JP2020103499A - Electric kettle - Google Patents

Abstract

To further improve performance of a protective member for suppressing excessive heating of a heating part in an electric kettle that has a heating part.SOLUTION: An electric kettle 100 is mainly constituted of a kettle body 200 and a power supply base 500. The kettle body 100 includes: a liquid container 321; a heater unit (heating part) 340 for heating the inside of the liquid container; a protective member for suppressing excessive heating of the heating part and the like. The heater unit (heating part) 340 has a sheath heater 602. The electric kettle 100 includes a thermostat 611 as a protective member.SELECTED DRAWING: Figure 3

Description

The present invention relates to an electric kettle having a boiling water function.

The electric kettle can boil the water in the container in a short time by mounting a liquid container containing water on a power supply table and turning on the switch. In such an electric kettle, a heating means is provided at the bottom of the liquid container.

As a heating means of the electric kettle, for example, a sheath heater is used. The sheathed heater has a structure in which a heating wire (nichrome wire) is covered with a metal sheath. When this sheathed heater is used in an electric kettle, the sheath is formed into a substantially annular shape and attached to the bottom of the liquid container by brazing or the like (see, for example, Patent Document 1).

Patent Document 1 discloses an electric kettle having a heating means 60. The heating means 60 is a member that has a heater 61 and a heater housing member 62 in which the heater 61 is embedded by aluminum die casting, and has a generally inverted C-shaped vertical cross-section in plan view.

A thermal fuse 70 is electrically connected to the heating means 60. The thermal fuse 70 is an overheat protection component that senses the heat generation of the device caused by an overcurrent resulting from a circuit short circuit of an electrical device or a failure of a circuit component, and shuts off the circuit.

JP-A-2018-19835

However, there is a possibility that the temperature detection performance of the thermal fuse may vary depending on the mounting position. Therefore, if a thermal fuse is used as a protective member to suppress overheating of the heating device, the time from the start of heat generation of the equipment to the interruption of the circuit may vary depending on the individual equipment. The reliability decreases.

Therefore, it is an object of the present invention to provide an electric kettle in which the performance of a protective member that suppresses overheating of a heating unit is further improved.

An electric kettle according to one aspect of the present invention includes a liquid container, a heating unit that heats the inside of the liquid container, and a protection member that suppresses overheating of the heating unit. In this electric kettle, the heating unit has a sheathed heater, and the protection member has a thermostat.

According to the above configuration, in the electric kettle provided with the heating unit having the sheath heater, the thermostat having higher temperature responsiveness is used as the protective member for suppressing overheating of the heating unit. Therefore, the temperature detection performance of the protection member can be further improved.

In the above electric kettle according to one aspect of the present invention, it is preferable that the thermostat is arranged so as to straddle a lower surface of the sheath heater.

According to the above configuration, the thermostat can be more reliably attached to the lower surface of the sheathed heater in which it is easier to detect overheating of the heating portion (that is, the temperature during heating becomes higher). Therefore, it is possible to improve the detection accuracy of overheating when the thermostat is used.

In the electric kettle according to one aspect of the present invention, the thermostat may have a contact surface with the lower surface of the sheath heater.

According to the above configuration, since the thermostat has the contact surface with the lower surface of the sheathed heater, the temperature rise of the sheathed heater can be detected more accurately.

In the above electric kettle according to one aspect of the present invention, a resin member may be provided at the bottom of the liquid container, and the thermostat may be attached to the resin member via a cushioning member.

According to the above configuration, the buffer member is interposed between the thermostat and the resin member, so that the arrangement position of the thermostat can be easily adjusted.

In the above electric kettle according to one aspect of the present invention, the cushioning member may have at least one of thermal insulation and elasticity.

According to the above configuration, since the cushioning member has the heat insulating property, it is possible to prevent the heat of the thermostat from being easily transmitted to the resin member. Moreover, since the cushioning member has elasticity, it is possible to easily adjust the mounting position of the thermostat.

As described above, in the electric kettle according to one aspect of the present invention, the thermostat having higher temperature responsiveness is used as the protection member of the heating unit. Therefore, the temperature detection performance of the protection member can be further improved. Thereby, a more reliable electric kettle can be provided.

It is a perspective view showing the appearance composition of the electric kettle concerning one embodiment of the present invention. It is a side view which shows the external appearance structure of the kettle main body of the electric kettle shown in FIG. It is a perspective view which shows the structure of the heater unit provided in the bottom face part of the kettle main body shown in FIG. It is the perspective view which looked at the heater unit shown in Drawing 3 from another angle. It is a top view which shows the structure of the heater unit provided in the bottom face part of the kettle main body shown in FIG. It is sectional drawing of the AA line part of the kettle main body shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are designated by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

In the present embodiment, the electric kettle 100 will be described as an example. FIG. 1 shows the external appearance of the electric kettle 100. The electric kettle 100 is mainly composed of a kettle body 200 and a power supply stand 500. FIG. 2 shows the configuration of the side surface of the kettle main body 200.

(Overall structure of electric kettle)
The kettle body 200 is detachably mounted on the power supply stand 500. A user of the electric kettle 100 can place the kettle body 200 on the power supply table 500 when he wants to boil hot water, and can remove the kettle body 200 from the power supply table 500 when using hot water.

The kettle main body 200 is mainly composed of a main body unit 300 and a lid unit 250. The kettle main body 200 is provided with a spout 301 for pouring a liquid such as hot water at one upper end. Further, when the kettle main body 200 is viewed from above, a grip portion 401 is provided at a position facing the spout 301.

When pouring the liquid in the kettle body 200, the user holds the grip portion 401 and tilts the kettle body 200 so that the spout 301 faces downward, whereby the liquid can be discharged from the spout 301. .. In this specification, for convenience of description, the side on which the spout 301 is arranged is called the front side of the kettle body 200, and the side on which the grip 401 is arranged is called the rear side of the kettle body 200. Further, with the kettle body 200 placed on the power supply base 500, the side where the lid unit 250 is located is called the upper side of the kettle body 200, and the side where the bottom member 331 of the body unit 300 is located is the kettle body 200. It is called the lower side (see FIG. 2).

The lid unit 250 is detachably attached to the main body unit 300. The user of the electric kettle 100 can remove the lid unit 250 from the main body unit 300 by releasing the lock mechanism 252 provided on the upper surface 251 of the lid unit 250. Then, water or the like for boiling the hot water can be put in the liquid container 321 (see FIG. 6) in the electric kettle. Further, when boiling the hot water, the lid unit 250 is attached to the main body unit 300 to make the inside of the liquid container 321 a closed space.

Further, an opening/closing button 253 is provided substantially at the center of the upper surface portion 251 of the lid unit 250. The open/close button 253 is connected to a shaft portion of an open/close valve (not shown) provided in the lid unit 250. When the opening/closing button 253 is pressed downward by the user of the electric kettle 100, the opening/closing valve moves downward in conjunction with the pressing operation. As a result, the on-off valve is opened. When the open/close valve is opened, the liquid flow path from the liquid container 321 to the spout 301 is opened. By tilting the kettle body 200 toward the pouring port 301 with the liquid flow path opened in this way, the user can pour the liquid inside the liquid container 321 into another container such as a drinking cup or a tea bowl. ..

The power supply stand 500 plays a role of a power supply unit that supplies electricity to the electric kettle 100 and a stand of the electric kettle 100. The power supply stand 500 is provided with a connection terminal, a power supply cord, a power supply plug, etc. that are electrically connected to the heater unit 340 in the kettle body 200. For the power supply table 500, the same configuration as that of a conventionally known power supply table for an electric kettle can be applied.

Hereinafter, a specific configuration of each component of the body unit 300 of the kettle body 200 will be described. FIG. 6 shows the internal configuration of the kettle main body 200. FIG. 6 is a diagram showing a cross-sectional structure of a portion taken along line AA shown in FIG. FIG. 6 shows the kettle body 200 with the bottom member 331 removed.

(About the main unit)
The main body unit 300 includes a sidewall member 310, a liquid container 321, a heater unit (heating unit) 340, a bottom member 331, a handle unit 400, and the like as main constituent members.

The side wall member 310 is a member formed of metal or resin and forms the outer peripheral surface of the main body unit 300. In addition, in the present embodiment, the side wall member 310 has a shape in which a part of the peripheral surface of a substantially cylindrical member is cut off. Then, the main body connecting portion 402 of the handle unit 400 is fitted into the cut-out portion. That is, most of the outer peripheral surface of the main body unit 300 is configured by the side wall member 310, and a part thereof is configured by the main body connecting portion 402 of the handle unit 400.

A front protrusion 311 is provided on the front upper portion of the side wall member 310. The front protrusion 311 constitutes a part of the spout 301 together with other constituent members.

The liquid container 321 is arranged inside the side wall member 310. The liquid container 321 is formed of a metal such as stainless steel or a resin, and has a container shape capable of storing a liquid such as water therein. The inner peripheral surface of the liquid container 321 may be coated with a corrosion resistant resin (not shown) such as a fluororesin. Below the bottom surface 321a of the liquid container 321, a sheathed heater 602, which is a component of the heater unit 340, is attached, as will be described later. The bottom surface 321a of the liquid container 321 is formed of metal such as stainless steel.

On the outer periphery of the bottom surface 321a of the liquid container 321, an annular support member (resin member) 333 made of resin is provided. The annular support member 333 supports the liquid container 321. The annular support member 333 is arranged so as to surround the sheath heater 602.

Further, a plurality of ribs 322 are provided on the outer peripheral surface of the side wall of the liquid container 321. The rib 322 is an annular body that extends along the outer periphery of the liquid container 321, and is also a plate-like body that is parallel to the horizontal plane (the mounting surface of the electric kettle 100). As shown in FIG. 6, the rib 322 is provided on the outer periphery of the liquid container 321, so that a predetermined space is formed between the outer peripheral surface of the liquid container 321 and the inner peripheral surface of the side wall member 310. As a result, the heat insulation of the liquid container 321 can be improved.

The heater unit (heating unit) 340 is provided below the liquid container 321. The heater unit 340 includes a sheath heater 602, a power supply unit 601 that supplies electricity to the sheath heater 602, and the like. The power feeding unit 601 is electrically connected to a connection terminal provided on the power supply stand 500. Thereby, electricity is supplied to the power supply unit 601 through the power supply stand 500. The detailed configuration of the heater unit 340 will be described later.

The bottom member 331 is a member made of resin and constitutes the bottom portion of the main body unit 300. The upper end of the bottom member 331 is connected to the lower end of the side wall member 310 and the lower end of the main body connecting portion 402 of the handle unit 400. A heater unit 340 is housed inside the bottom member 331.

The handle unit 400 constitutes the rear side of the kettle body 200. The handle unit 400 has a grip portion 401, a main body connection portion 402, a power button 421, and the like as main constituent members.

The grip portion 401 is a member formed of resin or the like, and is a portion that serves as a handle when a user carries the kettle body 200. The grip portion 401 is integrally formed with the main body connecting portion 402 so as to project from the main body connecting portion 402.

The main body connecting portion 402 constitutes a part of the outer peripheral surface of the main body unit 300 as described above. The handle unit 400 is connected to the annular support member 333 of the main body unit 300 by a connection portion 431 (see FIG. 3) provided below the main body connection portion 402.

A power button 421 is arranged above the grip 401. The power button 421 is connected to a power switch (not shown) inside the grip portion 401. When the user presses the power button 421 while the kettle body 200 is placed on the power supply table 500, the power switch in the grip 401 is turned on (connected), and the heater unit 340 is energized with the power supply table 500. It As a result, electricity is supplied to the heater unit 340 and the water stored in the liquid container 321 is warmed. Regarding the configuration of the power switch, the configuration of a conventionally known power switch of an electric kettle can be applied.

(Specific configuration of heater unit)
Subsequently, a specific configuration of the heater unit 340 will be described. 3 to 5 show the internal structure of the bottom portion of the main unit 300.

The heater unit 340 includes a power supply unit 601, a sheath heater 602, a thermostat 611, and a bimetal holding unit 612 as main constituent members.

The power feeding unit 601 has a socket to which the connection terminal of the power supply stand 500 is electrically connected. Thereby, electricity is supplied to the power supply unit 601 through the power supply stand 500. The power supply unit 601 is arranged at a substantially central portion of the bottom surface 321a of the liquid container 321. The power feeding unit 601 supplies electricity to an electric circuit in the electric kettle 100 including the sheath heater 602 and the like.

The sheathed heater 602 has a metallic sheath-like structure, and accommodates a heating wire (for example, a nichrome wire) 602a therein. The sheathed heater 602 is manufactured by, for example, aluminum die casting.

The sheathed heater 602 has a substantially C-shaped shape in plan view (see FIG. 4 ). The longitudinal cross section of the sheathed heater 602 has an inverted trapezoidal shape (see FIG. 6). The upper surface of the sheathed heater 602 is attached to the bottom surface 321a of the liquid container 321 by brazing or the like. The sheathed heater 602 has a side surface portion 602b and a lower surface portion 602c.

Since the upper surface of the sheathed heater 602 is attached in contact with the bottom surface 321a of the liquid container 321, heat from the sheathed heater 602 can be efficiently transferred to the inside of the liquid container 321. As shown in FIG. 6, the sheathed heater 602 may be integrated with the bottom surface 321a of the liquid container 321 by brazing, for example.

The thermostat 611 detects overheating of the heater unit 340 caused by an overcurrent caused by a circuit short circuit of an electric component, a failure of the electric component, heat generation of various components, and the like, and interrupts the electric circuit. The thermostat 611 has a temperature detection unit such as a bimetal inside and a switch unit connected to an electric circuit. In this embodiment, the temperature detection unit of the thermostat 611 detects the temperature of the sheath heater 602. Then, when the temperature detection unit detects that the temperature has risen above a predetermined temperature, the switch unit operates to cut off the electric circuit in the electric kettle 100. As a result, the supply of electricity to the sheathed heater 602 is cut off. As described above, the thermostat 611 has a function as a protection member that suppresses overheating of the heater unit 340.

The bimetal holding portion 612 is a member for detecting the empty heating of the electric kettle 100. In this embodiment, two bimetal holding portions 612 are provided. As shown in FIG. 3, the bimetal holding portions 612 and 621 are arranged so as to face each other with the power feeding portion 601 interposed therebetween. The bimetal holding portion 612 has a bimetal which is an empty-fire detection switch.

The bimetal is attached in contact with the bottom surface 321a of the liquid container 321. When the bimetal is heated to a temperature equal to or higher than a predetermined temperature, the switch operates due to the change in the shape of the bimetal, and the supply of electricity to the sheathed heater 602 is cut off. As a result, in a state where the liquid such as water is not contained in the liquid container 321, the empty heating due to the continuous heating by the heater unit 340 is suppressed. Therefore, the bimetal holding portion 612 can also be referred to as another protective member that suppresses overheating of the heater unit 340.

(About mounting structure of thermostat)
Subsequently, a mounting structure of the thermostat 611 will be described with reference to FIGS. 3 to 6.

In this embodiment, the thermostat 611 has a substantially columnar shape. As shown in FIG. 6, an upper surface 611 a of the thermostat 611 is in contact with a lower surface portion 602 c of the sheath heater 602.

When energizing the heater unit 340, the lower surface portion 602c of the sheathed heater 602 becomes hot. Therefore, the temperature of the sheath heater 602 can be more reliably transmitted to the thermostat 611 by bringing the thermostat 611 into contact with the lower surface portion 602c of the sheath heater 602. This further improves the temperature response performance of the thermostat 611. The temperature detection unit provided in the thermostat 611 is preferably arranged on the upper surface 611a of the thermostat 611 or in the vicinity thereof.

In the present embodiment, the thermostat 611 is attached so as to straddle the lower surface portion 602c of the sheath heater 602 in order to more reliably maintain the above-mentioned positional relationship between the sheath heater 602 and the thermostat 611.

Around the thermostat 611, a flange portion 621, an inner holding portion 622, an outer holding portion 623, a cushioning member 631, a locking member 641, and the like are provided as a configuration for holding the thermostat 611.

The flange portion 621 is formed of a plate-shaped material such as sheet metal. The flange portion 621 is provided so as to surround the outer circumference of the thermostat 611 and supports the thermostat 611. As a result, the positioning of the thermostat 611 can be accurately performed when the thermostat 611 is attached, and the positional deviation of the thermostat 611 after the attachment can be suppressed. The flange portion 621 is preferably formed of a material having heat resistance that can withstand the heating temperature of the heater unit 340. In the present embodiment, the flange portion 621 is formed of a metal (for example, stainless steel, aluminum, etc.) having higher heat conductivity than resin.

The inner holding portion 622 supports the thermostat 611 from the central portion side of the bottom surface 321a of the liquid container 321. The inner holding portion 622 is a member that extends downward from the bottom surface 321a toward the end of the flange portion 621. The inner holding portion 622 and the flange portion 621 are fixed by a locking member 641 such as a screw. As a result, the thermostat 611 is held on one side by the inner holding portion 622 via the flange portion 621.

The inner holding portion 622 is preferably made of a material having heat resistance that can withstand the heating temperature of the heater unit 340. In this embodiment, the inner holding portion 622 is formed of a metal such as stainless steel or aluminum.

The outer holding portion 623 supports the thermostat 611 from the outer peripheral side of the bottom surface 321a of the liquid container 321. In the present embodiment, the outer holding portion 623 is formed integrally with the annular support member 333. Therefore, the outer holding portion 623 is formed of the same resin material as the annular support member 333.

The other side portion of the thermostat 611 is held by the outer holding portion 623 via the flange portion 621. In the present embodiment, a cushioning member 631 is provided between the outer holding portion 623 and the flange portion 621. More specifically, one end of the flange portion 621 that holds the thermostat 611 is supported by the outer holding portion 623 via the cushioning member 631.

The buffer member 631 is formed of, for example, a resin material (for example, a phenol resin having heat resistance), a silicon material, a rubber material, or the like. Since the cushioning member 631 is formed of such a material, the cushioning member 631 has heat insulating properties and elasticity.

Since the cushioning member 631 has a heat insulating property, the heat transferred from the sheath heater 602 to the thermostat 611 can be suppressed from being transferred to the outer holding portion 623. As a result, the influence of heat transfer between the thermostat 611 and the outer holding portion 623 is reduced, and it is possible to prevent the detection accuracy of overheating by the thermostat 611 from decreasing. Further, when the outer holding portion 623 is formed of a resin material which is relatively weak against heat, heat transfer to the outer holding portion 623 is reduced, so that the resin material may be melted or deformed. Can be prevented.

Further, since the cushioning member 631 has elasticity, it is possible to compensate for a slight error in the dimension of the peripheral member such as the outer holding portion 623 and the flange portion 621 during molding. Therefore, the stability of the mounting position of the thermostat 611 can be improved.

In this way, one side of the thermostat 611 (the side close to the center of the bottom surface 321a) is supported by the inner holding portion 622 with respect to the bottom surface 321a of the liquid container 321. The other side of the thermostat 611 (the side close to the outer periphery of the bottom surface 321a) is supported by the outer holding portion 623 via the flange portion 621 and the cushioning member 631.

By arranging each member as described above, the thermostat 611 is attached so as to straddle the lower surface portion 602c of the sheath heater 602. Accordingly, the thermostat 611 can be more surely brought into contact with the lower surface portion 602c of the sheathed heater 602, which makes it easier to detect overheating of the heater unit 340 (that is, the temperature during heating becomes higher). Therefore, it is possible to improve the detection accuracy of overheating when the thermostat 611 is used.

Further, the thermostat 611 can be installed in a stable state by supporting the thermostat 611 with the inner holding portion 622 and the outer holding portion 623 positioned so as to face each other with the thermostat 611 interposed therebetween. Therefore, the positional deviation of the thermostat 611 can be suppressed.

(Summary)
As described above, the electric kettle 100 according to the present embodiment has the kettle body 200 and the power supply stand 500. The kettle main body 200 is mainly composed of a main body unit 300 and a lid unit 250. The kettle main body 200 includes a liquid container 321, a spout 301, a heater unit (heating unit) 340, a gripping unit 401, and the like.

In the electric kettle 100 according to this embodiment, the heater unit 340 has the sheath heater 602. Further, the thermostat 611 is used as a protective member that suppresses overheating of the heater unit 340.

Conventionally, a thermal fuse has been used as a protective member for suppressing overheating of the heater unit. However, the temperature fuse is inferior in temperature detection accuracy to the thermostat. Therefore, if the mounting positions vary, an error is likely to occur in the temperature detection accuracy of each product even if they are the same product. Therefore, the reliability as a protective member is lacking. If the thermal fuse does not correctly detect the high temperature, the temperature of the heater unit rises endlessly and there is a risk that the resin member around the heater unit will melt. When the resin member melts, a short circuit of electric parts may occur.

Therefore, in this embodiment, a thermostat having a good temperature response is used as the protective member instead of the thermal fuse. Therefore, the temperature detection performance can be improved as compared with the conventional electric kettle using the thermal fuse as the protection member. Thereby, a more reliable electric kettle can be provided.

The relatively inexpensive thermostat tends to increase in size. As the size of the thermostat increases, the mounting position of the thermostat may be restricted. Therefore, in the present embodiment, the thermostat 611 is arranged so as to straddle the lower surface portion 602c of the sheath heater 602. As a result, even if the thermostat 611 has a relatively large size, it is possible to prevent the arrangement of other components from being restricted.

Further, the thermostat 611 has a contact surface (upper surface 611a) with the lower surface portion 602c of the sheathed heater 602. By bringing the thermostat 611 into contact with the lower surface portion 602c of the sheathed heater 602, the temperature of which becomes higher during heating, the thermostat 611 can more reliably detect the temperature rise of the sheathed heater 602.

Further, the thermostat 611 arranged so as to straddle the lower surface portion 602c of the sheath heater 602 is supported from both sides by an inner holding portion 622 and an outer holding portion 623. As a result, the positioning of the thermostat 611 can be accurately performed when the thermostat 611 is attached, and the positional deviation of the thermostat 611 after the attachment can be suppressed.

In the above-described embodiment, the cushioning member has been described as an example having both heat insulating properties and elasticity, but in another aspect of the present invention, the cushioning member has a heat insulating property and elasticity. It may have at least one of elasticity. Further, the cushioning member may be composed of two members, a first member having a heat insulating property and a second member having elasticity.

The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope. Further, configurations obtained by combining the configurations of the different embodiments described in the present specification are also included in the scope of the present invention.

100: Electric kettle 200: Kettle main body 250: Lid unit 300: Main body unit 301: Spout 321, Liquid container 321a: Bottom surface 333: Annular support member (resin member)
340: heater unit (heating unit)
400: Handle unit 500: Power supply platform 602: Sheath heater (heating part)
602c: Lower surface (lower surface)
611: Thermostat (protective member)
611a: contact surface 631 (with lower surface of sheath heater): cushioning member

Claims (5)

A liquid container,
A heating unit for heating the inside of the liquid container,
A protective member for suppressing overheating of the heating unit,
The heating unit has a sheathed heater,
The protection member has a thermostat,
Electric kettle. The thermostat is arranged so as to straddle the lower surface of the sheathed heater.
The electric kettle according to claim 1. The thermostat has a contact surface with the lower surface of the sheathed heater,
The electric kettle according to claim 2. A resin member is provided at the bottom of the liquid container,
The thermostat is attached to the resin member via a cushioning member,
An electric kettle according to any one of claims 1 to 3. The electric kettle according to claim 4, wherein the cushioning member has at least one of thermal insulation and elasticity.

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