JPH035768Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) The present invention relates to a roasting device such as a toaster oven, and relates to the structure of a circuit board of a circuit for controlling a heater.

(Prior Art) Conventionally, this type of roasting equipment has a structure in which components forming a control circuit for timer control of a heater, etc. are connected to a circuit board without separating the components into a high-voltage circuit section and a low-voltage circuit section. It is becoming.

(Problem that the invention attempts to solve) However, since the insulation distance between component wiring stipulated by the Electrical Appliance and Materials Regulations differs between high-voltage circuit sections and low-voltage circuit sections, if they are designed integrally, for example, high-voltage circuit section If the low-voltage circuit and the high-voltage circuit are adjacent to each other, an insulation distance must be provided to match the high-voltage circuit, which increases the size of the circuit board, and if the circuit board is to be made smaller, the arrangement of parts, printed wiring, etc. The problem was that it became complicated and unreasonable.

Furthermore, since a breather resistor is installed in the low-voltage circuit, there is a problem that the circuit board is affected by the heat generated by the breather resistor. This was an obstacle to downsizing.

The present invention was devised in view of the above-mentioned problems, and the high-voltage circuit and the low-voltage circuit are separated and connected to separate circuit board parts, and the circuit components can be connected to each other without forming unnecessary insulation distances. This reduces the effect of heat generated by the breather resistor, allows efficient wiring design and component placement, and allows for good heat dissipation, making it possible to reliably control the heater without being affected by temperature rises in the roasting chamber. The present invention provides a roasting device in which the circuit board can be made smaller and the ease of assembly is improved.

[Structure of the idea]

(Means for Solving the Problems) The roasting apparatus of the present invention has a time constant circuit determined by a heater, a high voltage circuit section including a power supply circuit, and a capacitor and a resistor in which a breather resistor is connected to this high voltage circuit section. and a low-voltage circuit section including a control circuit for controlling the energization time to the heater, in which components of the high-voltage circuit section and components of the low-voltage circuit section are separated and placed on separate circuit board sections. a cutout plate portion forming an arrangement hole for arranging the breather resistor in correspondence with the arrangement position of the breather resistor connected to the low voltage side circuit board portion to which the components of the low voltage circuit portion are connected; is removably provided at a board connection part located offset from the center line position, and a high voltage side circuit board part to which parts of the high voltage circuit part are connected is arranged in the roaster main body in which the heater is arranged. However, the cutout plate portion is removed and a low voltage side circuit board portion in which a breather resistor is installed in the installation hole is placed outside the roaster main body.

(Function) In the roasting apparatus of the present invention, parts of the high-voltage circuit section are wired while maintaining the insulation distance required for the high-voltage circuit, and components of the low-voltage circuit section are wired while maintaining the insulation distance necessary for the low-voltage circuit. This eliminates the need to create unnecessary insulation distances, and the breather resistor, which generates a large amount of heat, can be installed in the installation hole of the circuit board of the low-voltage circuit installed outside the roaster body. As a result, the circuit board section is not affected by the temperature rise due to heat generated by the breather resistor, and heat is effectively radiated outward from the roaster main body, allowing the circuit board section to be made smaller. In addition, the installation hole for arranging the breather resistor can be easily removed by pressing the part where the board connection part is not formed, which is offset from the center line of the notch plate. Therefore, if the notch plate is removed after the breather resistor is soldered in the solder bath and the breather resistor is disposed in the installation hole, solder can be prevented from adhering to the breather resistor.

(Example) Next, an example of the present invention will be described based on the drawings.

In FIG. 1, 1 is a roaster main body, and this main body 1 has a roasting chamber (not shown) whose front surface can be opened and closed with a door body 2. Heaters 3 and 4 shown in the figure are provided, respectively. Further, on the front side of the decorative plate 5 provided on one side of the front side of the main body 1, there is a switching knob 6 for a switch that changes the heater power, a time setting knob 7 for a mechanical timer switch operated by a spring, etc., a lamp 8,
Volume 9 is the time setting knob for the electronic timer.
A slide knob 10 and an electronic timer operating knob 11 are provided.

Next, the electric circuit of the roasting device will be explained with reference to FIG.

15 is an AC power supply that outputs AC100V, and a mechanical timer switch 1 is connected between both ends of this power supply 15.
Both the upper and lower heaters 3, 4 and a heater power changeover switch 19 are connected through a parallel circuit with power switches 17, 18 connected in series.
The mechanical timer switch 16 is closed for the time set by the time setting knob 7, and the power switches 17 and 18 are closed when the operating knob 11 is pressed down and are self-maintained by a relay coil 20, which will be described later. be done. Further, the changeover switch 19 is configured so that contacts a and b are changed over by operating the changeover knob 6 to change the heater power.

An electronic timer circuit consisting of a high voltage circuit section 21 and a low voltage circuit section 22 is connected between the connection point of the power switches 17 and 18 and one end of the AC power source 15.

A series circuit of a resistor 23 and a lamp 8, and a DC constant voltage power supply are connected between the connection point of the power switches 17 and 18 and one end of the AC power supply 15. This constant voltage power supply includes a resistor 25,
26, breather resistors 27, 28, 29, capacitors 30, 31, Zener diodes 32, 33, and a diode 34.

A diode 3 is connected between both terminals of this constant voltage power supply.
A time constant circuit consisting of a resistor 36 and a capacitor 37 is connected through the resistor 36 and the capacitor 37. This capacitor 3
A Zener diode 38 and a resistor 39 are connected in parallel to 7, and a resistor 40,
A time constant circuit of a volume 9 and a capacitor 41 is connected. The volume control 9 is used to change the set time of the electronic timer by changing the time constant of the time constant circuit, and the resistance value is changed by operating the slide shaft 10.

Further, between the connection point of the volume 9 and the capacitor 41 and the - extreme, an NPN type transistor 42, a PNP type transistor 43, and resistors 44, 4 are connected.
5 and a discharge path consisting of a capacitor 46 are connected.

Furthermore, the connection point between the volume 9 and the capacitor 41 is an N-channel junction type via a resistor 47.
Connected to the gate of FET48. This FET
The drain of 48 is connected to the + terminal via a resistor 49, to the base of the transistor 52 via resistors 50 and 51, and to the - terminal via a resistor 53, and its source is connected to the emitter of the transistor 52. It is also connected to the -extreme via a resistor 54.

Furthermore, the collector of the transistor 52 is connected to a resistor 55.
is connected to the + terminal through a resistor 56 and to the base of a transistor 57 through a resistor 56. The emitter of this transistor 57 is connected to the + terminal, the collector is connected via a resistor 58 to the base of a transistor 59 as a switching element, and the collector is connected via a resistor 60 to the - terminal.

Further, the collector of the transistor 59 is connected to the + terminal through a parallel circuit of the relay coil 20 and the diode 61, and to the base of the transistor 42 via the resistor 62, and the emitter is connected to the - terminal.
Extremely connected.

The operation of this circuit will be explained.

First, when using a mechanical timer, when the roasting time is set with the time setting knob 7, the timer switch 16 is turned on for the set time, and the heaters 3 and 4 are energized.

In addition, when using an electronic timer, after setting the roasting time by operating the slide knob 10,
When the operation knob 11 is pushed down, the power switch 1
7 and 18 are closed, the heaters 3 and 4 are energized, and the lamp 8 is turned on. Also, resistance 3
6, 40 and capacitor 3 via volume 9
Charging starts on 7.41. At this point, the terminal voltage of the capacitor 41 is approximately 0V, so the FET
48 is off, and transistors 52, 57, and 59 are on. Therefore, the relay coil 20 is energized and energized to maintain the closed state of the power switches 17 and 18.

Next, when the set time has elapsed, the terminal voltage of the capacitor 41 reaches the set value and the FET 48 is turned on.
When this FET48 is turned on, the transistor 52,
57 and 59 are turned off, and the relay coil 20 is de-energized, so the power switches 17 and 18 are turned off.
will be released. At the same time, the collector of the transistor 59 becomes "H" level for a moment, so the transistor 42 is turned on, the transistor 43 is also turned on, and the charge in the capacitor 41 is discharged through the discharge path.
Further, the electric charge of the capacitor 37 is reduced by the power switch 17.
After being turned off, it is gradually discharged via the resistor 39 in accordance with the heat capacity of the roasting chamber and the heaters 3 and 4. For this reason, the roasting time from the second time onwards will be adjusted depending on the length of the interval time from the previous time.

As shown in FIG. 3, this electric circuit is formed by attaching each component to a printed wiring board 70 having printed wiring on its back surface. Board 7
As shown in FIG. 4, 0 indicates a high-voltage side circuit board section 71 to which components of the high-voltage circuit section 21 are attached, and a low-voltage circuit section 2.
and a low voltage side circuit board part 72 to which parts No. 2 are attached, and both parts are integrally formed and have a structure that can be easily divided at a perforation 73. In addition, the second
Only the volume 9 of the low voltage circuit section 22 shown in the figure is attached to the high voltage side circuit board section 71.

This low voltage side circuit board section 72 has a capacitor 3.
Notch plate portions 74 and 75 are provided corresponding to the mounting positions of the breather resistors 0, 31, 37, and 41 and the breather resistors 27, 28, and 29, respectively. This notch plate portion 74 has three parts, and the notch plate part 75 has two parts provided at a board connecting part 76 which is biased to one side from the center line position.
As shown in FIG. 5, installation holes 77 and 78 are formed by separating them.

Further, a substantially U-shaped lead wire notch 79 is formed at one outer end of the low voltage side circuit board portion 72 .

Further, lead wire connection holes 80 are provided as lead wire connection terminals at the outer end of the high voltage side circuit board section 71, on one side of the outer end of the low voltage side circuit board section 72, and on the inner end side of the lead wire notch section 79. It is being

In addition, Fig. 3 and Figs. 6 to 9 described below
In the figures, the numbers of some parts are omitted.

On the thus formed substrate 70, as shown in FIG. 3, each component, a lead wire 81 for external connection, and a lead wire 82 for connection between the high voltage circuit section 21 and the low voltage circuit section 22 were arranged. After that, the back surface of the board 70 opposite to the component mounting surface is immersed in a solder bath, and each component and lead wires 81 and 82 are soldered to the printed wiring.

After the solder connection is completed, the cutout plate parts 74 and 75 of the low voltage side circuit board part 72 are cut out, and the installation hole 7 is cut out.
Form 7,78. At this time, the cutout plate portion 74,
75 is connected to the low voltage side circuit board part 72 at a board connecting part 76 formed offset from the center line position, so it can be easily connected by pressing the part where the connecting part 76 is not provided toward the back side. Can be cut out.

In this way, after the solder connection, the cutout plate portion 74,
By notching 75, it is possible to avoid problems such as adhesion of solder to capacitors 30, 31, 37, 41 and breather resistors 27, 28, 29 when immersed in a solder bath, which adversely affects the characteristics of the components. Then, by pressing the capacitors 30, 31, 37, and 41 toward the mounting hole 77 after providing the mounting hole 77, the capacitors 30, 31, 37, and , 41 are inserted into the arrangement hole 77, and the height L of the entire circuit board can be reduced by the thickness of the low voltage side circuit board portion 72 compared to the case where the arrangement hole 77 is not provided. Also,
By providing the installation hole 78, the breather resistor 2
7, 28, and 28 are improved, and the influence of temperature on each component on the low-voltage side circuit board section 72 can be prevented.

Furthermore, the lead wire 82 connecting the high voltage circuit section 21 and the low voltage circuit section 22 can be made longer because it extends between both ends of the substrate 70 with the perforation 73 for division inside. Therefore, the operability when connecting wiring to the board 70 can be improved, and when the high-voltage side circuit board section 71 and the low-voltage side circuit board section 72 are separated as described later, the length of the lead wire 82 can be increased. Moreover, since it can be made uniform, it is convenient when arranging the high-voltage side circuit board section 71 and the low-voltage side circuit board section 72 apart from each other.

Note that when the distance between the lead wire connection holes 80 is short, in order to arrange the lead wires 82 in a long state, the lead wires 82 curve sharply and the height becomes higher. The problem is that it is difficult to handle.

Next, the circuit board parts 71 and 72 are energized and their operation is tested. Note that this inspection may be performed after the solder connection is completed and before cutting out the cutout plate portions 74 and 75.

After the inspection is completed, this board 70 is divided at the perforation 73, and the low voltage side circuit board part 7 is divided as shown in FIG.
2 is provided on the outside of the lower surface of the bottom plate 83 of the roaster main body 1, and the high-voltage side circuit board part 71 is provided on the inside upper part of the bottom plate 83 and the lower part of the inner surface of the decorative plate 5. stands out.

As shown in FIG. 9, this low-voltage side circuit board section 72 is attached to the lower surface of a bottom plate 83 with an insulating plate 84 interposed therebetween, with the back surface opposite to the component mounting surface facing upward, and the component mounting surface facing outward. It is fixed with screws 85. The periphery of this low-voltage side circuit board section 72 is covered with a cover body 89 having a ventilation hole 86 and having one end engaged with an engagement hole 87 of the bottom plate 83 and the other end fixed to the bottom plate 83 with screws 88. ing.

Note that, corresponding to the lead wire notch 79 of the resistance voltage side circuit board portion 72, a notch guide portion 91 having an upwardly rising guide piece 90 is provided on the insulating plate 84, and a notch guide portion 91 having a guide piece 90 rising upward is also provided on the bottom plate 83. A letter-shaped notch 92 is formed. Therefore, the lead wire 82 connecting the low voltage side circuit board section 72 and the high voltage side circuit board section 71 is connected from the surface of the low voltage side circuit board section 72 to the notch 79 of the low voltage side circuit board section 72, and the insulating plate 84. It is pulled out to the upper surface of the bottom plate 83 via the notch guide part 91 and the notch part 92 of the bottom plate 83.

Note that since the lead wire connection hole 80 of the low voltage side circuit board section 72 is located near the notch plate section 79, the low voltage side circuit board section 72 and the high voltage side circuit board section 71 are connected by the length of the lead wire 82. This allows the lead wires 82 to be used effectively.

Note that the structure that allows the high-voltage side circuit board section 72 and the low-voltage side circuit board section 72 to be separated is not limited to the perforation 73.

[Effect of idea]

According to the present invention, the components of the high voltage circuit section and the components of the low voltage circuit section are separated and placed on the board, which eliminates unnecessary insulation caused by the adjacent printed wiring of the high voltage circuit and the printed wiring of the low voltage circuit. There is no need to provide a distance, allowing for efficient design of circuit board printed wiring and efficient placement of components. Since the breather resistor is installed in the installation hole formed at the location where the breather resistor is installed, the low voltage side circuit board part is not affected by the temperature rise due to the heat generated by the breather resistor, and the low voltage side circuit board part is roasted. Coupled with the arrangement outside the main body of the device, the breather resistor has good heat dissipation, and the circuit board can be made smaller. In addition, even if the circuit board is miniaturized, the arrangement of parts and printed wiring are easy, which improves the workability of assembly and inspection, and allows better control of the heater without being affected by temperature rises in the roasting chamber. The heater can be controlled reliably. Furthermore, the cutout plate part that forms the installation hole for arranging the breather resistor is removably provided at the board connection part at a position offset from the center line position, so that the breather resistor can be installed. The notch plate can be easily removed by pressing the part where the board connecting part is not formed, which is offset from the center line of the notch plate, so the breather resistor can be soldered. If the notch plate is removed and the breather resistor is placed in the installation hole after the solder connection is made in the tank, it is possible to prevent solder from adhering to the breather resistor.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the roasting device of the present invention, FIG. 2 is an electric circuit diagram of the same roasting device, and FIG. 3 is a perspective view showing a state in which circuit components are arranged and connected to the same circuit board.
FIG. 4 is a perspective view of the same circuit board, FIG. 5 is a perspective view of the circuit board with the notch portion cut out,
Fig. 6 is a side view of the circuit board to which the above circuit components are connected, Fig. 7 is a plan view of the above circuit board, Fig. 8 is an exploded perspective view showing the state in which the above circuit board is attached to the roasting device, and Fig. 9 is the same as above. FIG. 3 is a cross-sectional view showing how the low-voltage side circuit board section is attached to the roasting device. 1...Roaster main body, 3, 4...Heater, 9...
Volume, 21... High voltage circuit section, 22... Low voltage circuit section, 27, 28, 29... Breather resistor, 3
6,40...Resistor, 37,41...Capacitor,
71... High voltage side circuit board part, 72... Low voltage side circuit board part, 75... Notch plate part, 76... Board connection part, 78... Installation hole.

Claims (1)

[Claims for Utility Model Registration] A heater, a high-voltage circuit section including a power supply circuit, and a time constant circuit determined by a capacitor and a resistor connected to the high-voltage circuit section via a breather resistor; In the roasting apparatus, the components of the high voltage circuit section and the components of the low voltage circuit section are separated and connected to separate circuit board sections, and the components of the low voltage circuit section are connected to separate circuit board sections. The cutout plate portion that forms the installation hole for installing the breather resistor, which corresponds to the installation position of the breather resistor connected to the low-voltage side circuit board portion to which the component is connected, is offset from its center line position. A high-voltage side circuit board part is provided in a roaster main body in which the heater is disposed, and the high-voltage side circuit board part is connected to the parts of the high-voltage circuit part, and the high-voltage side circuit board part is removably provided at the board connection part of the position, and the high-voltage side circuit board part is connected to the parts of the high-voltage circuit part. A roasting device characterized in that a low-voltage side circuit board section, which is removed and has a breather resistor arranged in an arrangement hole, is disposed outside the roaster main body.