JPH0537174Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is an automatic ice maker equipped with an air-cooled condenser that can reliably detect clogging of the condenser even when the outside temperature fluctuates, thereby reducing ice-making capacity. This invention relates to a detection device that can effectively prevent this.

BACKGROUND ART Automatic ice making machines for continuously producing large numbers of ice cubes, ice sheets, and other ice shapes of various shapes are suitably used depending on their purpose. For example, a large number of ice-making compartments defined in the ice-making compartment and open downwards are closed by a water tray so that they can be opened and closed, and ice-making water is injected from the water tray to gradually pour ice cubes into the ice-making compartments. There are so-called closed-cell type ice-making machines that form ice cubes, and so-called open-cell type ice-making machines that directly supply ice-making water to a number of ice-making chambers that open downward, without going through a water tray, and form ice cubes in the chambers. 2. Description of the Related Art Drop-down ice making machines are widely used in which an ice making plate is arranged at an angle, and ice making water is supplied flowing down onto the front or back side of the ice making plate to form ice sheets on the surface of the ice making plate.

These automatic ice making machines generally include an ice making mechanism above the machine body and a refrigeration system below the machine body that cools the ice making section of the ice making mechanism, and the refrigeration system includes:
It consists of various parts such as a compressor, condenser, capillary reach tube, and evaporator. The evaporator is
The ice is extracted from the refrigeration system and placed in the ice making section of the ice making mechanism, and ice having a desired shape is generated by circulating and supplying ice making water to the ice making section. When the ice has grown to a predetermined size, the ice-making completion detection device detects this and stops the supply of ice-making, and switches the valve body to supply high-temperature refrigerant gas from the compressor to the evaporator to start the ice-making section. heat up. As a result, the ice produced in the ice making section falls under its own weight and is collected and stored in a stocker located below. As a refrigeration system condenser,
Generally, a fin-and-tube type is used, and the condenser is forcedly air-cooled by a cooling fan.

Further, the following method is generally used to detect the completion of the ice-making operation. That is, it is monitored by a temperature detection device such as a thermostat that converts a temperature change when ice-making water freezes into an electrical resistance change, and a predetermined temperature drop in the ice-making section is detected to determine the end of the ice-making operation. Alternatively, the time required from the start to the end of ice making is determined experimentally, this time is set in advance in a timer, and the completion of the ice making operation is detected by the time-up of the set time limit. Furthermore, the above may be used in combination.

Problems that the invention aims to solve In the ice maker equipped with the air-cooled condenser mentioned above,
An air suction port and a discharge port are provided at the bottom of the casing, and the air sucked in from the suction port by the rotation of a cooling fan installed inside the casing comes into contact with a condenser and is cooled by heat exchange. The air whose temperature has increased is discharged to the outside through the discharge port. In this case,
Dust is also sucked into the housing along with air, but if this dust adheres to the condenser and grows over time, it reduces heat exchange efficiency and causes failures due to overheating and the like. Therefore, the air sucked in by the cooling fan needs to be purified to remove as much dust as possible from the air before it comes into contact with the condenser. A configuration in which a collection filter is attached is generally adopted.

Since the filter gradually becomes clogged with the collected dust, it is necessary to periodically replace or clean the filter. Furthermore, even if a filter is installed, clogging of the condenser cannot be completely prevented, and as mentioned above, dust will accumulate on the condenser over time, reducing heat exchange efficiency and reducing power consumption due to this. There was a problem in that it not only led to waste, but also reduced Nissan's ice making capacity.

Therefore, we installed a condenser clogging detection device in the ice maker, and in order to prevent the ice maker from continuing to operate with a clogged condenser, we installed an alarm system to prevent the operation from continuing. The system makes the person aware that the condenser is clogged, and then stops the operation of the ice maker and cleans the filter and condenser. An example of this detection device is to install a high-pressure switch in the refrigerant circuit, detect the pressure in the condenser (if the temperature of the liquefied refrigerant increases due to insufficient cooling, the pressure in the condenser will increase), and activate an alarm device. There is something that makes me Also,
A device has also been proposed in which a temperature sensor is installed in the refrigerant pipe on the outlet side of the condenser, and the surface temperature of the refrigerant pipe is detected by the sensor, and an alarm device is activated when the surface temperature of the refrigerant pipe reaches a predetermined value. .

However, the former method had the disadvantage that when the outside temperature temporarily rose, the temperature of the liquefied refrigerant would rise, causing the high-pressure switch to malfunction. Furthermore, in the latter method, a problem has been pointed out that accurate detection cannot be performed because the temperature sensor is easily affected by changes in the outside temperature. In other words, when the outside air temperature is low, even though the refrigerant temperature rises due to clogging of the condenser, the clogging condition is not detected and operation continues with reduced cooling capacity. There was a problem. Furthermore, as the outside temperature increases,
On the other hand, even if the condenser was not clogged, a rise in outside temperature could cause the alarm system to malfunction.

Purpose of the Invention The present invention was proposed in order to suitably solve the above-mentioned drawbacks inherent in various clogging detection means in conventional condensers. It is an object of the present invention to provide a means that can reliably detect clogging of a condenser without being affected.

Means for Solving the Problems In order to overcome the above-mentioned problems and achieve the intended purpose, the present invention provides an ice-making compartment equipped with an evaporator connected to a refrigeration system equipped with an air-cooled condenser; a temperature detection device that detects a predetermined temperature drop and outputs an ice-making completion signal, and a timer device that outputs an ice-making completion signal when a predetermined time has elapsed from the start of ice making, the temperature detection device and the timer device In an automatic ice maker that is controlled to switch from ice making operation to deicing operation in response to an ice making completion signal from On the condition that the switching operation from ice-making operation to de-icing operation has been repeated a predetermined number of times,
It is characterized by being configured to issue a required alarm.

Embodiments Next, a preferred embodiment of the condenser clogging detection device according to the present invention will be described below with reference to the accompanying drawings. Although the present invention will be explained using an example of an automatic ice making machine as an example of an ice making machine in which the present invention is suitably implemented, the present invention is not limited to the ice making method shown in the embodiments. It can also be applied to ice-making machines that employ ice-making methods such as the open-cell method and the flowing-down method.

FIG. 1 shows an example of an automatic ice maker in which the present invention is suitably implemented. This automatic ice-making machine includes an ice-making chamber 1 defining a large number of ice-making compartments 2 that open downward, and an evaporator 3 connected to a refrigeration system is disposed on the outer upper surface of the ice-making chamber 1. Further, a water tray 4 is tiltably disposed below the ice-making chamber 1, and normally closes the ice-making chamber 2 horizontally from below. The water tray 4 is pivotally supported at one end by a shaft (not shown), and is forcibly tilted by an actuator to open the ice making chamber 2 during deicing operation. A distribution pipe 6 for supplying ice-making water to each ice-making compartment 2 is provided on the lower surface of the water tray 4, and an ice-making water tank 5 is further provided below the water tray 4. A required amount of ice-making water necessary for one ice-making cycle is supplied and stored in this tank 5 from an external water supply system 10 via a water supply valve WV.

The water in the ice-making water tank 5 is sent from the bottom to the distribution pipe 6 via the water supply pipe 11 and the pump PM, and from the numerous fountain holes 7 formed in the water tray 4 corresponding to each of the ice-making compartments 2. It is injected into the ice making compartment 2. A part of this ice-making water freezes on the inner wall surface of each ice-making compartment 2, and the water that has not yet frozen is left in the water tray 4.
The ice water is then returned to the ice-making water tank 5 through a drainage hole 9 formed adjacent to the fountain hole 7. By circulating ice-making water through the ice-making water supply system 8 having this configuration, ice is gradually grown in layers within the ice-making chamber 1.

On the outer surface of the ice-making compartment 1, there is a temperature detection device consisting of a temperature sensing element such as a thermostat or a thermistor.
Th ₁ is closely placed. This temperature sensing device
Th ₁ detects the temperature of the ice making compartment 1, and indicates that the ice has grown sufficiently in the ice making compartment 2.
When the temperature drops, the temperature detection device _Th1 is activated to end the ice making operation and shift to the deicing operation.

FIG. 2 shows a schematic configuration of the refrigeration system. The refrigerant gas compressed by the compressor 20 is condensed and liquefied by the condenser 21, dehumidified by the dryer 22, and then decompressed by the capillary reach tube 23.
Freezing is performed in each ice making compartment 2 by evaporating in the evaporator 3 disposed on the outer upper surface of the ice making compartment 1 and exchanging heat with ice making water supplied from a fountain into each ice making compartment 2. . The refrigerant that has evaporated and vaporized in the evaporator 3 and the liquid refrigerant that has not been completely evaporated flow into the accumulator 24 in a gas-liquid mixed phase state, where the gas-phase refrigerant and liquid-phase refrigerant are separated, and the gas-phase refrigerant is passed through the suction pipe. The liquid refrigerant is returned to the compressor 20 via the refrigerant 25 and stored in the accumulator 24. In addition, the symbols in Figure 2
FM indicates a fan motor for the condenser 21.

Further, a hot gas pipe 26 branched from the discharge side of the compressor 20 is connected to the evaporator 3 via a hot gas valve HV.
The high-temperature refrigerant discharged from the compressor 20 during deicing flows into the evaporator 3 from the hot gas pipe 26 through the hot gas valve HV, warms the ice making chamber 1, and flows into each ice making compartment 2. The surrounding surface of the generated ice blocks is heated, and each ice block is caused to fall under its own weight.
The high-temperature refrigerant flowing out of the evaporator 3 flows into the accumulator 24, heats and evaporates the liquid phase refrigerant staying in the accumulator 24, and returns it to the compressor 20 from the suction pipe 25 as a gas phase refrigerant.

FIG. 3 shows an example of the electric control circuit of the automatic ice maker according to this embodiment. In this figure, various electrical equipment and parts are connected between power supply line A and power supply line B. A control device 27 having a built-in microcomputer for controlling operations such as the like is connected. Also, between this control device 27 and the power supply line B, a compressor CM and a condenser 2 are connected.
1 cooling fan motor FM, ice making water circulation pump motor PM, water supply valve WV, hot gas valve HV,
Actuator motor that tilts and returns the water tray 4
AMs are connected in parallel.

Further, the temperature detection device Th ₁ and the outside temperature detection device Th ₂ are connected to the control device 27, and based on the detected temperature of the outside temperature detection device Th ₂ , the set time limit of the timer device T, which will be described later, is determined based on the change in outside temperature. It is configured to adjust in response to the That is, the control device 27 has previously inputted data determined through experiments etc. (see Fig. 5), compares this data with the newly inputted outside temperature, and sends the data to the timer T. A time limit is set.

Further, a timer device T and an alarm lamp L are connected to the control device 27. The set time limit of this timer device T is set longer than the ice making time when normal ice making operation is performed, and when the set time limit expires from the start of energization, an ice making completion signal is output. That is, when normal ice-making operation is being performed, control for switching from ice-making operation to de-icing operation is performed based on the output of the ice-making completion signal from the temperature detection device _Th1 . The control device 27 is configured to determine whether the output signal is from the temperature sensing device _Th1 or the timer device T, and to count the number of times the determination is made. As will be described later, the alarm lamp L is set to be activated when the operation has been switched a predetermined number of times in succession based on an output signal from the timer T (see FIG. 3).

Operation of the embodiment Next, the operation of the automatic ice maker according to the embodiment described above will be explained. First, the automatic ice maker is powered on (the power switch is not shown). At the same time as the power is turned on, compressor (CM) 20, fan motor FM
Then, power is started to be applied to the pump motor PM and ice making operation begins. As a result, the refrigerant circulation and ice-making water circulation described with reference to FIGS. 1 and 2 are performed, and the temperatures of the ice-making water and the ice-making chamber 1 gradually decrease. When the ice-making operation is normal, the temperature of the ice-making water becomes 0° C. after the required time has elapsed from the start of ice-making, and ice begins to grow in the ice-making chamber 1. Note that the timer device T starts integrating its set time period at the same time as the power is turned on.

When ice making is completed, the temperature detection device Th ₁ detects a predetermined temperature drop in the ice making chamber 1, and the power supply to the fan motor FM and pump motor PM is stopped.
Actuator motor AM is energized and the deicing operation begins. This actuator motor AM
As the water tray 4 and ice-making water tank 5 rotate, the water tray 4 and the ice-making water tank 5 are tilted, and the water supply valve WV is opened, and water at room temperature is newly supplied to the tank 5 from the external water supply system, and the hot gas valve HV is also switched to the evaporator 3. Hot gas is supplied to the ice, which facilitates deicing.
Furthermore, when switching from ice making operation to deicing operation,
Said timer device T is cleared.

When the ice in the ice-making compartment 2 falls due to its own weight, the temperature of the ice-making compartment 1 rises, and when a detection device (not shown) detects the completion of ice removal, the actuator motor AM is reversed and the water tray is removed. 4 returns to the horizontal position and starts ice making operation again. By repeating the above-described operations, a predetermined amount of ice is stored in the ice storage (not shown).

If the condenser 21 becomes clogged, the temperature of the refrigerant increases due to insufficient cooling of the liquefied refrigerant in the condenser 21, and the rate at which ice cubes are produced in the ice making compartment 1 slows down. In other words, the ice making compartment 1 is a temperature detection device.
It takes longer than normal to reach the detected temperature of Th ₁ , and before the temperature detection device Th ₁ outputs the ice making completion signal, the timer device T times out, and the ice making of this timer device T is completed. The signal shifts from ice making operation to deicing operation.

As described above, when the heat exchange efficiency decreases due to clogging of the condenser 21, the ice making time becomes longer and the control to shift from the ice making operation to the deicing operation is performed by the ice making completion signal of the timer device T. Become so. Further, the control device 27, as described above,
It is configured to determine whether the output signal is from the temperature detection device _Th1 or the timer device T, and to count the output signal. Then, when the operation is switched a predetermined number of times (for example, three times) in succession based on the ice-making completion signal from the timer device T,
The control device 27 operates the alarm lamp L to visually notify the user of the occurrence of clogging in the condenser 21. In addition, a warning sound means such as a buzzer is installed,
It may be operated simultaneously with the alarm lamp L so that the user is also alerted by hearing.

Note that if the ice making time becomes longer due to a temporary rise in outside temperature and the operation is switched by the ice making completion signal from the timer device T, the warning device will not activate unless this control is continued for a predetermined number of times doesn't work. Therefore, malfunctions caused by mere changes in outside temperature can be effectively prevented.

Effects of the Invention As explained above, the condenser clogging detection device according to the present invention distinguishes the signals input from the temperature detection device and the timer device that detect the completion of ice making, and
This system is designed to warn of clogging of the condenser when the operation is continuously switched based on a signal from the timer device. Further, since the timer device automatically adjusts its set time period according to changes in outside temperature, accurate clogging detection can be performed without being affected by changes in outside temperature. Furthermore, since the alarm device is activated, it is possible to prevent wasted power consumption and a decrease in ice making capacity.

[Brief explanation of the drawing]

The drawings show a preferred embodiment of the condenser clogging detection device according to the present invention, and FIG. 2 is a refrigeration system diagram of the automatic ice maker according to the embodiment, FIG. 3 is an electrical control circuit diagram of the automatic ice maker according to the embodiment, FIG. 4 is a flowchart of the detection device according to the embodiment, and FIG. 5 is a graph showing the relationship between the set time of the timer device and the outside temperature. 1...Ice making room, 3...Evaporator, 21...Condenser, _Th1 ...Temperature detection device, T...Timer device,
L...Alarm device.

Claims (1)

[Scope of Claim for Utility Model Registration] [1] An ice-making compartment 1 equipped with an evaporator 3 connected to a refrigeration system equipped with an air-cooled condenser 21, and an ice-making completion signal detected by detecting a predetermined temperature drop in the ice-making compartment 1. and a timer device T that outputs _an ice-making completion signal when a predetermined time elapses from the start of ice-making _.
In an automatic ice maker that is controlled to switch from ice making operation to deicing operation in response to an ice making completion signal from either of the timer device T and the timer device T, prior to the output of the ice making completion signal by the temperature detection device Th ₁ , the timer device T A condenser clogging detection device characterized in that it is configured to issue a required alarm on condition that an ice-making completion signal is output and the switching operation from ice-making operation to de-icing operation is performed a predetermined number of times in succession. . [2] The timer device T is an outside temperature detection device
The condenser clogging detection device according to claim 1, wherein the set time period is automatically changed based on the detected temperature of _Th2 .