JPS648266B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an energy saving system for a refrigerated product vending machine. The present invention relates in particular to a control circuit for a refrigeration system of conventionally known construction for vending machines dispensing chilled articles such as canned or bottled soft drinks.

Until now, in vending machine refrigeration systems that included a compressor/condenser, evaporator coil, and evaporator fan, the compressor was operated repeatedly between ON and OFF under the control of a thermostat, and air was passed through the evaporator coil for cooling. The compressor of the evaporation fan that circulates air inside the vending machine is turned off.
It was operated continuously even during the period. This unnecessarily large energy use and waste due to continuous operation of the evaporation fan(s) is a problem due to today's high energy costs. One logical solution to reduce this energy consumption is to shorten the operating time of the evaporator fan by repeatedly turning it on and off together with the compressor. However, this approach poses several problems, the solution of which forms part of the present invention.

First, if the evaporator fan cycles OFF in synchronization with compressor shutdown, freezing of the evaporator coil can occur in hot and humid conditions.
Second, keeping the evaporation fan shut off during the compressor OFF cycle causes a large change in temperature in the vending machine, which in turn causes a large change in the temperature of the next item sold. Also, during this shutdown period of the evaporation fan, the lack of air flow causes large temperature changes throughout the vending machine, and the temperature sensed by the thermostat that controls the compressor's operating cycle does not have the required accuracy. I can't get it. Thirdly, if the vending machine is placed in a freezing environment (0℃, 32〓) or below,
A quiescent state of the evaporation fan may cause the refrigerated article to freeze. That is, while the evaporator fan is in operation and blows air across the evaporator coil and vending machine, this air flow dissipates the heat generated by the evaporator fan motor, thus preventing the freezing of stored items. Acts as a heater. In this way, the evaporator fan is turned on/off along with the compressor.
Even though a substantial reduction in energy consumption results when OFF is repeated, the aforementioned problems still exist.

Therefore, it reduces the energy consumption in the vending machine's refrigeration system, but at the same time reduces the freezing of the evaporator coil in hot and humid conditions, the freezing of goods in sub-freezing environmental conditions, and the subsequent sale of goods and vending. There is a need in the art for a system that solves the aforementioned problem of large variations in temperature distribution within an aircraft cabin.

Accordingly, a primary object of the present invention is to provide an energy management system for a vending machine that saves energy while still maintaining efficient and accurate cooling of vending items within acceptable limits.

Another object of the invention is to save energy and
The present invention provides an energy management system for vending machines that prevents evaporator coils from freezing in hot and humid conditions.

Another object of the present invention is to provide an energy management system for a vending machine that ensures that the dispensed vending items are within an acceptable and predictable temperature range.

Another object of the invention is to provide an energy management system for a vending machine in which temperature fluctuations within the entire volume of the vending machine are kept to a minimum.

Still another object of the present invention is to provide an energy management system for a vending machine whereby articles are prevented from freezing when the vending machine is placed in an environment below freezing point.

The foregoing and other objects of the present invention are accomplished by the provision of a control circuit that includes at least three timers to periodically turn on and off an evaporator fan independent of the operation of a refrigeration system compressor. Ru. In the system of the present invention, the evaporator fan is turned ON periodically along with the compressor and continues to run while the entire compressor is in the ON cycle as before, but a first timer causes the evaporator fan to follow the OFF cycle of the compressor. You will be allowed to drive for an extra delay period. During this extra delay period of the evaporator fan, the fan continues to blow air through the evaporator coil until the temperature of the evaporator coil is well above the freezing point of water (0°C, 32°C), and then is switched OFF. It will be done. In one typical example, this OFF cycle of the evaporator fan allows the evaporator coil temperature to reach equilibrium above 0° C. (32° C.) within 2 to 5 minutes after the compressor shuts off. It can be any length.

A second periodic timer causes the compressor to run at short predetermined intervals following the aforementioned delay period.
Intermittently turn on the evaporator fan while it is in the OFF state.
Provided to repeat ON/OFF. This intermittent cyclic operation of the evaporator fan forces air flow through the vending machine's article row and
It provides a relatively even temperature distribution during the OFF period, allowing the vending machine's thermostat to properly and accurately sense the temperature of the item. This intermittent action of the fan and air flow also
To limit and maintain beverage temperature fluctuations within acceptable tolerances.

A third timer is provided to prevent freezing of the vendable articles and/or the evaporator coil when the vending machine is placed in a sub-freezing point environment. This timer is energized when the thermostatic temperature switch controlling the compressor is opened, and is activated when the temperature switch remains open for more than a predetermined period of time, e.g., 4 hours. The evaporator fan is placed into an ON cycle to operate continuously for a defined period of time. In other words, the compressor OFF period (the period when the temperature switch is open)
By detecting the
Freezing of articles is prevented when the OFF period (temperature switch open period) exceeds a predetermined limit, such as 4 hours.

Turn on the refrigeration system at a predetermined time in the morning
Any other timer may be provided in combination with the other timers of the invention to turn off the system at a predetermined time in the evening. This optional timer would clearly facilitate the energy saving objective of the present invention by stopping all power consumption during periods when the vending machine is not in use.

The timer used in the control circuit of the present invention is an electromechanical cam that is a commercially available component and is connected in circuit with the power supply and other components of the refrigeration system in the manner described below.
It's a timer. However, the timing functions of the present invention can be implemented by a general purpose digital computer or microprocessor technology programmed to perform the required functions.

The objects and attendant advantages of the present invention will become more readily apparent from the following detailed description taken in conjunction with the accompanying drawings. In the figures, the same reference numbers indicate similar parts.

If we examine Figure 1 in detail, we can see that a plurality of items, such as canned or bottled soft drinks, are stored on the item shelf PS, and these items are placed at an appropriate location at the bottom of the vending machine at the same time as they are billed. A typical article vending machine that is sequentially dispensed from a vending machine is generally shown in a cutaway view. As shown in FIG. 1, this vending machine also incorporates the conventional components of a refrigeration compressor: fan CF, pump CP, evaporator coil EC, evaporator fan motor EFM, and temperature sensed within the vending machine. Thermostatic temperature switch TS for controlling operation of the refrigeration system in response to
(not shown). The conventionally known convection type refrigeration system shown in Fig. 1 uses an evaporator fan motor EFM to blow air against an evaporator coil EC to store articles at a ps.
It acts to cool the articles in the article rack ps by circulating cooling air between and throughout it. Air returns from the rack as shown by arrow AR. In conventional convection refrigeration systems for vending machines known up to now, compressor C
is periodically turned on and off under the control of thermostatic temperature switch TS, but evaporator fan motor EFM operates continuously even during periods when compressor C is deenergized. Evaporator fan
This continuous operation of the motor EFM clearly consumes a large amount of unnecessary electrical energy, generates heat and wastes unnecessary energy. Accordingly, in accordance with the objectives of the present invention, the control circuit of FIG. 2 is configured to energize the evaporator fan motor EFM only for optimal periods of time when its operation is clearly required. For example, according to the invention, the evaporator fan
The motor EFM operates continuously during the period when the compressor C is operating, and operates only for a predetermined delay period following the compressor OFF cycle to prevent the evaporator coil EC from freezing.
In a near-freezing environment, the compressor is operated intermittently for predetermined periods in the OFF cycle, and then placed in the ON cycle to operate continuously for a period of time, followed by extended intervals in which the compressor is not operated. Preventing items from freezing in vending machines at locations.

Referring in detail to FIG. 2, there is shown an electrical schematic diagram of the control circuit of the present invention for operating the convection refrigeration system shown in FIG. 1 pair of main power wiring
PL1 and PL2 are provided, both ends of which are connected to a normal 120 volt, 60 Hz power supply. Also, a plurality of timers E, fp, D, and cy are connected in parallel between the power lines PL1 and PL2. Since each of these timers are connected in parallel,
Effectively hardwired to form OR logic for the evaporator fan motor EFM.
In this way, each timer E, fp, D and cy is
This creates a time control function for the evaporator fan motor EFM, which will be described in more detail below.

Starting from the top of FIG. 2, the first timer E may be a 24-hour clock controller for periodically turning the refrigeration system on and off at predetermined times. That is, timer E allows the refrigeration system to be energized or deenergized for specific periods of the day. Timer E connects the power line via temperature switch TS at its terminal C.
Connected to PL1. Inside timer E, there is a time control switch S1 between terminals C and NC, and a timer motor between terminals L1 and L2.
TM1 is included. Terminal NC is also coupled to the compressor and condenser fan motor of the refrigeration system of FIG. 1, and terminals L1 and L2 are coupled to power lines PL1 and PL2, respectively. Timer E in one embodiment is
Eagle Signal's "Multiple Pulse Timer"
This is a multi-pulse cam timer with catalog No. MP-1-A6-32-MP5-48.

The control circuit of FIG. 2 includes a timer fp that continuously energizes the evaporator fan motor EFM when the refrigeration system compressor C is not operated for a certain length of time, e.g., four hours or more.
If compressor C is stopped for such a long period,
This typically occurs when vending machines are installed in near-freezing environments where there is no need for internal cooling of the vending machine.
However, such near-freezing environments can also create problems in that the refrigerated items may freeze if the vending machine is installed in very cold outdoor environmental conditions. Therefore, this timer fp
In order to detect such a long period when the compressor C is not operating and the evaporation fan motor EFM is turned ON and not operated continuously, this prevents the goods from freezing without blowing air onto the goods. used. Timer fp is external terminal 1, 2, 3,
4 and 11 included. Timer fp terminal 1
is connected to terminal C of terminal E. Terminal 2 of timer fp is externally connected to the power line.
Connected to PL2. Terminal 3 of timer fp is connected to terminal 5 of terminal D, and is connected to fan motor EFM via junction FJ. Terminal 4 of timer fp is hardwired to its terminal 11, which is further coupled to power line PL1. timer fp
It also includes a timer motor TM2 connected to its wiring terminals 1 and 2 at one end and to terminal 11 via a switch S2 at the opposite end. A clutch coil C1 is also provided in the connection between terminals 1 and 2 of the timer fp. Furthermore, a switch S3 is connected between terminals 3 and 4 of timer fp. For example, the timer fp is
"Cycle Flex Timer Catalog No.
An electromechanical cam timer manufactured by Eagle Signal named ``HB58-A6-01'' will suffice.

Evaporator fan motor EFM for a predetermined time, i.e. a delay period after compressor C is shut off.
A timer D is provided to keep it ON.
This delay period may occur under certain environmental conditions when the evaporator coil
Necessary to prevent freezing of EC. That is, as the evaporator fan motor EFM continues to operate at the end of the compressor cycle for a predetermined period of time, the temperature of the evaporator coil will be lower than that of timer D because of this moving air. It is allowed to rise to a safe temperature above the freezing point of water before being switched off under control. timer fp
As with the corresponding terminal, timer D
includes a plurality of external terminals labeled 1, 2, 3, 4, 5 and 11. Timer D, in the preferred embodiment of the invention, is similar to timer fp except for its specific function, with the addition of terminal 5, and the way it is connected in the circuit of FIG. Terminal 1 of timer D is connected to terminal NC of timer E. Terminal 2 of timer D is connected to power line PL2. Terminal 3 of Timer D is the timer described below.
Connected to Cy's terminal L2. Terminal 4 of timer D is further wired to terminal 11 of timer D, which is coupled to power line PL1. As mentioned above, terminal 5 of timer D is directly connected to terminal 3 of timer fp,
Connected to fan motor EFM via junction FJ. Timer D is also coupled to a clutch coil C2 coupled between terminals 1 and 2, at one end thereof between clutch coil C2 and terminal 2, and at the other end coupled to terminal 11 via switch S4. Includes timer motor TM3. A switch S5 is also provided on timer D to complete a circuit between terminals 3 and 4 or between terminals 4 and 5, as controlled by timer motor TM3 in the manner described below.

A cycle timer Cy is provided which intermittently energizes the evaporator fan motor EFM during periods when compressor C is deenergized. This provides a more even temperature distribution within the vending machine during the compressor OFF cycle, thus allowing more accurate temperature sensing within the vending machine during said cycle, and of the cooled articles in the article shelf ps. Desirable to allow more limited fluctuations in temperature. Timer Cy is connected to multiple external terminals L1,
Includes L2, 2 and 3. Terminal L1 of timer Cy is coupled to power line PL2. Terminal L2 of timer Cy is directly connected to terminal 3 of timer D, as described above. Terminal 2 of timer Cy is wired with terminal L2 of timer Cy. Terminal 3 of timer Cy is connected to the evaporator fan motor of the refrigeration system of the invention via junction FJ. A timer motor TM4 is provided in the timer Cy between terminals L1 and L2 for timing a switch S6 connected between terminals 2 and 3 in a manner that will be explained in more detail below. Timer Cy in one embodiment of the present invention is
It is an electromechanical cam timer manufactured by Eagle Signal named "Flexopulse Timer No. HG-94-A6".

The operation of the control circuit of FIG. 2 is best understood with respect to the timing diagrams of FIGS. 3 and 4, as discussed below.

Looking closely at FIG. 3, waveform E shows the output of timer E at terminal NC. Waveform TS
is thermostatic temperature switch TS ON/
Indicates OFF state. Waveform D shows the output of timer D at terminal 5 during the control period shown in FIG. Waveform Cy shows the intermittent timing pulse output generated by timer Cy at output terminal 3 during the control period. The remaining waveforms in FIG. 3, labeled FAN(S), illustrate the operating cycle of the evaporator fan motor EFM in response to the timing controls provided by waveforms E, TS, D, and Cy.

A closer look at FIG. 4 shows multiple timing waveforms that illustrate the functionality of timer fp. Waveform
TS represents the ON/OFF period of temperature switch TS. The waveform fp shows the output at terminal 3 of timer fp as a function of time; the waveform shown FAN(S) shows the evaporator fan motor EFM in response to the combined control of temperature switch TS and timer fp.
Indicates the ON/OFF period.

Although the contents of the timing diagrams in FIGS. 3 and 4 have been generally explained, for the detailed operation of the control circuit in FIG. 2, refer to FIG. 2 in conjunction with FIGS. 3 and 4. This will be explained next.

During normal operation, the compressor C of the refrigeration system shown in Figure 1 switches the temperature switch when the temperature inside the vending machine rises above a predetermined level.
Switched ON in response to TS closing. However, temperature switch TS will not turn on compressor C unless switch S1 of timer E is closed to create a closed circuit between power line PL1, the compressor, and power line PL2. The function of switch S1 will be further described below. The closing of temperature switch TS provides a circuit via the clutch coil of timer fp and power lines PL1 and PL2. That is, the closing of temperature switch TS energizes clutch coil C1. When clutch coil C1 is energized, timer motor TM2 of timer fp cannot rotate. Timer E sets the refrigeration system of the present invention for a specific time.
Any 24 hour clock/controller that can be used to turn ON/OFF. For example, waveform E
As shown in Figure 3, the refrigeration system is turned on at 9:00 AM by timer E.
It will be turned off at 5:00PM. This ON/OFF
The period is controlled by timer E by the opening and closing operation of switch S1, which is controlled by timer motor TM1 in conjunction with a suitable timing cam. If this selection is not requested, switch S1 is fixed in the closed position and terminal C
and NC are effectively shorted to open terminals L1 and L2, thereby disabling timer E. If switch S1 is continuously closed in this position, the availability of the refrigeration system and compressor C is under control of the temperature TS.

Delay timer D is provided with a clutch coil C2 which is energized when temperature switch TS is closed. When clutch C2 is energized, timer motor TM3 is not activated. However, at the end of the compressor cycle when temperature switch TS opens, clutch C2 is deenergized and timer motor TM3 is started and runs until it times out. Timer motor TM3
The switch S5 remains in the position shown between terminals 4 and 5 until it times out, thus completing the circuit from the power line PL1 to the evaporator fan motor EFM via junction FJ. At the beginning of the operating cycle of compressor C, switch S5
is normally in the position shown connecting terminals 4 and 5 of timer D, so that power is passed from power line PL1 to terminals 4, 5 of timer D and junction point FJ to the evaporator fan motor EFM.
supplied to Timer D is temperature switch TS
Determines how long power is supplied to the evaporator fan motor after the compressor shut-off time determined by . That is, when temperature switch TS is opened, clutch coil C2 is deenergized, causing timer TM3 to expire;
At this time, switch S5 switches from terminal 5 to terminal 3, thereby cutting off the power supply to the evaporator fan motor EFM. When switch S5 couples together terminals 4 and 3 of timer D, cycle timer Cy is enabled.

Thus, timer motor TM4 of cycle timer Cy operates continuously following each delay period generated by timer D until reset by the end of another delay period. The cycle timer alternately opens and closes the contacts between terminals 2 and 3 of timer Cy at a selectable rate that produces a small pulse waveform shown as Cy in FIG. Thus, as shown in the waveform "FAN(S)" at the bottom of FIG.
Turn off. In this way, as shown in Figure 3, the evaporator fan motor EFM
The compressor is switched ON for the entire time it is switched ON, remains ON for a delay period determined by timer D, and following each delay period, the next compressor is switched ON.
It is intermittently switched to the ON state during the period preceding the ON period. The compressor ON and OFF periods are represented in FIG. 3 as C _ON and C _OFF , respectively. Thus, the operation of timers E, D and Cy will now be explained with respect to FIG.

The operation of timer fp to prevent freezing of goods for sale in a near-freezing environment may be understood from FIG. 4 in conjunction with FIG. As shown by the waveform TS at the top of FIG. 4, temperature switch TS is closed and opened to switch the compressor OFF at the time indicated by C _OFF in FIG.
Power is removed from coil C1. When this condition occurs, timer motor TM2 is allowed to rotate to begin its timing function. If temperature switch TS remains open for a predetermined period of time, e.g. 4 hours continuously, timer fp will time out and switch S3
This closes the contact between terminals 3 and 4. The closing circuit of switch S3 is power line PL1 and PL2.
Complete the circuit between the evaporator fan and motor EFM. The evaporator fan then operates continuously until the temperature switch closes again, energizing clotch coil C1 and deactivating the timer motor. Once this condition occurs, timer fp is readily automatically reset to its initial condition for subsequent operation in response to a compressor OFF period that exceeds the predetermined four hour period. 4
It should be understood that the period of time is merely exemplary and that the period selected will vary according to the type of vending machine being controlled. Thus, due to the continuous operation of the evaporator fan motor following long compressor OFF periods representing near-freezing conditions in the environment, freezing of the items inside the vending machine is caused by the heating action of the air circulating within the vending machine. Prevented.

It should be understood that the system described herein may be modified as envisioned by those skilled in the art without departing from the spirit and scope of the invention.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional perspective view of the interior of a typical refrigerated goods vending machine equipped with a convection cooling system, and FIG. 2 is a perspective view of the present invention for operating the convection cooling system inside the vending machine of FIG. 3 is a timing diagram of the electrical signals present at selected terminals of the circuit diagram of FIG. 2, which is referenced in the text, and FIG. 4 is a timing diagram of the electrical signals present at selected terminals of the circuit diagram of FIG. FIG. 3 is a timing diagram of electrical signals present at other terminals of the circuit. C...Compressor, CF...Compressor fan, CP...Pump, EC...Evaporator coil, EFM...Evaporator fan motor, TS...Thermostatic temperature switch, ps...Product shelf, PL1, PL2...Power line, E, fp , D, Cy...timer, L1, L2...
Terminal, 1 to 5, 11...External terminal, S
1 to S6...Switch, C1, C2...Clutch coil.

Claims (1)

[Claims] 1. Refrigeration acting compressor; temperature for detecting the temperature within the vending machine and switching the compressor to an ON/OFF state to define a compressor cycle in response to detection of a predetermined temperature limit. a sensor device; an evaporator coil; and an evaporator fan device for blowing air toward the evaporator coil and circulating the air throughout the vending machine.
A refrigeration system for a refrigerated goods vending machine, comprising: an evaporator fan device EFM;
At the same time, turn on or turn off the compressor.
the temperature sensor device TS capable of keeping the evaporator fan device ON for a period longer than the compressor cycle and turning the evaporator fan device OFF for a predetermined period after being switched to TS;
a first timer device D responsive to, where the time point is long enough to stabilize the temperature of the evaporator coil above the freezing point of water after the compressor is switched OFF; and After the first timer device D switches the evaporator fan device OFF, the evaporator fan device is intermittently turned ON/OFF for a predetermined period during a cycle of the compressor, thereby A refrigeration system characterized in that it comprises a cycle timer device Cy for maintaining a uniform distribution of cooling air within the vending machine and minimizing temperature fluctuations of the refrigerated articles. 2. A sensor device for detecting when the compressor is in an OFF state; measuring the length of time that the compressor is in the OFF cycle and generating an energizing signal when the length of this period exceeds a predetermined time period; for,
a timer device responsive to the sensor device; and a circuit device responsive to the energization signal to periodically turn the evaporator fan device ON until the compressor is in an ON cycle. A system according to claim 1, characterized in that: 3. A refrigeration compressor; a temperature sensor device for detecting the temperature within the vending machine and switching the compressor into an ON/OFF state to define a compressor cycle in response to detection of a predetermined temperature limit; an evaporator coil; and an evaporator fan device for blowing air toward the evaporator coil and circulating the air throughout the vending machine.
a refrigeration system for a refrigerated goods vending machine, the system comprising: an EFM; a sensor device for detecting when the compressor is in the OFF cycle; a timer device responsive to the sensor device for generating an energization signal when the time period exceeds a period of time; and a timer device for periodically turning the evaporator fan device ON continuously until the compressor turns ON.
A refrigeration system comprising: a circuit device responsive to the energization signal.