JPH0685738B2 - 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 electric water heater for pouring hot water.

[0002]

2. Description of the Related Art Conventionally, this type of electric water heater has a bellows pump driven by a motor or an electromagnet so that air is pumped into the container so that the hot water in the container is poured out. It was common.

[0003]

However, in the conventional electric water heater, the air is pumped into the container, and the inner solution is discharged by pressurizing the air in the container.
Especially when the hot water is just after boiling, the pressure inside the container becomes abnormally high due to the vapor pressure of the hot water, and even if a small amount of air is pumped, a larger amount of hot water than expected is discharged. On the other hand, when the amount of remaining hot water in the container is reduced, it is necessary to store the air in the container this time, and there is a time delay until the air is discharged. Further, since the air and the hot water come out from the discharge port in a mixed state, the hot water may be scattered to cause burns. Thus, there is a problem in the conventional method of sending air into the container and indirectly discharging hot water.

Further, there has been proposed a device in which an impeller is directly connected to a motor shaft to discharge hot water, but there are problems such as leakage of hot water to the motor side or damage to the motor due to heat of high-temperature hot water. It wasn't. A magnetic coupling type pump is known (for example, Japanese Patent Laid-Open No. Sho 50-3).
No. 8103), it is conceivable to divert this pump to a hot water supply device to eliminate leakage and heat damage of hot water, but this is because the drive side and passive side magnets are magnetically coupled in the radial direction. However, the shape of the magnet becomes large, and therefore the mass becomes large, and there is a problem that the hot water leaks out due to the inertia of the pump even after the discharge of the hot water is stopped, which cannot be simply diverted to the hot water supply device.

The present invention solves the above-mentioned problems of the prior art. The hot water can be stably discharged, and the problems of the hot water leaking to the motor side and the heat damage to the motor can be eliminated. An object of the present invention is to provide a hot water supply device that eliminates leakage of hot water after the discharge is stopped.

[0006]

In order to achieve the above object, the present invention provides a centrifugal pump for pumping hot water in a container and pouring it from a water injection port at a lower part of a container for storing hot water having a heater for heating. Centrifugal pumps have an impeller that has a magnet and is movable in the thrust direction, a magnet that faces the magnet in the thrust direction via a partition wall of the pump chamber, and this magnet is attached to a motor shaft to rotate the impeller by magnetic coupling. And a motor for driving.

[0007]

According to the above construction, the hot water can be directly discharged according to the rotation speed of the motor. When the hot water is discharged, the pressure inside the pump rises and the impeller moves away from the partition wall of the pump chamber, but when the motor drive is stopped, the pressure inside the pump decreases and the magnet of the impeller and the motor side Since the magnet is attracting, the impeller comes into strong contact with the partition plate of the pump chamber. Further, since the magnets are magnetically coupled so as to face each other in the thrust direction, the shape of the magnet can be reduced and the mass can be reduced. Therefore,
There is no rotation due to the inertia of the impeller, the discharge of hot water is stopped immediately, and the hot water does not leak after the discharge of hot water is stopped.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, reference numeral 1 is an exterior main body of a hot water supply apparatus, in which a container 2 for storing hot water is provided. Reference numeral 3 is an inner plug attached so as to seal the mouth of the container 2. Reference numeral 4 denotes an upper lid attached so that the upper portion of the exterior body 1 can be opened and closed.

Reference numeral 5 is a check valve, which penetrates the inside plug 3 and communicates with the inside of the container 2, and also communicates with the atmosphere through a boiling detection portion 6. Reference numeral 7 is a motor provided at the bottom between the exterior main body 1 and the container 2. A centrifugal pump 8 is driven by a motor 7. The pump 8 is provided at the bottom of the container 2, and its suction port 9 communicates with the center of the bottom of the container 2. Reference numeral 10 denotes a discharge port of the centrifugal pump 8, in which hot water is pumped upward through a discharge pipe 11 and poured into a cup or the like from a spout 12. A heating heater 13 is mounted on the lower side surface of the container 2.

Reference numeral 14 is a start switch for driving the motor 7, which is operated via the rod 16 by the push operation of the push button 15. Reference numeral 17 is a compression type spring, and this spring 17 constantly biases the rod 16 so as to push it upward.

Next, the centrifugal pump 8 will be described with reference to FIGS. Reference numeral 17 denotes an impeller provided with a plurality of blades 18 radially and provided with a magnet 19, and a pump chamber 20 is formed concentrically along the outer circumference of the impeller 17. The magnet 19 of the impeller 17 is connected to the pump chamber 20.
And a magnet 22 on the motor side in the thrust direction. The magnet 22 is fixed to the shaft of the motor 8 and is magnetically coupled by the magnets 19 and 22, and the rotation of the motor 8 is transmitted to the impeller 17 by magnetic force.

Here, the structure of the centrifugal pump 8 will be described in detail. The pump chamber 20 is composed of a casing 23 and a partition plate 21, and a fixed shaft 25 is provided at a central suction port 24 of the casing 23. A bearing 27 is inserted into the end portion 26 of 25 so as to slide in the thrust direction and rotate. Further, a plurality of protrusions 27a are provided on the outer periphery of the bearing 27, and the impeller 17 is inserted therein and fixed in the rotational direction. This allows the impeller 17 to move in the thrust direction via the bearing 27. Bearing 2
Since the tip 28 of 7 has a spherical shape and the magnets 19 and 22 are magnetically coupled, the tip 28 is always in contact with the partition plate 21.

The operation of the above configuration will be described. Container 2
The hot water inside is kept at a high temperature by the heater 13 for heating.
When pouring hot water in this state, the start switch 14 is turned on by pushing down the push button 15, and the resistance is changed by pushing it down further, and the applied voltage is changed to energize the motor 7. As the motor 7 rotates, the impeller 17 rotates due to the magnetic coupling of the magnets 19 and 22, and hot water is sucked from the suction port 9 of the centrifugal pump 8, pressurized by the impeller 17 and discharged from the discharge port 11 to the discharge pipe 11.
Through the spout 12 to the outside.

Here, the operation of the centrifugal pump will be described in detail. Figure 5
Normally, as shown in FIG.
Since the magnet 19 in the impeller 17 and the magnet 22 on the driving side are magnetically coupled to each other, the tip 28 of the abutment 28 is in contact with the partition plate 21 and the impeller 17 rotates from this state. Here, when the rotation speed of the impeller 17 is increased to increase the discharge amount, the internal pressure in the pump chamber 20 increases as shown in FIG. 6, and back pressure is applied from below the impeller 17 in the direction of the arrow. The impeller 17 floats. Accordingly, the bearing 27 moves in the direction of the suction port portion 24, separates from the partition plate 21, and the inner inner surface comes into contact with the end surface of the fixed shaft 25 to rotate and discharge hot water.

When the driving of the motor 7 is stopped after the discharge of a predetermined amount of hot water is completed, the state shown in FIG. 5 is restored. In this case, since the magnets 19 and 22 are attracted, the bearing tip 28 of the impeller 17 comes into strong contact with the partition plate 21,
Since the magnets are magnetically coupled against each other in the thrust direction, the shape of the magnets can be made smaller and the mass can be made smaller, so that there is no rotation due to the inertia of the impeller 17 and the discharge of hot water immediately stops and the hot water is poured out. There is no leakage from 12 even after the discharge is stopped.

[0016]

As described above, according to the present invention, unlike the conventional method of sending air into a container and indirectly discharging the air, the discharge amount can be freely controlled by a direct centrifugal pump.
The discharge amount is stable and can be used for a long period of time, and hot water can be supplied without scattering of hot water and without causing burns or the like. At the same time, since the impeller and the motor side are separated by magnetic coupling, there is no problem of sealing or heat damage of the motor.

After the hot water discharge is stopped, the magnet of the impeller and the magnet on the motor side are attracted to strongly contact the impeller with the partition plate of the pump chamber, and the magnets face each other in the thrust direction. Because of this, the magnet shape can be made smaller and the mass can be made smaller, so there is no rotation due to the inertia of the impeller, the hot water discharge is stopped immediately, and the hot water does not leak due to the inertia of the pump after the hot water discharge is stopped. .

As described above, the hot water supply device of the present invention is a very practical device that solves the conventional problems.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a water heater showing an embodiment of the present invention.

FIG. 2 is a front view showing a cross section of a part of a centrifugal pump incorporated in the apparatus.

FIG. 3 is a vertical sectional view of the centrifugal pump.

FIG. 4 is a perspective view showing a bearing of the centrifugal pump.

FIG. 5 is an operation explanatory view of the centrifugal pump in a discharge state at a low flow rate.

FIG. 6 is an operation explanatory view of the centrifugal pump in a discharge state at a high flow rate.

[Explanation of symbols]

 2 container 8 centrifugal pump 17 impeller 19 magnet 21 partition wall plate 22 magnet 25 fixed shaft 27 bearing

Claims (1)

[Claims] 1. A centrifugal pump for pumping hot water in a container and pouring it from a water injection port is provided below a container for storing hot water having a heater for heating. The centrifugal pump has a magnet and is movable in a thrust direction. A hot water supply apparatus comprising: a magnet that faces the magnet in a thrust direction via a partition wall plate of the pump chamber; and a motor that attaches this magnet to a motor shaft and rotates an impeller by magnetic coupling.