JPS623063Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a lid knob equipped with a boiling water alarm device.

Conventionally, this type of lid knob is shown in FIG. 1, for example. That is, a flute plate 22 is attached to the upper end of a steam jet tube 21 attached to a lid 20, and a plurality of reeds 24 are fixed in a cantilever manner facing several ventilation holes 23 provided in the flute plate 22. A hollow knob 25 having several steam discharge holes 25a on the wall is attached to a steam ejection tube 21.

When the hot water boils, high-pressure steam flows from the inside of the steam jet tube 21 through the ventilation hole 23 and into the steam release hole 2.
5a to the outside, and a blowing sound caused by the vibration of the reed 24 when passing through the ventilation hole 23 is used to notify boiling.

By the way, the quality of the blowing sound of the reed depends on the presence or absence of dew condensation on the reed surface, but in the above conventional example, the reed 24 is always open to the outside air through the steam release hole 25a, In addition, since it is in communication with the inside of the container body through the steam jet tube 21, the temperature of the reed 24 rises more slowly than the temperature of the water inside the water heater's container body, and the surface of the reed 24 does not have enough water to reach boiling point. There was a drawback in that the steam generated from within the main body condensed, and the adhesion of water droplets prevented the reed 24 from fully exerting its blowing effect.

In view of the above points, the present invention aims to block the steam flow path to the reed until the boiling temperature and vapor pressure of the water is reached, thereby suppressing dew condensation on the reed surface and increasing the blowing effect of the reed. A valve operated by a spring made of a two-way memory shape memory alloy is used to open and close the steam flow path.

Next, the present invention will be explained with reference to illustrated embodiments.

In FIG. 2, reference numeral 1 denotes a lid made of metal (for example, stainless steel), and a fitting part 1a for fitting into the container body (not shown) of the water heater is formed on the lower surface of the outer periphery, and on the upper surface of the lid 1. A hollow knob 2 in the shape of a square tube (cylindrical shape is also acceptable) made of synthetic resin and containing a built-in reed and a steam flow hole opening/closing valve constituting the boiling alarm device is attached by crimping or the like.

The inner cavity of the knob 2 is divided into an upper chamber 2b and a lower chamber 2c by a partition wall 2a formed in the middle part, and several steam release holes 2d are provided in parallel on the top wall. .

3 is a whistle plate fitted into the upper chamber 2b inside the knob 2,
Several steam vents 3a are provided in parallel on the flute plate 3, and a plurality of reeds 4 are fixed in a cantilever manner facing the vents 3a.

As shown in FIG. 3, the partition wall 2a is provided with a rectangular steam circulation hole _2a1 offset from the center, and the ventilation hole _2a1 is located on the long side as shown in FIG. A tapered surface with symmetrical upward and downward expansion is formed on the opposing surfaces.

Reference numeral 5 designates a rotatable valve that is fitted into the steam flow hole _2a1 and is pivotally supported on the partition wall 2a.As shown in FIG. The other end of a coil spring 6 made of a two-way memory type shape memory alloy is attached, one end of which is fitted and locked into a recess formed in the inner wall of the chamber 2c.

The transformation temperature of the coil spring 6 made of the shape memory alloy is set to the steam temperature at which hot water boils, and the valve 5 normally maintains the steam flow hole _2a1 in a substantially closed state.

With the above configuration, when the lid 1 having the knob 2 equipped with a boil alarm device is fitted into the opening of the container body and the water heater is heated, the shape memory is maintained as described above until the water in the container body boils. The alloy coil spring 6 holds the valve 5 in a state where the steam flow hole 2a ₁ is almost closed, so that high-temperature steam inside the container body is suppressed from flowing into the upper chamber 2b inside the knob 2, and is prevented from flowing into the surface of the reed 4. There is almost no condensation.

When the water boils, the coil spring 6 exposed to the boiling steam temperature expands due to the transformation temperature, causing the valve 5 to rotate counterclockwise (fourth
), steam distribution hole 2a ₁ of partition wall 2a
to open.

Therefore, high-temperature, high-pressure steam within the container body flows into the upper chamber 2b within the knob 2, passes through the steam vent hole 3a of the flute plate 3, and is discharged to the outside from the steam release hole 2d.

At this time, high-temperature, high-pressure steam hits the reed 4, and although there is some condensation at first due to the temperature difference, the pressure is high, so the condensed water droplets are blown away, and the reed 4 continues to blow with a good tone to notify boiling. do.

As described above, the present invention includes a reed in a knob attached to the lid of a water heater, and a two-way memory type shape memory alloy coil spring whose transformation temperature is set to the steam temperature at which water boils. We have installed a boil alarm device consisting of a valve that shuts off the steam flow hole to the reed until it boils, so we can suppress condensation on the reed surface as much as possible until it boils.
During boiling when the steam passage holes to the reed are open, some dew droplets on the reed surface due to the temperature difference are blown away by the steam pressure, so the blowing effect of the reed can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional example, FIG. 2 is a longitudinal sectional view of an embodiment of the present invention, FIG. 3 is an enlarged perspective view of a partition wall, and FIG. 4 is an enlarged sectional view of a steam passage hole. 1... Lid, 2... Knob, 2a... Partition wall, 2
a ₁ ...steam distribution hole, 3...whistle plate, 4...reed,
5...Valve, 6...Two-way memory type shape memory alloy coil spring.

Claims (1)

[Scope of utility model registration request] The interior of a hollow knob attached to the top surface of the lid of the water heater is divided into two by a partition wall, a reed is attached to the upper chamber of the knob, and a steam circulation hole is provided in the partition wall, and the valve is inserted into the circulation hole and is pivoted. A boil alarm for a water heater characterized in that a two-way memory type shape memory alloy coil spring is suspended between the lower part and the inner wall recess of the lower chamber in the knob, and the steam flow hole is closed until boiling occurs. Lid knob with device.