JPH03116911A - Transformer - Google Patents

Abstract

PURPOSE:To prevent generation of a defective solder connection in a soldering process conducted on the part of users by a method wherein a metal terminal is bent in Z-shape, a straight-lined part is fixed in sandwich form by pinching the part between a case and the wall of the bottom plate, and a user's metal terminal is exposed to outside. CONSTITUTION:The pectinated metal terminal 8 provided on the lower end flange of a bobbin, is bent downward almost at right angle, and a transformer main body, having an almost Z-shaped metal terminal 8 formed by bending its tip at right angle toward outside in horizontal direction, is incorporated into a plastic case 10 of almost square pectinated shape. A part 8i, which is located in the middle part of almost Z-shaped section which is bent toward the lower part of the metal terminal 8 of a transformer, is fixed in such a manner that the part 8i is pinched between the inner wall and a wall 13 having the grooves, on a plastic square-shaped tabular bottom plate 12, wherein each metal terminal will be fitted. The above-mentioned bottom plate 12 is inserted from the hole opened on a case 10. As a result, the incomplete soldering, short circuits due to soldering and the like generating in a user's soldering process can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to transformers used in various audio equipment, video equipment, industrial equipment, and the like.

Prior Art FIG. 5 shows a perspective view of a conventional transformer, and FIG. 6 shows a sectional view of the conventional transformer as seen from the side. First, the structure of the bobbin will be explained using FIG. 6. Lower end flanges 14° and lower end flanges 2 are provided at the upper and lower ends of the cylindrical portion 1, and plate terminals 8 a - d made of metal are attached to the lower end flanges 2. Attach by inserting or outsert in the lateral direction. Then, connect the lead wires 5a to 5d to the user metal terminal 8a.
- Wrap around the base of 8d by bending it downward at a certain angle, leaving a few millimeters of connection dimension, and then setting the tip at a certain angle so that it is at the same position as the bottom surface of the lower end flange 2 by 2 degrees. It has a structure in which user metal terminals 8a to 8d are bent outward. The process of winding the winding around the bobbin with the above structure will be explained using Figs. 5 and 6.
is wound on the cylindrical part 1, and the lead wire 5a at the beginning of the winding passes through the lead-out groove 15a provided in the lower end collar 2 and is connected to the base 8e of the user metal terminal 8a. Also, end of winding lead line 5
b passes through the pull-out groove 15b and is wound and connected to the base 8f of the user metal terminal 8b. Furthermore, the secondary coil 4 is wound on the primary coil 3 completed in this way, and the lead wire 5c at the beginning of the winding passes through the lead-out groove 15c provided in the lower end collar 2b in the same way as the primary coil 4, and is connected to the user metal terminal. The winding is connected to the base 8g of 8c. The process for the winding end lead wire is exactly the same as that for the secondary coil 3. As described above, the lead wires 5 are wound and connected to the bases 8e, 8f, 8g, and 8h of the user metal pin terminals 8a-b, 8c=d.
a-b, 5cmd are connected to user metal pin terminals 8a-b, 8cmd by soldering. Next, the E-type magnetic material 9 is inserted into the cylindrical part 1 of the bobbin from the upper and lower sides.
Furthermore, they are fixed with adhesive or tape to form a magnetic path and the transformer is completed.

Problems to be Solved by the Invention Generally, this type of transformer is used in a wide variety of ways. For example, they are used in many devices such as vacuum cleaners, irons, telephones, video cameras, and LCD televisions. Furthermore, as electronic devices are rapidly becoming smaller, lighter, thinner, more sophisticated, and more multifunctional, transformers are also required to have a structure that can be mounted on the surface of a printed circuit board. In addition, the operating conditions have become harsher, especially mechanical loads such as vibrations and shocks caused by dropping equipment during transportation and movement, as well as vibrations from ultrasonic cleaning during the set assembly process, which can affect transformer coil lead wires. This can lead to wire breakage and make the device completely unusable. This will be explained using FIG. The transformer is attached to the user's printed circuit board 16. Its structure consists of user metal pin terminals 8a, 8b, 8c, 8d provided on the transformer,
Several other empty terminals (user metal terminals 8 in FIG. 5) to which no lead wires are connected are placed on the cream solder applied to the conductive parts provided at specified locations on the printed circuit board 16, and then reflow soldered. By passing through the furnace, the lead wires 5a5b, 5c, and 5d of the transformer coil and a set of circuits are connected by soldering. When a load is applied to the transformer installed in this way, such as vibration or a drop impact, which moves it in the upper load direction 17a, the user metal terminals 8a, 8b, 8c, 8d of the transformer will Since it is soldered and fixed to the printed circuit board 16, the transformer body receives a load that moves in the upward load direction 17a.The primary coil lead wires 5a, 5b, and Manufacturer metal terminals 8e, 8f, 8g, and 8h to which the next coil lead wires 5c and 5d are wound and connected are subjected to a load in the downward load direction 17b. That is, the secondary coil lead wires 5a, 5b, the secondary coil lead wires 5
c and 5d are pulled in the upper load direction 17a and are cut at the corner of the bobbin. In addition, when vibration or drop shock is applied that causes the transformer body to move in the lateral load direction 18a, the same phenomenon as described above occurs, and the primary coil lead wires 5a and 5b are connected to the manufacturer's metal terminals 8e, If a load is applied in the pulling direction between 8f and the bobbin collar 2, and a force exceeding the allowable strength of the leader wire is applied, the wire will break. Further, vibrations 17a, 17b, or 18a with high frequency and small amplitude such as ultrasonic cleaning are applied.

When added in the direction of 18b, the winding is the connected manufacturer's metal terminals 8e, 8f, 8g, 8h, or the soldered primary and secondary lead wires 5a, 5b.

Coupled with the fact that 5c and 5d have become brittle due to soldering, phenomena such as metal fatigue progress, and eventually the lead wires are cut. Furthermore, if a large load is applied, the load applied to the manufacturer's metal terminals 8a to 8d will be directly transmitted to the lower end collar 2 of the bobbin, causing the root 1a connecting to the cylindrical portion 1 to break.

Also, the overall length of the user metal terminals 8a, 8b, 8c, and 8d is measured from the side of the lower end collar 2 of the bobbin to the manufacturer's metal terminal 8e.
, 8f, 8g, and 8h, the dimensions are a few millimeters of the lead wire winding part plus the dimension bent to the bottom at a certain angle,
Even if a slight impact is applied to the tip, it tends to deform vertically or horizontally, making it difficult to achieve precision. Therefore, during the user's soldering process, the user metal terminals 8a to 8d may float and create a gap between them and the printed circuit board 16, resulting in incomplete soldering, or the solder joint position may shift, resulting in incomplete soldering or other problems. Defects such as short circuits connected to the circuit will occur.

As mentioned above, if a device equipped with a transformer is dropped or subjected to impact during the ultrasonic cleaning process during the set assembly process, the metal terminals of the transformer may bend and wrap around the base, pulling the connected lead wire. This may cause the metal terminal to break, or the load applied to the metal terminal may be transmitted through the metal terminal and directly to the bobbin, causing the bobbin to break.Also, the exposed length of the metal terminal in a single transformer is vulnerable to impact. Even a small impact deforms the terminals, resulting in large variations in the terminal spacing and dimensions in the vertical direction, which has many drawbacks, such as frequent solder joint failures during the user's soldering process.

Means for Solving the Problems The technical means of the present invention for solving the above problems is to bend a comb-shaped metal terminal provided on the lower end flange of the bobbin downward at an almost right angle, and then bend the tip at a right angle outward horizontally. The main body of the transformer, which has a roughly double-shaped metal terminal, is assembled into a rectangular box-shaped plastic case with one side open. The bottom plate is fixed by being sandwiched between the inner wall of the case and a wall having grooves into which each metal terminal fits into a square plate-shaped bottom plate made of plastic, which is inserted and fitted through the open opening of the case. It is structured as follows.

The effect of this technical means is to bend the downwardly bent straight part in the middle of the metal terminal used by the user, which has a shape of bending downward at an almost right angle and then bending the tip outward at an almost right angle, into a plastic case. It has a structure in which it is sandwiched and fixed by the inner wall of the plastic bottom plate and the wall that grows the U-shaped groove provided with the plastic bottom plate. The shape of a so-called metal terminal is bent into a roughly two-shape combination of a - and an L, and the middle part, the straight part bent downwards, is sandwiched between the plastic case and the bottom wall and fixed in a sandwich-like manner. The structure is such that only the user metal terminals are exposed to the outside. As a result, the length of the metal terminal exposed to the outside is shortened, and even if a user applies a load to the tip of the metal terminal, it becomes difficult to deform due to the moment of force. When a load is applied to the metal terminal, the load is absorbed by the sandwiched portion between the case and the bottom plate, and is not transmitted to the base of the metal terminal inserted in the bobbin. Therefore, the lead wire connected to the base of the metal terminal will not be pulled and cut, and the bobbin will not be deformed even if the load is transferred to the metal terminal and the lower end flange of the bobbin. Since it does not reach 100%, it is possible to eliminate defects such as cracks and breakage.

EXAMPLE An example of the present invention will be described below. Figure 1 is a perspective view of the completed product of the present invention, Figure 2 is a sectional view of the completed product of the present invention,
FIG. 3 is a perspective view of the assembly process of the present invention, and FIG. 4 is a diagram showing the shape of a metal terminal that is insert-molded on the bobbin.

First, the shape of the metal terminal will be explained using FIG. 4. A user metal terminal and a manufacturer metal terminal 7 are provided as a pair and have a substantially U-shape in which their tips are connected. Then, a hoop 21 connected by a band having a specified width is provided on the back of the hoop 21, and a continuous hoop 21 is formed by press cutting.

The U-shaped tip of such a metal terminal will be described next. The bobbin is completed by insert molding into the lower end flange of the bobbin.

Next, the bobbin structure will be explained using FIG. 2. A lower end collar 14 is provided on the outer periphery of both ends of the cylindrical portion 1 made of plastic.
A lower end flange 2 is provided, and the lower end flange 2 has approximately U-shaped comb-shaped metal terminals 7a, 7b, 8a', 8b that are insert-molded.
' is attached in a direction parallel to the insertion direction of the magnetic members 9a and 9b. Manufacturer metal terminals 7a and 7b are user metal terminals 8a
'8b' is connected inside the lower end flanges 2a and 2b of the bobbin, and immediately after molding, the user metal terminal 8a8b
', but before winding starts, it is separated into individual bobbins, cut to a specified length as terminals for connecting lead wires 5 and 6, and bent at a nearly right angle at the bottom. . In addition, the shape of the user metal terminals 8a', 8b'' remains the same, and the back part is connected to metal terminals from other manufacturers.The lower end flanges 2a, 2b are provided with primary coil lead wires 5.
Lead-out grooves 15a and 15b are provided for the secondary coil lead-out wire 6 to pass through.

Next, the case 10 and the bottom plate 12 will be explained using FIG. 3. The case 10 is made of plastic and has a square box shape with one side open, and has a pair of undercuts 19 on the inner walls of both sides in the X direction.The bottom plate 12 is made of plastic and has a square shape several millimeters high on the top surface of the plate shape. Install a frame wall of Y
Several U-shaped bottom plate walls 13 are provided on both sides in the direction.

In addition, there are undercuts 19 of the case 10 on both sides in the X direction.
This structure is provided with a bottom plate protrusion 20 that is fitted into the bottom plate protrusion 20.

Next, the assembly process will be explained using FIG. 2.

The primary coil 3 is wound around the bobbin cylindrical portion 1, and the secondary coil lead wire 5 is wound and connected to the manufacturer's metal terminal 7a through the lead-out groove 15a provided in the lower end collar 2a. In addition, the next carp/P lead wire 5 is connected to the user metal terminal 8a' at the base part 8.
There is no problem in connecting the winding to g. In the same way, the secondary coil 4 is wound around the cylindrical part 1, and the secondary coil lead wire 6 is passed through the lead-out groove 15b of the lower end collar 2b and connected to the manufacturer's metal terminal 7b.
The windings are connected to. Further, it is acceptable to connect the winding to the base 8e of the user metal terminal 8b'. The bobbin lower end collars 2a, 2 of the completed wound coil
Manufacturer metal terminal 7a provided at b.

7b and the primary coil lead wire 5. It is connected to the secondary coil lead wire 6 by soldering. Manufacturer metal terminal 8a
The same applies to those connected to the bases 8g and 8e of ', 8b'.

Next, insert the E-type magnetic material 9a into the inner wall of the cylindrical part 1 from the left side,
The I-type magnetic material 9b is inserted from the right side, and the abutting surfaces are bonded or the outer periphery is wrapped with tape and joined to form a magnetic path. The forming process of the user metal terminals 8a' and 8b' of the completed magnetic material assembled coil will be explained with reference to FIG.

As described in the above description of the metal terminal and bobbin, the manufacturer's metal terminal 7 is cut to a specified size before winding starts, and is further bent at a substantially right angle below the lower end collar 2 of the bobbin.

On the other hand, the user metal terminals 8 are cut horizontally from the bobbin side end as shown in FIG. 2, 8a'' and 8b, and the backs of the respective metal terminals are connected while being separated and cut into individual bobbin pieces.

The process of bending such manufacturer metal terminals 8a', 8b' will be explained. A manufacturer's metal terminal 8a protrudes in the same direction as the insertion direction of the magnetic material 9 of the bobbin lower end collar 2 and has a back portion connected to another manufacturer's metal terminal.

8 is bent downward at a substantially right angle from the side end surface of the lower end flange 2, leaving a prescribed distance. It is then bent laterally and outwardly at a nearly right angle, leaving a specified distance. Such a process is completed simultaneously on the primary coil side manufacturer's terminal 8a side and the secondary coil side terminal 8b side.

Next, the assembly process will be explained using FIG. 3.

The transformer main body formed by forming the metal terminals completed as described above is inserted into a rectangular tree-like case 10 made of plastic with one side open, from the direction of the lower end collar 14 of the bobbin. As shown in FIG.
The structure is such that it comes into contact with the side inner wall 11 of the. Insulating resin is then injected into the case-assembled transformer in which the transformer main body is assembled into the case 10 from one open side of the case 10. Thereafter, the bottom plate protrusion 20 provided on the bottom plate 12 and the bottom plate wall 13 are inserted into the case 10 from the open side. At this time, the undercut portion 19 provided on the side inner wall of the case 10 is engaged with the bottom plate protrusion 20 provided on the bottom plate 12. In other words, the bottom plate protrusion 20
By setting the outside dimension of the hooked part to be larger than the inside dimension of the undercut provided on the inner wall of the case, the protrusion 20 of the bottom plate 12 is mechanically bonded and fixed to the undercut 19 of the case 10 by being pushed in and snapped into place. The structure is as follows. In addition, the bottom plate wall 13 having a groove stores the straight portion 81 of the user metal terminal 8 bent downward in the groove, and fixes it by sandwiching it between the case inner wall 11 and the bottom plate wall 13 as shown in FIG. The structure becomes

The transformer in which the case 10 and the bottom plate 12 are assembled as described above is manufactured by cutting off the hoop part 21 at the back to which the user terminals 8a and 8 are connected to a specified length, and converting the transformer according to the present invention as shown in FIG. The vessel is completed.

The transformer completed as described above will be explained using FIG. The lower linear bent portion 81 of the user metal terminal 8b is sandwiched and fixed between the side inner wall 11 of the case 10 and the bottom wall 13 of the bottom plate 12, and furthermore, the bottom wall 13
The structure has a recessed groove into which the metal terminal 81 fits.

Therefore, the protruding dimension from the transformer is the manufacturer's metal terminal 8b.
In addition to being short in size, the case inner wall 11 and bottom plate wall 13
Since it is firmly held by the user metal terminal 8b, it is difficult to deform even if a small amount of weight is applied to the tip of the user metal terminal 8b, and the manufacturer's metal terminal can be made solid. Furthermore, even if the tip of the manufacturer's metal terminal 8b is deformed due to load applied during the assembly process, it can be corrected by the bottom plate wall 13 having a concave groove of the bottom plate 12 shown in FIG. Also, the bottom plate wall 13 of the bottom plate 12 is attached to the inner wall 11 of the case 10,
Correction can be made by inserting the user metal terminal 81 while pinching it. Therefore, the dimensional accuracy in the vertical direction with respect to the surface of the printed circuit board 16 and the dimensional accuracy in the X direction in FIG. 3, which are the performance most strongly required of a surface mount transformer, can be greatly improved. Further, a case where the device is attached to a user's printed circuit board 16 and soldered, and is further incorporated into a device and subjected to a drop impact will be described with reference to FIG. The user metal terminals 8a and 8b of the transformer are soldered to the user printed circuit board 16, and if the transformer body is subjected to a load that moves in the upward load direction 17a, the transformer will be pulled away from the printed circuit board 16. The portions that receive the added weight apply a force that causes the user metal terminals 8a, 8b to be torn off. However, since the bent portion 81 of the user metal terminal 8b is sandwiched and fixed between the inner wall 11 on the side surface of the case and the bottom plate wall 13, the weight is absorbed by the user metal terminal 8b and the bottom plate wall 13, and the bobbin It is not transmitted to the lower end flange 2b, and the lower end flange 2a, 2
The base of b and the cylindrical part 1 will not be damaged. Also, a user metal terminal 8a.

Even when the primary coil and secondary coil lead wires 5 and 6 are wound and connected to the bases 8a and 8g of 8b, the falling load is not transmitted to the manufacturer's metal terminals 8e and 8g, so no deformation occurs, and the -next .

The secondary coil lead wire 5.6 is no longer pulled and cut.

Next, when the transformer receives a load that causes it to move in the downward load direction 17b, the load is received by the bottom plate 12 attached to the transformer and the user metal terminals 8a and 8b. This is similar to the case where the load is applied in the upper load direction 17a, since the load on the user metal terminals 8a and 8b is fixed as a sandwich between the side inner wall 11 of the case 10 and the bottom plate wall 13 of the bottom plate 12. It is absorbed in the lower end of the bobbin 2
a.

2b, and the bobbin lower end collar 2a.

This prevents cracking at the base of the cylindrical portion 2b and the cylindrical portion 1, and prevents the secondary coil lead wires 5 and 6 from being pulled and cut. Also, if the transformer body is subjected to a load such that it moves in the lateral load direction 18a, the transformer will move in the direction of 18a and vice versa.

Since 8b is soldered to the printed circuit board 16, it receives a force in the opposite direction 18b. In such a case, the bent straight portion 81 of the user metal terminal 8b will be connected to the bottom plate wall 13.
Since the case inner wall 18 is sandwiched and fixed, the load applied to the manufacturer's metal terminals 8a, 8b is absorbed by the bottom plate wall 13 and the inner wall 11 on the side of the case, and the bobbin lower end flanges 2a, 2b and The structure is such that no weight is transmitted to the metal terminals 8e and 8f, which are the connecting portions of the secondary coil 5.6.

As described above, in the transformer of the present invention, soldering defects in the user soldering process can be reduced by making the dimensional accuracy of the user metal terminal extremely high in the surface direction or the lateral direction. Furthermore, after being installed in a device, it is possible to obtain a highly reliable transformer that will not be damaged or the coil lead wires will be disconnected even if it is subjected to loads such as drop impact and vibration during the cleaning process.

The present invention, as described in detail, involves insert-molding a comb-shaped metal terminal into the lower end flange of the bobbin, cutting it into individual pieces, bending the metal terminal to be connected to the user downward leaving a specified dimension, and then cutting the tip of the metal terminal. A bobbin with a substantially Z-shaped terminal bent outward horizontally at a nearly right angle, and the inner wall of a square tree-shaped plastic case with one side open at the downwardly bent straight part, which is the middle part of the user metal terminal. Furthermore, a rectangular plate-shaped bottom plate made of plastic is provided with a wall having a concave groove into which the metal terminal fits, and by inserting and fitting the bottom plate through the case opening, the middle of the metal terminal The lower bent linear part of the part is fixed in a sandwich-like manner between the inner wall of the case and the wall of the bottom plate. With the above structure, the exposed dimension of the user metal terminal is shortened, and the middle part Due to the structure that is fixed between the case and the bottom plate,
The solid structure prevents deformation even if a small amount of weight is applied to the tip, and when inserting the bottom plate into the case, even if the metal terminal becomes deformed, it will be corrected by the wall with a concave groove on the bottom plate.
The metal terminal is housed in the groove in the bottom plate while the metal terminal is being held. In addition, since the downwardly bent linear part, which is the middle part of the metal terminal, is fixed to the inner wall of the case and the wall of the bottom plate in a sandwich-like manner, even if the metal terminal is deformed in the vertical direction, it will be corrected when inserting the bottom plate. become.

As described above, the dimensional accuracy with respect to the printed circuit board surface, which is the required performance of surface mount transformers, or the dimensional accuracy with respect to the foil of the conductive part of the board can be significantly improved, and the user soldering process Solder defects such as incomplete soldering and solder short circuits can be significantly reduced.

In addition, even if a drop impact load or vibration load due to cleaning process etc. is applied after installation in the device, the load applied to the user metal terminal is absorbed by the portion fixed in a sandwich-like manner between the case inner wall and the bottom plate wall, and the bobbin The load will not be transmitted to the lower end collar and the bobbin base of the user metal terminal, so if the lower end collar of the bobbin is damaged or the lead wire is connected, the lead wire may be pulled and disconnected. Significant improvements can be made in terms of quality and reliability, such as by eliminating the occurrence of such problems.

[Brief explanation of drawings]

Fig. 1 is a perspective view of one embodiment of the transformer of the present invention, Fig. 2 is a sectional view of the same side, Fig. 3 is an exploded perspective view of the transformer main body and bottom plate after the case, winding, and core are assembled; FIG. 4 is a top view showing a metal terminal inserted into the bobbin of the present invention, FIG. 5 is a perspective view of a conventional transformer, and FIG. 6 is a side sectional view of the conventional transformer. 1...Cylindrical part, 2...Lower end flange, 3...
...-Secondary coil, 4...Secondary coil, 5.
・・・・・・−Secondary coil lead wire, 6...Secondary coil lead wire, 7...Manufacturer metal terminal, 8.
...User metal terminal, 9...Magnetic material,
10... Case, 11... Case inner wall, 12... Bottom plate, 13... Bottom plate wall, 1
4...Top end flange, 15...Drawer groove, 1
6... Printed circuit board, 17... Vertical load direction, 18... Lateral load direction, 19...
・Case undercut, 20...bottom plate protrusion,
21... Hoop.

Claims (1)

[Claims] A cylindrical part made of a plastic molded product with a magnetic material passing through it in the center and a coil wound around the outer periphery, and a pair of lower end flanges provided at both lower ends of this cylindrical part with comb-shaped metal terminals insert-molded, The comb-shaped part of this metal terminal is bent downward at an almost right angle, and the tip thereof is bent at a right angle outward in the horizontal direction to form a substantially Z-shaped metal terminal, and the transformer body having the above structure is left open on one side. The transformer body is inserted into a rectangular box-shaped plastic case, and then the straight part located in the middle of the almost Z-shape bent below the metal terminal of the transformer body is inserted into the inner wall of the case and a square plate-shaped plastic case. On the bottom plate of
A transformer comprising a bottom plate which is fixed by being sandwiched between a wall having concave grooves into which each metal terminal fits, and which is inserted and fitted through an open opening of the case.