JP2005076998A - Operation control system of cooling device group - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a trouble in control of a cooling device group resulted from that a regular signal cannot be outputted. <P>SOLUTION: This system comprises three cooling devices 11A-11c installed to a single prefabricated refrigerator 10, in which communication units 30A-30C attached thereto are successively connected through a transmission line 31, so that the operation or the like of all cooling devices 11 is controlled while mutually exchanging signals according to a predetermined rule. Each communication unit 30 can execute a pass mode for transmitting a signal received from the adjacent communication unit 30 to the next communication unit 30 as it is in the state where the operation of the corresponding cooling device 11 is stopped. Accordingly, when operation of a certain cooling device 11 is stopped, no signal for the state of the communication unit 30 concerned is outputted, and the communication is substantially performed between the remaining communication units 30, so that the normal control based on the signals can be performed in at least the remaining cooling devices 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a system for controlling the operation of a plurality of cooling devices.

For example, in a large cooling space such as a large prefabricated refrigerator, a single cabinet is cooled using a plurality of cooling devices (see, for example, Patent Document 1).
An example of the operation is as follows. First, each cooling device individually performs a so-called cooling operation in which the compressor of the cooling device is controlled to be turned on and off based on the detected internal temperature and cooled to the set temperature. In addition, a defrosting operation is performed as appropriate, and this is performed by energizing the heater equipped in the cooler, but when one cooling device performs the opposite operation such as the cooling operation and the other defrosting operation, Since the inside of a store | warehouse | chamber is not cooled or the malfunction that defrosting does not end easily arises, defrosting operation is simultaneously performed by each cooling device. Also, when the defrosting thermistor installed in the cooler detects the predetermined temperature, it is considered that the defrosting has been completed and the operation returns to the cooling operation. There are many places where the temperature is relatively high and there is a place where the temperature is low like the back, and there is a possibility that the timing of completing the defrosting by the cooling device may shift. After waiting to do so, the cooling operation is started again.
For this reason, each cooling device is provided with a communication unit and connected by a transmission line, and the operation of each cooling device is controlled by exchanging signals.

More specifically, if there are three cooling devices, the communication units equipped in each cooling device are connected in series via the transmission line, and each communication unit is sequentially connected from one side to the master, slave, and end. It is said. With respect to the cooling operation, a cooling signal is output from the master and is transmitted to the slave and the end sequentially, whereby each cooling device performs the cooling operation. In the meantime, when one cooling device enters the defrosting operation by a timer or manual switch operation, a defrosting signal is output from the communication unit of that cooling device and transmitted to the other communication unit. The device also enters the defrosting operation.
For the end of defrosting, the communication unit sends the defrosting end signal to the upper communication unit on the condition that the defrosting of the corresponding cooling device itself is completed and the defrosting end signal is received from the lower communication unit. In particular, when the master receives a defrosting end signal, it is guaranteed that the defrosting has been completed by the cooling device corresponding to the slave and end of the slave, and the defrosting of the master cooling device If is completed, defrosting has been completed for all the cooling devices. Then, the master cooling device restarts the cooling operation, and the other cooling devices also receive the cooling signal to restart the cooling operation.
JP 2002-181430 A

By the way, while the control operation as described above is being performed, the user turned off the operation switch and stopped the operation (operation standby state) due to, for example, one cooling device in the defrosting state becoming abnormal. In this case, since the defrosting of the cooling device is stopped, appropriate information, that is, a defrosting end signal cannot be output to another communication unit. If it does so, since it cannot be considered that defrosting was complete | finished with all the cooling devices indefinitely, cooling operation could not be restarted and there existed a possibility of damaging a store thing as a result.
The present invention has been completed against the background described above.

The operation control system of the cooling device group according to the invention of claim 1 is provided with a communication unit in each of a plurality of cooling devices, and each communication unit is connected in series via a transmission line, from one communication unit to another communication unit. The cooling device group is controlled by sequentially transmitting a signal to a predetermined operation in one of the cooling device groups and a predetermined signal is received from an adjacent communication unit. When the predetermined signal is transmitted to the adjacent communication unit as a condition, the communication unit receives the signal received from the adjacent communication unit as it is when the operation of the cooling device is stopped. It is characterized in that the path mode transmitted to the unit can be executed.
According to a second aspect of the present invention, in the first aspect, the predetermined operation is a defrosting operation in each cooling device, and the predetermined signal indicates the end of the defrosting operation. It has the characteristic in that.

  The operation control system of the cooling device group according to the invention of claim 3 is provided with a communication unit in each of the plurality of cooling devices, and transmits each of the pair of connection terminals provided in the communication units to the connection terminal of the adjacent communication unit. Each communication unit is connected in series by connecting via a wire, the communication unit located at the head of those communication units is used as a master unit, and the other communication units are operated as slave units. In a unit that outputs a signal to a unit and sequentially transmits the signal from the slave unit to the next slave unit, whether the signal is input to the connection terminal on the master unit side in each communication unit. A signal input detecting means for determining whether or not the signal is input. It is operated as a slave unit the communication unit if is detected, if the absence of signal input is detected is characterized at operating the communication unit as a master unit.

According to a fourth aspect of the present invention, in the communication unit according to the third aspect, when the communication unit is operating as the master unit and the operation of the cooling device is stopped, the sleep does not output the signal. It is characterized in that the mode can be executed.
According to a fifth aspect of the present invention, in the apparatus according to any one of the first to fourth aspects, the last one of the communication units transmits a signal to a lower-level communication unit that does not exist. It has the characteristics in the place.

<Invention of Claim 1>
The communication unit in which the operation of the cooling device is stopped enters the pass mode, and functions to simply transmit a signal from the adjacent communication unit to the next communication unit. In other words, if there is something that has stopped the operation of the cooling device, communication will be carried out substantially only between the remaining communication units, and at least the remaining cooling device has a normal control based on the signal. Is possible.

<Invention of Claim 2>
For example, when it is controlled so that the cooling operation is resumed only after the defrosting is completed in all the cooling devices, when the operation of one cooling device is stopped, the defrosting end signal is obtained from that cooling device. In other words, the entire cooling device cannot resume the cooling operation.
In that respect, in the present invention, when the operation of one cooling device is stopped, the communication unit of the cooling device is in the pass mode, and the defrosting end signal received from the adjacent communication unit is directly transmitted to the next communication unit. Therefore, if this communication unit is in a state where it has disappeared and all the remaining cooling devices have been defrosted, they can be assembled and the cooling operation can be resumed.

<Invention of Claim 3>
In the case where signals are transmitted sequentially from the master unit to the slave units connected in series below the master unit, for example, when the master unit fails or is removed, there is no signal output from the master unit In this case, the next communication unit can newly operate as a master unit by detecting that there is no signal input from the upper side.

<Invention of Claim 4>
When the master unit and the cooling device corresponding to the master unit are stopped, the master unit does not output a signal when the signal is transmitted sequentially from the master unit to the slave units connected in series below it. It becomes a mode. Then, the next communication unit can newly operate as a master unit by detecting that there is no signal input from the upper side.
<Invention of Claim 5>
In a system that controls a cooling device group by sequentially transmitting signals from a master unit to slave units connected in series below the master unit, when a communication unit is added to the last slave unit, the communication unit is It can immediately operate as a slave unit. Even when the communication unit is not added, a signal is output to the lower communication unit, but the operation of the communication unit itself does not cause a problem.

<Embodiment>
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
In this embodiment, as shown in FIG. 1, three cooling devices 11 are provided for a single prefabricated refrigerator 10. The cooling device 11 includes a compressor 13 as an outdoor unit 12, a condenser with a condenser fan 14, and the like, and also includes a cooler 15 as an indoor unit, and these are circulated and connected through a refrigerant pipe. Yes. From the side close to the door 10A in the figure, the first machine 11A, the second machine 11B, and the third machine 11C are designated. Hereinafter, reference numeral 11 is used to collectively refer to the cooling device 11, and suffixes A, B, and C are added to the reference numeral 11 to distinguish between the first to third machines.

  On the upper surface of the refrigerator 10, a relay box 16 is installed at each position where the cooling devices 11A, 11B, and 11C are arranged, and the main board 17 accommodated in the relay box 16 is cooled as shown in FIG. A control unit 18 composed of a microcomputer for controlling the operation of the apparatus 11 is mounted. On the input side of the control unit 18, an in-compartment thermistor 19 that detects the in-compartment temperature and a defrosting thermistor 20 attached to the cooler 15 are connected. In addition, the compressor 13, the condenser fan 14, the internal fan 21, and the defrost heater 22 attached to the cooler 15 are connected to the output side of the control unit 18. In addition, operation boards 24 are individually connected to the control unit 18.

During the cooling operation of each cooling device 11, as shown in FIG. 3, if the internal temperature detected by the internal thermistor 19 is higher than the set temperature input from the operation board 24, the compressor 13, the condenser The fan 14 and the internal fan 21 are driven, and the cold air generated in the vicinity of the cooler 15 is circulated and cooled in the internal compartment, while when the internal temperature becomes lower than the set temperature, they are stopped, The inside of the cabinet is maintained at a substantially set temperature (lower limit value to upper limit value).
Each cooling device 11 appropriately performs a defrosting operation, which is performed by energizing a defrosting heater 22 provided in the cooler 15 while the compressor 13 and the like are stopped. For this defrosting operation, in order to avoid the opposite operations such as the cooling operation and the defrosting operation between the cooling devices 11, when one unit enters the defrosting operation, all the cooling devices are followed in accordance with it. 11 at the same time.

Further, during the defrosting operation, when it is detected by the defrosting thermistor 20 that the temperature of the cooler 15 has risen to a predetermined level, the energization to the defrosting heater 22 is interrupted, that is, the defrosting operation is terminated, and the cooling operation is performed. Resumed. However, since there is a possibility that the timing of the defrosting ends in each cooling device 11, all the cooling devices 11 wait for the defrosting to end, and then the cooling operation is started again. .
Note that the display unit 25 of the operation board 24 displays a set temperature during the cooling operation and a wording “defrosting operation” during the defrosting operation.

As described above, each cooling device 11 performs a kind of synchronous operation while exchanging information necessary for the operation. Therefore, as shown in FIG. 2, the communication unit 30 is provided for each cooling device 11. And is connected to the control unit 18. Between the OUT terminal of the communication unit 30A of the first unit 11A and the IN terminal of the communication unit 30B of the second unit 11B, and between the OUT terminal of the communication unit 30B of the second unit 11B and the IN terminal of the communication unit 30C of the third unit 11C. Each is connected by a transmission line 31 to exchange information between the communication units 30A to 30C.
Hereinafter, reference numeral 30 is used to collectively refer to communication units, and suffixes A, B, and C are attached to reference numeral 30 to distinguish those equipped in Units 1-3.

The communication system will be described in more detail.
When there are three cooling devices 11 as in this embodiment, the communication units 30 provided in each of them operate in master, slave, and end modes that sequentially form a parent-child relationship.
-Determination of each mode-
Each mode (master, slave, end) is determined by how the transmission line 31 is connected.
(1) When there is no communication unit 30 on the IN side (parent side) and there is a communication unit 30 on the OUT side (child side), it operates in the “master mode”.
Specifically, each communication unit 30 is provided with a signal detection circuit (not shown) that detects the input of a pulse signal to the IN terminal and the OUT terminal, and a predetermined time (for example, 20 seconds) from power-on. If no pulse signal is input to the IN terminal even after the elapse of time, and no pulse signal is input to the OUT terminal (child side) within a predetermined time (for example, 4.5 seconds) after outputting the pulse signal from the OUT terminal Since it can be determined that there is no parent but a child, it operates in “master mode”.

(2) When the communication unit 30 is on the IN side (parent side) and the OUT side (child side), it operates in the “slave mode”.
Specifically, a pulse signal is input to the IN terminal within a predetermined time (for example, 20 seconds) after the power is turned on, and the OUT signal is output within a predetermined time (for example, 4.5 seconds) after the pulse signal is output from the OUT terminal. When a pulse signal is input to the terminal (child side), it can be determined that there are a parent and a child, and therefore, it operates in “slave mode”.
(3) When the communication unit 30 is on the IN side (parent side) and the communication unit 30 is not on the OUT side (child side), the operation is performed in the “end mode”.
Specifically, a pulse signal is input to the IN terminal (parent side) within a predetermined time (for example, 20 seconds) after power is turned on, and after a pulse signal is output from the OUT terminal (child side), the predetermined time (for example, If a pulse signal is not input to the OUT terminal (child side) within 4.5 seconds), it can be determined that there is a parent but no child, so the operation is performed in the “end mode”.
As described above, in the case of FIG. 2, the communication unit 30A of the first machine 11A is in the master mode, the communication unit 30B of the second machine 11B is in the slave mode, and the communication unit 30C of the third machine 11C is in the end mode. In the following, the communication units 30A to 30C and the cooling devices 11A to 11C corresponding to the communication units 30A to 30C may be collectively referred to as a master, a slave, and an end, respectively.

[Normal mode]
First, a case where the entire cooling device 11 is in a normal operation, that is, a case where the communication operation mode is the normal mode will be described.
-Communication method-
Information necessary for operation is exchanged by communication pulses. There are three types of communication pulses used in this embodiment as shown in FIG.
(a) Cooling pulse (pulse width 1 second): Output when the cooling device 11 is in the cooling operation.
(b) Defrosting pulse (pulse width 3 seconds): Output when the cooling device 11 is in the defrosting operation.
(c) Defrosting end pulse (pulse width 2 seconds): Output in a state where the defrosting operation of the cooling device 11 is completed.

The basic exchange of communication pulses (the above-described three types of pulse signals) will be described with reference to FIG.
(1) The master sends a pulse signal indicating the operating state of the cooling device 11A to which it is connected, for example, every 20 seconds from the OUT terminal to the child (slave) (this is referred to as a pulse signal “A”).
(2) When the slave receives the pulse signal “A” from the parent (master), the pulse signal “I” indicating the operating state of the cooling device 11B to which the slave is connected from the IN terminal to the parent (master) after 4 seconds, for example. At the same time, the pulse signal “c” is sent from the OUT terminal to the child (end). “I” and “U” are the same pulse signal. Therefore, the parent (master) outputs the pulse signal “A”, and 4 seconds later, receives the pulse signal “I” from the child (slave) to the OUT terminal.
(3) When the end receives the pulse signal “c” from the parent (slave) to the IN terminal, the pulse signal indicating the operating state of the cooling device 11C to which the terminal is connected from the IN terminal to the parent (slave) after 4 seconds. At the same time, the pulse signal “o” is sent from the OUT terminal to the child (not existing). “D” and “O” are the same pulse signal. Therefore, the parent (slave) outputs the pulse signal “c”, and receives the pulse signal “d” from the child (end) 4 seconds later.
It should be noted that the pulse signal is sent to the non-existent child because, when another communication unit 30 is added together with the cooling device 11 below the end, the communication unit 30 receives a pulse of “O”, This is for recognizing that there is a parent.
As described above, information is repeatedly transmitted in the order of (1) → (2) → (3) → (1) → (2) →.

-Operation-
Subsequently, the operation will be described.
A. During cooling operation As shown in FIG. 6, the master, slave, and end are all sending cooling pulses.
Specifically, as shown in FIG. 16, the master sends a cooling pulse a (a) from the OUT terminal to the slave as “its own state” every 20 seconds.
When the slave receives the cooling pulse a (A) from the parent (master) to the IN terminal, after 4 seconds, the slave returns the cooling pulse a (I) as the “own state” from the IN terminal to the parent (master). Similarly, a cooling pulse a (c) as “your state” is sent from the OUT terminal to the child (end).
Upon receiving the cooling pulse a (c) from the parent (slave) to the IN terminal, the end returns the cooling pulse a (d) as “your state” from the IN terminal to the parent (slave) after 4 seconds. Similarly, the cooling pulse a (v) as “my state” is sent to the child (absence).

B. Defrosting operation When any one of the master, the slave, and the end enters the defrosting operation, as described later, a defrosting pulse is transmitted centering on one of them, and all the cooling devices 11 enter the defrosting operation. The timing at which each cooling device 11 enters the defrosting operation is as follows.
When the master receives a defrosting start signal from the defrosting switch 26 of its own operation board 24 during the cooling operation or by an instruction of the all-day timer, or when receiving a defrosting pulse twice from the child (slave), The cooling operation is switched to the defrosting operation, and the “own state” flag is set to “defrosting operation”.
When the slave receives a defrost start signal from the defrost switch 26 of its own operation board 24 during the cooling operation or by an instruction of the all-day timer, or continuously from the parent (master) or child (end) When it is received twice, it switches to the defrosting operation in the same manner, and the “own state” flag is set to “during defrosting operation”.
The end receives a defrosting start signal from the defrosting switch 26 of its own operation board 24 during the cooling operation or when it receives a defrosting start signal in response to an instruction from the all-day timer, or receives two consecutive defrosting pulses from the parent (slave). Then, the mode is switched to the defrosting operation, and the “own state” flag is set to “during defrosting operation”.

A case where the defrosting operation is started from the end will be described with reference to FIG.
As soon as the end receives the defrosting start signal, it switches to the defrosting operation. After that, when receiving a cooling pulse a from the slave (during cooling operation) to the IN terminal, 4 seconds later, the defrosting pulse b, which is its own operating state, is returned from the IN terminal to the slave, and at the same time a child (absent) ) To send the defrost pulse b. At this time, since the slave has only received the defrost pulse b once, it remains in the cooling operation. In the next cycle, when the end receives the cooling pulse a from the slave, the defrosting pulse b is returned to the slave after 4 seconds. Thereby, since the slave has received the defrost pulse b twice continuously, it switches from cooling operation to defrost operation.
In the next cycle, when the slave receives a cooling pulse a from the master (during cooling operation) to the IN terminal, 4 seconds later, the defrost pulse b, which is its own operating state, is returned from the IN terminal to the master, and at the same time OUT A defrost pulse b is sent from the terminal to the end. Since the master has only received the defrost pulse b once, it remains in the cooling operation. In the next cycle, when the slave receives the cooling pulse a from the master, the defrosting pulse b is returned to the master after 4 seconds. Thereby, since the master has received the defrost pulse b twice continuously, it switches from cooling operation to defrost operation.
In short, when entering the defrost from the end, as schematically shown in FIG. 9, the defrost pulse is transmitted from the end to the slave to the master.
When defrosting is started from the master, the defrosting pulse is transmitted from master to slave to end as schematically shown in FIG.
When entering the defrosting from the slave, the defrosting pulse is transmitted simultaneously from the slave to the master and the end as schematically shown in FIG.

C. Defrosting is completed Defrosting is not considered until the master, slave, and end are all defrosted. After that, a cooling pulse is sent from the master to the child (slave, end), and all the cooling devices 11 resume the cooling operation.
Specifically, when the end of the defrosting is completed, the end sets “own state” to “defrosting completed” and sends a defrosting end pulse to the parent (slave) unconditionally.
On the condition that the slave has completed the defrosting and has received two consecutive defrosting end pulses from the child (end), the slave sets “My State” to “Defrosting End” and sends the defrosting end pulse. Send to parent (master).
On the condition that the master has completed the defrosting and has received two consecutive defrosting pulses from the child (slave), the master returns his operation to the cooling operation and sets the “own state” flag to “cooling operation”. Set to “Medium”.

As an example, the case where the slave defrosts first, the end ends, and finally the master ends will be described with reference to FIG. 10 and FIG. 18 showing details.
(1) The slave defrosted first, but the child (end) has not finished defrosting, and the defrosting end pulse c does not come from the child (end) to the OUT terminal. It does not end. Therefore, the defrost pulse b is output from the IN terminal and OUT terminal of the slave.
(2) Thereafter, when the end of the defrosting is completed, a defrosting end pulse c is sent from the IN terminal to the parent (slave).
(3) The slave receives the defrosting end pulse b from the child (end) twice including the next cycle, and has also completed the defrosting. Therefore, in the next cycle, the slave (from the IN terminal) The defrosting end pulse c is sent to the master).
Even if the master receives the defrosting end pulse c twice continuously from the child (slave) including the next cycle, the master does not end the defrosting as long as the master has not finished the defrosting.
(4) After that, the master completes the defrosting and has received the defrosting completion pulse c from the child (slave) twice in succession, so that all the cooling devices 11 consider the defrosting complete and shift to the cooling operation by themselves. The cooling pulse a is sent from the OUT terminal to the child (slave).
(5) When the slave receives the cooling pulse a from the parent (master) to the IN terminal twice, including the next cycle, the slave shifts to the cooling operation and also sends the cooling pulse a from the OUT terminal to the child (end). send.
(6) When the end receives the cooling pulse a twice from the parent (slave) to the IN terminal including the next cycle, the end shifts to the cooling operation.

[Pass mode]
Now, when all the cooling devices 11 are in normal operation, that is, in the normal mode, as described above, when one cooling device 11 in the defrosting state is abnormal, When the user turns off the operation switch 27 (see FIG. 1) and stops the operation (operation standby state), the cooling device 11 stops in the defrosting state, so that appropriate information, that is, a defrosting end signal is sent to another communication unit. 30. Since it cannot be considered that defrosting has been completed in all the cooling devices 11 at any time, there is a possibility that the cooling operation cannot be resumed.
As a countermeasure, in the present embodiment, the communication unit 30 provided in the cooling device 11 whose operation is stopped can execute the “pass mode”.

Hereinafter, this pass mode will be described.
-Overview-
In short, the pass mode is to transmit the communication pulse as it is to the next communication unit 30 when it receives a communication pulse from the adjacent communication unit 30, and it appears as if the existence of oneself has disappeared. This prevents the state of the user from affecting other communication units 30.
Strictly speaking, when the operation of the corresponding cooling device 11 is stopped, the master is in a state in which no communication pulse is issued, and rather it should be referred to as a sleep mode. Since it is the same as the pass mode in that it has no effect, it may be treated as a kind of pass mode in the following description as appropriate.

In each cooling device 11, switching between the normal mode and the pass mode is performed as follows.
The operation switch 27 provided on each operation board 24 is a momentary switch. As shown in FIG. 11, when the power is turned on, the operation mode is first set to “pass mode”, and the operation switch 27 is turned on. Then, the cooling device 11 is normally operated, and the operation mode is set to the “normal mode”. When the operation switch 27 is turned on during normal operation, the operation is stopped (operation standby state) and the operation mode is set to the “pass mode”.

Specifically, regarding each communication unit 30, when the master enters the pass mode, no communication pulse is issued (sleep mode).
In the slave, the communication pulse from the parent (master) is sent to the child (end) as it is, and the communication pulse from the child (end) is sent to the parent (master) as it is.
At the end, when a communication pulse is received from the parent (slave), it is sent to the child (absence) as it is.

-Outline operation-
An example in which the operation switch 27 is turned off by the slave and returned to the operation standby state will be described with reference to FIG.
(1) The master sends a pulse signal “A” indicating the operating state of the cooling device 11A to which it is connected, for example, every 20 seconds from the OUT terminal to the child (slave).
(2) When the slave receives the pulse signal “A” from the parent (master), the slave passes through itself and sends it directly from the OUT terminal to the child (end).
(3) The end receives the pulse signal “A” from the parent (slave), and simultaneously receives the pulse signal “D” from the IN terminal to the parent (slave) and the pulse signal “O” from the OUT terminal to the child (absence). send.
(4) The slave sends the pulse signal “d” received from the child (end) to the OUT terminal as it is to the parent (master).
Therefore, (1) → (2) → (3) → (4) → (1) → (2) →...
As a result, the slave's own pulse signals “I” and “U” (see FIG. 5) do not exist, and in short, the pulse signal “A” from the master passes through the slave and is transmitted to the end. The pulse of the pulse signal “D” is also transmitted to the master through the slave.
As a result, it is possible to make the slave appear to disappear, and such an operation becomes the “pass mode”.

-Example of specific operation-
Hereinafter, the operation when the operation switch 27 is turned off during defrosting for each of the master, the slave, and the end will be described.
A. First, a case where the end operation switch 27 is turned off will be described with reference to FIG. 15 and FIG. 19 showing details.
(1) Three units are defrosting.
(2) When the end operation switch 27 is turned off, the end becomes the pass mode. The end passes through the defrost pulse b received from the parent (slave) to the IN terminal and sends it to the child (absence) from the OUT terminal. On the other hand, since there is no child at the end, a pulse signal does not come from the child, so a pulse signal is not sent to the parent (slave).
(3) Since the slave does not receive a pulse signal from the child, the mode is switched to the end (hereinafter referred to as “new end”). Since the defrosting of the new end has been completed, the defrosting end pulse c is output 4 seconds after receiving the pulse signal (defrosting pulse b) from the parent (master) next time and the parent terminal is connected to the parent terminal from the IN terminal. Return to (Master). The defrosting end pulse c is also sent to the old end, but it is not effective.
(4) When the master has completed the defrosting and has received two consecutive defrosting pulses from the child (new end), it considers that all the cooling devices 11 have completed the defrosting and cooling The pulse a is sent to the child (new end), and the cooling operation is started.
(5) When the new end receives the cooling pulse a from the parent (master) twice in succession, the new end shifts to the cooling operation.

B. Next, a case where the master operation switch 27 is turned off will be described with reference to FIG.
(1) Three units are defrosting.
(2) When the master operation switch 27 is turned off, the master enters the pass mode (sleep mode) and does not send a pulse signal to the child.
(3) Since the slave does not receive a pulse signal from the parent even after a lapse of a predetermined time (20 seconds), the mode is switched to the master (hereinafter referred to as “new master”). The new master sends a defrost pulse to the child (end).
(4) When the new master completes the defrosting and receives the defrosting end pulse from the child (end) (twice), the new master considers that all the cooling devices 11 have completed the defrosting, and sends the cooling pulse to the child (end). ) And shift to cooling operation.
(5) When the end receives a cooling pulse from the parent (new master) (twice), the end shifts to the cooling operation.

C. A case where the slave operation switch 27 is turned off will be described with reference to FIG.
(1) Three units are defrosting.
(2) When the slave operation switch 27 is turned off, the slave enters the pass mode. The slave sends the defrost pulse of the parent (master) through itself to the child (end). When the child (end) finishes defrosting, a defrosting end pulse from the child (end) is passed through and sent to the parent (master).
(3) When the master completes the defrosting and receives the defrosting end pulse from the slave (slave) (twice), the master regards that all the cooling devices 11 have completed the defrosting, and sends the cooling pulse to the child ( (Slave) to move to cooling operation.
(4) When the end receives the cooling pulse from the parent (slave) (twice), the end shifts to the cooling operation.

As described above, according to the present embodiment, when the cooling device 11 is brought into the operation stop state during the defrosting, the communication unit 30 corresponding to the cooling device 11 is set to the pass mode, and the communication is substantially performed. It will be performed only between the communication units 30 of the other cooling devices 11, and if all these remaining cooling devices 11 have been defrosted, at least they can be aligned and the cooling operation can be resumed, It can be prevented before it hurts.
If the master enters the pass mode (sleep mode), the next slave replaces the new master and transmits a cooling pulse, so that the cooling operation in the remaining cooling devices 11 is resumed without any problem.

  In this embodiment, when each communication unit 30 is set to the pass mode, the cooling device 11 such as the corresponding compressor 13 is not energized, but the control unit 18 is energized unchanged. Even during the pass mode, the abnormal temperature detection and the disconnection detection by the internal thermistor 19 and the defrosting thermistor 20 are functioning, and the abnormality is reliably detected.

<Related technologies>
In the said embodiment, the example which installed the three cooling devices 11 in the prefabricated refrigerator 10 was shown. As described above, each cooling device 11 is provided with the operation board 24 so that the set temperature can be inputted and the internal temperature detected by the internal thermistor 19 is displayed on the display unit 25. It has become.
On the other hand, in such a large prefabricated refrigerator, the temperature in the refrigerator inevitably varies depending on the location in the refrigerator. For example, in the vicinity of the door 11, there is a large amount of heat penetration, the temperature is relatively high, and the depth tends to be low.
For this reason, for example, it has been pointed out that the user is confused when the set temperatures are the same in all the cooling devices 11 but different internal temperatures are displayed.

Therefore, the master displays the internal temperature detected by the internal thermistor 19 associated with its own cooling device 11 on the display unit 25 of the operation board 24, but goes off when the slave, end, and pass modes are entered. Alternatively, a character that is not a temperature, for example, “-” is displayed on the display unit 25.
As described in the above embodiment, when the master enters the pass mode, the next child (slave) becomes the new master, so only this new master displays the internal temperature.
Therefore, when the user confirms the internal temperature, it is easy and easy to understand because only one unit needs to be viewed. Moreover, since it displays only with one, it can contribute to power saving. For each operation board 24, it is possible to save the trouble of setting whether or not to display.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) In the above embodiment, the case where the number of cooling devices and communication units is three is exemplified, but two or four or more may be used.
(2) As a form for controlling a plurality of cooling devices based on signals, in addition to the above-described embodiment, for example, the set temperature of the internal temperature changed by a certain unit is transmitted to another, or is reset, or In the case where a failure occurs in one unit, such control as informing the other of the unit and performing any processing is conceivable. In such a case, the present invention can be similarly applied.

The front view of the prefabricated storehouse concerning one embodiment of the present invention. Block diagram showing configurations of cooling device and communication system Graph showing chamber temperature control Waveform diagram of various pulses Simple model diagram showing communication method in normal mode Simplified model of communication status during cooling operation Simple model diagram of communication status when entering defrosting operation from master Simplified model diagram of communication status when entering defrosting operation from slave Simple model diagram of communication status when entering defrosting operation from end Simplified model diagram of communication status when defrosting is finished and cooling operation is restarted Flow chart showing operation mode switching procedure Simple model diagram showing the communication method in pass mode Simplified model diagram of communication status when master is in pass mode Simplified model diagram of communication status when slave is in pass mode Simplified model of communication status when end is in pass mode Timing chart when all cooling devices are in cooling operation Timing chart when entering defrosting from the end Timing chart when defrosting is completed in normal mode and cooling operation is started Timing chart when the end is in the pass mode during defrosting and the other switches to cooling operation

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Prefabricated refrigerator 11, 11A, 11B, 11C ... Cooling device 13 ... Compressor 15 ... Cooler 18 ... Control part 19 ... Inside thermistor 20 ... Defrosting thermistor 21 ... Inside fan 22 ... Defrosting heater 24 ... Operation board 26 ... Defrost switch 27 ... Operation switch 30, 30A, 30B, 30C ... Communication unit 31 ... Transmission line a ... Cooling pulse b ... Defrost pulse c ... Defrost end pulse

Claims (5)

A communication unit is provided in each of a plurality of cooling devices, each communication unit is connected in series via a transmission line, and the cooling device group is controlled by sequentially transmitting a signal from one communication unit to another communication unit. The predetermined signal is transmitted to the adjacent communication unit on the condition that the predetermined operation is completed in any of the cooling device groups and the predetermined signal is received from the adjacent communication unit. In what
The cooling unit group, wherein the communication unit is capable of executing a pass mode in which a signal received from an adjacent communication unit is directly transmitted to the next communication unit in a state where the operation of the cooling device is stopped. Operation control system. 2. The cooling device group according to claim 1, wherein the predetermined operation is a defrosting operation in each cooling device, and the predetermined signal is a defrosting end signal indicating the end of the defrosting operation. Operation control system. Each cooling unit is provided with a communication unit, and each communication unit is connected in series by connecting each of a pair of connection terminals provided in those communication units to a connection terminal of an adjacent communication unit via a transmission line, The communication unit at the head of those communication units is used as a master unit, the other communication units are operated as slave units, a signal is output from the master unit to the next slave unit, and from that slave unit to the next slave unit. In what is to transmit the signal sequentially,
Each communication unit is provided with signal input detection means for determining whether or not the signal is input to the connection terminal on the master unit side, and when the signal input detection means detects that there is a signal input And operating the communication unit as a slave unit, and when it is detected that there is no signal input, the communication unit is operated as a master unit. 4. The communication unit is capable of executing a sleep mode in which the signal is not output when the operation of the cooling device is stopped when the communication unit is operating as the master unit. The operation control system of the described cooling device group. 5. The cooling device group according to claim 1, wherein the last one of the communication units is configured to transmit a signal to a lower-order communication unit that does not exist. Operation control system.

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