JP5078799B2 - Induction heating cooker - Google Patents

Description

  The present invention relates to an induction heating cooker, and more particularly to a connection structure between an inverter circuit that generates a high-frequency current and a heating coil for induction heating.

In a conventional induction heating cooker, a heating coil terminal serving as an output terminal of an inverter circuit is connected to a printed circuit board on which the inverter circuit is configured, and a lead wire for supplying high-frequency current to the heating coil is directly connected to the heating coil terminal. It was connected with a screw.
In addition, on the coil base that supports the heating coil, a connection fixing means for relaying and fixing the terminal of the lead terminal of the heating coil and the terminal of the lead wire terminal of the printed circuit board is prepared, and the connection fixing means In this case, a locking means for locking the terminal terminal of the lead portion of the heating coil is formed, and the terminal terminal of the lead wire from the printed circuit board is connected to the terminal terminal of the lead portion of the heating coil locked by the locking means. A configuration in which the terminals are connected by screwing or faston terminals has been employed (see, for example, Patent Document 1).

Japanese Patent No. 3610896 (page 7, FIGS. 4 and 5)

However, in such a conventional configuration, when the heating coil terminal is disposed inside the printed circuit board and the lead wire connected to the heating coil is directly screwed to the heating coil terminal, the physical shape of the heating coil terminal As a result, the distance from the output terminal of the inverter circuit to the heating coil terminal increases, resulting in an increase in the printed pattern area, which makes it difficult to design the pattern and increases the pattern loss, which makes it difficult to cool the substrate. there were.
In addition, the heating coil side lead wire must be screwed to the heating coil terminal before assembling the board assembly formed of the printed circuit board and the board holder, and there is a problem that the assembly process is complicated.

When installing a relay terminal on the heating coil base, the heating coil side lead wire going out of the board assembly is connected to the board assembly formed by the printed board and the board holder, which similarly complicates the assembly work process. There was a problem.
The present invention has been made to solve the above-described problems. By reducing the print pattern area through which a high-frequency, high-current flows, the board design can be facilitated and the board pattern loss can be reduced. An induction heating cooker that can facilitate assembly work is provided.

An induction heating cooker according to the present invention includes a board on which an inverter circuit that converts current supplied from a commercial power source into high-frequency current is mounted, and a board holder that holds the board in a state substantially parallel to the vertical direction and protects the board from insulation. When having a heating coil for heating an object by a high-frequency current is placed under the object to be heated is supplied, and the substrate is configured in the terminal of the lead wires connected to the heating coil A relay terminal for relay connection between the terminal connected to the terminal of the jumper wire connected to the output terminal of the inverter circuit , and the substrate holder has an opening for exposing the relay terminal, It is arranged in the vicinity of the heating coil and is exposed from the opening so that the screw hole of the relay terminal for screwing the terminal of the lead wire faces the upper surface side.

The induction heating cooker of the present invention includes a board on which an inverter circuit that converts a current supplied from a commercial power source into a high-frequency current and a board that accommodates the board in a state substantially parallel to the vertical direction and protects the board from insulation. a holder, and a heating coil for heating an object by a high-frequency current is placed under the object to be heated is supplied, has, on the substrate holder, the terminal lead wires connected to the heating coil A relay terminal is provided for relay connection between the configured terminal and the terminal configured on the terminal of the jumper wire connected to the output end of the inverter circuit , and the board holder is used for screwing the terminal of the lead wire It arrange | positioned at the side of the heating coil so that the screw hole of a relay terminal may face an upper surface side.

According to the induction heating cooker of the present invention, it is possible to reduce the printed pattern area of the substrate through which a high-frequency and high-current flows, and it is possible to facilitate the substrate design and reduce the pattern loss of the substrate. is there. In addition, it becomes possible to screw the heating coil terminal after assembly (attachment work) of the board assembly (assembly structure) that combines the board and board holder into an integrated structure, which facilitates assembly of the main body. There is an effect that can be.

Embodiment 1 FIG.
1 is an induction heating cooker according to Embodiment 1 of the present invention, which is shown in a perspective view with outer shell structures such as a top plate removed. FIG. 2 is a perspective view of the board assembly structure, and FIG. 3 is a perspective view showing a mounting example of the relay terminal for the heating coil.

  1 to 3, reference numeral 1 denotes a main body of the induction heating cooker, which is composed of a thin metal plate as a whole, and has a box-shaped housing 1 </ b> A whose upper surface is open, and its upper surface opening so as to cover it. The outer shell is composed of a top plate (also referred to as an upper plate) (not shown) fixed to the housing.

  A grill heating chamber (also referred to as a grill box) 3 surrounded by a metal wall and having an opening 7 on the front surface is defined in the main body 1. A heating coil 5 described later is disposed above the grill heating chamber. An upper space in which the etc. are accommodated is formed. Although there is actually an openable / closable door that closes the opening 7, it is not shown.

Reference numeral 5 denotes a heating coil that serves as an induction heating source. In the first embodiment, one heating coil is arranged on each of the left and right sides, so that energization conditions (such as energization start, stop, and energization amount) can be independently selected by the user. However, the number of heating coils referred to in the present invention is not limited to this.
The heating coil is disposed on the lower surface side of the top plate (upper plate) constituting the upper surface of the main body 1 so as to be close to the heating coil with a minute gap. In the first embodiment, the left and right heating coils 5 are, for example, those having a capacity of maximum power consumption (maximum heating power) of 3 KW.

  The heating coil 5 is formed by winding a bundle of about 30 thin wires of about 0.1 mm in a spiral shape while winding one or more bundles (hereinafter referred to as a collecting wire) so that the outer shape is circular. Finally, it is formed into a disk shape. Its diameter (maximum outer diameter dimension) is about 180 mm. In addition, the one heating coil 5 may divide the collective line into a plurality of parts so as to be energized independently. For example, one spiral coil is wound on the inner side, and another large-diameter spiral coil is placed on the outer circumferential side of the coil concentrically and on the same plane, and the inner heating coil is energized and the outer IH heating coil is placed. You may make it heat a to-be-heated object by three electricity supply patterns called electricity supply, and electricity supply to both IH heating coils of an inside and an outside. Thus, from at least one of the output level, duty ratio, and output time interval of the high-frequency power flowing through the two IH heating coils, or a combination thereof, it is efficient from a small pan to a large (large diameter) pan. You may make it heat. These conditions are not restrictive conditions for carrying out the present invention.

  The CU is a pair of blower units that are inserted into the right and left spaces of the grill heating chamber 3 from above and fixed inside the main body 1. As shown in FIG. 2, the blower unit 4 installed on the left side of the grill heating chamber 3 has a box-shaped substrate holder 4 that is integrally formed of an electrically insulating material such as plastic, as shown in FIG. A case 8 is formed so as to cover the entire right side opening of the substrate holder and is coupled to the case holder with screws or the like.

  The case 8 is integrally formed of an electrically insulating material such as a transparent plastic as a whole, and a multi-blade fan (not shown) such as a sirocco fan is rotated at the rear end of a motor (not shown). An annular wall 8C that is supported rotatably on the shaft and forms an air blowing chamber 8D for housing it is integrally formed. A plate-like lid (not shown) is fixed to the case 8 so as to cover the entire wall 8C. That is, the inner space of the wall 8C becomes the blower chamber 8D by attaching the lid. Although not shown, the air blowing chamber communicates with the outside of the main body 1 by a suction cylinder on the duct, and fresh air from outside is sucked into the air blowing chamber 8D. Moreover, since a pair of ventilation unit is a left-right symmetric shape, description of the right side ventilation unit is abbreviate | omitted.

  In the coupled state of the case 8 and the substrate holder 4, the blower unit CU is formed with a substantially hermetic chamber communicating with the blower chamber 8 </ b> D therebetween, and a substrate 10, which will be described later, is formed inside the chamber. Is housed. The substrate is generally called a printed circuit board. Moreover, in order to discharge the cooling air pushed into the substantially sealed room of the blower unit CU from the blower chamber 8D, exhaust ports 8A and 8B are formed at two locations, respectively. And since the said heating coil 5 is located above these exhaust ports, the said whole heating coil 5 which becomes high temperature at the time of cooking with the wind which blows off from the exhaust ports 8A and 8B is cooled from the downward direction.

Three openings are formed in a part of the upper surface wall of the substrate holder 4, and a relay terminal 9 made of sheet metal is installed so that the upper surface is exposed from the openings. This relay terminal serves as a relay base for electrical connection to the heating coil 5, and is fixed to the upper edge of the substrate 10 as shown in FIG. The substrate 10 is mounted with an inverter circuit (not shown) for supplying a high-frequency current to the heating coil 5 on the surface (the right side in FIG. 3).

  The inverter circuit here is usually a rectifier circuit connected to a commercial power supply of 100V or 200V, a coil connected to the DC side output terminal of the rectifier circuit, a smoothing capacitor, and connected to the coil and the smoothing capacitor. A resonant capacitor and a circuit composed of a power control semiconductor switching element (IGBT or the like) serving as a switching means connected to these components, which is a high-frequency power supply circuit that is essential for induction heating. Various electric / electronic circuit component groups excluding electric components (such as diodes) for circuits and printed circuit patterns thereof are realized on the substrate 10. Reference numeral 12 shown in FIG. 3 denotes aluminum radiating fins mounted on the substrate 10, and the semiconductor switching element means that generates heat in accordance with the power control operation of induction heating is attached by heat transfer, and its self-heating. In order to prevent the efficiency from being reduced, the air is cooled by being exposed to the cooling air passage from the multi-blade fan described above.

  The relay terminal 9 is disposed on a substantially end surface of the substrate 10 and is fixed to the substrate 10 by soldering. Here, two screw holes 9A and 9B are formed in the relay terminal 2. The screw hole 9A on the upper surface enables the terminal fitting of the lead wire 6 having one end connected to the heating coil 5 and the terminal fitting fixed to the other end to be screwed. On the other hand, a screw hole 9B is formed on the side surface of the relay terminal 9 so that the screw hole 9A can be screwed from a direction different by 90 degrees. That is, the screw hole 9B is a hole that can be screwed from the right side to the left side in FIG.

  Reference numeral 11 denotes a jumper wire, one end of which is connected to the inverter circuit output end on the substrate 10 and the other end is connected to the relay terminal 9. Note that a terminal fitting (not shown) for screwing is attached to the end of the jumper wire 11 on the side connected to the relay terminal 9.

  The substrate 10 is insulated and protected by being covered by the substrate holder 4 and the case 8 from both the front and rear and left and right directions. The substrate 10 is installed so as to hold a predetermined gap with the inner wall surface of the substrate holder 4 by being screwed and fixed to a protruding leg 4D integrally formed at several locations inside the substrate holder 4.

  In FIG. 4, reference numeral 4 </ b> C denotes a mounting seat formed on the substrate holder 4 for screwing the case 8. Similarly, in FIG. 2, 8F is a mounting seat formed on the case 8 for screwing a plate-shaped lid forming the air blowing chamber 8D.

The blower unit CU is coupled to the substrate holder 4 containing the substrate 10 constituting the inverter circuit, and a space (room) in which cooling air from the blower fan is introduced between the substrate holder 4 and the substrate holder 4. The case 8 to be formed is integrally joined, and can be transported as a single structure or installed in the internal space of the main body 1. Moreover, although not shown, the lead wire for supplying power to the substrate 10 and the power supply lead wire for the driving circuit of the blower fan driving motor are not shown, so that they can be handled as one blower unit. Are pulled out to the outside through a lead-out opening (gap) formed between them, and connectors and terminal fittings for preparing connections are attached to the terminal portions of these lead wires. For this reason, after inserting and installing the blower unit CU in the main body 1, electrical connection work to the connectors and terminals can be easily performed above the blower unit CU, and the lead wire having one end connected to the heating coil 5. The other end of 6 can be easily screwed with the relay fitting 9.
In the above description, the covered conductor through which a current flows is described with a comprehensive name called a lead wire, but the type, type, thickness, etc. of the conductor are not limited. The number of the relay terminals 9 may be three instead of two depending on the form of the heating coil (this embodiment corresponds to a structure having three such terminals, 9 is also on a straight line.

Next, a method for wiring the relay terminal 9 will be described.
The terminal fitting of the jumper wire 11 soldered directly to the through hole of the substrate 1 formed at the output end of the inverter circuit is connected to the side surface of the relay terminal 9 (the left cooling unit CU shown in FIG. 3). If the tool is rotated on the horizontal line from the right direction in this state, the screw is fixed.
On the other hand, if the lead wire fitting connected to the heating coil 5 side is positioned above the relay terminal 9 and screwed into the screw hole 9A, the electrical connection work from the substrate 1 to the heating coil 5 is completed.

  Thus, in the first embodiment, the relay terminal 9 and the inverter circuit are not connected by the print pattern, and the relay terminal 9 and the inverter circuit are connected by the jumper line. In order to attach the relay terminal 9, it is only necessary to form only through holes and lands for attachment on the substrate 10. Note that the shape of the through hole for attaching the relay terminal 9 formed on the substrate 10 may be a non-symmetrical structure so that the attachment direction of the relay terminal 9 is always correct. In other words, if the attachment is made in a direction other than the correct direction, the shape of the through hole does not match and the attachment is prevented. For example, the shape may be asymmetric in the forward and reverse directions so that it cannot be erroneously inserted in directions different by 180 degrees. The relay terminal 9 has, for example, four tongue-like legs for mounting. The legs are inserted into the four through holes formed in the substrate 10, solder is placed on the tip of the leg protruding to the opposite side, and the leg is the substrate. In the case of 10 fixed, if the relationship is such that the positions and shapes of the four legs and four throughs are matched only when the relay terminal 9 is oriented in the correct mounting direction, this correct mounting Since installation in directions other than directions is not possible, the installation direction of important relay terminals 9 can be reliably guaranteed.

As described above, in the first embodiment, since the relay terminal 9 and the output terminal of the inverter circuit are connected by the jumper wire 11, it is possible to reduce the print pattern area on the substrate 10 through which the high frequency and large current flows. This makes it possible to facilitate the substrate design and reduce the pattern loss of the substrate 10. Further, after assembly (attachment work) of the board assembly (assembly structure) including the board 10, the lead wire terminal (metal fitting) connected to the heating coil 5 is screwed from above, that is, from the direction of the heating coil 5. Therefore, there is an effect that the main assembly work can be facilitated.
Furthermore, by making the shape of the through hole on the board 10 to which the relay terminal 9 is to be attached a non-symmetrical structure, the correct mounting direction of the relay board 9 can be guaranteed, and the assembly process of the board 10 and consequently the blower unit CU There is an effect that work errors in the assembly process can be reduced.

Embodiment 2. FIG.
FIG. 4 is a perspective view of the main part of the substrate holder according to Embodiment 2 of the present invention. Hereinafter, in the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals.
In the first embodiment described above, the relay terminal 9 is mounted and disposed on the end face of the substrate 10. In this embodiment, the relay terminal 9 is disposed on the substrate holder 4.
In FIG. 4, the relay terminal 9 is attached to the upper wall of the substrate holder 4, which is entirely made of plastic, and a latching means such as a claw, which is integrally formed in advance on one or both of the substrate holder 4 and the relay terminal 9, It is preferable that fixing means such as screws be used because a fixing tool such as a screw can be omitted.

Here, also in the second embodiment, the screwing direction of the terminal metal fittings and jumper wires with respect to the relay terminal 9 is one downward from the heating coil 5 (vertical direction), and the other is the horizontal direction. That is, the relay terminal 9 is formed with a screw hole 9A on the upper surface and a screw hole 9B on the side surface adjacent to the upper surface so as to ensure two different screwing directions. Yes. Therefore, for example, the lead wire 6 led from the heating coil 5 from the upper space of the blower unit CU is screwed to the relay terminal 9 even after the blower unit CU is installed and fixed in the internal space of the main body 1 from above. It can be fixed by means such as.

As described above, in the second embodiment, the relay terminal 9 and the output terminal of the inverter circuit are connected by the jumper wire 11, and the relay terminal 9 is disposed on the substrate holder 4, so that the heating is performed. Relay terminal connected to terminal of lead wire 6 connected to coil 5 directly or via another intermediary and terminal configured of terminal of jumper wire 11 connected to output terminal of inverter circuit It can be electrically connected via the terminal 9. In addition, when the terminal is screwed, it is possible to perform the tightening stress without applying the stress to the substrate 10, so that in addition to the effects of the first embodiment, problems such as solder cracks and substrate cracks in the substrate 10 can be prevented. There is an effect that can be.
Further, since the relay terminal 9 is not arranged on the substrate 10, it is possible to reduce the number of components on the substrate 10 and to facilitate the board design.

INDUSTRIAL APPLICABILITY The present invention can be widely used for stationary and built-in induction heating cookers used for home use and business use.

The induction heating cooker in Embodiment 1 of this invention which removed outer shell structures, such as a top plate, and was shown with the perspective view. The perspective view of the board | substrate assembly structure. The perspective view which shows the example of mounting of the relay terminal for the heating coils. It is a principal part perspective view of the board | substrate holder in Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body 2 Upper space 3 Grill heating chamber 4 Substrate holder 5 Heating coil 6 Lead wire 7 Opening 8 Case 9 Relay terminal 9A Screw hole 9B Screw hole 10 Substrate 11 Jumper wire.

Claims (5)

A board equipped with an inverter circuit that converts a current supplied from a commercial power source into a high-frequency current ;
A substrate holder for accommodating the substrate in a state substantially parallel to the vertical direction, and insulatingly protecting the substrate ;
A heating coil that is placed under the object to be heated and is heated to heat the object by being supplied with the high-frequency current ;
Have
The substrate includes
A relay terminal is provided for relay connection between the terminal configured at the terminal of the lead wire connected to the heating coil and the terminal configured at the terminal of the jumper cable connected to the output terminal of the inverter circuit ,
The substrate holder is
An opening for exposing the relay terminal;
The opening is disposed in the vicinity of the heating coil;
An induction heating cooker characterized by being exposed from the opening so that a screw hole of the relay terminal for screwing a terminal of the lead wire faces an upper surface side . A board equipped with an inverter circuit that converts a current supplied from a commercial power source into a high-frequency current ;
A substrate holder for accommodating the substrate in a state substantially parallel to the vertical direction, and insulatingly protecting the substrate ;
A heating coil that is placed under the object to be heated and is heated to heat the object by being supplied with the high-frequency current ;
Have
In the substrate holder,
A relay terminal is provided for relay connection between the terminal configured at the terminal of the lead wire connected to the heating coil and the terminal configured at the terminal of the jumper cable connected to the output terminal of the inverter circuit ,
The substrate holder is
An induction heating cooker, which is arranged on the side of the heating coil such that a screw hole of the relay terminal for screwing a terminal of the lead wire faces an upper surface side . In the relay terminal,
Claim that the direction of screwing terminals of said lead wires, the terminals of the jumper wire so that the direction of screwing differs, characterized in that the formation of the respective fixing screw holes on a surface different substantially 90 degrees with respect to each other The induction heating cooker according to 1 or 2. The substrate includes
A through hole serving as an attachment portion of the relay terminal is formed, and the shape of the through hole is a non-linearly symmetric shape so that the relay terminal cannot be erroneously inserted in a direction different from a normal direction. The induction heating cooker according to 1. In the substrate holder,
A through hole serving as an attachment portion of the relay terminal is formed, and the shape of the through hole is a non-linearly symmetric shape so that the relay terminal cannot be erroneously inserted in a direction different from a normal direction. 2. The induction heating cooker according to 2.

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