JPH0246237B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronically controlled iron.

In most conventional electric irons, the temperature of the base surface (hanging surface) is controlled by using a bimetal, and the temperature is varied by the curved displacement dimension of the bimetal.However, this bimetal method is simple in terms of structure. However, it has the following drawbacks in terms of temperature control.

The temperature difference (temperature waveform) between on and off operation is large compared to the set temperature.

There is a limit to the speed at which the base temperature is sensed by the bimetal, and a temperature difference occurs between the initial stage after the input is turned on and the time when it stabilizes (overshoot).

Temperature setting in a bimetal type was generally done by directly rotating an operating knob, etc., and changing the vertical movement by an intervening member connected to the bimetal and a screw or cam plate, and by the amount of displacement. Because it is made up of layers, it is easy for errors to occur, and it takes time for producers to make fine adjustments.

In particular, the above concerns the basic performance of irons, and it was necessary to carefully manage materials that are sensitive to temperature, such as synthetic fibers, as this could lead to damage to the fibers.

Therefore, an object of the present invention is to provide an electronically controlled iron that can perform highly accurate temperature control and simplify temperature setting operations.

The electronically controlled iron of the present invention has an output switching circuit that sequentially switches the output state each time the switch is turned on and off, and detects the selected resistance and base temperature according to the output state of the output switching circuit. 2 of the bridge circuit including the temperature sensing element
The output is compared by a comparator, and the power control element is turned on and off depending on the output level of the comparator to control the energization of the heater, and the indicator is activated depending on the output state of the output switching circuit. By this,
By accurately controlling the temperature of the base part and displaying the set temperature, the temperature setting operation is simplified, and the set temperature is displayed to make it easier for the user to understand.

An electronically controlled iron according to an embodiment of the present invention will be explained based on FIGS. 1 to 5.

FIG. 1 shows a block diagram of an electronically controlled iron. In the figure, 1 is a base portion of the iron, 2 is a temperature detection element for detecting the temperature of the base portion 1, and 3 is an output switching circuit consisting of a ring counter and the like. This output switching circuit 3 switches the resistance value of one side of the bridge circuit based on the output of the ring counter, and also drives a set temperature display 8 to display the set temperature. A switch 4 operates the output switching circuit 3, and shifts the output of the output switching circuit 3 every time it is turned on or off. 5 is a comparator that compares the two outputs of the bridge circuit including the temperature detection element 2 and the resistance selected by the output of the output switching circuit 3, and drives the power control element 6 with the output to control the energization of the sheathed heater 7. The temperature of the base portion 1 is maintained at a predetermined set temperature. That is, by turning the switch 4 on and off, the temperature of the base portion 1 can be maintained at an arbitrary set temperature, and the set temperature is notified by the display 8.

FIG. 2 shows a specific electrical circuit diagram of the electronically controlled iron. In the figure, reference numeral 9 denotes an AC power source, to which a series circuit of a sheathed heater 7 and a normally open relay contact 10a is connected. This relay contact 10a closes when a current flows through a relay coil 10b, which will be described later, and energizes the sheathed heater 7. Also, the AC power supply 9 has a resistor 11 and a capacitor 1.
Two series circuits are connected. This capacitor 12 serves as a constant voltage DC power source for a control circuit to be described later. Reference numeral 13 denotes a ring counter with a preset function connected in parallel to the capacitor 12, one end 13a of which is connected to one end of the capacitor 12, and the other end 13b connected to the other end of the capacitor 12 and kept at ground potential. Reference numeral 4 denotes a switch which is opened and closed by operating an operating means to be described later, and one end of the capacitor 12 and the preset function are connected between the first input terminal 13c of the ring counter 13.
14 is a resistor connected between the second input terminal 13d and the third input terminal 13e of the ring counter 13 with a preset function, and 15 is a resistor connected between the third input terminal 13e of the ring counter 13 with a preset function and the capacitor 1.
The time constant of the clock pulse for switching the output of the ring counter 13 with a preset function is determined by the values of the resistor 14 and the capacitor 15. 13f, 13g,
13h and 13i are the 1st output terminal, the 2nd output terminal, the 3rd output terminal, and the 4th output terminal, respectively, of the ring counter 13 with a preset function, and these output terminals 13f, 13g, 13h, 13
i are light emitting display elements 16a, 16b, 16, respectively
The resistor 17 is commonly connected to one end of the resistor 17 through the resistors 16c and 16d, and the other end of the resistor 17 is connected to one end of the capacitor 12. The circuit diagram shows four luminous temperature display elements 16a, 16b, 16 as an example.
c and 16d constitute a set temperature display.

The temperature sensing element 2 has one end connected to one end of the capacitor 12 and the other end connected to the inverting input terminal 5 of the comparator 5.
a, and is connected to the second output terminal 13g of the ring counter 13 with a preset function via a resistor 18, and to the third output terminal 13h of the ring counter 13 with a preset function via a resistor 19.
Furthermore, it is connected via a resistor 20 to a fourth output terminal 13i of a ring counter 13 with a preset function. 21 and 22 are resistors connected in series, and this series circuit is connected in parallel to the capacitor 12. The connection point between the resistor 21 and the resistor 22 is connected to the non-inverting input terminal 5b of the comparator 5. 23 is a transistor connected in series to the relay coil 10b, and the series circuit of this relay coil 10b and the transistor 23 is connected to the capacitor 1.
2 are connected in parallel. The output of the comparator 5 is inputted to the base electrode of the transistor 23 via the resistor 24, and when the output of the comparator 5 is at H level, it becomes conductive and current flows through the relay coil 10b, closing the relay contact 10a. . 25 is the relay coil 10
This is a diode connected in parallel to b.

Next, the operation of this circuit configuration will be explained. First, a ring counter 13 with a preset function is constructed based on the specific block diagram shown in FIG.
Explain the operation. 26 is a ring counter, and when a voltage is applied to the terminal 13a as shown in FIG. It is set to L level as shown in C. Note that at this time, the second output circuit 26b, the third
Both the output circuit 26c and the fourth output circuit 26d have an open collector type configuration, and the respective outputs of the second output terminal 13g, the third output terminal 13h, and the fourth output terminal 13i are as shown in FIG. As shown in F, both become H level.

Next, the switch 4 is closed and the first input terminal 1
When the input of 3c is set to H level, the second input terminal 1
The oscillation circuit 28 oscillates according to the time constant determined by the values of the resistor 14 and capacitor 15 connected to the third input terminal 13e and the fourth input terminal 13e.
A clock pulse as shown in Figure B is output. When this clock pulse is input to the ring counter 26, the second output circuit 26b is driven, and only the output of the second output terminal 13g becomes low as shown in FIG. 4D.
level, and the other output terminals 13f, 13h, 1
The output of 3i becomes H level as shown in FIG. 4C, E, and F.

When the next clock pulse is further input to the ring counter 26, the third output circuit 26c is driven, and only the output of the third output terminal 13h becomes L level as shown in FIG. 4E.

When the next clock pulse is input to the ring counter 26, the fourth output circuit 26d is driven.
Only the output of the output terminal 13i becomes L level as shown in FIG. 4F. Furthermore, when the next clock pulse is input to the ring counter 26, the first output circuit 26a is driven, and only the output of the first output terminal 13f becomes L level as shown in FIG. 4C. Repeat the same below.

Next, the operation of the circuit configuration shown in FIG. 3 will be explained.

First, when the AC power supply 9 is connected, the first output terminal 13f of the ring counter 13 with preset function is connected.
The output becomes L level, and the first light emitting display element 16
Current flows through a and it lights up. second output terminal 13g,
Since the outputs of the third output terminal 13h and the fourth output terminal 13i are at H level, the potential at the connection point between the temperature sensing element 2 and the resistor 18 is high, and therefore the input of the inverting input terminal 5a of the comparator 5 is inverted. Input terminal 5b
Since the output of the comparator 5 becomes L level, the transistor 23 is not conductive and no current flows through the relay coil 10b, so the relay contact 10a is opened and the sheathed heater 7 is not energized. Therefore, the lighting of the first light emitting display element 16a indicates the "off" state in which the sheathed heater 7 is not energized.

Next, when the operating means is operated to close the switch 4, only the output of the second output terminal 13g becomes L level, and the second light emitting display element 16b lights up.
Furthermore, since the output of the second output terminal 13g is at the L level, the potential at the connection point between the resistor 18 and the temperature sensing element 2 decreases, and the input of the inverting input terminal 5a of the comparator 5 becomes lower than the input of the non-inverting input terminal 5b. The output of the comparator 5 becomes H level. Therefore, the transistor 23 becomes conductive, current flows through the relay coil 10b, and the relay contact 10a closes, so that the sheathed heater 7 is energized and the temperature of the base portion 1 increases. As the temperature of the base portion 1 increases, the resistance value of the temperature sensing element 2 decreases, and when the input level of the inverting input terminal 5a and the input of the non-inverting input terminal 5b of the comparator 5 are reversed, the output of the comparator 5 is inverted. Then, it becomes L level, and the power supply to the sheathed heater 7 is stopped.
As a result, when the resistance value of the temperature sensing element 2 becomes high, the sheathed heater 7 is energized again. By repeating such operations, the temperature of the base portion 1 is maintained at the first predetermined temperature _T1 . That is, when the second light emitting display element 16b lights up, it means that the set temperature has been set to the first predetermined temperature _T1 . The resistance value R _TH1 of the temperature sensing element 2 at this time is determined by the following equation.

R _TH1 = R ₂₁・R ₁₈ /R ₂₂ Note that R ₁₈ , R ₂₁ , and R ₂₂ are resistors 18 and 2, respectively.
The resistance values of 1 and 22 are shown.

Next, when the operating means is operated to close the switch 4, only the output of the third output terminal 13h becomes the L level, the third light emitting display element 16c lights up, and the temperature of the base part 1 reaches the second predetermined level. Temperature T ₂
is maintained. That is, the third light emitting display element 16
When c lights up, it means that the set temperature has been set to the second predetermined temperature _T2 . The resistance value R _TH2 of the temperature sensing element 2 at this time is determined by the following equation.

R _TH2 = R ₂₁ · R ₁₉ /R ₂₂ Note that R ₁₉ is the resistance value of the resistor 19.

Further, when the switch 4 is closed, only the output of the fourth output terminal 13i becomes L level, the fourth light emitting display element 16d lights up, and the set temperature is set to the third predetermined temperature _T3 . The resistance R _TH3 of the temperature sensing element 2 at this time is determined by the following equation.

R _TH3 = R ₂₁ · ₂₀ / R ₂₂ Note that R ₂₀ is the resistance value of the resistor 20.

As described above, the set temperature is sequentially switched by operating the operating means, and the relationship between the predetermined temperatures T ₁ , T ₂ , and T ₃ is as follows:
Since it is determined by the relationship between the resistance values R ₁₈ , R ₁₉ , and R ₂₀ , by setting R ₁₈ > R ₁₉ > R ₂₀ , the temperature of the base portion 1 can be sequentially switched to low temperature, medium temperature, and high temperature. become.

FIG. 5 shows a partially cutaway side view of this electronically controlled iron. In FIG. 5, 1 is the base part of the iron, 2 is a temperature sensing element that is in close contact with the inner surface of the base part, 30 is a cover that covers the upper part of the base part 1, and 31 is a part with a certain gap above and behind the cover 30. The cover 30 is fixed to the cover 30 by passing the cover 30 through the boss 31a provided on the lower surface and tightening the screws 32. Reference numeral 33 denotes a handle body with an open bottom surface, and a locking claw 31b at the rear of the heat shield plate 31 is inserted into a locking hole (not shown) provided at the rear opening edge.
The heat shield plate 3
Fixed to 1. Reference numeral 35 denotes a handle back cover that closes the rear opening of the handle body 33. By tightening a screw 36 to a boss 33b on the inner wall surface of the rear leg portion of the handle body 33 through a boss 35a provided on the inner surface, the handle back cover 35 is closed. It is fixed to the handle body 33. 37 is a control board placed in the space formed by the handle body 33, the heat shield plate 31, and the handle back cover 35, and the components constituting the temperature control circuit are mounted on a tall board such as a power transformer, a power control element, and a capacitor. The parts are located in the rear leg space of the handle body 33, and the other short parts are mounted on the upper surface so as to be located in the body space. 38
and 39 are auxiliary heat insulating plates, which are interposed between the heat shield plate 31 and the control board 37 to form a plurality of layers of heat insulating space;
At corresponding positions on the mutually opposing surfaces of 8 and 39, there are concave and convex fitting parts 3 for securing a heat insulating space and for mutual positioning.
1d, 38a, 38b, and 39a are provided, and a protrusion 39b that supports the control board 37 is provided on the upper surface of the uppermost auxiliary heat insulating board 39, and this protrusion 39b and a downward step provided inside the handle body 33 33d and the control board 37 is held between them. 4
Reference numeral 0 denotes a switch board, which is disposed within the grip portion of the handle body 33 and fixed with a screw 41, on which the switch 4 is mounted. Reference numeral 42 denotes an operation knob for operating the switch 16, which is located in the recess 33e on the upper surface of the grip part of the handle body 33.
It protrudes outward from the bottom surface of and is located within the recess 33e.

43 is a water tank attached to the front part of the handle body 33, and a button 44 for switching between steam and dry is located at the top.
A nozzle 4 for supplying water to the base portion 1 is provided below the steam/dry switching button 44.
5 is formed, and its opening/closing is controlled by moving the operating stick 46 up and down. When the water supply nozzle 45 opens, the water in the water tank 43 drips into the vaporization chamber 47 of the base part 1 to generate steam, which is ejected from the steam hole formed in the base part 1. Also,
The water tank 43 can be removed from the handle body 33 by operating a lock knob 48 provided near the grip portion of the handle body 33.

In this way, in this embodiment, the desired predetermined temperature can be easily and accurately obtained by simply turning the switch 4 on and off, and the temperature control accuracy is high. 8, so it is easier to distinguish at a glance compared to the conventional bimetal type, and when the power cord is connected, one of the light emitting display elements 16a to 16d is always lit. , it is possible to provide a visual notification function for forgetting to turn off the power.

Another embodiment of the invention is shown in FIG. That is, in this electronically controlled iron, diodes 48 to 50 are added to the output of the ring counter 13 in the circuit shown in FIG.
The output is as shown in FIG. This is because, for example, when the output of the fourth output terminal 13i is at L level, the third output terminal 13h becomes L level due to the diode 50. When the third output terminal 13h becomes L level, the second output terminal 13g is connected due to the diode 49.
becomes L level, and when the second output terminal 13g becomes L level, the first output terminal 13f becomes L level due to the diode 48.

Waveforms (corresponding to FIG. 4) of various parts of the ring counter 13 with preset function in this embodiment are shown in FIGS. 7A to 7F.

As mentioned above, in this embodiment, the number of lit set temperature display elements is 1 → 2 → 3 → 4 →
It is designed to switch between 1 piece...

The effects of this embodiment are similar to those of the previous embodiment.

In the above two embodiments, a ring counter in four notation order is used: off -> low temperature -> medium temperature -> high temperature -> off, etc. However, it is also possible to set the counter to any predetermined temperature display number.

As described above, the electronically controlled iron of the present invention includes a base portion heated by a heater, a temperature detection element attached to the base portion to detect the temperature of the base portion, a switch, and a temperature sensing element attached to the base portion to detect the temperature of the base portion. an output switching circuit whose output state is switched by the output switching circuit; a plurality of temperature setting resistors selected according to the output state of the output switching circuit; and a bridge circuit configured by the temperature sensing element and the temperature setting resistor. 1
and a second resistor, a comparator for comparing two outputs of the bridge circuit, and a display having a plurality of display elements, the display displaying a set temperature according to the output state of the output switching circuit. This has the advantage that highly accurate temperature control can be performed and the temperature setting operation can be simplified.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an electronically controlled iron according to an embodiment of the present invention, Fig. 2 is a specific circuit diagram thereof, Fig. 3 is a specific block diagram of its main parts, and Figs. 4 A to F are waveforms of each part thereof. 5 is a partially cutaway side view showing the configuration of this electronically controlled iron, FIG. 6 is a circuit diagram of another embodiment of the invention, and FIGS. 7A to 7F are waveform diagrams of each part thereof. . 1...Base part, 2...Temperature detection element, 3...
Output switching circuit, 4... switch, 5... comparator,
6... Power control element, 7... Sheathed heater, 8...
...Display, 18-22...Resistance.

Claims (1)

[Claims] 1. A base heated by a heater, a temperature detection element attached to the base to detect the temperature of the base, a switch, and an output whose output state is switched by the switch. A first bridge circuit configured by a switching circuit, a plurality of temperature setting resistors selected according to the output state of the output switching circuit, and the temperature sensing element and the temperature setting resistor.
and a second resistor, a comparator for comparing two outputs of the bridge circuit, and a display having a plurality of display elements, the display displaying a set temperature according to the output state of the output switching circuit. An electronically controlled iron that performs the following functions. 2. The electronically controlled iron according to claim 1, wherein the display device lights up any one of the plurality of display elements when the power cord is connected. 3. The electronically controlled iron according to claim 1, wherein the display device lights up a display element whose temperature is lower than the set temperature when the set temperature is changed.