JPS6226029Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to a heating device for a liquid container such as an electric pot.

Prior Art This type of heating device controls the energization of a heater wrapped around the lower part of the container side according to the temperature of the liquid content using a temperature-sensitive control member attached to the outer surface of the container to bring the liquid content to a predetermined temperature. Heat it up to a high temperature and keep it warm. Conventionally, a temperature-sensitive control member is attached to the lower surface of the bottom of a container to sense the temperature of the liquid content without being significantly affected by heat from the heater, and to control the energization of the heater. However, the temperature fuse, which detects the sudden rise in temperature of the container when the liquid content is completely exhausted and cuts off the power to the heater, is attached to the bottom of the container, where the temperature rises rapidly when the liquid content is completely exhausted. It is appropriate to be On the other hand, if the temperature-sensitive control member is attached to the bottom of the container, it will continue to detect the temperature and control the heater until the content liquid is completely exhausted. It cannot cope with the heating of the part of the container that is higher than the liquid level of the heater, that is, the part of the container that is empty of liquid, that is, the part of the container that is partially empty.

Therefore, a temperature-sensitive control member is provided above the heater wrapping around the side of the container, so that even if the partially empty cooking state is reached, the temperature control member does not boil the water or operates within the control temperature range for keeping the water warm, so that the partially empty heating section does not boil the water. Or by cutting off or limiting the power supply to the heater when the temperature exceeds the heat retention temperature,
It is also conceivable to prevent the partially empty cooking section from boiling water or being overheated above the heat retention temperature.

In this case, in order to achieve normal temperature control by detecting the temperature of the liquid content until the final point of partial dry cooking, the temperature-sensitive control member is close to the boundary where partial dry cooking occurs on the side circumference of the container. Although this is moderate, it becomes susceptible to the temperature influence of the wrapped heater during normal operation, which impedes proper temperature control.

Purpose This invention takes into account the installation position of the temperature-sensitive control member as well as its location conditions, and aims to reduce the temperature at or near the final point in time when a partial dry state is reached without any heat influence from the heater during normal operation. It is an object of the present invention to provide a heating device for a liquid container that can accurately detect the temperature of the liquid contained therein and perform normal temperature control.

Structure/Function This invention provides a temperature-sensitive control member that controls the energization of the heater according to the temperature at a position near the upper part of the open part of the annular heater that is provided at the lower part of the periphery of the container and is open between both ends. The gist of achieving the above object is to provide a notch extending from the installation position of the temperature-sensitive control member to the vicinity of the temperature-sensitive control member in the heat insulating wall covering the surface.

Since the temperature-sensitive control member provided under the above conditions is located near the upper part of the heater installation part, that is, in the upper part of the heater installation area or just above the heater installation part, the temperature-sensitive control member provided under the above conditions It is possible to accurately detect up to that point, and in addition, a notch corresponding to the installation position of the temperature-sensitive control member is provided in the heat insulating wall covering the side circumferential surface of the container, so that the heat of the open part of the heater is transferred from the exposed part to the surrounding area. In addition to making it easier for the heat to escape, it also makes it less susceptible to the effects of heat from the heater.

Embodiment To explain the embodiment shown in FIGS. 1 to 3, the container body 1 includes an aluminum inner container 3 housed in an outer case 2, a hot water boiler in the lower part of the side circumference of the inner container 3, and a heat-retaining heater. 4 and 5 are wrapped around each other to heat the content liquid to a predetermined temperature and keep it warm. As shown in FIG. 2, the heaters 4 and 5 are wound alternately around an insulating strip core plate 6,
It is formed into a partially open annular shape with the metal bag-shaped holding band 8 sandwiched therebetween.
Due to this shape, the heaters 4 and 5 are wound around the side of the inner container 3 by fastening the bent pieces 8a of both open ends of the band 8 with screws 9. The heaters 4 and 5 are provided in a control circuit as shown in FIG.
The lead wires 1 are drawn out from one open end of the
4 and 15 are drawn out separately from the other open end of the band 8 and connected to the circuit shown in FIG.
16, 17, 18 are each lead wire 11, 14, 15
It is a pull-out hole and is opened in the front plate of the band 8.

In the circuit shown in FIG. 3, numeral 19 is a thermostat that switches between the water boiling state and the heat retention state, and is in the on state until the content liquid reaches a predetermined water boiling temperature, and the heat retention heater 5 is turned on when the short-circuited water heater 4 is energized alone. When a predetermined boiling temperature is reached, the heater is turned off to release the short-circuited state of the insulating heater 5, and low-temperature heating is performed by energizing in a high resistance state where the kettle heater 4 and the insulating heater 5 are connected in series. Let them do it. Reference numeral 20 denotes a temperature-sensitive reed switch, which is connected to the thermostat 1 together with the heat-retaining heater 5.
The thermostat 19 is provided in series with the heat insulating heater 5 and in parallel with the thermostat 19 so that the short circuit can be made or broken by the heat insulating heater 5. The content liquid is kept at a constant temperature by energization control.

Here, the thermostat 19 and the temperature-sensitive reed switch 20 constitute a temperature-sensitive control member that controls the energization of the wrap-around heaters 4 and 5. The temperature-sensitive reed switch 20 that controls low-temperature heating is attached to the outer surface of the bottom of the inner container 3 together with a temperature fuse 21.
A thermostat 19 which switches from high-temperature heating to low-temperature heating as the temperature of the content rises is particularly attached to the heater open portion _3a1 around the container of the heater wrapped portion 3a on the outer surface of the inner container 3.

When the content liquid is poured out by a pump, the content liquid is reliably poured out to the height position of the lower end 22a of the liquid lifting pipe 22. This position is considerably lower than the upper edges of the wrapped heaters 4 and 5, and the upper edges of the wrapped heaters 4 and 5 are higher than the liquid level of the liquid content, and are used to partially heat the part of the inner container 3 where there is no liquid content. It becomes empty cooking state. At this time, the temperature of the partially heated portion of the inner container 3 is about to rise rapidly, but the thermostat 19 senses this and switches to the low-temperature heating state when the predetermined boiling temperature is reached. The low-temperature heating continues, the partial dry cooking state caused by the high-temperature heating is avoided, and the content liquid is kept in the low-temperature heating state.

Temperature reed switch 20 is also thermostat 19
It may also be installed in the same position as shown in the imaginary line in Figure 2.
In this case, each time the partially empty heating section of the inner container 3 reaches the set temperature, the temperature-sensitive reed switch 20 turns off and cuts off the electricity to the heaters 4 and 5. It is possible to prevent the cooking part from being heated above the temperature range for keeping the contents warm.

The container surrounding heater open portion 3a1 in the heater wrapping portion 3a of the inner container ₃ forms a low heat receiving portion in the heater installation portion. This low heat receiving part 3a ₁ is a lead wire extraction part from the band 8 of the heaters 4 and 5,
Between the open ends of the band 8 where the heaters 4 and 5 are cut,
To be exact, the lead wire 11 at the heater opening part 3a ₁ ,
14, 15, and the parts corresponding to the respective lead-out parts from the band 8, etc., and in the case of this embodiment, the content directly above the part corresponding to the lead wires 14, 15 individual lead-out parts of the heaters 4, 5. A thermostat 19 is attached to the side circumferential surface of the vessel 3, and in some cases, a temperature-sensitive reed switch 20 is also attached. In addition, a heat insulating wall 2 is installed around the outer circumference of the inner container 3, including the area where the heaters 4 and 5 are wrapped.
However, the parts corresponding to the lead wires 11, 14, 15 of the heaters 4, 5 are cut out as a heat release part 23a, and the heaters 4, 5 are
By making it easy for the heat at both ends to escape to the surroundings,
The heat received from the heaters 4 and 5 at the heater open portion _3a1 of the inner container 3 is further reduced.

A thermostat 19 located directly above the heater opening portion 3a1 in the heater winding portion _3a of the inner container 3
Such temperature-sensing control elements are less susceptible to thermal effects from the heaters 4, 5 and normally properly control the flow of electricity to the heaters by detecting the temperature of the contents. Even if the liquid level of the contents falls below the upper edge of the wrapped heaters 4, 5 and partial dry cooking occurs, the temperature rise caused by partial dry cooking can be immediately detected and dealt with because they are close to the heater wrapped portion 3a.

The heater wrapping part 3a has a slightly small diameter so that the outer periphery of the wrapped heaters 4 and 5 and the outer periphery of the inner container 3 are almost flush with each other, and the attached part of the thermostat 19 etc. is made into a recess 24, so that the attached part The thermostat 19 and the like are prevented from protruding to the side circumferential surface of the inner container 3, and the heaters 4, 5 and the thermostat 19 are prevented from interfering with the attachment of the heat insulating wall 23.

In the figure, 25 is a timer, which has a timing motor 26 and a changeover switch 27 as shown in the third figure.
At the time-up position, the changeover switch 27 is connected to the NC terminal to turn on the circuits of the heaters 4 and 5, and during time setting, it is connected to the NO terminal to turn on the timing motor 26. 25a is a timer time setting knob. Reference numerals 28, 29, and 30 indicate pilot lamps for boiling water, keeping warm, and operating a timer.

FIG. 4 shows that the notch 23a of the heat insulating wall 23 connects the fastening part of the band 8 and each lead wire 14 of the heaters 4, 5.
The heat loss is reduced by reducing the size to a range corresponding to 15 individual drawer portions.

FIG. 5 shows that the notch 2 of the heat insulating wall 23 extends to the part corresponding to the temperature sensitive control member such as the thermostat 19.
3a is expanded to further reduce the thermal influence from the heaters 4 and 5 on the thermostat 19 and the like. The portion of the notch 23a corresponding to the wound heaters 4 and 5 can be made narrower as shown in FIG. 4 as shown by the imaginary line.

FIG. 6 shows that a notch 31 is formed at the upper edge of the band 8 corresponding to the heater opening part 3a ₁ in the inner container heater wrapping part 3a, and the heater opening part 3a ₁ is exposed by the notch 31. A thermostat 19 is attached to the upper part of the heater wrapping portion 3a.
As a result, the thermostat 19 sufficiently achieves normal control operation by detecting the temperature of the liquid content until the point where partial dry cooking actually occurs, and at the point when partial dry cooking starts, the thermostat 19 can prevent the temperature of that part from rapidly increasing. It also improves the overheat prevention function when partially empty cooking.

Effects According to this invention, a temperature-sensitive control member that controls the energization of the wrapped heater according to the temperature is attached to a position near the upper part of the open part of the annular heater that is open between both ends. Even if the level of the liquid content drops below the upper edge of the wrapped heater and partial dry cooking occurs, the heater will operate within the normal set temperature range and control the heater in response to the sudden temperature rise in the partially dry cooking area. Therefore, overheating due to partial dry cooking can be prevented, and by providing a cutout in the heat insulating wall covering the side circumferential surface of the container that extends to the installation position or the vicinity of the temperature-sensitive control member, the heater is not heated during normal operation. It is even less susceptible to heat effects from
Appropriate operation is possible according to the temperature of the content liquid.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an embodiment with the main parts exposed, Fig. 2 is an enlarged external view with the main parts partially cut away, Fig. 3 is a control circuit diagram, and Fig. 4 6 to 6 are external views of main parts showing other embodiments. {2... Exterior case, 3... Inner container} 1... Container body, 3a... Heater wrapping part, 3a ₁ ... Heater opening part, 4... Water boiler heater, 5... Warming heater, 8
... Bag-shaped holding band, 11, 14, 15 ... Lead wire, 16, 17, 18 ... Extraction hole, {19
... thermostat, 20 ... temperature-sensitive reed switch, } temperature-sensitive control member, 23 ... heat insulation wall, 23a ...
...Notch.

Claims (1)

[Claims for Utility Model Registration] (1) In a heating device for a liquid container, which is provided with an annular heater with both ends open at the lower part of the periphery of the container, the heater is energized at a position near the open part of the heater to maintain the temperature. 1. A heating device for a liquid container, characterized in that a temperature-sensitive control member for controlling the temperature-sensitive control member is provided, and a notch extending from the installation position of the temperature-sensitive control member to the vicinity of the temperature-sensitive control member is provided in a heat insulating wall that covers the circumferential surface of the container side. (2) The heating device for a liquid container according to claim 1, wherein the temperature-sensitive control member is a heat-sensitive element such as a temperature-sensitive reed switch or a thermostat.