JPH0334622Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is a pump motor that can immediately melt the flocculent ice generated in the ice-making water circulation path of an automatic ice-making machine and prevent the formation of cloudy ice. It is related to the structure of

Prior Art FIG. 5 shows a schematic structure of a downstream type automatic ice maker, in which ice making water stored in an ice making water tank 1 is passed through a pump motor 6 and a hose 2 shown in FIG. 6 to a water sprinkler pipe 3. Ice-making water is sprayed onto ice-making plates 4 arranged at an angle. Since the ice-making plate 4 is cooled by an evaporator (not shown) connected to a refrigeration system attached to the back thereof, plate-shaped ice is gradually formed on the plate surface. Upon detecting the formation of this ice sheet, the ice making operation is stopped, the refrigeration system valve is switched, hot gas is supplied to the evaporator, the ice is thawed between the ice making surface and the ice sheet, and the ice sheet is transferred to the ice making plate. A large number of ice cubes are produced by sliding the ice cubes down from the ice cubes 4 and melting them with a grid-shaped heating wire 5 located on the falling locus.

FIG. 6 shows a sectional view of a conventional pump motor for pumping ice-making water. This pump motor 6 is
A motor 7 and a cylindrical body 8 that supports the motor 7
, a pump chamber 9 fixed to the lower part of the cylindrical body 8 and immersed in the water of the tank 1, and a screw 11 attached to the rotating shaft 10 of the motor 7 and rotatably housed in the pump chamber 9. It basically consists of. Through holes 12 and 13 are formed in the peripheral wall of the cylindrical body 8 at a submerged position close to the pump chamber 9 and at a position above the water surface close to the motor 7, respectively. Further, a water suction hole 14 is formed in the bottom surface of the pump chamber 9, and a discharge port 15 is formed in the side wall of the pump chamber, and the end of the hose 2 is connected to the discharge port 15. The screw 11 includes a disc 16 connected to the motor shaft 10, and three blades 17 that are curved in the rotational direction and protrude from the disc 16 toward the water suction hole 14, as shown in FIG. It consists of

The pump motor 6 configured in this way is generally called a vertical pump because the motor 7 is installed above the water surface, but it is widely used because it does not require a mechanical seal to prevent water leakage and can be manufactured at low cost. . That is, the motor shaft 10 and this shaft 10
A gap 1 formed at the top of the pump chamber 9 through which the
8 can be used without blocking it, but since ice-making water enters and exits through this gap 18, the through hole 12 is provided in the main body 8 to ensure a water circulation path,
The through hole 13 is formed so that the motor 7 will not be infiltrated even if the water level inside the cylindrical body 8 rises.

During the ice-making cycle, the screw 11 is driven to rotate in the pump chamber 9 by the rotation of the motor 7, and the ice-making water in the tank 1 is sucked in through the water suction hole 14, and is force-fed through the discharge port 15 and the hose 2.
The water is sprinkled onto the ice-making plate 4 from the sprinkler pipe 3. A part of the ice-making water sprinkled onto the ice-making plate 4 is rapidly cooled and grows as sheet ice, while the remaining unfrozen water comes into contact with the ice-making plate 4 and the ice being formed and is cooled. In a state where the temperature has decreased, the ice is returned to the tank 1, mixed with the ice-making water in the tank 1, and then sucked into the pump chamber 9 again to repeat the circulation.

Problems to be Solved by the Invention When the ice-making cycle proceeds using the conventional pump motor 6, the cooled unfrozen residual water that returns to the tank 1 gradually cools the entire ice-making water in the tank 1. As a result of the ice-making water thus cooled being pumped from the tank 1 and sprayed again onto the ice-making plate 4, the ice-making water is supercooled below the surface of the ice-making plate, and begins to freeze with impurities in the water as nuclei. Incomplete ice having a cotton-like or mud-like appearance (hereinafter referred to as "cotton ice") is generated in spots in the ice-making water.
This cotton ice flows down into the water tank 1 together with the unfrozen water, and cotton ice is also generated within the tank. This cotton ice is sucked into the pump chamber 9, gets stuck between the blades 17 of the screw 11, and condenses into a cylindrical shape as a whole. This phenomenon is more likely to occur as the cooling gradient is made steeper in order to cool the ice-making water sprinkled on the ice-making plate 4 in a shorter time and to increase the amount of ice made.

When the cotton ice gets stuck between the blades 17 of the screw 11 and becomes cylindrical, the pump discharge pressure decreases and pulsation occurs, the amount of spray from the sprinkler pipe 3 decreases, and eventually the ice-making water circulates. leading to suspension.
In addition, if the amount of cotton ice generated on the ice-making plate 4 decreases as described above or if the spraying stop time is prolonged, the cotton ice formed on the ice-making plate 4 becomes uneven ice 19 as shown in FIG. 5, and the appearance This causes the formation of cloudy ice with poor appearance. In extreme cases, the ice-making plate 4 is extremely supercooled, and the ice-making completion thermostat reacts even though no ice is growing, causing the ice-making cycle to start.

Purpose of the invention The purpose of this invention was proposed in order to suitably solve the problems of the prior art described above. To provide a pump motor for an automatic ice making machine which can effectively prevent a drop in the discharge pressure of ice making water and prevent the formation of cloudy ice which is inferior in commercial value.

Means for Solving the Problems In order to overcome the above-mentioned problems and achieve the intended purpose, the present invention rotates a screw installed in the pump chamber with a motor to make ice from the ice-making water in the ice-making water tank. In the pump motor of an automatic ice making machine configured to pump ice to the ice making section, a reflux path is directly branched from the ice making water pressure feeding path between the pump chamber and the ice making section, and this reflux path is communicatively connected to the pump chamber, It is characterized in that a portion of the ice-making water pumped from the pump chamber is returned to the pump chamber via the reflux path.

Operation The ice-making water that returns to the pump room through the return path has a higher temperature than the ice-making water that returns after coming into contact with a forcedly cooled ice-making unit such as an ice-making plate. Therefore, even if generated cotton ice flows into the pump chamber, it is immediately melted by this return water, and the situation where the screw becomes clogged with cotton ice is avoided. Also, the formation of cloudy ice is prevented.

Embodiment Next, a preferred embodiment of the pump motor of an automatic ice maker according to the present invention will be described with reference to FIGS. 1 to 4. Components common to those of the pump motor of the conventional automatic ice maker explained with reference to FIG. 6 will be designated by the same reference numerals. FIG. 1 is a sectional view of a pump motor according to a preferred embodiment of the present invention, and FIG. 3 is a bottom view of the pump chamber shown in FIG. 1.

In FIG. 2, an L-shaped branch pipe 21 is connected in communication with the root portion 3a of the water spout 3, in which water sprinkling holes 20 are bored at predetermined intervals. Also the first
In the pump motor shown in the figure, a portion (third
(see figure), the reflux water inflow pipe 22 is connected to the
This inflow pipe 22 extends substantially parallel to the discharge port 15. The branch pipe 21 and the return water inflow pipe 22 are connected by a hose 23 as shown in the figure. In this case, the size ratio of the return water inflow pipe 22 to the discharge port 15 of the pump chamber 9 is set to about 1/2 in diameter, or about 4 to 1 in cross-sectional area, as shown in FIG. 3 in this embodiment. be. Note that the inner diameter of the branch pipe 21 is set to such a thickness that it will not be clogged with cotton ice.

Next, an example of operation using the pump motor according to the present embodiment configured as described above will be described. When making ice using the automatic down-flow ice maker shown in Fig. 5, the ice-making water is originally pumped from pump chamber 9 → discharge port 15 → hose 2 → watering pipe 3 → ice-making plate 4 → water tank 1 → pump chamber 9. However, in the present invention, in addition to the above-mentioned main circulation route, the pump chamber 9→
A secondary reflux path is formed from the discharge port 15 to the hose 2 to the branch pipe 21 to the hose 23 to the reflux water inflow pipe 22 to the pump chamber 9. At this time, the ice-making water that returns to the water tank 1 via the main circulation path becomes supercooled as the ice-making cycle in the ice maker progresses, and the water temperature in the water tank 1 drops to a state where it is easy to generate ice fluff. let However, since the ice-making water that returns to the pump chamber 9 via the aforementioned secondary circulation path does not come into contact with the ice-making plate 4, there is a positive temperature difference with respect to the ice-making water that returns to the water tank 1 via the main circulation path. have.

Therefore, even if the ice making water in the water tank 1 is supercooled and the cotton ice is generated in the tank, and this cotton ice is sucked into the pump chamber 9 from the water suction hole 14 together with the ice making water,
The cotton ice comes into contact with the relatively high temperature ice-making water that returns to the pump chamber 9 via the reflux path and is instantly melted. This prevents the cotton ice flowing into the pump chamber 9 from becoming clogged between the blades 17 of the screw 11 and reducing the discharge force. Furthermore, due to the presence of the relatively high-temperature return water described above, the generation of cotton ice inside the pump chamber 9 is easily suppressed, and cotton ice is also prevented from forming inside the hose 2 and the sprinkler pipe 3. It's getting difficult.

However, if the degree of supercooling in the water tank 1 is large and a large amount of cotton ice is generated in the water tank 1, even if the above-mentioned reflux water is used, the cotton ice flowing into the pump chamber 9 will not be completely removed. It cannot be melted. If the cotton ice that has flowed into the pump chamber 9 in this way blocks the water sprinkling hole 20 of the water sprinkling pipe 3, or furthermore, the cotton ice becomes clogged between the blades 17 of the screw 11 and reduces the discharge pressure. Even if there is a case, it is virtually impossible for the tip of the blade 17, where the centrifugal force is strong, to become clogged with cotton ice and the discharge pressure becomes zero. teeth,
It is still returned to the pump chamber 9 via the branch pipe 21 and hose 23. Since this return water melts the cotton ice stuck between the blades 17 at an early stage, the time required until the spraying of ice-making water in the sprinkler pipe 3 is resumed is shortened. If the watering stop time is shortened in this way, even if the uneven ice 19 (Fig. 5) that causes cloudy water forms, the temperature of the uneven ice 19 itself has not decreased that much, so watering will not be restarted. The ice is melted by spraying ice-making water, and the formation of cloudy ice is prevented. Therefore, compared to using a conventional pump motor,
It can produce high quality ice.

In this embodiment, the recirculating water inflow pipe 22 is connected to the water intake port 14.
The reason why it is provided adjacent to the water inlet 14 is that the closer it is to the water intake port 14 (the closer it is to the center of rotation of the screw), the stronger the water absorption force is, and the easier it is for the return water to return. Therefore, as a communication port for the return water inflow pipe 22 to the pump chamber 9, for example, as shown in FIG.
Even if the structure is used in common with the embodiment shown in FIG. 1, the same effects as in the embodiment shown in FIG. Furthermore, in each of the above embodiments, the screw was rotated by a motor shaft, but other types of motors, such as a magnetic pump type motor that uses a motor that rotates the screw without contact using the external magnetic attraction force of a magnet, may also be used. It goes without saying that the present invention can be applied to.

Effects of the invention According to the invention, water with a temperature higher than the temperature of the ice-making water in which cotton ice is generated is constantly refluxed into the pump chamber during ice making, so that the cotton ice that has flowed into the pump chamber is The ice can be melted instantly, avoiding the need to stop watering for a long time, suppressing the formation of cloudy ice, and producing a large quantity of high-quality ice with high commercial value. Furthermore, there is no need to partition the inside of the water tank for the purpose of dealing with cotton ice, resulting in lower costs. In the illustrated example, ice cubes are produced by spraying ice-making water onto ice-making plates arranged at an angle.
We have described an automatic ice maker that melts this sheet ice into a large number of ice cubes using grid-shaped heating wires. The present invention can also be suitably implemented in a fountain type automatic ice maker that forms ice cubes in a small chamber.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a pump motor according to a first embodiment of the present invention, FIG. 2 is a partial sectional view of a water sprinkler pipe connected to the pump motor shown in FIG. Fig. 3 is a bottom view of the pump chamber in the pump motor shown in Fig. 1, Fig. 4 is a sectional view of the pump motor according to the second embodiment of the present invention, and Fig. 5 is a diagram of the conventional automatic ice making machine. FIG. 6 is a sectional view of a conventional pump motor, and FIG. 7 is a cross-sectional view of a pump chamber showing a screw structure. 3... Water pipe, 4... Ice plate, 6... Pump motor, 9... Pump room, 11... Screw,
14... Water inlet, 15... Outlet, 21... Branch pipe, 22... Return water inflow pipe, 23... Hose (for return water).

Claims (1)

[Scope of Claim for Utility Model Registration] A pump for an automatic ice making machine configured to drive ice making water in an ice making water tank 1 to an ice making section 4 by rotationally driving a screw 11 disposed in a pump chamber 9 with a motor 6. In the motor, reflux paths 21 and 23 are directly branched from the ice-making water pressure feed path 2 between the pump chamber 9 and the ice-making section 4, and the reflux paths 21 and 23 are connected to the pump chamber 9 in communication with the pump chamber. A pump motor for an automatic ice making machine, characterized in that a part of the ice making water pumped from the pump chamber 9 is returned to the pump chamber 9 via the reflux paths 21 and 23.