JP4531736B2 - Transformer unit - Google Patents

Description

The present invention relates to a transformer unit used in an inverter type high frequency heating apparatus or the like.

  As shown in FIG. 17, the inverter-type high-frequency heating device includes a transformer unit 73 in which a transformer 72 is mounted on a printed circuit board 71.

  Here, the circuit of the transformer unit 73 will be described with reference to FIG.

  The commercial power supply 74 is full-wave rectified by a rectifier circuit 75 such as a diode bridge, converted into a high-frequency voltage by an inverter 76, and applied to the primary winding 77 of the transformer 72. As a result, a high-frequency high voltage of several kV is generated in the secondary winding 78 of the transformer 72. The high frequency high voltage is rectified by a voltage doubler rectifier circuit 81 including a capacitor 79 and a diode 80. Thereby, a high voltage is applied to the magnetron 82 which is a microwave generator. The heater winding 83 of the transformer 72 is connected to the filament 84 of the magnetron 82 and heats the filament 84. The magnetron 82 oscillates microwaves by heating the filament 84 and applying a high voltage.

  As shown in FIG. 19, the transformer 72 used in the transformer unit 73 has a bobbin 85 in which a primary winding 77, a secondary winding 78, and a heater winding 83 are concentrically wound. A core 86 is inserted into the center of the bobbin 85 from both sides. As shown in FIG. 20, the transformer 72 has a primary connection pin 87, a secondary connection pin 88, a heater connection pin 89, and a ground connection pin 90 on the bottom thereof. The printed circuit board 71 is inserted into a through hole of the mounting destination and connected to the circuit pattern of the printed circuit board 71 by soldering.

FIG. 21 shows an example of the circuit pattern of the printed circuit board 71. The primary connection pin 87, the secondary connection pin 88, the heater connection pin 89, and the ground connection pin 90 of the transformer 72 are inserted. Through holes 87A, 88A, 89A, 90A are formed.
Of these through-holes, through-holes 88A and 89A through which the secondary connection pins 88 and heater connection pins 89 of the transformer 72 are inserted are formed in the high-voltage component region A, respectively. In addition, in this high voltage component region A, in addition to a part of the transformer 72 being mounted, high voltage components constituting the voltage doubler rectifier circuit 81 such as a capacitor 79 and a diode 80 are mounted. Further, various parts constituting a weak voltage circuit such as a control circuit are mounted in an area other than the high voltage parts area A of the printed circuit board 71.

Note that the transformer having the configuration shown in FIG. 19 is described in Patent Document 1, for example.
JP 2001-189221 A (FIG. 3)

  By the way, since the high frequency heating apparatus is required to be compact and highly functional, the size of each part is reduced and parts with higher added value are used.

  However, high-voltage components such as the capacitor 79 and the diode 80 that constitute the voltage doubler rectifier circuit 81 are extremely large components as compared with the components that constitute the control circuit, and a space for mounting these high-voltage components is ensured. In addition, the high voltage component area A of the printed circuit board 71 becomes large.

  In addition, in the transformer unit 73 described above, it is necessary to widen the interval between the circuit patterns in order to prevent leakage between the primary side that is the input side of the transformer 72 and the high-pressure secondary side that is the output side. Thus, the high-voltage component region A on the printed circuit board 71 has to be made large.

  As described above, in the transformer unit 73 having the above structure, since the high-voltage component area A must be made large, it is difficult to satisfy the demand for a compact high-frequency heating device because the printed circuit board 71 itself is enlarged. It was.

  On the other hand, as shown in FIG. 22, high voltage components such as a capacitor 79 and a diode 80 constituting the voltage doubler rectifier circuit 81 are mounted on another small board 91, and the small board 91 is erected on the printed board 71. Things are also done. However, in such a configuration, a small substrate 91 is separately required, resulting in an increase in cost. Further, the small substrate 91 occupies a large installation space in the printed circuit board 71, which hinders downsizing. turn into.

  The present invention has been made in view of the above circumstances, and without compromising the performance of the transformer and without increasing the cost, the occupied space in the printed circuit board can be reduced to save space, and the size of the unit can be reduced. It is an object of the present invention to provide a transformer that can be realized and a transformer unit including the transformer.

  In order to achieve the above object, a transformer according to a first aspect of the present invention includes a bobbin around which at least a primary winding and a secondary winding are wound, and a core inserted through the center of the bobbin. The transformer is mounted on the outer peripheral portion of the transformer except for the mounting side on the printed circuit board.

  The transformer of the second invention is characterized in that the component holding portion is formed on a side surface of the bobbin.

  In the transformer according to the first or second aspect of the present invention, the component holding portion that holds the component is provided in the outer peripheral portion excluding the side mounted on the printed circuit board such as the side surface of the bobbin, so that the component is held in the component holding portion. By doing so, the number of components to be mounted on the printed circuit board can be reduced. Therefore, the size of the printed circuit board can be reduced without sacrificing the performance of the transformer and without increasing the cost, and the transformer unit in which the transformer is mounted on the printed circuit board can be downsized. . Thereby, it is possible to obtain a configuration suitable for use in, for example, a high-frequency heating device or the like, which is required to be compact and highly functional.

  The transformer according to a third aspect is characterized in that the component holding portion is formed on a component fixing plate separate from the bobbin, and fixes the component fixing plate to the bobbin.

  In this transformer, since the component holding part is formed on the component fixing plate separate from the bobbin, the component mounting operation is performed on the component fixing plate alone, thereby simplifying the operation. In addition, automatic assembly of parts is facilitated, and assembly costs can be reduced.

  In the transformer according to a fourth aspect of the invention, the bobbin includes a bobbin base on which at least the primary winding and the secondary winding are wound, and a side end flange portion attached to one end of the bobbin base. The component holding part is formed in the end flange part.

  In this transformer, the bobbin is divided into a bobbin base and a side end flange, and a part holding part is formed on the side end flange that is separate from the bobbin base. This is performed for a single unit, and the work can be simplified.

  According to a fifth aspect of the present invention, there is provided a transformer according to a fifth aspect of the present invention, further comprising an insulating cover that covers the component held by the component holding portion and is attached to the bobbin side.

  In this transformer, by covering the component held by the component holding portion with an insulating cover, it is possible to prevent occurrence of a short circuit and ensure high safety.

  The transformer according to a sixth aspect is characterized in that an end of the secondary winding is provided so as to protrude from an outer peripheral portion excluding the side mounted on the printed circuit board.

  In this transformer, since the end portion of the secondary winding protrudes from the outer peripheral portion excluding the mounting side on the printed circuit board, for example, the secondary winding can be directly connected to the end portion. The circuit pattern in can be reduced. In particular, the circuit pattern in the high-voltage component region, which has had to increase the spacing between the patterns because of the high voltage, can be eliminated, and the printed circuit board can be greatly downsized.

  In addition, the transformer of the seventh invention is configured such that the lead wire of the component held in the other component holding portion and at least the connecting end portion of the secondary winding with respect to the lead wire of the component held in the component holding portion. One of them is connected.

  In this transformer, the lead wires of the components held in the component holding portion or the lead wires and the end portions that become the lead wires of the secondary winding are directly connected and connected, so that the circuit pattern on the printed circuit board can be further reduced and simplified. Can be achieved.

  According to an eighth aspect of the present invention, there is provided a transformer unit comprising the transformer according to any one of the first to seventh aspects mounted on a printed circuit board, the high frequency high voltage from the secondary winding of the transformer. The high voltage component which comprises this voltage doubler rectifier circuit is hold | maintained at the said component holding part.

  In this transformer unit, a relatively large high-voltage component that constitutes a voltage doubler rectifier circuit that rectifies high-frequency high voltage from the secondary winding is held in the component holding part of the transformer. The occupied space can be minimized, and miniaturization can be achieved without sacrificing the performance of the transformer and without increasing the cost. Thereby, it is possible to obtain a transformer unit suitable for use in, for example, a high-frequency heating apparatus that is required to be compact and highly functional.

  In the transformer unit of the ninth invention, the connection end of the secondary winding is directly or indirectly connected to the lead wire of the high-voltage component via a post protruding on the bobbin. It is characterized by that.

  The conductor wire used for the secondary winding is very thin, so when assembling the transformer to the printed circuit board, it is connected to the connection pin due to run-out or backlash of the component holding part due to the operating force during assembly. If a certain tension or more is applied to the connection end of the secondary winding, the secondary winding may be cut.

  However, since the connection end of the secondary winding is directly or indirectly connected to the lead wire of the high voltage component through the post protruding on the bobbin, the lead wire of the high voltage component is displaced. However, the displacement can be absorbed by the space of the secondary winding spanned between the post and the lead wire, and the secondary winding can be prevented from being cut.

  In addition, by temporarily holding the secondary winding on the post, when soldering to the lead wire of a high voltage component, it is possible to eliminate the weakening of the winding due to copper cracking due to high-temperature solder corresponding to the recent lead-free .

  A transformer unit according to a tenth aspect of the present invention is a structure in which a plate-shaped relay terminal is joined to a lead wire of the high-voltage component that connects the connection end of the secondary winding, and the connection end of the secondary winding is connected. The relay terminal is connected to the relay terminal.

  The conductor wire used in the secondary winding is very thin as described above. Therefore, the solder wire is weakened by copper cracks, etc., and the non-solder joint such as fusing is welded. Because of the weakening caused by damage, the connecting end of the secondary winding connected to the connecting pin when the transformer is assembled to the printed circuit board or the component holding part is shaken or rattled due to vibration after assembly. If a certain tension or more acts on the wire, there is a risk of cutting.

  However, in this transformer unit, the connecting pin may be shaken or wobbled due to the operating force during assembly, etc., and the high-voltage component to which the connection end of the secondary winding is connected due to the wobbling or wobble Even if it is displaced, the displacement is absorbed by the relay terminal and the post which is a preliminary holding portion thereof, and the secondary winding is used to prevent the tension more than a certain level from acting on the connecting portion between the secondary winding and the terminal portion. As a result, the reliability against vibration during assembly of the transformer to the substrate or during transportation on the way is improved.

  According to an eleventh aspect of the present invention, there is provided a transformer unit according to any one of the eighth to tenth aspects, wherein the electrical connection between the lead wires of the high voltage components on the component holding portion is performed by a heat sink. It is performed through a plate-like connection terminal that also serves as a connector.

  In this transformer unit, the plate-like connection terminals used for electrical connection between the lead wires of high-voltage components have, for example, a wide heat dissipation surface with respect to the lead wires of these components. Because it excels, heat generated by each high-voltage component is efficiently dissipated into the surrounding atmosphere, suppressing the temperature rise of each high-voltage component, and at the same time suppressing the stress generated in the connection due to the thermal expansion of the component, It is possible to improve the operational stability of each high-voltage component and the life of the connection part.

  A transformer unit according to a twelfth aspect is the transformer unit according to any one of the eighth to eleventh aspects, wherein a pair of diodes connected in series with the voltage doubler rectifier circuit is connected in series. The capacitor is such that the lead terminal of the diode is individually connected to one lead of the heater winding incorporated in the transformer, and the lead terminal of the capacitor is individually connected to the other lead of the heater winding. Features.

  In this transformer unit, when the diode and capacitor of the voltage doubler rectifier circuit are connected to the heater winding built in the transformer, the heater winding side connection between these diode and capacitor is connected to the heater with a single jumper wire. Although it is possible to connect to one lead of the winding, in such a connection structure, a dummy terminal is used on the printed circuit board to support the other lead of the heater winding on the wiring path. Becomes indispensable.

  However, as described above, the diode lead terminal is connected to one lead of the heater winding, and the capacitor lead terminal is connected to the other lead of the heater winding, respectively. Thus, the pair of leads of the heater winding can be stably supported on the wiring path of the printed circuit board, and the use of dummy terminals can be omitted.

  A transformer unit according to a thirteenth aspect is the transformer unit according to any one of the eighth to twelfth aspects, wherein the voltage doubler rectifier circuit and the core are connected to the print via a common ground connection terminal. It is connected to a ground terminal on the substrate.

  In this transformer unit, since one earth connection terminal serves as both the earth connection of the voltage doubler rectifier circuit and the earth connection of the core, the number of use of the earth connection terminals is reduced as compared with the case where the earth connection is individually made. At the same time, the work process of ground connection can be reduced, and the productivity of the transformer unit can be improved and the cost can be reduced by reducing the number of parts.

  A transformer unit according to a fourteenth aspect of the invention is the transformer unit according to the thirteenth aspect of the invention, wherein the ground connection terminal is connected to a lead connection portion of a high voltage component constituting the voltage doubler rectifier circuit. A core connecting portion connected to the earth contact, and between the lead connecting portion and the substrate connecting portion, a core connecting portion that elastically contacts the outer surface of the core and realizes conduction with the core. It is characterized by having a provided configuration.

  In this transformer unit, the ground connection terminal can connect the high voltage component and the core to the ground terminal on the printed circuit board with a relatively simple structure including the lead connection portion and the core connection portion.

  In the transformer unit according to the fifteenth aspect of the invention, a partition wall is provided on the outer periphery of the bobbin where the component holding portion is formed to separate the core and the high voltage component held by the component holding portion. It is characterized by that.

  In this transformer unit, a partition wall protruding from the bobbin is disposed between the core and the high-voltage component, and the linear communication between the core and the high-voltage component is lost. The insulation effect between the voltage component and the core to be grounded is increased. As a result, it is possible to reliably prevent a decrease in insulation due to discharge between the core and the high-voltage component and dust accumulated over a long period between the core and the high-voltage component. In addition, since the insulation effect between the high-voltage component and the core is enhanced, the gap between the core and the high-voltage component can be reduced compared to a structure without a partition wall, and the transformer unit can be made more compact. Can also be achieved.

  The transformer unit of the sixteenth invention is the transformer unit of the fifteenth invention, characterized in that the partition wall is extended higher than the protruding height of the high-voltage component from the bobbin. .

  In this transformer unit, the partition wall extends higher than the protruding height of the high-voltage component from the bobbin, so that the insulation distance between the core and the high-voltage component can be further increased by keeping the insulation distance long. .

  According to the transformer of the present invention and the transformer unit including the same, since the component holding portion for holding the component is provided in the outer peripheral portion excluding the mounting side on the printed circuit board, the high voltage component is held in the component holding portion. By doing so, it is possible to eliminate the mounting of high voltage components on the printed circuit board. Therefore, the printed circuit board can be reduced without sacrificing the performance of the transformer and without increasing the cost, and the transformer unit can be reduced in size. Thereby, it can be set as a transformer unit suitable for a high frequency heating apparatus in which compactness and high functionality are required.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a transformer of the present invention and a transformer unit including the transformer will be described with reference to the drawings.

  1 is a sectional view and a side view of a transformer according to the present invention, FIG. 2 is a perspective view of the transformer, and FIG. 3 is a perspective view of a transformer unit.

  As shown in FIGS. 1 to 3, a transformer 11 mounted on a transformer unit of the present invention is mainly composed of a resin bobbin 13, a primary winding 15 wound around the bobbin 13, and a secondary winding. It is composed of a wire 17, a heater winding 19, and a core 21.

  The core 21 is composed of an I-shaped core 21a having a rectangular cross section inserted through the center of the bobbin 13, and a U-shaped core 21b having a U-shape in side view connected to both ends of the I-shaped core 21a. These are mounted on the printed circuit board 23 with the U-shaped core 21b facing downward.

  The bobbin 13 has a plurality of (four in total in the present embodiment) component holding parts each including a pair of sandwiching pieces 25 and 27 on its side surface. The capacitor 31 that is a high-voltage component that constitutes is sandwiched between the pair of sandwiching pieces 27, and the diode 33 is sandwiched between the pair of sandwiching pieces 25.

  In addition, although the component holding | maintenance part of this embodiment is formed in the side surface of the bobbin 13 by spaced apart about a thickness of a high voltage component and standing up a pair of clamping pieces 25 and 27, respectively, As long as it can hold | maintain, not only this clamping piece 25 and 27 but the thing of what kind of structure may be sufficient.

  Further, the lead wires of the capacitor 31 and the diode 33 as high-voltage components are provided so as to protrude from the outer peripheral portion excluding the mounting side on the printed circuit board 23, and the secondary winding 17 and the heater winding 19 are connected to these lead wires. The connection ends are connected to each other based on circuits. Therefore, a connecting cord from a magnetron or the like is directly connected without passing through the printed board 23 at the outer peripheral portion of the transformer 11 excluding the side mounted on the printed board 23.

  Thus, according to the transformer 11 and the transformer unit 100 in which the transformer 11 is mounted on the printed circuit board 23, a component holding unit that holds high-voltage components such as the capacitor 31 and the diode 33 is provided on the side surface of the bobbin 13. Since the high voltage component is held in the component holding portion, the high voltage component to be mounted on the printed circuit board 23 can be eliminated.

  Thereby, the size of the printed circuit board 23 can be reduced without sacrificing the performance of the transformer 11 and without causing an increase in cost, and the transformer unit 100 can be downsized. And it can be set as the transformer unit 100 suitable for using for the high frequency heating apparatus with which compactization and high functionality are requested | required.

  Further, since the connection end portions of the secondary winding 17 and the heater winding 19 are connected to the outer peripheral portion of the transformer 11 except for the mounting side on the printed circuit board 23, a connection cord from a magnetron or the like is connected via the printed circuit board 23. Therefore, it is possible to connect directly to the transformer 11. As a result, the circuit pattern on the printed circuit board 23 can be reduced. In particular, the high voltage circuit pattern of the transformer 11 that has had to increase the interval between the patterns because of the high voltage can be eliminated. For this reason, as shown in FIG. 3, the printed circuit board 23 can be significantly reduced in size.

  In addition, the lead wires of the high voltage components such as the capacitor 31 and the diode 33 held in the component holding portion are at least one of the lead wires of the other high voltage components, the connection ends of the secondary winding 17 and the heater winding 19. Since these are directly connected, the circuit pattern on the printed board 23 can be further reduced and simplified.

  Note that the mounting direction of the transformer 11 on the printed circuit board 23 is not limited to the direction in which the U-shaped core 21b of the core 21 shown in FIG. The I-type core 21a may be arranged perpendicular to the printed circuit board 23. As shown in FIG. 5, the I-type core 21a is arranged parallel to the printed circuit board 23 and the U-shaped core 21b. May be arranged on the side of the transformer 11, or as shown in FIG. 6, a high voltage component may be arranged on the lower printed circuit board 23 side.

  In the configuration of the transformer unit 200 shown in FIG. 4, a gap corresponding to the protrusion of the I-type core 21 a from the bobbin 13 is generated between the side surface of the bobbin 13 below the transformer 11 and the printed board 23. A component 41 having a flat shape or the like can be mounted. For this reason, the mounting surface of the printed circuit board 23 can be used effectively, and space efficiency improves. Further, the height of the transformer 11 from the surface of the printed circuit board 23 is suppressed, and the mounting stability is improved. Furthermore, since the high-voltage components that generate heat are arranged on the upper surface, heat transfer to other parts of the transformer 11 during heat dissipation can be suppressed, and the influence of the high-voltage components on the transformer 11 can be eliminated.

  On the other hand, in the configuration of the transformer unit 300 shown in FIG. 5, the flat primary winding 15, the secondary winding 17, and the heater winding are arranged as a vertical type similarly to the configuration shown in FIG. 3. Therefore, the mounting area of the printed circuit board 23 can be improved.

  Further, in the configuration of the transformer unit 400 shown in FIG. 6, the distance between each winding and the printed board becomes long, and it is possible to prevent noise from being superimposed on the circuit of the printed board as much as possible.

  In each of the transformer units 100 to 400, the terminal of the heater winding and the lead wire terminal connected to the magnetron are arranged on the transformer 11 side. However, these terminal portions may be connected to the printed circuit board 23. Good. In other words, these terminal portions are connected to the circuit pattern of the printed circuit board 23, and the printed circuit board 23 is connected to the magnetron through a tab terminal or the like by a high-voltage lead wire. Thus, by changing the length of the high voltage lead wire connecting the printed circuit board 23 to the magnetron, there is no need to change the wiring length to the magnetron for each type of unit, and the type of transformer unit and the high voltage Complicated assembly work such as adjusting the combination with the lead wire can be prevented. Furthermore, this makes it possible to make the component surface on the side surface of the bobbin 13 limited in size into an orderly array of components. In this case, the circuit pattern for high voltage insulation required for the printed circuit board 23 is only one high potential, and can be accommodated in a slightly increased area.

  Next, a modification of the transformer of this embodiment will be described.

  The transformer 11 shown in FIG. 7 uses two U-shaped cores 35a and 35b formed in the same shape instead of the core 21 including the I-shaped core 21a and the U-shaped core 21b. 35 a and 35 b are inserted from both ends of the bobbin 13. In addition, the part inserted in the bobbin 13 of these U-shaped cores 35a and 35b is formed in the cross-sectional circle shape.

  According to this configuration, by forming the cores 35a and 35b in the same shape, the productivity of the cores 35a and 35b is improved, and the assembly work can be simplified because it is not necessary to distinguish between them. . Moreover, in this transformer 11, the winding part of the winding of the center of the bobbin 13 can also be made circular in cross section, and thereby the winding work of the primary winding 15, the secondary winding 17 and the heater winding 19 can be performed. This can be carried out smoothly without being affected by the peripheral speed change in the case of a square cross section.

  Here, another method for attaching the high-voltage component to the above-described transformer 11 will be sequentially described with reference to FIGS.

  In the form shown in FIG. 8, the high voltage component is provided on the component fixing plate 43 formed separately from the bobbin 13 on the bobbin 13 around which the primary winding 15, the secondary winding 17 and the heater winding 19 are wound. Is configured to be attached. The component fixing plate 43 is formed with clamping pieces 25 and 27 as an example of a component holding portion, and fixes the capacitor 31 and the diode 33 which are high voltage components. According to this configuration, the high voltage component is assembled to the component fixing plate 43 before the winding process of each winding, and the component fixing plate 43 is connected to the bobbin 13 by the joining means (not shown), and the component fixing plate 43 and the bobbin 13 are connected. The winding process can be performed in a state in which and are integrated. This makes it possible to easily handle the winding ends by connecting the ends of each winding to the lead wires of high-voltage components, etc. after winding processing, improving workability and improving the handling of the transformer itself. it can.

  Next, in the form shown in FIG. 9, the high voltage component attached to the side of the bobbin 13 is covered and an insulating cover 45 attached to the bobbin 13 is provided. By attaching the insulating cover 45 to the side of the bobbin 13, the high-voltage components 31 and 33 are accommodated inside the insulating cover 45 and are not exposed to the outside. Thereby, generation | occurrence | production of a short circuit etc. can be prevented and high safety | security can be ensured.

  In addition, the insulating cover 45 may have a configuration in which a component holding portion for fixing a high voltage component is formed on the inner surface and the high voltage component is fixed on the insulating cover 45 side. The insulating cover 45 is preferably provided with a heat radiating hole for releasing heat from the high voltage component as appropriate.

  Next, in the form shown in FIG. 10, the bobbin includes a bobbin base 47 that winds at least the primary winding and the secondary winding, and a side end flange portion 49 that is attached to one end of the bobbin base 47. A component holding portion is formed on the end flange portion 49. More specifically, the bobbin base 47 has a core portion 47a and a flange portion 47b so that the primary winding and the secondary winding can be wound, and the side end flange portion 49 winds the heater winding. A space for rotation is formed by the inner flange 49a and the outer flange 49b. On the outer surface of the outer flange 49b, sandwiching pieces 25 and 27 as an example of a component holding portion for fixing a high voltage component are formed. The bobbin base 47 and the side end flange portion 49 are connected and integrated by a joining means (not shown).

  According to this configuration, before the winding process of each winding of the bobbin base 47, the high-voltage parts are assembled to the side end flange portion 49 and the heater winding is attached, and the side end flange portion 49 is connected to the bobbin base 47. In the state where the bobbin base 47 and the side end flange portion 49 are integrated, the winding process of the primary winding and the secondary winding can be performed. This makes it possible to easily handle the winding ends by connecting the ends of each winding to the lead wires of high-voltage components, etc. after winding processing, improving workability and improving the handling of the transformer itself. it can.

  Thus, since the component holding part is formed on a member separate from the bobbin base 47, the component mounting operation is not complicated and the operation can be simplified. In addition, automatic assembly of parts is facilitated, and assembly costs can be reduced.

  11 to 14 show still another embodiment of the transformer unit according to the present invention.

  The transformer 11 used in the transformer unit 500 of this embodiment has a pair of U-shaped cores 35 a and 35 b inserted from both ends of the bobbin 13, and the core that goes around the outside of the bobbin 13 is the printed circuit board 23. It is attached to the printed circuit board 23 in a form that becomes a side position of the bobbin that is a certain distance away from.

  Also in the transformer 11 of the present embodiment, since the central axis of the bobbin 13 is parallel to the printed circuit board 23, the primary winding 15, the secondary winding 17, and the heater winding 19 are vertical with respect to the printed circuit board 23. Arrangement.

  As shown in FIG. 12, the secondary winding 17 and the heater winding 19 of the bobbin 13 are lead wires for high voltage components that constitute a voltage doubler rectifier circuit 93 that rectifies the high frequency high voltage from the secondary winding 17. Clamping pieces 26 and 28 are projected as component holding portions for clamping the.

  Each of the sandwiching pieces 26 and 28 is formed with an engaging groove in which a lead wire is tightly fitted at the tip. The sandwiching piece 26 is for holding the diode 33, and the sandwiching piece 28 is for holding the capacitor 31.

  The circuit of the transformer unit 500 of the present embodiment has the configuration shown in FIG.

  The commercial power supply 74 is full-wave rectified by a rectifier circuit 75 such as a diode bridge, converted into a high-frequency voltage by an inverter 76, and applied to the primary winding 15 of the transformer 11. As a result, a high-frequency high voltage of several kV is generated in the secondary winding 17 of the transformer 11. The high frequency high voltage is rectified by a voltage doubler rectifier circuit 93 including a capacitor 31 and a diode 33. Thereby, a high voltage is applied to the magnetron 82 which is a microwave generator. The heater winding 19 of the transformer 11 is connected to the filament 84 of the magnetron 82 and heats the filament 84. The magnetron 82 oscillates microwaves by heating the filament 84 and applying a high voltage.

  In the case of the present embodiment, the capacitor 31 and the diode 33 as high voltage components arranged on the component holding unit are connected to the lead wire L connected to the secondary winding 17 and the heater winding 19 and the relay terminal 51 is connected. Joined by spot welding or the like.

  The relay terminal 51 is formed of a metal plate such as a phosphor bronze plate, for example. As shown in FIG. 14A, a hook-shaped tip 51a around which the winding M is wound and connected, and a high-voltage component The base end part 51b joined to the lead wire L and the flexible part 51c facing the front end part 51a.

  The connection end of the secondary winding 17 and the connection end of the heater winding 19 are both connected to the relay terminal 51 via a post 22 protruding on the bobbin 13.

  When the secondary winding 17 and the heater winding 19 can be soldered, the relay terminal 51 is used for soldering. Further, when soldering is impossible, fusing is possible by applying a large current while pressing the relay terminals 51 close to each other, as shown in FIG.

  In this way, by temporarily holding the windings 17 and 19 on the post 22, in the case of soldering, the weakening of the windings 17 and 19 due to copper cracking due to high-temperature solder corresponding to the recent lead-free is eliminated. Further, in the case of a non-soldering winding, it is possible to minimize stress on the relay terminal 51 by receiving stress on the post 22 against weakening due to stress during welding such as fusing.

  The winding connection locations 1) to 4) by the relay terminal 51 shown in FIG. 12 correspond to the connection portions 1) to 4) on the circuit diagram of FIG.

  That is, the connecting portion 1) is a connecting portion between one connecting end of the secondary winding 17 and the pair of capacitors 31, and the connecting portion 2) is the other connecting end of the secondary winding 17 and a pair of diodes 33. It is a connection part between.

  The connecting portion 3) is a connecting portion between one lead of the heater winding 19 and the anode lead L of the diode 33, and the connecting portion 4) is a connection between the other lead of the heater winding 19 and the lead L of the capacitor 31. Part.

  In general, the conductor wires used for the secondary winding 17 and the heater winding 19 are very thin. Therefore, when the transformer 11 is assembled to the printed circuit board 23, the component holding portion may be shaken due to the operation force during assembly. -If tension more than a certain level acts on the connection end of the secondary winding 17 or the heater winding 19 due to rattling or vibration during transportation, etc., there is a risk of disconnection.

  However, in this transformer unit 500, the component holding portion may be shaken or rattled by an operating force during assembly, and the connection end of the secondary winding 17 is connected to the swinging and rattling. Even if the components 31 and 33 are displaced, the displacement is absorbed by the space between the post 22 and the relay terminal 51, and a certain tension or more acts on the connection portion of the secondary winding 17 and the heater winding 19. In order to prevent this, the secondary winding 17 and the heater winding 19 are not cut, and the handling property when the transformer 11 is assembled to the substrate and the reliability during transportation are improved.

  Further, in the present embodiment, as shown in FIGS. 11 and 12, the electrical connection between the lead wires of the high-voltage components on the component holding portion is performed not directly but via the plate-like connection terminals 53. Yes.

  In the illustrated example, a plate-like connection terminal 53 is used at a place where the pair of diodes 33 are connected in series.

  The connection terminal 53 is preferably a metal plate having characteristics that are excellent in heat dissipation (thermal conductivity) as well as conductivity.

  Since the connection terminal 53 has a wide heat dissipation surface with respect to the lead wires of the high voltage component and has excellent heat dissipation, the heat generated by each high voltage component is efficiently dissipated into the ambient atmosphere, and each high voltage component At the same time as suppressing the temperature rise of the component, it is possible to suppress the stress generated in the connection portion due to the thermal expansion of the component, thereby improving the operational stability of each high voltage component and the life of the connection portion.

  In this embodiment, the diode 33 and the capacitor 31 of the voltage doubler rectifier circuit 93 connected to the heater winding 19 incorporated in the transformer 11 are connected in series as shown in 3) and 4) of FIG. The lead terminal of the diode 33 is connected to one lead of the heater winding 19, and the lead terminal of the capacitor 31 connected in series is individually connected to the other lead of the heater winding 19, respectively. .

  As described above, the relay terminal 51 is used to connect each lead terminal and the winding.

  In the above embodiment, the secondary winding 17 and the heater winding 19 are joined to the lead wire L of the high-voltage component via the relay terminal 51, but the relay terminal is omitted as shown in FIG. The secondary winding 17 and the heater winding 19 may be soldered and directly joined to the lead wire L of the high voltage component via the post 22 protruding on the bobbin.

  Even in this configuration, the displacement of the lead wire L of the high voltage component can be absorbed by the space of the winding wires 17 and 19 spanned between the post 22 and the lead wire L. , 19 can be prevented.

  Further, by temporarily holding the windings 17 and 19 on the post 22, it is possible to eliminate the weakening of the windings 17 and 19 due to high-temperature solder corresponding to lead-free.

  When the diode 33 and the capacitor 31 of the voltage doubler rectifier circuit 93 are connected to the heater winding 19 incorporated in the transformer, the connection portion between these diodes and the capacitor is a single unit as shown in the circuit diagram of FIG. In general, a jumper wire is connected to one lead of the heater winding. In such a connection structure, the other lead of the heater winding is supported on the wiring path, so The use of dummy terminals becomes indispensable.

However, as described above, when the lead terminal of the diode 33 is connected to one lead of the heater winding 19 and the lead terminal of the capacitor 31 is connected to the other lead of the heater winding 19, respectively, The pair of leads of the heater winding 19 can be stably supported on the wiring path by the connection with the diode 33 and the capacitor 31, and the use of the dummy terminal on the bobbin 13 can be omitted. The reason why the dummy terminal can be omitted is that the voltage obtained by the voltage doubler rectifier circuit 93 is 100 to 500 times the voltage generated at both ends of the heater winding 19, and is apparently the same as the circuit shown in FIG. Because it moves.

  In the present embodiment, the ground connection terminal 55 for connecting the voltage doubler rectifier circuit 93 on the component holding part to the ground contact 24 on the printed circuit board 23 is made of a metal wire having excellent conductivity and spring property in a predetermined shape. The lead connection portion 55a connected to the lead wire L (in this example, the cathode of the diode 33) of the high voltage component constituting the voltage doubler rectifier circuit 93 and the ground contact 24 on the substrate. And a board connecting portion 55b.

  In addition, the ground connection terminal 55 is integrally formed between the lead connection portion 55a and the substrate connection portion 55b with a core connection portion 55c that elastically contacts the outer surface of the core 35b of the transformer 11 and realizes conduction with the core 35b. Is formed.

  When the ground connection terminal 55 is used for ground connection, one ground connection terminal 55 serves as both the ground connection of the voltage doubler rectifier circuit 93 and the ground connection of the core 35b. As a result, the number of ground connection terminals 55 used can be reduced, and at the same time, the number of ground connection work steps can be reduced, thereby improving the productivity of the transformer unit and reducing the cost by reducing the number of parts.

  Further, the earth connection terminal 55 is attached after the withstand voltage test of the transformer 11, so that the withstand voltage test of the transformer 11 can be performed with the diode 33 mounted.

  FIG. 16 shows an embodiment in which a bobbin of a transformer unit according to the present invention is provided with a partition wall.

  The transformer 11 used in the transformer unit 600 of this embodiment is such that a pair of U-shaped cores 35a and 35b are inserted from both ends of the bobbin 13, and the core that goes around the outside of the bobbin 13 is the printed circuit board 23. It is attached to the printed circuit board 23 in a form that becomes a side position of the bobbin that is a certain distance away from.

  Also in the transformer 11 of the present embodiment, since the central axis of the bobbin 13 is parallel to the printed circuit board 23, the primary winding 15, the secondary winding 17, and the heater winding 19 are vertical with respect to the printed circuit board 23. Arrangement.

  The secondary winding 17 and the heater winding 19 of the bobbin 13 sandwich the lead wires of the high voltage components constituting the voltage doubler rectifier circuit 93 (see FIG. 13) that rectifies the high frequency high voltage from the secondary winding 17. As part holding parts to be held, clamping pieces 26 and 28 (only the clamping piece 26 is shown in FIG. 16; see FIG. 12 for the clamping piece 28) are provided so as to project.

  Each of the sandwiching pieces 26 and 28 is formed with an engaging groove in which a lead wire is tightly fitted at the tip. The sandwiching piece 26 is for holding the diode 33, and the sandwiching piece 28 is for holding the capacitor 31.

  In the capacitor 31 and the diode 33, the relay terminal 51 is joined to a lead wire connected to the secondary winding 17 or the heater winding 19 by spot welding or the like. Both the connecting end of the secondary winding 17 and the connecting end of the heater winding 19 are connected to the relay terminal 51 via a post 22 protruding on the bobbin 13. Further, the electrical connection between the lead wires of the high-voltage components on the component holding portion is performed not directly but via the plate-like connection terminals 53.

In this transformer unit 600, a core 35b and a capacitor 31 and a diode 33, which are high-voltage components held by the sandwiching pieces 26 and 28, are disposed on the outer peripheral portion of the bobbin 13 where the sandwiching pieces 26 and 28 that are parts holding portions are formed. A partition wall 61 is provided upright. The partition wall 61 extends at least higher than the protruding height of the component from the bobbin side surface 13a on which the high voltage component is held, and is arranged so as to exist on a straight line connecting the high voltage component and the core 35b. The partition wall 61 is integrally formed with the bobbin 13, but a separate member may be fixed to the bobbin 13. The partition wall 61 is preferably formed in a cylindrical shape so as to surround the core 35b. However, the partition wall 61 does not have a significant effect on the insulation effect from the high voltage component (for example, in a non-electrode portion of the high voltage component). (Corresponding position) may be divided as shown and formed in a U-shape as in this example. Note that a stopper ( not shown ) for preventing the core 35b from coming off from the bobbin 13 is engaged with the dividing position of the partition wall 61 of the present embodiment.

  Therefore, according to the transformer unit 600, since the partition wall 61 protruding from the bobbin 13 is disposed between the core 35b and the high voltage component, the linear communication between the core 35b and the high voltage component is lacking. As a result, the insulation effect between the high voltage component to which a high voltage is applied and the core 35b to be grounded can be enhanced. As a result, it is possible to reliably prevent a reduction in insulation due to discharge between the core 35b and the high voltage component, dust or the like accumulated over a long period of time between the core 35b and the high voltage component. Further, since the insulation effect between the high voltage component and the core 35b is enhanced, the gap between the core 35b and the high voltage component can be reduced as compared with the structure in which the partition wall 61 is not provided. A compact size can also be achieved.

  In each of the above embodiments, a component holding portion is formed on the side surface of the bobbin 13, and the high voltage component is held by the component holding portion. However, the high voltage component is held on the printed circuit board 23. As long as it is the outer peripheral part of the transformer 11 excluding the side, it is not limited to the side surface of the bobbin 13 and may be any other position.

  It is also possible to form a component holding part on a component fixing plate configured separately from the bobbin 13 and integrate it with the bobbin 13.

It is sectional drawing and the side view of a transformer explaining the structure of the transformer of this invention. It is a perspective view of a transformer explaining the structure of a transformer. It is a perspective view of a transformer unit explaining the structure of a transformer unit in which a transformer is mounted. It is a perspective view which shows the transformer unit which has arrange | positioned the I type core of the transformer perpendicularly | vertically with respect to the printed circuit board, and has arrange | positioned high voltage components upwards. It is a perspective view which shows the transformer unit which has arrange | positioned the I-type core of a transformer in parallel with the printed circuit board, and has arrange | positioned the U-type core to the side of the transformer. It is a perspective view which shows the transformer unit which has arrange | positioned the I type core of the transformer perpendicularly | vertically with respect to the printed circuit board, and has arrange | positioned the high voltage component below. It is sectional drawing and the side view of a transformer which show the transformer of other structures. It is explanatory drawing which shows the structure which formed the component holding part in the component fixing plate separate from a bobbin. It is explanatory drawing which shows a mode that the insulating cover which covers a component holding part is attached. It is explanatory drawing which shows the structure which decomposed | disassembled the bobbin into the bobbin base | substrate and the flange part, and formed the component holding part in the flange part. It is a perspective view of other embodiments of a transformer unit concerning the present invention. It is A arrow directional view of FIG. FIG. 12 is a circuit diagram of the transformer unit shown in FIG. 11. 11A is an enlarged perspective view of a portion B in FIG. 11, where FIG. 11A is a diagram when soldering the winding M, and FIG. FIG. 15 is a modified example shown in an enlarged perspective view of a portion B in FIG. 14, in which a secondary winding of a transformer is directly connected to a lead wire of a high voltage component through a post protruding on a bobbin. It is a perspective view of the transformer unit which provided the partition between the bobbin and the core. It is a perspective view of the transformer unit which shows the conventional transformer unit installed in a high frequency heating device. It is a circuit diagram explaining the circuit structure of a transformer unit. It is a schematic sectional drawing which shows the structure of the transformer mounted in the transformer unit. It is the perspective view seen from the lower surface side which shows the structure of a transformer. It is a back view of the printed circuit board explaining the circuit pattern of the printed circuit board with which a transformer is mounted. It is a perspective view of a transformer unit explaining other conventional examples.

Explanation of symbols

11 Transformer 13 Bobbin 15 Primary Winding 17 Secondary Winding 19 Heater Winding 21 Core 22 Post 23 Printed Circuit Board 24 Ground Contact 25, 26, 27, 28 Nipping Piece (Part Holding Section)
31 Capacitor (high voltage component)
33 Diode (high voltage component)
35a, 35b Core 43 Component fixing plate 44 Component fixing plate 45 Insulating cover 47 Bobbin base 49 Side end flange portion 51 Relay terminal 51c Flexible portion 53 Plate connection terminal 55 Ground connection terminal 55c Core connection portion 61 Bulkhead 93 Voltage doubler rectification circuit
100, 200, 300, 400, 500, 600 transformer unit

Claims (5)

A transformer unit comprising a printed circuit board mounted with a transformer having at least a bobbin around which a primary winding and a secondary winding are wound, and a core inserted through the center of the bobbin,
A voltage doubler rectifier circuit for rectifying a high frequency high voltage from the secondary winding of the transformer;
The transformer has a component holding portion that holds components on a side surface of the bobbin that is an outer peripheral portion excluding the mounting side of the bobbin on the printed circuit board and perpendicular to the central axis of the bobbin,
A high voltage component that is held in the component holding unit and constitutes the voltage doubler rectifier circuit;
A relay terminal formed of a metal plate and having a flexible portion and joined to a lead wire of the high voltage component;
A post projecting on the bobbin ,
The secondary winding, the transformer unit, characterized in that the connection end, and connected indirectly to the leads of the high-voltage component by pre via Kipo strike connected to the relay terminal . 2. The transformer unit according to claim 1, wherein electrical connection between the lead wires of the high-voltage components on the component holding portion is performed via a plate-like connection terminal that also serves as a heat sink. A pair of capacitors connected in series with a pair of diodes connected in series in the voltage doubler rectifier circuit has a lead terminal of the diode connected to one lead of a heater winding incorporated in the transformer. but the other lead of the heater winding, the transformer unit according to claim 1 or 2 respectively, characterized in that connected individually. Transformer unit according to any one of claims 1 to 3, characterized in that connected to the voltage doubler rectifier circuit and the ground terminal on the printed circuit board through a common ground connecting terminal and said core. The ground connection terminal includes a lead connection portion connected to a lead wire of a high voltage component constituting the voltage doubler rectifier circuit, and a substrate connection portion connected to the ground contact, and these lead connection portions; 5. The transformer unit according to claim 4 , wherein a core connecting portion is provided between the substrate connecting portion and the outer surface of the core so as to achieve conduction with the core by elastic contact.

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