JPH05203310A - Freezing device with heating mechanism - Google Patents

Abstract

PURPOSE:To reduce the number of ON-OFF operations of a refrigerant compressor by preventing the control from a freezing process to a heating process from being transferred owing to subcooling and superheating in a short time by performing a temperature adjustment between temperatures of predetermined temperature differences where the control is transferred to processes of freezing temperature, cold keeping temperature, and heating temperature. CONSTITUTION:A temperature difference between setting temperature and freezer temperature detected by a freezer temperature sensor 44 is calculated upon temperature control in a freezer 20 by a control device 40 to control the operation of cooling means 32 or heating means 51 in accordance with the calculated temperature difference. More specifically, the operation is transferred to a cold temperature keeping process with a first predetermined temperature difference when the fregoing temperature difference is 0 or higher, and transferred to a freezing process with a second predetermined temperature difference when the foregoing temperature difference is 0 or higher in the cold temperature keeping process transferred from the freezing process, and further transferred to a heating process with a third predetermined temperature difference when the foregoing temperature difference is the first predetermined temperature difference or lower. Additionally, the operation is transferred to the cold temperature keeping process with a fourth predetermined temperature difference when the foregoing temperature difference is 0 or higher. In the cold temperature keeping process transferred from the heating process the operation is transferred to the heating process with a fifth predetermined temperature difference when the foregoing temperature difference is 0 or lower.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus with a heating mechanism for controlling air in a freezer mounted on a refrigerating vehicle to a desired temperature by cooling means and heating means.

[0002]

2. Description of the Related Art Conventionally, in order to control the temperature inside a freezer mounted on a refrigerating vehicle with a heating mechanism, cooling air having a constant temperature is circulated in the freezer to cool the air in the freezer. There is a refrigerating apparatus provided with a means and a heating means for heating the air in the freezer by circulating warm air having a constant temperature in the freezer.

In such a refrigerating apparatus, as shown in FIG. 9 (a), a refrigerating process A by a cooling means, a heating process B by a heating means, a cooling means and a heating means are performed in accordance with the temperature inside the refrigerator. Insulation process C that stops the operation of the
The temperature control is performed by the following three processes.

That is, when the temperature in the freezer is high, the freezing process A is controlled, and the freezer is cooled by the cooling means. When the internal cold storage temperature further decreases to a predetermined temperature, the control shifts to the cold insulation temperature process C. When the temperature inside the refrigerator decreases in the controlled state in the cold insulation process C, the cold insulation process C
The control shifts from the heating process B to the heating process B. Between the temperature when transitioning from the freezing process A to the cold insulation process C and the heating process B, and the temperature when transitioning from the warming process B to the cold insulation process C and the freezing process A, Hysteresis is provided to prevent frequent transfer of control.

According to this temperature control method, the freezing process A and the cold insulation process C are transitioned in a temperature region higher than the target set temperature Tset in the freezer set by the vehicle occupant, and the temperature is lower than the target set temperature Tset. In the temperature range, the cold insulation process C and the heating process B are transitioned.

It is assumed that the temperature in the freezer detected by the temperature sensor in the freezer is TA when the temperature control in the freezer is turned on. At this time, the air in the freezer is cooled by the cooling means in order to bring the inside temperature to the target set temperature Tset (freezing process A).

Since the cooling means performs cooling by discharging cold air having a constant temperature into the freezer, the target set temperature T
Even if the operation of the cooling means is stopped at the temperature t1 higher than the set temperature and the process proceeds to the cold-keeping temperature process C, the temperature inside the refrigerator is not maintained at this temperature t1 but is overcooled above the temperature t1. Due to this supercooling, the internal cold storage temperature continues to decrease until it approaches the target set temperature Tset. That is, when the freezing process A shifts to the cold insulation process C at a temperature t1 higher than the set temperature Tset, the internal temperature is controlled near the set temperature Tset by supercooling.

In the state of the cold insulation process C, the internal temperature rises due to the heat effect from the outside of the freezer or the like, and when the temperature reaches t4, the cold insulation process C shifts to the freezing process A and the internal temperature of the cold storage is again provided by the cooling means. Is cooled. That is, the freezing process A
The cycle of the cold-keeping temperature process C and the freezing process A is repeated to control the temperature of the inside temperature.

On the other hand, in the state of the cold insulation process C, the temperature inside the refrigerator further decreases below the target set temperature Tset, and the temperature t
When it reaches 2, the cold insulation process C is shifted to the heating process B, and warm air of a constant temperature is circulated in the freezer so as to bring the internal temperature close to the target set temperature Tset. After that, when the internal temperature rises to the temperature t3, the heating process B shifts to the cold insulation process C, and when the temperature further rises to the temperature t4, the cold insulation process C shifts to the freezing process A.

As described above, this control is provided with hysteresis, and the respective temperatures at which the control shifts and the target set temperatures have a relationship of t4>t1>Tset>t3> t2.

[0011]

When the temperature control in the freezer is carried out from the state of the temperature TA in the freezer by the above-mentioned conventional method, the inside of the freezer is cooled by the cooling means in the freezing process A and kept cold at the temperature t1. By shifting to the temperature process C, temperature control is performed up to near the target set temperature Tset.

However, when the amount of heat received from the outside of the freezer is large, the target set temperature Tset is reached when the process proceeds to the cold insulation process C.
The temperature in the refrigerator rises in a relatively short time without being kept nearby. Then, when the temperature inside the refrigerator reaches the temperature t4, the cold insulation process C shifts to the freezing process A, and the inside of the freezer stores the freezing process A.
It is cooled again by the control of. After the transition to the cold-keeping temperature process C, the inside of the freezer rises in a short time due to the heat effect as described above, so the control cycle of freezing process A → cooling temperature process C → freezing process A is repeated. In this control cycle, temperature t1 and temperature t1 with hysteresis
The temperature between 4 and 4 will control the temperature in the freezer. That is, the temperature is controlled at a temperature distant from the set temperature Tset.

On the other hand, as shown in FIG. 9 (b), from the freezing process A to the cold insulation process C so as to extend above and below the set temperature Tset.
The temperature t1 for transition to the cold storage process C and the temperature t4 for transition from the cold insulation process C to the freezing process A are set, and similarly the transition from the heating process B to the cold insulation process C is performed so as to extend above and below the set temperature Tset. It is conceivable to set the temperature t3 and the temperature t2 at which the cold insulation process C shifts to the heating process B. That is, the respective temperatures at which the control is transferred and the target set temperature Tset are t4> t
3>Tset>t1> t2.

In this case, the temperatures t1 and t4 are set so as to extend above and below the set temperature Tset.
The temperature inside the freezer is controlled near the set temperature Tset to control the temperature inside the freezer.

However, if the temperature between the temperatures t1 and t4 and the temperature between the temperatures t2 and t3 are set near the set temperature, when the temperature changes from the refrigeration process A to the cold insulation process C, the temperature will exceed the temperature t1. Since it is cooled, it may be cooled to the temperature t2 at which the cold insulation process C shifts to the heating process B due to this supercooling.

When the process is moved to the heating process B, the inside of the freezer is heated, and when the temperature is raised to the temperature t3, the process is transferred to the cold insulation process C. At this time, since the temperature is overheated above the temperature t3, the temperature t at which the cooling process C shifts to the freezing process A due to this overheating.
May be heated up to 4.

That is, when the temperature control is performed as shown in FIG. 9 (b),
Freezing process A → Cold insulation process C → Heating process B → Cold insulation process C
→ The cycle of freezing process A is performed in a short time. This is compared with the control cycle of the refrigeration process A → the cold insulation process C → the refrigeration process A in the case of FIG. 9 (a) above.
Since the warming process enters, the process returns to the freezing process faster than the control in the cold insulation process C, and the number of times the process returns to the freezing process increases. Therefore, the number of times the refrigerant compressor used as a component of the cooling device is turned on and off. However, there is a problem in that the drive source for driving the refrigerant compressor is likely to malfunction.

Therefore, according to the present invention, the temperature control is performed near the set temperature, and it is possible to prevent the control from shifting between the freezing process and the heating process in a short time due to the supercooling and overheating. An object of the present invention is to provide a refrigerating apparatus with a heating mechanism that can reduce the number of times the refrigerant compressor is turned on and off so that a drive source for driving the refrigerant compressor is less likely to malfunction.

[0019]

In order to achieve the above object, the present invention provides a freezer that is cut off from the outside, a cooling means that cools the air in the freezer, and warms the air in the freezer. Heating means, temperature setting means for setting a desired air temperature in the freezer, interior temperature detecting means for detecting the temperature of air in the freezer, and interior temperature detected by the interior temperature detecting means By subtracting the set temperature set by the temperature setting means from the temperature to calculate the temperature difference between the internal temperature and the set temperature, and according to the temperature difference calculated by the temperature difference calculating means, the cooling means Control of the temperature in the freezer in any one of a freezing process for cooling the inside of the freezer, a heating process for heating the inside of the freezer by the heating means, and a cold insulation process for stopping the cooling means and the heating means Temperature control means for performing In the refrigerating apparatus with a heating mechanism for controlling the temperature inside the freezer detected by the inside temperature detecting means to the set temperature, the temperature control means, during temperature control of the inside of the freezer in the freezing process, At the first predetermined temperature difference in which the temperature difference is 0 or more, the process proceeds to the cold insulation process,
During the temperature adjustment control in the freezer in the cold insulation temperature process transferred from the freezing process, the temperature difference shifts to the freezing process at the second predetermined temperature difference of 0 or more, and the temperature difference changes to the first predetermined temperature difference. The temperature shifts to the warming process at a third predetermined temperature difference of less than, and during the temperature control of the inside of the freezer by the heating process, at the fourth predetermined temperature difference of 0 or more, to the cold insulation temperature process. During the temperature control control in the freezer in the cold insulation process after the transition from the heating process, the temperature difference shifts to the heating process at a fifth predetermined temperature difference of 0 or less, and the temperature difference changes to the first temperature difference. The cooling means and the heating means are controlled so as to shift to the refrigerating process at a sixth predetermined temperature difference higher than the fourth temperature difference, and the third predetermined temperature difference is the fifth predetermined temperature. Less than the difference, the sixth
The predetermined temperature difference is larger than the second predetermined temperature difference by using the refrigerating apparatus with a heating mechanism.

[0020]

According to the method of controlling the temperature of the refrigerating apparatus with a heating mechanism of the present invention having the above structure, the refrigerating process for operating the cooling means and the heating means for keeping the temperature in the freezer at the set temperature. There are three processes, namely, a heating process for activating the cooling means and a cold keeping process for stopping the operation of both the cooling means and the heating means.

In order to control the temperature inside the freezer to a set temperature, the set temperature set by the temperature setting means is subtracted from the inside temperature detected by the inside temperature detection means to obtain the inside temperature and the set temperature. And the temperature difference between the inside and the set temperature are compared.

In this temperature difference, when it is shown that the temperature inside the refrigerator is higher than the set temperature, the inside of the freezer is cooled by the cooling means, and when it is shown that the temperature inside the refrigerator is lower than the set temperature. The temperature control of the inside of the freezer is performed by heating the inside of the freezer by the temperature means.

When the temperature inside the refrigerator is higher than the set temperature, first, the inside of the freezer is cooled by the cooling means. By this cooling, when the inside of the freezer is cooled to a temperature at which the first predetermined temperature difference is reached, the process proceeds to the cold insulation temperature process of stopping the operation of the cooling means.

In the cold insulation temperature process, the temperature inside the freezer changes due to the influence of heat from outside the freezer. When the temperature inside the freezer rises due to a heat effect such that the temperature inside the freezer rises and the temperature inside the freezer rises to a second predetermined temperature difference, the temperature control shifts to the freezing process.

On the contrary, if the temperature in the freezer further decreases and reaches the third predetermined temperature difference, the temperature control shifts to the heating process. When the temperature inside the refrigerator is lower than the set temperature, the inside of the freezer is heated by the heating means. By this heating, when the inside of the freezer is heated to a temperature at which the fourth predetermined temperature difference is reached, the process proceeds to a cold keeping process in which the operation of the heating means is stopped.

In the cold-keeping process, if the temperature inside the freezer falls due to the influence of heat from the outside of the freezer or the like, the control shifts to the heating means when the fifth predetermined temperature difference is reached. On the contrary, if the temperature in the freezer further rises and reaches the sixth predetermined temperature difference, the temperature adjustment control shifts to the freezing process.

When the above-mentioned operation is performed and the inside of the freezer is warmed by the heat effect from the outside of the freezer or the like, the temperature inside the freezer rises and the temperature difference from the set temperature becomes large. Will be controlled by. Then, the inside of the freezer is cooled by the cooling means. When it is cooled to a predetermined temperature (first temperature difference), the process proceeds to the cold insulation temperature process and is controlled. Since the inside of the freezer is warmed, the temperature inside the freezer rises. When the temperature rises to a predetermined temperature (second temperature difference), control shifts to the freezing process. After shifting to the freezing process, the inside of the freezer is cooled again by the cooling means. By repeating the control between the freezing process and the cold insulation temperature process, the temperature in the freezer is controlled near the set temperature.

On the contrary, when the inside of the freezer is cooled by the heat effect from the outside of the freezer or the like, each of them is controlled in the heating process. Then, after heating the inside of the freezer by the heating means, the process shifts to the cold insulation process. Since the inside of the freezer is being cooled, the temperature inside the freezer is lowered. When the temperature drops to a predetermined temperature (fifth temperature difference), the heating process starts. After shifting to the heating process, the inside of the freezer is heated again by the heating means. By repeating the control between the warming process and the cold keeping process, the inside of the freezer is controlled to near the set temperature.

A cold-retaining temperature process when the process shifts from the freezing process,
The temperature control can be controlled as described above by dividing the cold-keeping temperature process when the heating process is started from the case.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a refrigerating device and a heating device for a refrigerating vehicle of the present invention will be described based on an embodiment shown in FIG.

The freezer 10 comprises a freezer 20, a cooling unit 30 accommodating a cooling means 32, a heating unit 50 accommodating a heating means 50, a controller 40 and an in-compartment temperature sensor 44. ..

The freezer 20 is loaded in the rear half of the freezing vehicle 10. The freezer 20 has a heat insulating structure that is insulated from the outside by a heat insulating material or the like. A door 21 is provided at the rear of the freezer 20 so as to be openable and closable so that frozen or refrigerated food can be taken in and out.

The cooling unit 30 is mounted above the front of the freezer 20. The cooling unit 30 has an inlet 30a on the lower surface and an outlet 30b on the rear side. Inside the cooling unit 30, the air in the freezer 20 is sucked through the inlet 30a, and the sucked air is blown through the cooling means 32 to the outlet 30b.
An in-compartment blower 31 that blows out from the inside to the freezer 20 is attached. It should be noted that the interior blower 31 is energized and controlled by the control device 40.

On the other hand, the cooling means 32 is attached to the ventilation passage in the cooling unit 30. Cooling means 32 of the present embodiment
Is a refrigerant evaporator of the refrigeration cycle 33. Refrigeration cycle
33 is a refrigerant compressor 34, a refrigerant condenser other than the refrigerant evaporator 32.
It has a well-known configuration including a receiver 35, a receiver 36, a refrigerant decompression device 37, and a refrigerant pipe 38 connecting them. Then, in the refrigerant evaporator 32, the refrigerant flowing inside is a cooling unit.
Heat is taken from the air flowing through 30 to evaporate, and as a result, the air that has passed through the refrigerant evaporator 32 is cooled and the freezer 20 is cooled.

The refrigerant compressor 34 is provided with an electromagnetic clutch 34a, and when the electromagnetic clutch 34a is energized, the rotational torque of the vehicle engine 58 for traveling the vehicle is transmitted to the refrigerant compressor 34. Further, the refrigerant condenser 35 includes a condenser blower 35a for forcibly exchanging heat between the refrigerant passing through the inside and the air. The electromagnetic clutch 34a and the condenser blower 35a are energized and controlled by the controller 40.

The heating unit 50 is mounted below the front part of the freezer 20. The heating unit 50 has an inlet 50a on the upper surface and an outlet 50b on the rear side. Inside the heating unit 50, the air in the freezer 20 is sucked through the inlet 50a, and the sucked air is blown out through the heating means 51.
An in-compartment blower 60 that blows from b to the freezer 20 is attached. In addition, like the in-compartment air blower 31 in the cooling unit 30, the in-compartment air blower 60 is energized and controlled by the control device 40.

The heating device comprises a normally closed solenoid valve 52 and a heater core 51 which is a heating means.
Is opened by the excitation of the solenoid S and receives cooling water from the cooling system of the engine 58 of the refrigeration vehicle through the pipe 62 and applies it to the heater core 51. Further, the solenoid valve 52 is closed by demagnetizing the solenoid S to cut off the communication of the cooling water into the heater core 51. The cooling water that has passed through the heater core 51 is returned to the cooling system of the engine 58. Note that reference numeral 54
Indicates a radiator and 56 indicates a thermovalve for the radiator 54.

The control device 40 energizes and controls the inside air blower 31 in the cooling unit, the inside air blower 60 in the heating unit, the electromagnetic clutch 34a, the condenser air blower 35a and the solenoid S. The internal temperature sensor 44 is installed in the upper part of the freezer near the outlet 30b of the cooling unit 30.

Next, based on the flow charts of FIGS. 4 to 8, the operation of the microcomputer in the control unit 40 will be described together with the temperature control diagram shown in FIG. The freezing process A
For the sake of convenience, the cold insulation process C at the time of transition from
For the sake of convenience, the cold insulation process C when the heating process B is transitioned to is called the insulation process C2.

When the temperature control of the freezer 20 is started in step 100 as shown in FIG. 4, the set temperature Tset in the freezer 20 set by the vehicle occupant is read in step 110. The set temperature Tset is a temperature that can be freely switched by a temperature setting switch (not shown) and serves as a reference for temperature control. In step 120, the inside temperature Tr detected by the temperature sensor 44 inside the freezer 20 is read. In step 130, the temperature difference ΔT between the set temperature Tset and the internal compartment temperature Tr is calculated according to the following equation.

[0041]

## EQU1 ## .DELTA.T = Tr-Tset When the temperature difference .DELTA.T obtained by the above equation 1 is 0, it means that the internal compartment temperature Tr is controlled to the set temperature Tset. In FIG. 1, when the temperature difference ΔT has a positive value, the inside temperature Tr is higher than the set temperature Tset.

At steps 140 and 160, it is determined based on the temperature difference ΔT what range the internal temperature Tr is with respect to the set temperature Tset. Step 140
When the temperature difference obtained in step 130 is −0.5 ° C. or less, that is, when the in-compartment temperature Tr is lower than the set temperature Tset by 0.5 ° C. or more, “YES” is determined and step 150 The heating signal is output at and the step moves to. When it is determined to be “NO” in step 140, the process proceeds to step 160.

When the temperature difference ΔT is 0.5 ° C or more,
If "YES" is determined, the process proceeds to step 170, and the process proceeds to the step of outputting the refrigeration signal. If "NO" is determined in the step 160, the cold insulation signal is output in the step 180 and the process proceeds to the step.

In steps 100 to 180 described above, the temperature control in the freezer 20 is initialized. As shown in FIG. 1, the control method changes depending on the state of the inside temperature Tr with respect to the set temperature Tset.

When the heating signal is output in step 150 and the process shifts to, the process proceeds to step 200 as shown in FIG. In step 200 to step 220, the set temperature Tse is set as in step 110 to step 130 described above.
The temperature difference ΔT is calculated by reading t and the internal temperature Tr.

In step 230, the temperature difference ΔT causes the transition temperature T4 to change the control from the heating process B to the heat retention process C2.
(0.5 ° C) or more is determined. When the determination result is “YES”, the process proceeds to step 240, the heating signal is stopped, and the warming signal is output. Then, the process proceeds to step. When the determination result is "NO", the temperature control is performed again in the step.

When the freeze signal is output in step 170 and the process shifts to, the process proceeds to step 300 as shown in FIG. In step 300 to step 320, the set temperature Tse is set as in step 110 to step 130 described above.
The temperature difference ΔT is calculated by reading t and the internal temperature Tr.

At step 330, the temperature difference ΔT changes the control from the freezing process A to the cold keeping process C1 at the transition temperature T1 (-
0.5 ° C) or less is determined. The judgment result is "Y
When it is "ES", the process proceeds to step 340, the freezing signal is stopped, and the cold insulation signal is output. Then, the process proceeds to step. When the determination result is "NO", the temperature control is performed again in the step.

When the cold insulation signal is output in step 180 and the process shifts to, the process proceeds to step 400 as shown in FIG. In steps 400 to 420, the set temperature T is set in the same manner as in steps 110 to 130 described above.
The temperature difference ΔT is calculated by reading the set and the internal temperature Tr.

At step 430, the transition temperature T5 (-) at which the temperature difference ΔT changes the control from the cold insulation process C1 to the heating process B.
3 ° C) or less is determined. The judgment result is "YE
When it is "S", the process proceeds to step 440, the cold insulation signal is stopped, and the heating signal is output. Then, the process shifts to step to perform the temperature control shown in FIG.

When the determination result is "NO", the routine proceeds to step 450, where the temperature difference ΔT is the transition temperature T2 (0.5 ° C) or more for changing the control from the cold insulation process C1 to the freezing process A. To determine. When the determination result is “YES”, the process proceeds to step 460, the cold insulation signal is stopped, and the freezing signal is output. Then, the process shifts to step to perform the temperature control shown in FIG. When the determination result is "NO", the temperature control is performed again in the step.

When the heat retention signal is output in step 240 and the process shifts to, the process proceeds to step 500 as shown in FIG. In steps 500 to 520, the set temperature T is set in the same manner as in steps 110 to 130 described above.
The temperature difference ΔT is calculated by reading the set and the internal temperature Tr.

In step 530, the transition temperature T6 (3) at which the temperature difference ΔT changes the control from the heat retention process C2 to the refrigeration process A.
° C) or more is determined. Judgment result is "YES"
If so, the process proceeds to step 540 to stop the heat retention signal and output the freezing signal. Then, the process shifts to step to perform the temperature control shown in FIG.

When the result of the determination is "NO", the routine proceeds to step 550, where the temperature difference ΔT is below the transition temperature T5 (-0.5 ° C) at which the control is changed from the heat retaining process C2 to the warming process B. Is determined. When the determination result is "YES", the process proceeds to step 560, the heat retention signal is stopped, and the heating signal is output. Then, the process shifts to step to perform the temperature control shown in FIG. When the determination result is "NO", the temperature control is performed again in the step.

As described above, the control shown in FIG. 1 is performed according to the flow charts shown in FIGS. T1 attached to the transition temperature in the control diagram of FIG. 1 represents the transition temperature T1, and hereinafter T2 to T6 are similarly attached.

When the freezing signal and the heating signal are output, the energization of each device is controlled via the control device 40 as described above. Further, at the time of outputting the cold insulation signal and the warm insulation signal, the heating means and the cooling means are turned off, but only the in-compartment blowers 31 and 60 are energized and controlled in order to eliminate the uneven temperature distribution in the freezer 20.

In this embodiment, a temperature having a temperature difference ΔT of 0.5 ° C. is applied to the transition temperatures T2, T4, and the transition temperatures T1, T
5, the temperature difference ΔT is −0.5 ° C., and the transition temperature T3 is the temperature difference ΔT −3 ° C. and the transition temperature T6.
Although the temperature difference ΔT is 3 ° C., the temperature difference ΔT is not limited to this and may be changed as appropriate.

In the cold insulation process C1 and the heat insulation process C2 of the above control process, the internal temperature Tr changes due to the influence of the outside air temperature. When the internal temperature is higher than the set temperature Tset,
In the above control flow, the freezer controlled in the freezing process A
Inside 20 is cooled. When the temperature difference .DELTA.T is -0.5.degree. C. or lower, that is, when the internal temperature Tr becomes 0.5.degree. After that, the inside temperature Tr may be gradually increased due to the influence of the outside air temperature and the like. When the temperature difference ΔT is 0.5 ° or more, that is, when the internal temperature Tr becomes higher than the set temperature Tset, the freezing process A is performed again and the inside of the freezer 20 is cooled again.

The transition temperatures between the freezing process A and the cold insulation process C1 and between the heating process B and the heat insulation process C2 are above and below the temperature difference ΔT of 0 ° C. Since a hysteresis having a difference in transition temperature is set above and below the set temperature Tset, it is usually between the refrigerating process A and the cold insulating process C1 or between the warming process B and the warm insulating process C.
The temperature control can be performed in the vicinity of a temperature suitable for the set temperature Tset by being controlled between the steps 2 and.

During control in the heating process B and the heat retention process C2,
By opening and closing the door 21 of the freezer 20, outside air having a temperature higher than the inside temperature Tr enters the freezer 20 and a large heat load is put into the freezer 20, so that the inside temperature Tr is set to the set temperature Tset. It becomes higher, that is, the temperature difference ΔT is 3 °.
It may be over C. At this time, the inside temperature Tr becomes faster.
In order to bring the temperature to the set temperature Tset, the process goes to the control of the freezing process A and the inside of the freezer 20 is cooled by the cooling means.

During the control in the freezing process A and the cold keeping process C1, when the temperature difference ΔT becomes -3 ° C or less, the process moves to the heating process B, and the inside of the freezer 20 is heated by the heating means. However, since the temperature range controlled by the cold insulation process C1 and the heat insulation process C2 is wide, the number of times control is transferred from the cold insulation process C1 to the warming process B due to supercooling and overheating, and from the heat insulation process C2 to the freezing process. The number of times the control is transferred to the process A is reduced.

As a result, the number of times the refrigerant compressor 34 used as the cooling means is turned on and off can be reduced, and therefore the malfunction of the device that drives the refrigerant compressor 34 can be reduced.
In addition, there is an effect that the driving feeling of the vehicle is improved.

In addition, a timer (not shown) is added to the structure described in the above embodiment so that the freezing process A to the cold insulation process C1 can be performed.
The timer is activated when the control is shifted to the warming process B and the control to the warming process C2 is performed.
When the control shift is performed, the cold-keeping process C is performed even if the internal compartment temperature Tr changes greatly unless the time exceeds a certain time.
Transfer of control from 1 to heating process B, and heat retention process C2
From the control to the refrigerating process A.
By preventing ON / OFF of the refrigerant compressor 34 in a short time by the control by the timer, the above effect can be further enhanced.

[0064]

As described above, according to the present invention, the temperature between the predetermined temperature difference from the freezing process to the cold insulation process and the predetermined temperature difference from the cold insulation process to the freezing process. Since the temperature control in the freezer is performed between the predetermined temperature difference between the warming process and the warming process and the predetermined temperature difference between the warming process and the warming process, The temperature control in the freezer can be performed at a temperature near the temperature.

Further, as a result, the number of times the temperature control control is transferred between the freezing process and the heating process is reduced. Therefore, the refrigerant compressor used as the cooling means is turned on and off.
Since the number of times is reduced, it is possible to reduce defects in the drive source that drives the refrigerant compressor.

[Brief description of drawings]

FIG. 1 is a temperature control diagram showing an embodiment of the present invention.

FIG. 2 is a diagram corresponding to the claims.

FIG. 3 is a schematic view of a refrigeration vehicle used in this embodiment.

FIG. 4 is a flowchart showing temperature control control executed by a microcomputer.

FIG. 5 is a flowchart showing temperature adjustment control executed by a microcomputer.

FIG. 6 is a flowchart showing temperature control control executed by a microcomputer.

FIG. 7 is a flowchart showing temperature control control executed by a microcomputer.

FIG. 8 is a flowchart showing temperature control control executed by a microcomputer.

9 (a) and 9 (b) are diagrams showing conventional temperature control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Refrigerating vehicle 20 Freezer 31 Air blower for interior (for cooling means) 32 Cooling means 40 Control device 44 Interior temperature sensor 51 Heating means (heater core) 60 Fan for interior (for heating means)

Claims (1)

[Claims] 1. A freezer shut off from the outside, a cooling means for cooling the air in the freezer, a heating means for heating the air in the freezer, and a desired air temperature in the freezer. A temperature setting means, an inside temperature detecting means for detecting the temperature of the air in the freezer, and a setting temperature set by the temperature setting means from the inside temperature detected by the inside temperature detecting means, Temperature difference calculating means for calculating the temperature difference between the temperature and the set temperature, according to the temperature difference calculated by the temperature difference calculating means, a freezing process of cooling the inside of the freezer by the cooling means, the inside of the freezer by the heating means. A temperature control means for controlling the temperature in the freezer in any one of a warming step of heating and a cold insulation warming step of stopping the cooling means and the warming means; Freezer detected by In the refrigerating apparatus with a heating mechanism for controlling the temperature of No. 1 to the set temperature, the temperature control unit controls the temperature control in the freezer in the refrigerating process at a first predetermined temperature difference of 0 or more. In the cold insulation process transferred from the freezing process, during the temperature control control in the freezer, the temperature difference shifts to the freezing process at a second predetermined temperature difference of 0 or more, and the temperature difference Shifts to a heating process at a third predetermined temperature difference less than the first predetermined temperature difference, and at the time of temperature control control in the freezer by the heating process, the fourth predetermined temperature difference is 0 or more. At the temperature difference, the temperature shifts to the cold insulation process, and at the temperature control control in the freezer in the cold insulation process transferred from the heating process, the temperature difference shifts to the warming process at a fifth predetermined temperature difference of 0 or less. And the temperature difference is the fourth
The cooling means and the heating means are controlled so as to shift to the refrigeration process at a sixth predetermined temperature difference which is higher than the fifth temperature difference, and the third predetermined temperature difference is the fifth predetermined temperature difference. And the sixth predetermined temperature difference is a temperature difference larger than the second predetermined temperature difference.