, temperature sensing can be performed reliably.

FIG. 3A is a perspective view showing the state in which the primary coil bobbin 1 configured as described above is combined with the secondary coil bobbin 10, and one flange 4 of the primary coil bobbin 1 is in sliding contact with the secondary coil bobbin 10 and integrated. be done. The coil bobbin used in the small transformer of the present invention has a two-part structure as described above, and the secondary coil bobbin 10 has a primary coil bobbin storage section 11 formed therein.

That is, an end wall 13 and a side wall 14 are formed at one end edge and both side edges of the inner flange 12 formed on the secondary coil bobbin 10, respectively, and the space partitioned by these walls contains the primary bobbin storage section 1.
1, and the primary coil bobbin 1 is housed there.

In this case, an engaging piece 14a bent inward is formed on the outer edge of the side wall 14, and an engaging recess 3b is also formed on the corresponding outer side of the flange 3 of the primary coil bobbin 1, indicated by the arrow As shown in , when the primary coil bobbin 1 is stored in the primary bobbin storage section 11, the engagement piece 14a and the engagement recess 3b are engaged and can be integrated.

Figure B shows the situation. When integrated in this way, one flange 4 of the primary coil bobbin 1 and the corresponding one flange 12 of the secondary coil bobbin 10 are brought into contact with each other, and the temperature fuse insertion window 4a shown in FIG. is closed by the flange 12 of the secondary coil bobbin 10, so that heat generated during an abnormality does not escape to the outside. Therefore, the temperature fuse 7 quickly senses the temperature and is blown out.

A secondary winding 16 is wound around the body 15 of the secondary coil bobbin 10, and its lead wire (not shown) is pulled out through a notch 17b formed in the other flange 17 and directly soldered to a circuit board (not shown). Reference numeral 17a denotes a protrusion for positioning the circuit board. As is well known, a small transformer can be completed by incorporating an iron core (not shown) into this integrated coil bobbin.

(Effect of the invention) As described above, according to the invention, the temperature fuse is inserted through the temperature fuse insertion window formed on one flange of the primary coil bobbin, and the temperature fuse lead is inserted from the other flange on the opposite side. The temperature fuse insertion window is blocked by the flange of the secondary coil bobbin that houses the wire outside and the primary coil is housed in it, so the temperature can be detected quickly without escaping heat in the event of an abnormality. Because the temperature fuse can be blown without
This has the effect of improving safety.

In addition, during assembly, the temperature fuse is inserted through the temperature fuse insertion window formed on one flange, and the lead wire is pulled out from the flange on the opposite side, making assembly easier. .

[Brief explanation of the drawing]

Figure 1 is a perspective view of the primary coil bobbin used in the present invention, Figure 2 A is a side view of the same as above, Figure B is a bottom view, and Figure C is the temperature fuse provided on the primary coil bobbin and the winding. FIG. 3A is a perspective view of the primary and secondary coil bobbins, FIG. DESCRIPTION OF SYMBOLS 1...Primary side coil bobbin, 2b...Temperature fuse storage part, 3...Flange, 4a...Temperature fuse insertion window, 7...Temperature fuse, 10...Secondary side coil bobbin.

Claims (1)

[Scope of utility model registration request] Flanges 3 are provided at both ends of the hollow cylindrical body.
A temperature fuse insertion window 4a is formed in one flange 4, and a lead wire 7a of a temperature fuse 7 is inserted and stored in a temperature fuse storage part 2b formed on the outer periphery of the body 2. a primary coil bobbin 1 that is pulled out from the other flange 3 side, and a flange 1 that accommodates the primary coil bobbin 1 and slides into contact with the one flange 4 to close the entrance of the temperature fuse insertion window 4a.
2. A small transformer comprising: a secondary coil bobbin 10 having a secondary coil bobbin 10;