JPH0130071B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an ice maker, and more particularly, to an improvement in operation control when a compressor is overloaded.

(Prior art) Conventionally, as an ice maker, for example, JP-A-58-
As disclosed in Publication No. 28964, there is an ice-making plate for producing ice, a watering circuit that drives a water pump to sprinkle ice-making water onto the ice-making plate, and a cooling pipe of the ice-making plate by the operation of a compressor. The ice-making refrigerant circuit is equipped with an ice-making refrigerant circuit that distributes liquid refrigerant, and an ice-removing refrigerant circuit that distributes hot gas from the compressor to the cooling pipe of the ice-making plate by opening an ice-removing on-off valve. By sprinkling ice-making water and flowing a liquid refrigerant through the cooling pipe, the ice-making water sprinkled on the ice-making board is cooled and frozen by the endothermic action of the liquid refrigerant, thereby producing ice on the ice-making board, It is known that during ice-removal operation, hot gas is passed through the cooling pipe of the ice-making plate, so that the ice generated on the ice-making plate is released by the heat transfer effect from the ice-making plate due to the hot gas. There is.

(Problems to be Solved by the Invention) By the way, in the ice making machine as described above, the low pressure of each refrigerant circuit for ice making and ice removal gradually increases as the ice removal operation progresses, as shown in FIG. It reaches its maximum value at the end of the operation, and then gradually decreases from the maximum value due to ice-making operation, which is a characteristic that repeats. Therefore, the load on the compressor increases near the end of the ice-removal operation or near the start of the ice-making operation, and the compressor may repeatedly be overloaded depending on fluctuations in outside temperature or power supply voltage.

Therefore, in order to prevent overload operation of the compressor, an overload relay is provided that forcibly stops the operation of the compressor when it is overloaded, as disclosed in, for example, Japanese Utility Model Application No. 56-101142. It is possible to improve the reliability of the compressor.

However, in this case, especially when an overload condition occurs during ice removal operation, the compressor operation is stopped, but if the overload relay is reset and the compressor is restarted, ice removal operation continues. This causes a rise in low pressure and is likely to result in an overload condition again, and for this reason, the overload relay repeatedly starts and stops the compressor, causing ice removal operation to continue indefinitely.
There is a problem in that the operation does not shift to ice making operation.

The present invention has been made in view of these points, and its purpose is to detect an overload state of the compressor using the above-mentioned overload relay, etc., and to detect the overload state of the compressor once the overload state has been reached. When the compressor is subsequently restarted, the operation mode is set to ice-making operation in which the low pressure drops, thereby preventing the continuation of ice removal operation due to starting and stopping of the compressor, and returning the operation cycle to normal. be.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention, as shown in FIG. A water sprinkling circuit 8 that sprinkles water on the ice making plate 1; an ice making refrigerant circuit 11 that distributes liquid refrigerant from the compressor 13 to the cooling pipe of the ice making plate 1; 1 is provided with an ice-removing refrigerant circuit 12 through which hot gas from the compressor 13 flows, and during ice-making operation, the ice-making water sprinkled on the ice-making plate 1 is cooled and frozen by a liquid refrigerant to generate ice, In an ice making machine which uses hot gas to break ice generated on an ice making plate during ice removal operation, an overload state detection means 25 for detecting an overload state of the compressor 13, and the overload state detection means are provided. 25, the compressor 13 is stopped for a predetermined period of time, the ice removal on-off valve 20 is opened, and the water pump 5 is activated to remove ice from the ice making plate 1, and then the ice making operation is started. The configuration includes a control means 40 for controlling the speed.

(Function) With the above configuration, in the present invention, when the compressor is overloaded, especially when the compressor reaches an overload state near the end of ice removal operation, the compressor is stopped for a predetermined time and the ice removal operation is stopped. The on-off valve opens and the water pump 5 operates, reducing the load on the compressor and at the same time promoting ice removal so that the ice produced on the ice-making plate is removed from the ice-making plate. When the compressor is subsequently restarted, the operation mode is forced into ice-making operation, and the low pressure gradually decreases, so ice-making operation continues without the overload detection means operating again. Then, the normal driving cycle resumes.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings from FIG. 2 onwards.

FIG. 2 shows the overall configuration of the ice making machine, in which 1 is an ice making plate for producing ice, 2 is a watering tank placed above the ice making plate 1, and having a large number of watering holes 2a at the bottom, A water tank 4 having a water tray 4a disposed below the ice-making plate 1 is connected to the water tank 2 through a water pipe 3, and the water in the water tank 4 is stored in the water tank 4. A water pump 5 is disposed to pump and supply water to the watering tank 2 via a pipe 3, and the water receiving tray 4a of the water tank 4 has an opening at the other end of a water supply pipe 7 with a water supply solenoid valve 6 interposed therein. is facing the water tank 4 due to the drive of the water pump 5.
After the ice-making water is supplied to the water sprinkling tank 2, this ice-making water is sprinkled down from the water sprinkling hole 2a onto the ice-making plate 1 for ice-making, and the water falling from the ice-making plate 1 is returned to the water tank 4 from the water tray 4a. In addition, a water sprinkling circuit 8 is configured to restore the water level of the water tank 4, which has fallen due to ice making, to a predetermined high water level by supplying water from the water supply pipe 7. Note that 9 is an overflow pipe for discharging excess water from the water tank 4.

Furthermore, 10, 10 is the ice making plate main body 1 of the ice making plate 1.
a, the cooling pipe provided in 1a, 11 is the cooling pipe 10,
an ice-making refrigerant circuit that circulates liquid refrigerant to 10;
is an ice-removing refrigerant circuit that circulates hot gas through the cooling pipes 10, 10 of the ice-making plate 1; the ice-making refrigerant circuit 11 includes a compressor 13, an air-cooled condenser 15 equipped with a fan 14; , an expansion valve 16 and cooling pipes 10, 10 serving as an evaporator are successively connected by a refrigerant pipe 17. Note that 18 is an accumulator.

On the other hand, the deicing refrigerant circuit 12 is connected to the compressor 13.
A solenoid valve 20 for ice removal, which is an on-off valve for ice removal that operates to open when ice is removed, and cooling pipes 10, 10 are sequentially connected by a refrigerant pipe 17.

When making ice, the refrigerant is circulated in the compressor 13 as shown by the solid arrow in the figure by closing the ice-removing solenoid valve 20 and opening the expansion valve 16.
After the heat of the high-temperature, high-pressure refrigerant discharged from the cooling pipes 10 and 1 is radiated to the outside air in the condenser 15,
0 (evaporator) repeatedly absorbs heat from the ice-making water flowing down the ice-making plate 1, and the ice-making water is cooled and frozen on the ice-making plate 1 to generate ice. By opening the valve 20 and closing the expansion valve 16, the refrigerant (hot gas) is circulated as shown by the broken line arrow in the figure.
The ice produced on the ice-making plate 1 is released by repeatedly dissipating the heat contained in the refrigerant (hot gas) from the ice-making plate 1 through the cooling pipes 10, 10. In addition, around the ice-making plate main body 1a of the ice-making plate 1,
The water supply pipe 7 is arranged along this line, and when replenishing water to the water tank 4 during ice removal, the heat of this replenishment water is given to the ice on the ice making plate 1 to improve ice removal efficiency. It is done like this.

In addition, 21 is a float switch that detects predetermined high and low water levels in the water tank 4, 22 is a water supply pipe thermistor that detects the water temperature of the water supply circuit 8 based on the water temperature of the water supply pipe 7, and 23 is a suction to the compressor 13. It is a suction pipe thermistor that detects the refrigerant temperature of the side refrigerant pipe (suction pipe) 17, and the detection signals of each of the devices 21 to 23 are input to the controller 24, which controls the water pump 5, compressor 1, etc.
3. The operation of the condenser fan 14, the water supply solenoid valve 6, and the ice removal solenoid valve 20 is controlled.

As shown in FIG. 3, the controller 24 is connected to an overload relay 25 as overload state detection means, which is an overcurrent relay for detecting an overload state of the compressor 13, so as to be able to send and receive signals. There is. Further, inside the controller 24, there is an overload relay operation input section 30 that inputs the overload signal from the overload relay 25, and an overload countermeasure control section 31 that receives the output of the overload relay operation input section 30.
It is equipped with The overload countermeasure control section 31 controls, during the timer time (to) (for example, 3 minutes) of the overload timer 32, when the compressor 13 receives the output from the overload relay operation input section 30 and is overloaded.
The compressor 13 is stopped and the de-icing solenoid valve 2 is
0 and rotates the water pump 5 and condenser fan 15. In addition, in the figure,
33 to 36 are electromagnetic contactors, 37 is a compressor electromagnetic contactor, and 38 is an operation indicator light.

Next, the operation of the controller 24 will be explained based on the flowcharts of FIGS. 4 and 5. First, when the run/stop switch (not shown) is operated to the operating side in step _S1 , the operating indicator light 38 is turned on in step _S2 , and then the detection signal from the suction pipe thermistor 23 is turned on in step _S3 . Based on the inlet pipe temperature _T
If the answer is YES (T _F ≧15℃), it is determined that it is time to start ice making and the process proceeds to step _S4 onwards, while if the answer is NO (T _F <15℃), the ice making process will proceed. It is determined that it is time to start ice operation and immediately proceeds to step _S10 and subsequent steps.

Then, in step _S4 , the water pump 5, compressor 13, and condenser fan 14 are rotated to start the ice-making operation, and the ice-releasing electromagnetic valve 20 is closed, so that water is sprinkled from the water tank 2 and the cooling pipe 10 is ，
Ice-making on the ice-making plate 1 is started by the flow of low-temperature refrigerant to the ice-making plate 10. At this time, the water is pumped up into the sprinkler tank 2 by the rotational drive of the water pump 5, and the water supply solenoid valve 6 is operated for a predetermined period of time (t ₂ ) (e.g. 40 seconds)
The water level in the water tank 4 is maintained at a high level by opening the water tank 4.

After that, in step _S5 , it is determined whether or not there is a high water level detection signal from the float switch 21, and if the high water level detection signal is NO and there is no high water level detection signal, it is determined that there is a water outage, and in step _S6 , the water pump 5 and the compressor are switched on. After stopping the driving of the ice making machine 13 and the condenser fan 14, upon receiving the ice making period elapsed signal from the water making end timer 34 in step _S7 , the process returns to step _S4 to replenish the water tank 4 with water. . On the other hand, if the high water level detection signal from the float switch 21 is YES in step _S5 , it is determined that there is no water outage and the process proceeds to step _S8 to continue the ice making operation.
In step _S9 , it is determined whether or not there is a low water level detection signal from the float switch 21, and the step
In _S9 , the presence or absence of the ice-making period elapsed signal from the ice-making end timer 34 is determined, and the ice-making period elapsed signal that has not been received is determined.
In the case of NO, the ice making operation continues as it is, while on the other hand, if either signal is received and the answer is YES, it is determined that it is time to finish ice making, and the process proceeds to step _S10 .
Proceed to.

Next, in step _S10 , the water pump 5 and the condenser fan 14 are stopped to start the ice removal operation, and the ice removal solenoid valve 20 is opened.
Refrigerant (hot gas) from compressor 1 is transferred to cooling pipe 1
0 and 10 to start ice removal, and open the water supply solenoid valve 6 to restore the water level that has dropped due to the ice-making operation to a high water level in the water tank 4, and set the opening operation time to step S. ₁₁ , the water supply timer 44 measures the water supply time.

Then, in step _S12 , it is determined whether the opening operation time of the water supply solenoid valve 6 has elapsed for a predetermined time ( _t1 ) (for example, 2 minutes), and if YES, the water level in the water tank 4 is high. When it is determined that the water level has returned to the same level, the water supply solenoid valve 6 is closed in step _S13 to complete water supply to the water tank 4, and at the same time, in step _S14 , the water supply pipe thermistor 22 is closed in order to calculate the water sprinkling time during ice break-off.
In step _S15 , the higher the water temperature value, the shorter the watering time, for example, when the water temperature is 0 to 7°C, the first watering time is input.
T ₁ (e.g. 6 minutes) and the second watering time at 7-14°C.
T ₂ (e.g. 3 minutes), third watering time T ₃ at 14℃~
(for example, 1 minute).

After that, in step _S16 , the suction pipe thermistor 2 is
Wait for the suction pipe temperature T _F signal from step 3 to reach 16°C or higher, that is, for the ice on the ice making plate 1 to substantially start to break off due to the flow of hot gas, and then proceed to step 3.
In _{step S17} , the water pump 5 is driven to sprinkle water on the ice-making plate 1, and then, in step _S18 , the process waits for the watering time T _A , _T2 , or _T3 selected in step _S15 to elapse, and then proceeds to step _S19. Then, the water pump 5 is stopped, and in step _S20 , it is checked again that the suction pipe temperature T _F signal from the suction pipe thermistor 23 is 16°C or higher, and the process returns to step _S4 .

In addition, after the start of ice removal operation in step _S10 , the water tank 4 is filled with water based on the opening operation of the water supply solenoid valve 6.
The predetermined time (t ₁ ) for the water level to return to the high water level (2
If _the suction pipe temperature T _F becomes 16°C _or higher during the first watering period T ₁ (for 1 minute) to start watering for 1 minute from the watering tank 2, and then in step _S23 for a predetermined time (t ₁ ) (for example, 2 minutes).
After waiting for the elapse of 1 minute), the water supply solenoid valve 6 is closed in step _S24 to complete the water supply to the water tank 4, and the process returns to step _S4 .

Then, during ice making operation or ice removal operation based on the operation flow shown in Fig. 4 above, the overload relay 2
When an overload condition of the compressor 13 is detected in step 5, this is interrupted and the process proceeds to the overload reduction flow shown in FIG. In the overload reduction flow, the compressor 13 is stopped in step S _A to prevent overload operation, and the deicing solenoid valve 20 is opened to balance high and low pressures, and the water pump 5 is driven to rotate. In particular, ice removal is performed during ice removal operation, and furthermore, the condenser fan 14 is driven to rotate to lower the high pressure, and at the same time, the overload timer 32 is activated for a predetermined time (to).
(for example, 3 minutes).

After that, in step S _B , it is determined whether or not the time measurement by the overload timer 32 has been completed. If the answer is NO that the time measurement has not been completed, the overload reduction mode in step S _A is maintained. On the other hand, if the time measurement is completed and the answer is YES, the process proceeds to step S _C , where the _de -icing solenoid valve 20 is closed, and then the presence or absence of an overload condition is determined by the overload relay 25 at step S _D. After confirming that there is no longer an overload condition, the fourth step is performed to forcibly start ice-making operation.
Return to step _S4 in the diagram.

Therefore, according to the overload reduction flow shown in FIG. 5 above, upon receiving the output of the overload relay 25, the compressor 13 is stopped for the timer time (to) of the overload timer 32, and the deicing solenoid valve 20 is opened. It also constitutes a control means 40 which activates the water pump 5 to remove ice from the ice-making plate 1 and then shifts to ice-making operation.

Therefore, in the above embodiment, during the ice-making operation, water is sprayed down the ice-making plate 1 by the water spray circuit 8, and the cooling pipes 10, 1 of the ice-making plate 1 are sprayed with water.
When the low temperature liquid refrigerant from the ice-making refrigerant circuit 11 flows through the ice-making refrigerant circuit 11, the water sprayed down is cooled and frozen, and ice is generated on the ice-making plate 1. Further, during the ice-removing operation, hot gas from the ice-removing refrigerant circuit 12 flows through the cooling pipes 10, 10 of the ice-making plate 1, so that the ice generated on the ice-making plate 1 is removed.

If the outside air temperature or power supply voltage fluctuates near the end of the ice removal operation or near the start of the ice making operation (see Figure 7), especially in the former, and an overload condition of the compressor 13 occurs, the compressor 13 will be overloaded. By stopping, overload operation is prevented, and by opening the ice-removing solenoid valve 20, high and low pressures are balanced, and by driving the water pump 5, ice is removed from the ice-making plate 1.
Furthermore, the high pressure is reduced by rotating the condenser fan 14.

And the timer time (to) of the overload timer 32
When the time has elapsed, the low pressure will drop due to the forced transition to ice-making operation, so from now on, the compressor 1
Ice making proceeds without causing the overload condition of 3.
Therefore, unlike when ice removal operation is performed again after a predetermined period of time has elapsed from an overload state, there is no need to continue ice removal operation due to starting and stopping of the compressor, and the normal operation cycle can be returned to quickly. be able to.

In the above embodiment, when the compressor 13 is overloaded,
Although the condenser fan 14 is driven to rotate when the compressor 13 is stopped, this reduction in high pressure is effective during ice-making operation, but not during ice-removal operation, so it is not necessarily necessary.

(Effects of the Invention) As explained above, according to the present invention, in an ice maker that alternately repeats ice making operation and ice removal operation,
When the compressor is overloaded, especially near the end of ice removal operation, the load on the compressor is reduced and ice removed for a predetermined period of time, and then the system is forced to switch to ice-making operation to lower the low pressure. This not only improves the reliability of the compressor, but also prevents the continuation of de-icing operation caused by the compressor starting and stopping, making it possible to quickly return to normal operation. be.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention. 2 to 7 show embodiments of the present invention, FIG. 2 is an overall configuration diagram, FIG. 3 is a diagram showing the internal configuration of the controller, and FIGS. 4 and 5 are flowcharts showing the operation of the controller. The chart diagram, FIG. 6, is a diagram showing the change characteristics of the feed water temperature with respect to time, and FIG. 7 is a diagram showing the change characteristics of the low pressure. 1...Ice maker, 5...Water pump, 8...Water circuit, 10...Cooling pipe, 11...Ice making refrigerant circuit,
12... Refrigerant circuit for ice removal, 13... Compressor, 20
... Solenoid valve for ice removal, 24 ... Controller, 25
... Overload relay, 40 ... Control means.

Claims (1)

[Claims] 1 Ice-making plate 1 for generating ice and water pump 5
A water sprinkling circuit 8 that sprinkles ice-making water onto the ice-making plate 1 by driving the ice-making refrigerant circuit 11 that distributes liquid refrigerant from the compressor 13 to the cooling pipe of the ice-making plate 1; It is equipped with an ice-removing refrigerant circuit 12 that causes hot gas from the compressor 13 to flow through the cooling pipe of the ice-making plate 1 when activated, and during ice-making operation, the ice-making water sprinkled on the ice-making plate 1 is cooled and frozen by a liquid refrigerant. An overload state detection means 25 for detecting an overload state of the compressor 13 in an ice making machine that generates ice and uses hot gas to break ice generated on an ice making plate during ice removal operation; Upon receiving the output of the overload state detection means 25, the compressor 13 is stopped for a predetermined period of time, the ice removal on-off valve 20 is opened, and the water pump 5 is operated to remove the ice from the ice making plate 1. An ice-making machine characterized by comprising a control means 40 for later shifting to ice-making operation.