JP3313638B2 - Insulation structure of electric water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulation structure of an electric kettle such as an electric pot and a humidifier, and more particularly to an insulation structure of a portion related to a heater wire and a terminal.

[0002]

2. Description of the Related Art In a conventional electric pot or humidifier, a container equipped with a heater is housed in an exterior body, a heat shield plate facing the heater is fixed to the container, and a terminal made of an insulator is attached to the heat shield plate. And a single extraction hole common to a plurality of heater wires is provided in the heat shield plate, and the heater wire extracted through the extraction hole is connected to a power supply side lead wire in the terminal.

The above-mentioned heater wire is provided with a heat-resistant insulating coating, and a hole for taking out the heat shield plate is formed to have a size that allows the heater wire to pass with a required margin.

[0004]

The above-mentioned terminal material is excellent in insulation performance and hardly deteriorates by heat.
In addition, although insulators are used because of their low cost, the insulators are susceptible to impact and are liable to break. If the insulator breaks due to any shock during energization, the heater wire and power supply side lead wire connected to it will become free along with the insulator fragments and come into contact with the heat shield plate etc., causing problems such as insulation failure and short circuit Is generated.

[0005] Even when the terminal is made of a material which is strong against impact, if the heater wire is loosened due to variations in the dimensions of the heater wire, etc., the loosened portion may be formed on the heat shield plate or the adjacent lead wire. There was a risk of contact.

Accordingly, an object of the present invention is to provide an insulation structure of an electric water heater that does not cause an electrical problem such as insulation failure or short circuit even if the terminal is damaged or the dimensions of the heater wire are varied.

[0007]

In order to achieve the above-mentioned object, the present invention provides a container equipped with a heater, which is housed in an exterior body, and a terminal is attached to a heat shield plate facing the heater. An electric water heater provided with a plurality of connected heater wire extraction holes in the heat shield plate, and connecting the heater wire extracted through the extraction hole to a power supply side lead wire in the terminal.
The structure was such that an annular insulating bush was mounted around the extraction hole of the heat shield plate.

A structure in which a rib protruding toward the inside of the take-out hole is provided on the inner edge of the insulating bush, and a plurality of recesses through which the heater wires are individually inserted are formed on the inner side of the rib. The insulating bush has an annular flat plate portion surrounding the take-out hole on one surface of the heat shield plate, the terminal overlaps a part of the flat plate portion, and both are integrated with the heat shield plate. The fixed structure, the take-out hole is a long hole, and the rib is formed on the flat portion of the insulating bush along one long side of both long sides of the long hole, and the other long side is formed. While overlapping the terminal on the flat plate portion, a part of the terminal is protruded into the inside of the extraction hole, a concave portion facing the concave portion of the rib is formed in the protruding portion, and the heater wire is formed by abutting both concave portions. Shape insertion part A structure in which a vertical rib extending over the long side and the short side at both ends thereof is formed on an inner edge of a long side of the insulating bush where the rib is formed, and a partition wall is formed between the concave portions of the terminal. Can be taken.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The electric pot shown in FIG.
The container 2 is accommodated in the exterior body 1, and the opening of the container 2 is opened and closed by a lid 3 attached to the exterior body 1. The exterior body 1 includes a shoulder member 4, a trunk member 5, and a bottom member 6.
And a bottom cover member 7.

A heater 8 is mounted on the lower surface of the container 2, and a metal heat shield 9 is provided below the heater 8.
This heat shield plate 9 is fixed to the container 2 . A liquid supply passage 11 is connected to the bottom of the container 2, an electric pump 12 is interposed at a lower end of the liquid supply passage 11, and a rising portion thereof is a water level tube 13. A safety valve device 14 is provided above the water level pipe 13, and the outlet side of the safety valve device 14 is connected to the discharge port 15. Further, a terminal 16 is attached to the lower surface of the heat shield plate 9. In addition, 1 in the figure
7 is a temperature sensor, 18 is a plug receiver, and 19 is a control unit.

The safety valve device 14 is shown in FIG.
As shown in (b), a valve case 22 is provided below a ball case 21 having a conical bottom surface having an inclination angle of 10 to 15 degrees, and a valve hole 23 is provided in both partition walls. A check valve 24 is attached to the valve hole 23, and the check valve 24 closes the valve hole 23 from below by its own elasticity. A protrusion 25 projecting into the ball case 21 is provided on the upper surface of the check valve 24, and the ball 26 stored in the ball case 21 is placed on the protrusion 25 to depress the check valve 24, and the valve hole 23 is closed. Let open.

Radial ribs 27 are provided on the bottom surface of the ball case 21 to secure a passage around the ball 26.
The ball 26 has a weight that does not start moving due to the pressure of the liquid discharged through the liquid supply passage 11, but rolls away from the projection 25 when the electric pot is inclined or falls, and the check valve 24 itself The elastic member returns to the original state, closes the valve hole 23, and prevents leakage of the liquid.

FIG. 2C shows a bypass passage 28 provided between the valve case 22 and the ball case 21 to reduce the hydraulic pressure acting on the ball 26 when the liquid is discharged. In this case, the check valve 24 is urged by the coil spring 29.

As shown in FIG. 3, the heater wire 31 drawn from the heater 8 has a total of three wires, that is, two wires drawn from the water heater and the heat retaining heater, and a wire common to these heaters. It is a book, and is taken out to the terminal 16 side from a take-out hole 32 which is a long hole provided at a position offset to the outer peripheral edge of the heat shield plate 9.

The above-mentioned take-out hole 32 has a long side 32 inside.
a, the outer long side 32b and both short sides 32c are formed in a square shape with rounded corners.

On the surface (lower surface) of the heat shield plate 9 on the side where the terminal 16 is mounted, an insulating bush 33 is mounted around the extraction hole 32. This insulating bush 33
Is formed of an insulator such as rubber, and FIGS.
As shown in (a), the bush is an annular bush having an inner peripheral edge in the shape of a long hole along the take-out hole 32, and an outwardly-facing flat plate portion 34 is provided on the inner peripheral edge of the bush. It contacts the lower surface of the hot plate 9.

Of the inner peripheral edge of the insulating bush 33,
The inner long side 32a of the mounting hole 32 and the short sides 32 at both ends thereof
Horizontal ribs 35 protruding inward from the inner peripheral edge are provided on the inner flat plate portion 34a along c and 32c, and three concave portions 36 are provided on the side of the horizontal ribs 35 at required intervals. . Further, the inner long side 32 of the mounting hole 32 is provided on the inner peripheral edge of the insulating bush 33 provided with the horizontal rib 35.
a, and a vertical rib 37 is provided in a range extending over both short sides 32c, 32c. This vertical rib 37 is formed as shown in FIG.
As shown in FIG. 7, the inner peripheral surface of the inner long side 32a of the mounting hole 32 is covered.

The terminal 16 made of an insulator is overlapped on an outer flat portion 34b (see FIG. 3) of the inner peripheral edge of the insulating bush 33 along the outer long side 32b of the mounting hole 32. On the lower surface of the heat shield plate 9, a pair of positioning pieces 38, 38 are formed by cutting and raising outside the outer long side 32 b (see FIG. 3), and the outside of the insulating bush 33 is positioned between the positioning pieces 38, 38. The flat portion 34b and the terminal 16 superposed thereon are attached.

The terminal 16 is provided with three screw terminals 39 on the lower surface in the mounted state.
A mounting hole 41 penetrating in the vertical direction is provided, and the mounting hole 41 is aligned with the mounting hole 42 of the outer flat portion 34b and the mounting hole 43 of the heat shield plate 9 so as to be fixed to the heat shield plate with screws 44. Has become.

The inner surface of the terminal 16 is shown in FIG.
As shown in (a) and (b), it protrudes to the center of the extraction hole 32 and faces the side of the horizontal rib 35 of the insulating bush 33 at a small interval. A concave portion 45 is formed on the inner side surface of the terminal 16 at a position facing the three concave portions 36 of the horizontal rib 35, and an insertion portion 46 for each heater wire 31 is formed by opposing the two concave portions 36, 45. .
Further, two partition walls 47 projecting one step higher are provided between the concave portions 45 of the terminal 16.

Each of the heater wires 31 is taken out to the terminal 16 side through each of the insertion portions 46, attached to each screw terminal 39, and a lead wire 48 on the power supply side (FIG. 4).
(B)).

In use, even if the terminal 16 is damaged due to an impact or the size of the heater wire 31 is too long, the heater wire 31 is in contact with the heat shield plate 9 due to the presence of the insulating bush 33. Direct contact is avoided. Also, as in the above embodiment, the insulating bush 3
By providing the concave portion 36 in the horizontal rib 35 of the third and the concave portion 45 facing the concave portion 36 in the terminal 16 to form the insertion portion 46, the independence of each heater wire 31 is maintained, thereby the heat shielding. The danger of contact with the plate 9 and the lead wire 48 can be avoided more reliably.

The screw terminal 3 of the terminal 16
As shown in FIG. 5A, one end is sandwiched between the terminal 16 and the heat shield plate 9 in order to achieve electrical and thermal insulation between the relay unit 9 and the exterior body 1 in the vicinity thereof. It is desirable to interpose a flexible mica sheet 49 bent in a U-shape so as to surround the outside of the terminal 16.

As shown in FIG. 5 (b), the mica sheet 49 has a recess 51 at the center of one end, and the mounting screw 44 of the terminal 16 is inserted into the recess 51. Further, when the mica sheet 49 is bent into a U-shape, the bent shape can be maintained unless external force is applied.

By interposing the mica sheet 49 as described above, the distance between the terminal 16 and the exterior body 1 can be set short, and as a result, the electric pot can be made compact.

[0026]

As described above, according to the present invention, since the annular insulating bush is mounted around the outlet of the heater wire, even if the terminal is damaged or the heater wire is loosened due to a variation in the size of the heater wire. Even if the above occurs, the presence of the insulating bush eliminates the risk of the heater wire coming into contact with the heat shield plate, thereby providing a safe electric pot.

When a plurality of recesses are provided in the ribs of the insulating bush and the heater wires are inserted into the recesses, the heater wires are individually held in the recesses. Is prevented, and the insulation performance is enhanced (claim 2). Further, when a concave portion facing the concave portion is provided on the terminal side to form a heater wire insertion portion (claim 4), and in addition to this, a vertical rib is provided along an inner edge of the extraction hole (claim 5). The insulation performance is further improved.

The mounting structure can be simplified by overlapping the terminal on the insulating bush and integrally mounting the terminal on the heat shield plate.

[Brief description of the drawings]

FIG. 1 is a partially omitted cross-sectional view of an electric pot of an embodiment.

2A is a sectional view of a safety valve device according to the first embodiment; FIG. 2B is a cross-sectional view taken along a line bb in FIG.

FIG. 3 is an exploded perspective view of the same heat shield plate as viewed from the bottom side.

FIG. 4 (a) is a bottom view of the heat shield plate portion of the above, and (b) is a cross-sectional view taken along line bb in FIG. 4 (a).

FIG. 5 (a) is a partial cross-sectional view of a modification of the above, and FIG. 5 (b) is a perspective view of the mica sheet of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer body 2 Container 3 Lid 4 Shoulder member 5 Body member 6 Bottom member 7 Bottom cover member 8 Heater 9 Heat shield plate 11 Liquid supply passage 12 Electric pump 13 Water level tube 14 Safety valve device 15 Discharge port 16 Terminal 17 Temperature sensor 18 Plug receiving DESCRIPTION OF SYMBOLS 19 Control part 21 Ball case 22 Valve case 23 Valve hole 24 Check valve 25 Projection 26 Ball 27 Rib 28 Bypass path 29 Coil spring 31 Heater wire 32 Extraction hole 32a Inside long side 32b Outside long side 32c Short side 33 Insulation bush 34 Flat plate Portion 34a Inner flat plate portion 34b Outer flat plate portion 35 Horizontal rib 36 Recess 37 Vertical rib 38 Positioning piece 39 Screw terminal 41 Mounting hole 42 Mounting hole 43 Mounting hole 44 Screw 45 Recess 46 Insertion part 47 Partition 48 Lead wire 49 Mica sheet

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Hiroshi Yamane 1-20-5 Tenma, Kita-ku, Osaka-shi Zojirushi Ma Hobin Co., Ltd. (56) References JP-A-10-14765 (JP, A) 2-18331 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A47J 27/21 101

Claims (5)

(57) [Claims] 1. A container equipped with a heater is housed in an outer package, a terminal is attached to a heat shield plate facing the heater, and holes for taking out a plurality of heater wires connected to the heater are formed in the heat shield plate. In the electric water heater in which the heater wire extracted through the extraction hole is connected to the power supply side lead wire in the terminal, an annular insulating bush is mounted around the extraction hole of the heat shield plate. Insulation structure of electric water heater. 2. A rib protruding toward the inside of the take-out hole is provided on an inner edge of the insulating bush, and a plurality of recesses through which the heater wires are individually inserted are formed on the inner side of the rib. The insulating structure of an electric water heater according to claim 1, wherein: 3. The insulating bush has an annular flat plate portion surrounding one of the extraction holes on one surface of the heat shield plate, and the terminal overlaps a part of the flat plate portion. The insulation structure of an electric water heater according to claim 1 or 2, wherein the insulation structure is integrally fixed to the heat shield plate. 4. The take-out hole is a long hole, and the rib is formed on a flat plate portion of the insulating bush along one long side of both long sides of the long hole, and the other long side is formed. The terminal is overlapped with the flat plate portion, a part of the terminal is protruded into the inside of the take-out hole, a concave portion facing the concave portion of the rib is formed in the protruding portion, and the heater wire is formed by abutting both concave portions. 4. The insulation structure for an electric water heater according to claim 3, wherein the insertion portion is formed. 5. A vertical rib is formed on an inner edge on a long side of the insulating bush on which the rib is formed, and a vertical rib is formed on the long side and a short side on both ends thereof, and a partition is formed between the recesses of the terminal. The insulation structure for an electric water heater according to claim 4, wherein: