JP3411006B2 - How to tie a small transformer and a lead wire - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pin terminal type small transformer used as a power source and an audio output transformer mounted on a printed circuit board incorporated in a general equipment such as a television and a radio.

[0002]

2. Description of the Related Art A pin terminal type small transformer of this type has a pin terminal implanted in a coil bobbin, and a lead wire of a coil is tied to the pin terminal.

[0003]

The lead wire of this coil is composed of a thin wire. As a prior art for preventing the disconnection, there is JP-B-60-11622.

FIG. 6 shows a schematic explanatory view thereof. In this prior art example, the pin terminal 5'is attached to the flange 2'of the coil bobbin 1 '.
And to form a projection 6'on the flange 2'from the vicinity of the base of the pin terminal 5 ', and hook the lead wire 7'of the coil wound around the coil bobbin 1'on the projection 6'. The pin terminal 5'is configured so that it is soldered to the root of the pin terminal 5'by being wound several times between the root and the projection 6 '.

According to the above construction, since the lead wire 7'is laid around between the pin terminal 5'and the projection 6 ', the external force applied to the pin terminal 5'is generated between the pin terminal 5'and the projection 6'. Therefore, even if the leader wire 7'is a thin wire, there is an advantage that the breakage can be prevented. Further, even if there is shrinkage during soldering, it can be spun several times and covered with a plurality of wires, which has the advantage of preventing disconnection of the leader line due to shrinkage.

However, recently, in the field of soldering, there is a tendency to use lead-free solder, which is called lead-free due to environmental problems, and the work efficiency of running the lead wire 7'is improved. The situation is being screamed, and the following problems have arisen.

(1) With the introduction of lead-free solder, the phenomenon of copper erosion due to tin in the solder becomes remarkable, and in the case of fine wires,
Even in the conventional example, the result is that the wire is easily broken. That is, the composition of lead-free solder is Sn-3.5Ag-0.7Cu, S
Conventional eutectic solder Sn-37P like n-0.7Cu
The proportion of Sn is higher than that of b, which means that the copper erosion phenomenon is more likely to occur. For example, 0.06UE
In the case of W, the copper erosion phenomenon did not occur even in the conventional case of 430 ° C for 4 seconds, but in the case of lead-free solder, it was 420 ° C 2
Since the phenomenon of copper erosion occurs in seconds, 420 ° C for 1 second to 1.
Soldering work must be done within 5 seconds. Note that unsoldered portions occur in 1 second or less. In the case of lead-free, the range of work conditions is narrow and the work has been done by hand in the past, but it can be said that this work condition is extremely difficult in consideration of variations in manual work. (2) In the entwining work that reciprocates between the pin terminal 5 and the protrusion 6 several times, even if an automatic winding machine is used, the movement of the nozzle is X
Since it becomes three-dimensional in the YZ direction, there is a drawback that it takes a very long time. Of course, manual work is a difficult task. Further, if the number of times of running is large, the work becomes complicated accordingly.

The present invention has been proposed in view of the above, and an object thereof is to deal with lead-free solder and to entangle the small transformer and the lead wire for facilitating the wiring work. To provide a method.

[0009]

In order to achieve the above object, the present invention has a pin terminal 5 planted in a flange 2 of a coil bobbin 1 and a root portion of the pin terminal 5 on an outer end surface of the flange 2. A protrusion 6 extending outward from the vicinity is formed, and a lead wire 7 of a coil wound around the coil bobbin 1 is hooked on the protrusion 6 and then between the root of the pin terminal 5 and the protrusion 6. It is a small transformer that is soldered to the root of the pin terminal 5 by turning it several times, and the upper surface of the protrusion 6 is formed by an inclined surface that becomes lower as it approaches the pin terminal 5 from the outside, and The planar shape is a substantially inverted trapezoidal shape in which the side of the pin terminal 5 is narrow, and the narrowed bottom of the substantially inverted trapezoidal shape is configured to enter the center or the inside of the pin terminal 5.

When the lead wire 7 is entangled, the protrusion 6 is circulated around the outer periphery of the protrusion 6 about 5 to 10 times by the circular movement of the front and rear nozzles. It is characterized by being entwined around about 3 to 5 times.

Further, the lead wire 7 is wound around the projections 6 and the pin terminals 5 by circular movement of the nozzle of the automatic winding machine. .

Further, in this case, a feature is that lead-free solder is used for connecting the lead wire 7 and the pin terminal 5.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The soldering work of a transformer is performed by baking (melting) the coating of a urethane copper wire, which is a winding, by the heat of a solder pool, exposing the base of the copper wire, and then applying the pin terminal 5
It is a work to fix with solder. Therefore, depending on the melting temperature of the solder, the work is performed at a temperature of 150 ° C. or higher. Since the lead-free solder has a high proportion of tin as described above, the phenomenon of copper erosion is more likely to occur than before. To prevent this, it is effective to increase the number of times the electric wires are entangled (increase the total electric wire diameter) and perform soldering. The number of reciprocations between the pin terminal 5 and the protrusion 6 is adjusted depending on the size of the winding diameter. For example, in the case of 0.06 UEW, the wire is reciprocated (wound) 5 times, then wound around the pin terminal 3 times and then soldered. However, this five-winding work requires much time in the conventional work method of operating the nozzle in the XYZ directions, compared with the three-winding rotation work of winding the pin terminals, which is a hindrance to time reduction and cost reduction. It was Therefore,
According to the present invention, even if the number of entanglements is increased, the nozzle operation of the automatic winding machine is a simple circular operation in the vertical direction or a plane circular operation, so that the number of entanglements can be easily increased and the total number of entanglements can be increased. Even if the wire diameter is increased and lead-free solder is used, the phenomenon of copper erosion can be suppressed to a minimum to prevent disconnection.

Further, the planar shape of the protrusion 6 is substantially an inverted trapezoid in order to prevent the leader wire 7 from being loose when the lead wire 7 is entangled with the protrusion 6.

Further, the upper surface of the projection 6 is an inclined surface which is lowered toward the pin terminal 5 side, and the projection 6 has a substantially inverted trapezoidal shape.
The narrow bottom part of the upper surface of the pin terminal is inserted into the center or the inner side of the pin terminal 5 so that the lead wire 7 laid around the protrusion 6 surely contacts the base of the pin terminal 5 with a large contact surface. I have.

The running of the leader line through the nozzle is a simple circular motion to improve the working efficiency.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged perspective view of an essential part of the present invention seen obliquely from above, FIG. 2 is a side view of the essential part of the present invention, and FIGS.
Shows a process explanatory view of tying a leader line.

First, in FIGS. 1 and 2, 1 is a coil bobbin formed of an insulating resin in a proper shape, 2 is a flange formed at one end of a hollow winding barrel portion 3, A thick portion 4 is formed at the outer end of the flange 2.

A pin terminal 5 is provided at the outer end of the upper surface of the thick portion 4.
Has been planted.

A projecting portion 6 is formed at the outer end of the thick portion 4 and extends outward from the vicinity of the root of the pin terminal 5. The upper surface of the projecting portion 6 is an inclined surface that decreases from the outside of the upper surface toward the upper surface side of the thick portion 4, and this inclined surface is continuous with the upper surface of the thick portion where the pin terminal 5 is implanted. .

A coil (not shown) is wound around the winding barrel 3 of the coil bobbin 1 as is well known, and the lead wire 7 of this coil is inserted through a lead groove 8 formed below the thick portion 4. Pull out to the protrusion 6 side.

When the lead wire 7 is laid around, first, as shown in detail in FIG. 3, the lead wire 7 is laid around the projection 6 about 5 to 10 times. In this case, since the nozzle (not shown) of the automatic winding machine moves in the vertical circular motion A, the workability is good even if the number of entanglements increases.

Further, since the upper surface of the projection 6 is an inclined surface, the lead wire 7 can be surely brought into contact with the root of the pin terminal 5.

In this case, as shown in FIGS. 3 and 4, the width of the inclined surface of the protrusion 6 is such that the entangled wire, that is, the lead wire 7 entwined with the pin terminal 5 has a circular shape in contact with the pin terminal 5. The narrow bottom is made to enter the center or the inside of the pin terminal 5, the upper surface of the thick part of the root of the pin terminal 5 is formed in a concave shape, and the entanglement with the pin terminal 5 further increases the contact area of the lead wire 7. To improve reliability.

Further, the planar shape of the protrusion 6 is formed in a substantially inverted trapezoidal shape in which the connecting portion of the upper surface of the thick portion is narrow, so that the deviation of the entanglement line can be prevented.

Then, in order to make the connection between the lead wire 7 and the pin terminal 5 more complete, as shown in FIG. 5, the lead wire 7 is entwined about 3 to 5 times around the root of the pin terminal 5. wear.
Since the nozzle movement in this case is a planar circular movement B, workability is good. The end state of the entanglement work is as shown in FIG. A well-known core (not shown) is incorporated in the coil bobbin 1 to complete a pin terminal type small transformer.

After wrapping around each pin terminal 5, the connecting portion may be dipped in a lead-free solder bath. The number of entanglements to the protrusion 6 was increased to about 5 to 10 times, which was substantially the same as the diameter of the wire was increased. As a result, the proportion of tin is high, so that the copper erosion phenomenon is more likely to occur than before and is lead-free. Even if solder is used, the copper erosion phenomenon can be minimized.

[0028]

According to the present invention configured as described above,
It has the following advantages: a. Since the entwining work can be performed only by rotating the nozzle, the working time can be significantly shortened. b. As a lead-free measure, as described above, there is no choice but to increase the number of times the protrusions 6 are entangled. For example, even if the number of times is increased from 5 to 10 times, it is only necessary to rotate the nozzles, and as in the conventional case, the XYZ Since it is not three-dimensional, the number of steps can be shortened compared to the conventional one. c. Regarding the reliability of soldering, since the pin terminal 5 and the electric wire are always in contact with each other, the safety can be maintained without breaking even if the pin terminal 5 is bent.

[Brief description of drawings]

FIG. 1 is an external perspective view of a main part of an embodiment of the present invention.

FIG. 2 shows a side view of a main part of the embodiment.

FIG. 3 is a partial cross-sectional view of an essential part showing a first step of the step of entwining the leader wire in the example.

FIG. 4 is a plan view of a main part of the embodiment.

FIG. 5 shows a second (final) tying step in the same example.

FIG. 6 shows a conventional example.

[Explanation of symbols]

1 coil bobbin 2 flange 3 winding body 4 thick parts 5 pin terminal 6 protrusion 7 Leader 8 Drawout groove

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-58-125807 (JP, A) JP-A-6-96978 (JP, A) JP-A-10-37843 (JP, A) JP-A-8- 17654 (JP, A) JP 10-241986 (JP, A) Actual development 6-64297 (JP, U) Actual public 60-11622 (JP, Y1) International publication 00/018536 (WO, A1) 58) Fields investigated (Int.Cl. ⁷ , DB name) H01F 27/29 H01F 19/02 H01F 41/06 H01F 41/10

Claims (4)

(57) [Claims] 1. A pin terminal (5) is planted on a flange (2) of a coil bobbin (1), and an outer end surface of the flange (2) extends outward from a vicinity of a root portion of the pin terminal (5). A protruding portion (6) is formed, and a lead wire (7) of a coil wound around the coil bobbin (1) is hooked on the protruding portion (6), and then the base portion and the protruding portion of the pin terminal (5). (6) A small transformer that is connected to (6) several times and soldered to the root of the pin terminal (5), and the upper surface of the protrusion (6) is close to the pin terminal (5) from the outside. It is formed by an inclined surface that becomes lower as it is shredded, and the planar shape is a substantially inverted trapezoidal shape whose width becomes narrower on the pin terminal (5) side. Enter to the center or inside and connect to the upper surface of the thick part of the flange (2) Small transformers characterized by Rukoto. 2. When the leader line (7) is entangled with the small transformer according to claim 1, the leader line (7) is wound around the outer periphery of the protrusion (6) about 5 to 10 times. Then, the leader wire entanglement method in a small transformer is characterized in that the pin terminal (5) is entwined about 3 to 5 times around the root to entangle it. 3. The wire according to claim 2, wherein the lead wire (7) is wound around the protrusion (6) and the pin terminal (5) by a circular motion of a nozzle of an automatic winding machine. A method for tying a leader line in a small transformer, which is characterized in that 4. The method for tying a lead wire in a small transformer according to claim 2, wherein lead-free solder is used to connect the lead wire (7) and the pin terminal (5).