JP3539397B2 - Electric water heater - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to an electric water heater that heats and keeps a stored liquid and leads the liquid to the outside of the container.
[0002]
[Prior art]
Conventionally, an electric water heater that detects boiling by steam generated at the time of boiling water has been devised to prevent erroneous detection due to steam generated during the water heating as disclosed in JP-A-62-161326. That is, as shown in FIGS. 13 and 14, the first steam discharge passage 104 and the steam reservoir communicate with the opening 102 of the inner container 101 via the connecting pipe 103 and branch off at the connecting pipe 103. A chamber 105 is provided, and a hollow protrusion 106 is formed in the steam storage chamber 105 so as to protrude inward. A boiling detector 107 is provided in the protrusion 106.
[0003]
The heater 108 is energized to heat the water in the inner container 101, and the temperature of the water gradually rises to generate a small amount of steam. The boiling detector 107 does not operate because it flows out without accumulating in the 105.
[0004]
When a large amount of steam is generated from the inner container 101 due to the boiling state, all of the steam cannot flow completely into the first steam discharge passage 104 but enters the steam storage chamber 105, and the boiling detector 107 detects the steam temperature. Is detected and the power supply to the heater 7 is cut off.
[0005]
[Problems to be solved by the invention]
However, in such a conventional configuration, erroneous detection in which the boiling detector determines that boiling has occurred before boiling and cuts off the power supply to the heater (hereinafter referred to as “early cut-off”) can be prevented to some extent. In the early stage of boiling, since it is difficult for steam to enter the steam reservoir, it takes some time from boiling to detection.
[0006]
Therefore, there is a problem that a large amount of steam is released outside the body before the boiling is detected, and dew forms around.
[0007]
The present invention solves such a conventional problem, and prevents a malfunction of the temperature detecting means for detecting boiling at an early stage, and quickly detects a boiling state to surely boil the liquid. It is another object of the present invention to provide an electric water heater capable of minimizing the amount of steam discharged outside the body.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is to form an intermediate opening in the middle of the steam passage, the adjacent intermediate opening, arranged sensitive portion of the temperature detecting means attached to said body, said body The portion surrounding the base of the sensing portion is formed in a convex shape, and the inside of the steam passage is made substantially maze-shaped so as to guide the steam to the steam outlet while meandering.
[0009]
As a result, it is possible to delay the arrival of the steam to the sensing section, to prevent malfunction when the amount of steam is small, and to reduce the amount of the steam emitted to the outside of the body until the boiling is detected.
[0010]
In addition, it is possible to significantly reduce a large amount of vapor being released outside the body and condensing around.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The invention according to claim 1 of the present invention is directed to a container having an upper surface opening for storing a liquid arranged in a main body, a lid covering an opening of the container, a heat source for heating the liquid in the container, and the lid A steam passage communicating with a steam outlet formed in the outer shell of the body and the opening of the container, an intermediate opening formed in the middle of the steam passage, and attached to the main body in the vicinity of the intermediate opening; A sensing part of the temperature detecting means is arranged, and a portion of the main body surrounding a root of the sensing part is formed in a convex shape, and the inside of the steam passage is made substantially maze-shaped, so that the steam meanders. Since the electric water heater is used to guide the steam to the steam outlet, it is possible to delay the steam from reaching the sensing part by that much, to prevent malfunction when the steam is small, and to prevent the steam from reaching the outside of the body until the boiling is detected. The amount of release can be reduced.
[0012]
According to a second aspect of the present invention, there is provided a container having an upper surface opening for housing a liquid disposed in a main body, a lid covering an opening of the container, a heat source for heating the liquid in the container, and the lid. A steam passage communicating with a steam outlet formed in the outer shell of the body and the opening of the container, an intermediate opening formed in the middle of the steam passage, and attached to the main body in the vicinity of the intermediate opening; Arrange the sensing part of the temperature detecting means, and form a part of the main body surrounding the root of the sensing part in a convex shape, and in the middle of the route from the opening of the container to the intermediate opening, Since the electric water heater is provided with at least one place having a ceiling higher than the passage near the intermediate opening, the steam is filled in all the ceilings higher than the passage near the intermediate opening. After that, the steam reaches the sensing part, You can delay leads to the prevention of erroneous operation when the steam is small, it can reduce the release of the vessel outside of the steam to boiling detection.
[0013]
【Example】
(Example 1)
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, a first embodiment of the present invention will be described. FIG. 1 is a schematic configuration diagram of one embodiment of the present invention, wherein 1 is a main body, 2 is a container having an upper surface opening disposed in the main body 1, 3 is a lid covering the opening of the container 2, and 4 is a container. It is an electric heater that is a heat source for heating the liquid inside.
[0014]
Reference numeral 5 denotes an electric pump which is a means for drawing the liquid in the container 2 out of the body. The pump 5 sucks the liquid from the suction port 6 and communicates the discharge port 7 of the pump 5 with the outlet 8 to the outside of the body. The liquid is led out of the container via the water pipe 9.
[0015]
The cover 3 includes a hinge 10 serving as a center of rotation when opening and closing the opening of the container 2 for opening and closing, a lock member 12 which engages with the claw receiving portion 11 of the main body 1 when closed, and a steam discharge port 13. A steam passage 14 that communicates the opening of the container 2 with the steam outlet 13, a falling water prevention valve 15 for preventing the liquid in the container 2 from flowing out when the main body 1 is turned over, and the like. You.
[0016]
An intermediate opening 16 is formed in the middle of the steam passage 14, and a sensing portion 18 of a temperature detecting means 17 (hereinafter referred to as a “sensor unit”) is attached to the main body 1 in the vicinity thereof. Have been.
[0017]
When the liquid in the container 2 is heated by the heater 4 and boiled by heating, the steam generated by the heating flows into the steam passage 14, and reaches the steam outlet 13. The temperature hits the sensing section 18 of the unit 17 and its temperature is increased. Boiling is detected based on the temperature rising speed or the absolute temperature, and the power supply to the heater 4 is cut off.
[0018]
The path through which the steam is discharged to the outside of the container in this manner is called a normal path, and is indicated by solid arrows in FIGS.
[0019]
FIGS. 2 and 3 show the configuration around the lid 3, the opening of the container 2, and the sensor unit 17. In the middle of the steam passage 14, the cross section composed of the top surface and the right and left side surfaces is substantially U-shaped. A guide portion 19 having a character shape, a substantially U shape, or a substantially circular arc shape is formed, and an end of the guide portion 19 extends toward the sensing portion 18 of the sensor unit 17.
[0020]
A hole 20 is formed in the vicinity of the guide portion 19 and below the steam outlet 13, and when the steam passes through the steam passage 14 before reaching the intermediate opening 16, the steam outlet 20 is formed. 13 forms a short-circuit path for steam, in other words, a short-circuit path for steam.
[0021]
Accordingly, when the amount of steam in the middle of the water heater is small and the flow rate is low, the steam is discharged from the steam outlet 13 formed in the lid 3 to the outside of the body via the bypass path 51, and Since it hardly reaches the sensing unit 18, there is no erroneous detection that boiling has occurred. Note that the flow of steam flowing through the bypass path 51 is indicated by a dashed arrow.
[0022]
When the steam reaches the boiling point and the amount of steam increases and its flow velocity increases, the steam is guided to the sensing unit 18 of the sensor unit 17 by the guide unit 19, and the temperature of the sensing unit 18 is rapidly increased. Boiling is immediately detected, and the power supply to the heater 4 is cut off. The flow of the steam is indicated by solid arrows.
[0023]
The bypass route of the steam may be notched but not a hole, and an appropriate route may be selected according to the balance of the steam flow in the entire steam passage. When the cross-sectional shape of the guide portion 19 is substantially U-shaped as shown in FIG. 4, the guided steam is rectified by the left and right side walls 21 and 22 and is less likely to come off the guide portion 19 on the way. It is led to the feeling part 18.
[0024]
When the cross-sectional shape of the guide portion 19 is substantially rectangular or substantially arcuate as shown in FIGS. 5 and 6, since the guide portion has almost no flat surface on the wall surface, it flows down even if condensation forms on the wall surface by steam. Therefore, the amount of dew water accumulated in the steam passage 14 can be reduced.
[0025]
In FIG. 2 to FIG. 3, reference numeral 23 denotes a bypass rib for guiding the steam once generated in the container 2 into the inlet 24 of the steam passage 13 in a direction substantially opposite to the steam outlet 13. The inner wall of the steam passage 14 and the bypass rib 23 form a substantially maze state.
[0026]
As a result, the steam is guided to the steam outlet 13 while intentionally meandering, so that it is possible to delay the steam from reaching the sensing portion 18 by that much. It is possible to reduce the amount of steam released outside the body until the detection.
[0027]
Reference numeral 25 denotes a ceiling located in the middle of the path from the opening of the container 2 to the intermediate opening 16 of the steam passage 14, higher than the passage near the intermediate opening 16, and steam is filled in this portion. After that, the steam reaches the sensing unit 18, so that the steam can be delayed from reaching the sensing unit 18 accordingly. The amount of release outside the body can be reduced. Reference numeral 26 denotes a convex portion formed on the main body 1 and surrounds the base of the sensing portion 18.
[0028]
The protrusions 26 can reduce the amount of water droplets accumulated around the sensing portion 18, so that the accumulated water droplets hinder a rise in the temperature of the sensing portion 18 due to steam, thereby delaying boiling detection (late delay). Can be prevented.
[0029]
In FIGS. 1 to 3, the normal path (solid arrow) and the bypass path (dashed arrow) have one outlet to be discharged to the outside of the body, but the outlet to the body is separately provided. It does not matter.
[0030]
The main components of the sensor unit 17 are a metal cover 27 as an outer shell of the sensing portion 18, a mounting member 29 having a projection 28 substantially similar in shape to the inner surface of the metal cover 27, and a temperature detection element 30. A groove 31 is formed in the mounting member 29, the temperature detecting element 30 is disposed in the groove 31, and is substantially in close contact with the metal cover 27. The gap between the metal cover 27 and the mounting member 29 is filled with a filler 32 made of a non-cured material.
[0031]
The position of the temperature detecting element 30 can be stabilized by bringing the temperature detecting element 30 into a substantially close contact state with the metal cover 27 and arranging the temperature detecting element 30 in the groove portion 31. By filling the space with the filler, the air in that portion can be eliminated, and the heat received by the metal cover 27 by the steam can be quickly transmitted to the temperature detecting element 30.
[0032]
Moreover, since the filler 32 is made of a non-cured material, an external stress is applied when the sensor unit 17 is attached to the main body 1 or the like, and the relative position between the metal cover 27 and the attachment member 29 is changed from the initial position. In this case, that is, even if the gap changes, the filler 32 moves following the changing gap, so that air can be prevented from entering the gap and the heat transfer performance can be maintained.
[0033]
FIG. 7 shows that the attachment member 33 is formed of a material having a high elasticity, and a seal portion 34 that covers a gap between the main body 1 and the metal cover 27 is formed. This eliminates the need for a seal member for preventing water from entering the inside of the main body 1 from the gap.
[0034]
FIG. 8 shows that both lead wires 35 and 36 extending from both ends of the temperature sensing element 30 are arranged on the side facing the steam flow at least in a range where the metal cover 27 is exposed. The heat transmitted to the temperature detecting element 30 can be increased, and the boiling can be quickly detected.
[0035]
(Reference Example 1)
Next, a first reference example of the present invention will be described. In FIG. 9, reference numeral 37 denotes an integral part of the steam passage 38 in the middle of a path from the opening 39 of the container 2 to the intermediate opening 40 formed near the sensing part 18 of the sensor unit 17 in the steam passage 38. In the formed heat exchanging portion, a heat absorbing portion 41 for removing heat of steam is formed on the inner wall of the passage, and a radiating portion 42 for releasing the heat is formed on the outer wall of the passage.
[0036]
By removing the heat of the steam by the heat exchanging unit 37 to cause dew condensation, the amount of the steam released to the outside of the body before the boiling is detected can be reduced accordingly.
[0037]
In addition, by disposing the heat exchange unit 37 in the middle of the path from the opening of the container 2 to the intermediate opening 40, when the amount of steam in the middle of the water heater is small, the heat exchange unit 37 reaches the sensing unit 18. In most cases, dew condensation occurs, and the temperature of the sensing portion 18 is hardly increased, so that no erroneous detection is performed.
[0038]
Furthermore, by integrating the heat exchanging section 37 with the member forming the steam passage 38, the number of components can be reduced while achieving the desired performance.
[0039]
(Reference Example 2)
Next, a second embodiment of the present invention will be described. In FIG. 10, reference numeral 43 denotes a heat exchange unit disposed in the middle of a route from the intermediate opening 45 formed in the vicinity of the sensing unit 18 of the sensor unit 17 to the steam outlet 13 in the steam passage 44. It is formed separately from the member forming the steam passage 44 and is made of a material having good heat conductivity.
[0040]
By disposing the heat exchange section 43 at this position, sufficient steam for detection is sent to the sensing section 18 at the time of boiling, and vapor is condensed from there to the steam discharge port 13 to be discharged outside the body. It is possible to reduce the amount of steam generated.
[0041]
Further, by forming the heat exchange section 43 with a material having good heat conductivity, the heat exchange section 43 can be further reduced in size, and as a result, the lid 3 including the steam passage 44 can be reduced in size.
[0042]
(Reference Example 3)
Next, a third embodiment of the present invention will be described. 11 and 12, the sensor unit 17 is located near the intermediate opening 47 of the vapor passage 46 and in the left-right direction from the center 49 of the rotating shaft 48 when the lid 3 is opened and closed with respect to the opening of the container 2. It is arranged in the position shifted.
[0043]
Accordingly, when the lid 3 is opened and closed, the possibility that water droplets adhering to the surface 50 of the lid 3 facing the opening of the container 2 drop and drastically reduce the possibility of adhering to the sensing unit 18 and cause malfunctions. Can be prevented.
[0044]
【The invention's effect】
According to the first aspect of the present invention, it is possible to delay the arrival of the steam to the sensing portion, to prevent malfunction when the amount of steam is small, and to reduce the amount of steam released to the outside of the body until the boiling is detected. is there.
[0045]
According to the second aspect of the present invention, after the steam is filled in all the ceiling portions higher than the passage near the intermediate opening, the steam reaches the sensing portion, so that the steam is delayed from reaching the sensing portion. This can prevent malfunction when the amount of steam is small, and reduce the amount of steam released to the outside of the body until the boiling is detected.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a schematic configuration of an electric water heater showing a first embodiment of the present invention. FIG. 2 is an enlarged transverse sectional view of a main part around a lid of the electric water heater. FIG. 4 is a perspective view showing an embodiment of a shape of a steam guiding portion of a steam passage of the electric water heater. FIG. 5 is a steam passage of the electric water heater. FIG. 6 is a perspective view showing another embodiment of the shape of the steam guide portion of FIG. 6. FIG. 6 is a perspective view showing another embodiment of the shape of the steam guide portion of the steam passage of the electric water heater. FIG. 8 is an enlarged longitudinal sectional view of a main part showing an embodiment around the sensor unit of the electric heater. FIG. 8 is an enlarged longitudinal sectional view of a main part showing another embodiment around the sensor unit of the electric kettle. FIG. FIG. 10 is an enlarged longitudinal sectional view of a main part showing a periphery of a lid of the electric water heater of the first embodiment. FIG. FIG. 11 is an enlarged longitudinal sectional view of a main part showing the periphery of the lid of FIG. 11. FIG. 12 is an enlarged cross-sectional view of a principal part showing the periphery of the lid of the electric water heater according to the third embodiment of the present invention. FIG. 13 is an enlarged vertical sectional view showing a schematic configuration of a conventional electric water heater. FIG. 14 is an enlarged vertical sectional view showing the periphery of a steam discharge path.
DESCRIPTION OF SYMBOLS 1 Main body 2 Container 3 Lid 4 Heater 10 Hinge part 13 Steam outlet 14 Steam passage 16 Intermediate opening 17 Temperature detecting means (sensor unit)
18 Sensing part 19 Guide part 20 Hole part 25 Ceiling part 26 Convex part (of the main body) 27 Metal cover 28 Projection part 29, 33 Mounting member 30 Temperature sensing element 31 Groove part 32 Filler 34 Seal part 35, 36 Lead wire 37, 43 Heat exchange parts 38, 44 Steam passage 40 Intermediate opening 45, 47 Intermediate opening 46 Steam passage 48 Rotating shaft 51 Bypass path

Claims (2)

A container having an upper surface opening for storing a liquid disposed in the main body, a lid covering the opening of the container, a heat source for heating the liquid in the container, and a vapor outlet formed in an outer shell of the lid And a steam passage communicating with the opening of the container, an intermediate opening is formed in the middle of the steam passage, and a sensing portion of the temperature detecting means attached to the main body is arranged near the intermediate opening. An electric water heater in which a portion of the main body surrounding the base of the sensing portion is formed in a convex shape, and the inside of the steam passage is formed in a substantially maze shape, and the steam is meandered and guided to the steam outlet. A container having an upper surface opening for storing a liquid disposed in the main body, a lid covering the opening of the container, a heat source for heating the liquid in the container, and a vapor outlet formed in an outer shell of the lid And a steam passage communicating with the opening of the container, an intermediate opening is formed in the middle of the steam passage, and a sensing portion of the temperature detecting means attached to the main body is arranged near the intermediate opening. Forming a convex portion around the root of the sensing portion of the main body, and higher than a passage near the intermediate opening in the middle of a path from the opening of the container to the intermediate opening. An electric water heater provided with at least one location having a ceiling.

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