JPH0312920B2 - - Google Patents

Description

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

Conventional electric irons use a bimetal to control the temperature of the base surface (hanging surface), and in most cases the temperature is varied by the curved displacement dimension of the bimetal. However, although this bimetal system is simple in terms of structure, it has the following drawbacks in terms of temperature control. That is, (1) The temperature difference (temperature waveform) between on and off operation is large compared to the set temperature.

(2) There is a limit to the bimetal sensing speed of the base temperature, and a temperature difference occurs between the initial stage after input and the time of stability (overshoot).

(3) Temperature settings in bimetal systems were generally performed by directly rotating an operating knob, etc., replacing the intervening parts connected to the bimetal with a screw or cam plate that moved up and down, and setting the temperature by the amount of displacement. Because it is made up of many stacked parts, it is easy for errors to occur, and it takes time for producers to make fine adjustments.

In particular, since (1) and (2) above relate to the basic performance of irons, materials that are sensitive to temperature, such as synthetic fibers, may damage the fibers, so sufficient management is required.

Therefore, an object of the present invention is to provide an electronically controlled iron that can reduce overshoot and the range of temperature change in a stable state, as well as reduce temperature detection errors.

A first embodiment of this invention is shown in FIGS. 1 to 12.
As shown in the figure. That is, reference numeral 1 designates an iron base, which is provided with a lid 3 and a heater 4 forming a vaporizing chamber 2 on its upper surface, and has a groove G extending over the rear outer wall surface of the vaporizing chamber 2 and the outer wall surface of the heater 4, which will be described later.
A metal body 6 having a built-in thermistor (temperature sensing element) 5 is installed in the groove G, and the thermistor 5 is connected to a control board 11 of a control means to be described later. A notch H is formed to hold the lead wire 7 that is to be inserted. 8 is a cover provided to cover the base 1; 9 is a heat shield plate provided on the cover 8; 10 is a handle provided on the heat shield plate 9;
A control board 11 equipped with a power transformer, a power control device, an IC, a transistor, a resistor, a diode, a light emitting element, and other electronic components is adiabatically installed in the space formed between the power transformer 0 and the heat shield plate 9. ing. 12 is a lid at the rear of the handle 10; 13 is a water tank provided at the front of the handle 10; it has a button 14 for switching between steam and dry at the top; and a button 14 for switching between steam and dry at the bottom; It is equipped with a supply opening/closing nozzle 15 and is controlled by moving the operating rod 16 up and down. Further, the water tank 13 can be removed by operating a lock knob 17 provided near the grip portion of the handle 10. 18 is the lead wire 1 to the control board 11
It is a switch board connected by wires 9, and is equipped with a switch device 21 whose head 20 is exposed from the handle 10. 22 is a power cord, and 23 is a heater lead wire.

FIG. 11 shows the temperature control circuit of the control means of this electronically controlled iron. To explain the outline, the heater 4 to which AC power E ₀ is applied is controlled by the opening and closing of the normally open contact r _a of the relay Ry. , this relay Ry
is controlled by comparator 24. Said AC power supply
The voltage at E ₀ is converted into a DC voltage by a rectifier diode 25, a resistor 26, and a smoothing capacitor 27, and this voltage is supplied to an output switching circuit 28, a comparator 24, and a series circuit of the coil of the relay Ry and the drive transistor Q. The output switching circuit 28 is composed of a ring counter with a preset function, an open collector type inverting output circuit (not shown) is connected to each output terminal, and current limiting resistors are connected to the output terminals _a0 to _a3 .
Light emitting diode _LED for temperature display via R ₇ ~
An LED ₄ is connected, and temperature setting resistors _R4 to _R6 are connected to the output terminals _a1 to _a3 via thermistors 5. Therefore, when a DC voltage is applied to this output switching circuit 28, only the first output terminal _a0 becomes L level due to the preset function, and the light emitting diode LED ₁ lights up. Next, the switch 21
When you press , the output is shifted to the second output terminal _a1 by a clock pulse determined by the time constant of the external resistor _R1 and capacitor _C0 , and only this becomes the L level.
When the light emitting diode LED ₂ lights up, a current flows through the thermistor 5 and the resistor R ₄ , and a potential based on the resistance values of both appears at the connection point P. Similarly, when the switch device 21 is repeatedly turned on, the light emitting diode LED ₃ is turned on and the resistor R ₅ is energized, and then the light emitting diode LED ₄ ,
Resistor R ₆ is switched, but the switch device 21
When you turn on, it switches to the original light emitting diode LED ₁ . The comparator 24 compares the reference voltage set by the resistors R ₂ and R ₃ with the potential at the connection point P between the thermistor 5 and the resistors R ₄ to _{R 6} , and when the potential at the connection point P is higher than the reference voltage, the comparator 24 The output terminal of is at L level, and vice versa, it is at H level, and at this H level, current is supplied to the base of transistor Q via the base resistor, transistor Q is turned on, and the coil of relay Ry is energized. D ₀ is relay Ry
This is a surge absorption diode for the coil. Therefore, when the power cord 22 is plugged into an outlet, the light emitting diode LED ₁ lights up due to the preset of the output switching circuit 28, and the output terminals _a1 to _a3 are set to H.
The heater 4 is off due to the level, but when the switch device 21 is turned on once, the light emitting diode
The LED ₂ lights up, current flows through the thermistor 5 and the resistor R ₄ , and the potential at the connection point P becomes lower than the reference voltage, so the heater 4 is turned on. The resistance value of the thermistor 5 decreases as the temperature rises due to the heat generated by the heater 4, and when the potential at the connection point P exceeds the reference voltage, the heater 4 is turned off, and the temperature drops and the resistance value of the thermistor 5 decreases.
When the potential of the heater 4 falls below the reference voltage, the heater 4 is turned off, and this process is repeated thereafter. When the switch device 21 is operated to switch between the resistors R ₅ and R ₆ , the operation is the same except that the stable state temperature, that is, the set temperature is different.

The mounting position of the thermistor that detects the temperature of the base 1 does not need to take into account the installation space conditions unlike bimetals, so there is a large margin for mounting, but it is not possible to install it anywhere, and careful positioning is required, especially when using a steam iron. Possible locations on the base 1 include locations A to D and X (including symmetrical locations with respect to the center line L), as shown in FIG. When considered individually, if the thermistor 5 is located at location A, location C,
It is only close to the outer wall surface of the vaporization chamber that connects the two, and when steam is generated, heat of vaporization is taken away from the vicinity of the vaporization chamber, so the temperature naturally falls. Therefore, thermistor 5
immediately detects the temperature drop and energizes the heater 4, and if the drip nozzle 15 is continuously opened, energization continues in the same way during that time. Therefore, in the continuous energization state, the heater section 4a located inside the vaporization chamber 2 is cooled, but the heater section 4b outside the vaporization chamber 2 is continuously heated, and the temperature at the rear of the base 1 continues to rise. The temperature will be higher than the initially selected temperature during drying. This phenomenon not only damages the fibers, but also increases the radiant heat to the control board 11, which affects the reliability of electronic components. In addition, if the thermistor 5 is located at location C, it will be too far away from the vaporization chamber 2 and will directly sense the heat from the heater 4. In chamber 2, the balance between the supply of vaporization heat and the supply of water will be disrupted. Therefore, the next time the heater circuit is turned on, a large amount of water is vaporized at once, and the steam ejection becomes stronger or weaker. Further, along with this jet force, water may leak from the steam jet hole provided in communication with the vaporization chamber 2, which is not desirable in terms of quality. Furthermore, if the thermistor 5 is located at location X, the response speed will be significantly delayed since it is separated from the vaporization chamber 2 and the heater 4, which will cause adverse phenomena in the vaporization chamber 2 and the heater 4, respectively. Therefore, the locations A, C, and X are not suitable.

On the other hand, when the thermistor 5 is installed at location B of the base 1, the thermistor 5 is close to the outer wall surface of the vaporization chamber 2 connecting positions A and B, the outer wall surface of the vaporization chamber 2 connecting positions B and C, and the outer wall surface of the heater. Therefore, the temperature rise after the power is turned on during dry conditions is quickly sensed and a signal is sent to the control circuit to turn off the power control device, so no extra power is supplied. Further, as the temperature of the thermistor 5 decreases, the resistance value decreases and the control circuit is automatically turned on again. By repeating this operation, the width of the temperature change becomes smaller and smaller. Furthermore, the temperature difference between the initial stage and the stable stage after inputting is extremely small, and the desired fiber temperature can be adjusted without error. Furthermore, vaporization chamber 2
When using steam, the cooling of the vaporization chamber 2 can also be detected quickly. Further, if the continuous energization state continues and the temperature at the rear of the base 1 gradually rises, the temperature at the rear of the base 1 will be sensed rather than the temperature in the vaporization chamber 2, and the control circuit will be turned off. In other words, this location B is an ideal location where the temperature of the vaporization chamber 2 and the rear temperature of the base 1 can be controlled while maintaining a balance, and the temperature can be controlled well.

Since location D is close to the outer wall surface of the vaporization chamber and the outer wall surface of the heater that connect locations A and B, it has the same effect as location B. Furthermore, location E in the vaporization chamber having a different shape shown in FIG. 10 also has the same effect as location B because it is close to the outer wall surface of the vaporization chamber and the outer wall surface of the heater that connect locations A and E.

Next, the mounting structure of the thermistor 5 will be explained. That is, as explained in FIG.
and a groove (recess) G for attaching the metal body 6 containing the thermistor 5 and a lead wire 7.
A positioning notch H is provided, and the metal body 6 is attached to the base groove G in close pressure contact. In other words, if the base is installed in a floating state without being in close contact with the base groove G, there will be a large difference between the temperature after the input is turned on and the stable temperature as explained above, or the temperature at the rear of the base will rise abnormally during steam use, or water leakage may occur. This is because it leads to problems such as Generally, the thermistor 5 is coated with insulating glass, but applying direct stress to it during installation will result in poor insulation due to breakage, and it is difficult to determine whether it is good or bad after assembly. Products embedded in rubber are commercially available, but in this case, the silicone rubber acts as a thermal buffer, making them unsuitable for items that are sensitive to heat, such as irons. Therefore, the metal body 6 of this embodiment has the outer diameter 5 of the glass-coated thermistor 5.
It has a through hole 6a that is in close contact with a, and the through hole 6
The length of a is set to a dimension 6b with a margin for the length dimension 5b of the thermistor 5, and a wide mounting portion 6 is provided at the bottom of the through hole 6a so as not to apply stress.
c, and the mounting portion 6c is fixed by press-fitting into the base groove G having a pressure-contact dimension relationship with the mounting portion 6c or by caulking the edge g of the groove G inward. In view of its purpose, the metal body 6 is preferably a container made of a metal material such as copper, aluminum, or brass that has good thermal conductivity. With this configuration, the base groove G
By geometrically dividing the mounting portion 6c that is pressed into contact with the thermistor 5 and the through hole 6a that houses the thermistor 5, the metal body 6 and the base 1 can be firmly pressed together without directly applying stress to the thermistor 5. If the thermistor 5 is inserted into the through hole 6a after the pressure contact is made, the thermistor 5 will not be damaged due to attachment, resulting in a highly reliable attachment method and good temperature performance.

FIG. 12 shows the temperature change of the base 1 with respect to time, where the solid line shows this example and the broken line shows the case where bimetal is used. As is clear from this comparison, the temperature range t ₁ from the initial power-on to the stable state
In addition, the temperature range _t2 in the stable state is also smaller in the example.

The second embodiment of this invention is shown in FIGS. 13 to 1.
It is shown in Figure 5. That is, in this electronically controlled iron, the metal body 6' is formed into a cylindrical body with different diameters, a tight insertion hole 6a' for the thermistor 5 is formed in the radial direction on the small diameter side, and the large diameter part is used as the mounting part 6c'. There is. Further, the groove G' of the base 1 is a circular groove into which the mounting portion 6c' can be press-fitted, and its edge g' is fixed by caulking inward.
This metal body 6' has the advantage of good workability into parts.

As described above, the electronically controlled iron of the present invention includes a heated base, a thermistor that detects the temperature of the base, and a control means that controls the temperature of the base based on temperature information detected by the thermistor. , comprising a groove formed in the base and a metal body in which the thermistor is placed in the groove, the metal body being made of aluminum, copper or a copper alloy which is a good thermal conductor, and the thermistor being made of aluminum, copper or a copper alloy. Since it is disposed in the groove of the base via the metal body, the following effects can be obtained. In other words, since the base temperature is transmitted by the thermistor via a metal body made of a good thermal conductor, it is possible to eliminate the temperature difference with the base and control the base temperature with high sensitivity. In comparison, overshoot and the width of temperature change in a stable state can be reduced, and temperature detection errors can also be reduced. Furthermore, since the thermistor is placed on the base via the metal body, stress during fixing does not act on the thermistor, and therefore the thermistor can be reliably attached without being damaged. Moreover, since the thermistor and the metal body are integrally constructed prior to attachment to the base, assembly work is facilitated.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view of the first embodiment of the invention, Fig. 2 is a perspective view of the base, Fig. 3 is a perspective view of the thermistor, Fig. 4 is a perspective view of the thermistor guide, and Fig. 5. is its plan view, Figure 6 is its front view, and Figure 7 is its top view.
The figure is a perspective view of the thermistor guide with a built-in thermistor, Figure 8 is a sectional view of the thermistor guide attached to the base, Figures 9 and 10 are plan views of the base showing the thermistor installation location, and Figure 11 is temperature control. A circuit diagram, FIG. 12 is a time-temperature relationship diagram, FIG. 13 is a front view of the thermistor guide of the second embodiment, and FIG.
The figure is a plan view thereof, and FIG. 15 is a sectional view of the base mounted state. 1...Base, 5...Thermistor, 6, 6'...Metal body, G, G'...Groove portion.

Claims (1)

[Claims] 1. A base to be heated, a thermistor that detects the temperature of the base, a control means that controls the temperature of the base based on temperature information detected by the thermistor, a groove formed in the base, and a thermistor that detects the temperature of the base. and a metal body in which the thermistor is placed, the metal body being made of aluminum, copper, or a copper alloy that is a good thermal conductor, and the thermistor being placed in the groove of the base via the metal body. Electronically controlled iron.