JP2569771B2 - Low temperature maintenance device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a low-temperature maintenance device that maintains a temperature inside a heat-insulated room (hereinafter, heat-insulated room) mounted on a vehicle at a set temperature.

[Related Art] A low-temperature maintaining device includes a cooling unit that cools air in an insulated room that is insulated from the outside, a blower that generates an airflow in the insulated room, and a control device that controls the cooling unit and the blower. In addition, the blower increases the amount of air cooled by the cooling unit by generating an air flow in the insulated room, stirs the air in the insulated room, and equalizes the temperature in the insulated room.

Then, the conventional control device controls the cooling capacity of the cooling unit in accordance with the output of the temperature detecting unit that detects the temperature in the insulated room, and maintains the temperature in the insulated room at the temperature set by the temperature setting unit. .

The operation of the blower is reduced or stopped when the cooling capacity of the cooling means is reduced or stopped, and the heat generated by the blower prevents the temperature in the insulated room from rising, and also reduces the power consumption. To reduce air pollution and extend the life of blowers.

[Problems to be Solved by the Invention] However, the conventional low-temperature maintaining device can only lower the temperature in the heat-insulated room. Therefore, when the temperature outside the heat insulation chamber (hereinafter, outside the heat insulation chamber) becomes lower than the set temperature, there is a problem that the temperature inside the heat insulation chamber becomes lower than the set temperature.

The present invention has been made in view of the above circumstances, and an object thereof is to maintain the temperature in an insulated room at a set temperature even when the temperature outside the insulated room is lower than the set temperature set by the temperature setting means. The purpose of the present invention is to provide a low-temperature maintenance device capable of maintaining the temperature.

[Means for Solving the Problems] In order to achieve the above object, as shown in FIG.
A cooling means 2 for cooling air in the heat insulating chamber 1; a blower 3 provided in the heat insulating chamber 1 to generate an air flow in the heat insulating chamber 1; A temperature detecting means 4 for detecting the temperature in the heat insulating chamber 1 detected by the temperature detecting means 4 is higher than a set temperature, at least the cooling means 2 is operated to lower the temperature in the heat insulating chamber 1. Temperature lowering means 5 and temperature detecting means 4
When the temperature in the heat insulating chamber 1 detected by the air conditioner is lower than a set temperature, the control device 7 includes a temperature increasing means 6 for operating the blower 3 to increase the temperature in the heat insulating chamber 1. Adopt technical means.

[Operation] The operation of the low-temperature maintaining device configured as described above will be described.

When the temperature outside the insulation room is higher than the set temperature inside the insulation room.

The temperature lowering means of the control device activates at least the cooling means when the temperature in the adiabatic room detected by the temperature detecting means is higher than the set temperature. Then, the cooling means cools the air in the insulated room.

At this time, when the blower is operated, the blower generates an airflow in the insulated room, increases the amount of air cooled by the cooling unit, increases the cooling capacity in the insulated room, and reduces the air cooled by the cooling unit. The heat is diffused by the blower, and the temperature in the insulated room becomes uniform.

Conversely, when the temperature outside the insulation room is lower than the set temperature inside the insulation room.

The temperature increasing means of the control device activates the blower when the temperature in the adiabatic room detected by the temperature detecting means is lower than the set temperature. Then, the heat generated by the operation of the blower heats the air in the insulated room. Then, the air heated by the blower is diffused by the blower, and the temperature in the insulated room becomes uniform.

[Effects of the Invention] Since the present invention is configured as described above, it has the following effects.

When the temperature in the insulated room is higher than the set temperature, the temperature in the insulated room is kept at the set temperature by the temperature lowering means, and when the temperature in the insulated room is lower than the set temperature, the temperature in the insulated room is set by the temperature increasing means. Kept at temperature.

Example Next, an example in which the low-temperature maintenance device of the present invention is applied to a refrigerating vehicle will be described with reference to the drawings.

 FIG. 2 shows a schematic view of a refrigerator car.

In this refrigerating vehicle, a heat insulation chamber 10 is provided in the rear half of the vehicle, which is insulated from the outside by a heat insulating material or the like.

Above the front of the heat insulating chamber 10, a cooling unit 20 is attached. The cooling unit 20 has an inlet 21 on the lower surface and an outlet 22 on the rear. Further, inside the cooling unit 20, a blower 30 for the inside of a refrigerator that sucks air in the heat insulating chamber 10 from the inlet 21 and blows out the sucked air from the outlet 22 into the heat insulating chamber 10 is attached. In addition, the blower 30 for the interior is a blower of the present invention that generates an air flow in the heat insulating chamber 10 by operating, and a control device described below.
The energization is controlled by 50.

The refrigerant evaporator 41 of the refrigeration cycle 40 is attached to an air passage in the cooling unit 20. The refrigeration cycle 40
In addition to the refrigerant evaporator 41, it has a known configuration including a refrigerant compressor 42, a refrigerant condenser 43, a receiver 44, a refrigerant pressure reducing device 45, and a refrigerant pipe 46 connecting these. Then, the refrigerant evaporator 41 is a cooling unit of the present invention, and the refrigerant flowing therein takes heat from the air flowing in the cooling unit 20 and evaporates.As a result, the air passing through the refrigerant evaporator 41 is cooled, This is for cooling the inside of the heat insulating chamber 10. The refrigerant compressor 42 is provided with an electromagnetic clutch 47, and when the electromagnetic clutch 47 is energized, transmits the rotational torque of an engine (not shown) to the refrigerant compressor 42. The refrigerant condenser 43 includes a blower 48 for the condenser for forcibly exchanging heat between the refrigerant passing therethrough and air. The energization of the electromagnetic clutch 47 and the blower 48 for the condenser is controlled by a control device 50 described below.

The above-described internal blower 30, electromagnetic clutch 47 and condenser blower 48 are energized by a control device 50. FIG. 3 shows an example of an electric control circuit of the control device 50.
The control device 50 of the present embodiment includes a microcomputer 51. The microcomputer 51 includes a refrigeration operation switch 52, a heat retention switch 53, a temperature setting unit 54, and a temperature detection unit.
In accordance with the state 55, the first relay coil 56 and the second relay coil 57 are energized.

The refrigeration operation switch 52 is manually operated by a user such as a vehicle occupant, and is turned on by the user when the user wants to lower the inside of the heat insulating chamber 10 to the temperature set by the temperature setting means 54. Things. The heat retention switch 53 is provided when the temperature outside the heat insulating chamber 10 is lower than the set temperature set by the temperature setting unit 54, and when the temperature inside the heat insulating chamber 10 is not desired to be lower than the set temperature. By user
It is turned on. The temperature setting means 54 is a variable resistor, and is used by a user to manually set the temperature in the heat insulating chamber 10 as desired. The temperature detecting means 55 is a thermistor for detecting the temperature in the heat insulating chamber 10. When the first relay coil 56 is energized, the relay switch 56a
N, and energizes the electromagnetic clutch 47 and the blower 48 for the condenser. When the second relay coil 57 is energized, the relay switch 57a is turned on, and the blower 3
0 is energized.

Reference numeral 58 shown in the drawing indicates a battery as a vehicle power supply, and reference numeral 59 indicates a key switch.

Next, the operation of the microcomputer 51 will be described based on the flowchart of FIG.

With the key switch 59 turned ON, the refrigeration operation switch
When 52 is turned on (start), it is determined in step S1 whether or not the heat retention switch 53 is turned on.

If the determination result of step S1 is NO, the step
In S2, it is determined whether or not the temperature in the heat insulation chamber 10 detected by the temperature detecting means 55 is higher than the set temperature set by the temperature setting means 54. If the decision result in the step S2 is YES, in a step S3, the first relay coil 56 and the second relay coil 57 are energized, and then the process returns. If the judgment result in step S2 is NO, step S4
The first relay coil 56 and the second relay coil
The energization of 57 is stopped, and then the process returns.

If the decision result in the step S1 is YES, in a step S5, it is determined whether or not the temperature in the heat insulating chamber 10 detected by the temperature detecting means 55 is higher than the set temperature set by the temperature setting means 54. Do. If the decision result in the step S5 is YES, in a step S6, the first relay coil 56 and the second relay coil 57 are energized, and then the process returns. If the decision result in the step S5 is NO, in a step S7,
Stop the energization of the first relay coil 56 and set the second relay coil
Turn on 57. And then return.

The operation of steps S2 to S4 indicates the operation of the temperature decreasing means of the present invention programmed in the microcomputer 51, and the operation of steps S5 to S7 of the temperature increasing means of the present invention programmed in the microcomputer 51. Indicates operation.

 Next, the operation of the above embodiment will be briefly described.

B) When the temperature outside the heat insulating chamber 10 is higher than the temperature set by the temperature setting means 54. In this case, it is assumed that the user has turned on the freezing operation switch 52 and has not turned on the heat retention switch 53.

Immediately after the startup, if the temperature in the heat insulating chamber 10 is higher than the set temperature, the electromagnetic clutch 47, the blower 48 for the condenser, and the blower 30 for the refrigerator are energized by the operation of the control device 50.

The refrigeration cycle 40 operates by the energization of the electromagnetic clutch 47, and the refrigerant evaporator 41 cools the air in the cooling unit 20. Then, the cooled air is blown out of the cooling unit 20 into the heat insulating chamber 10 by the blower 30 for the inside of the refrigerator, and
Decrease the temperature inside.

And when the temperature in the heat insulation room 10 falls to the set temperature,
By the operation of the control device 50, energization of the electromagnetic clutch 47, the blower 48 for the condenser, and the blower 30 for the inside of the refrigerator is stopped.

Then, since the refrigerant evaporator 41 does not perform cooling of the air in the heat-insulating chamber 10, heat outside the heat-insulating chamber 10 is transmitted to the heat-insulating chamber 10 little by little through the heat-insulating material constituting the heat-insulating chamber 10.

Then, when the temperature in the heat insulating chamber 10 becomes higher than the set temperature, the electromagnetic clutch 47, the blower 48 for the condenser, and the blower 30 for the refrigerator are energized by the operation of the control device 50.

Note that the internal blower 30 generates heat when operating, but the cooling capacity of the refrigerant evaporator 41 is much larger than the amount of heat generated by the blower 30. Therefore, even if the blower 30 generates heat, the inside of the heat insulating chamber 10 is cooled by the operation of the refrigerant evaporator 41.

B) When the temperature outside the heat insulating chamber 10 is lower than the temperature set by the temperature setting means 54. In this case, the user turns on the heat retention switch 53 together with the freezing operation switch 52.

Immediately after the start, if the temperature in the heat insulating chamber 10 is lower than the set temperature, only the blower 30 for the refrigerator is energized by the operation of the control device 50.

Then, the blower 30 for the inside operates and the blower 30 generates heat. The heat generated by the blower 30 is
The air flow generated by the blower 30 blows out of the cooling unit 20 into the heat insulating chamber 10 to increase the temperature inside the heat insulating chamber 10.

And when the temperature in the heat insulation room 10 rises to the set temperature,
By the operation of the control device 50, the electromagnetic clutch 47 and the blower 48 for the condenser are energized in addition to the blower 30 for the refrigerator.
Then, as described above, the refrigerant evaporator 41 is moved to the heat insulating chamber 10.
Cool the air inside.

When the temperature in the heat insulating chamber 10 becomes lower than the set temperature, the control device 50 stops the energization of the electromagnetic clutch 47 and the blower 48 for the condenser, and again only the blower 30 for the inside of the refrigerator is energized again. .

By repeating the above, even if the temperature outside the heat insulating chamber 10 is lower than the set temperature, the temperature inside the heat insulating chamber 10 is kept near the set temperature.

In this embodiment, a heat-retaining switch is added to an existing refrigerator car (a refrigerant evaporator and a blower are provided in an adiabatic room, and the temperature is controlled by a control device using a microcomputer). Since it can be implemented by the change, there is also an effect that it can be provided at a low cost.

(Modification) In the present embodiment, an example having no hysteresis is shown to explain the basic operation. However, when actually mounted on a vehicle, FIG. 5 (operation by the temperature lowering means) And FIG. 6 (operation by the temperature increasing means),
Program the microcomputer to have hysteresis.

In the present embodiment, an example is shown in which the temperature raising means and the temperature lowering means are switched by the heat retention switch. However, the refrigeration operation switch and the heat retention switch may be combined into one switch. Further, an outside air temperature detecting means for detecting the temperature outside the heat insulating chamber may be provided instead of the heat retaining switch, and the temperature may be switched between the temperature increasing means and the temperature lowering means depending on the difference between the temperature outside the heat insulating chamber and the set temperature. By doing so,
Can be automated. Further, the temperature raising means and the temperature lowering means may be switched according to the difference between the temperature in the insulated room and the set temperature. In addition, by doing so, it is possible to automate, and it is possible to eliminate the heat retention switch and the outside air temperature detecting means.

Although the example in which the temperature lowering means and the temperature increasing means are programmed in the microcomputer has been described, the temperature lowering means and the temperature increasing means may be constituted by a discrete circuit using, for example, a comparator without using the microcomputer.

In the operation of the temperature increasing means, the blower is always operated, and when the temperature in the insulated room is increased, the cooling means is operated to adjust the temperature in the insulated room. By controlling the amount of air blown (the amount of electricity) and the amount of heat generated by the blower by controlling the ON-OFF operation, the temperature in the insulated room may be adjusted.

Although an example using a refrigerant evaporator as the cooling means has been described, an air compression refrigeration cycle that releases and absorbs heat by compressing and expanding air, and a semiconductor refrigeration element that releases and absorbs heat by energizing a semiconductor. Other cooling means may be used.

Although an example in which the present invention is applied to a refrigerator car is shown, the present invention is applied to other low-temperature maintaining devices such as a small refrigerator for a vehicle mounted on an ordinary passenger car and the like, and a free-standing refrigerator used for general home and business use. May be applied.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing the configuration of the present invention, FIG. 2 is a schematic diagram of a refrigerator car, FIG. 3 is an electric circuit diagram of a control device, and FIG.
FIGS. 5 and 6 are flowcharts showing the operation of the microcomputer, and FIGS. 5 and 6 are time charts showing an operation example in which hysteresis is provided for the temperature control in the insulated chamber. In the figure, 1... Adiabatic room, 2... Cooling means 3... Blower, 4... Temperature detecting means 5... Temperature decreasing means, 6.

Claims (1)

(57) [Claims] (A) a heat insulating chamber insulated from the outside; (b) a cooling means for cooling air in the heat insulating chamber; and (c) a cooling medium provided in the heat insulating chamber to generate an air flow in the heat insulating chamber. (D) (d-1) temperature detecting means for detecting the temperature in the insulated room, and (d-2) when the temperature in the insulated room detected by the temperature detecting means is higher than a set temperature. Temperature lowering means for operating at least the cooling means to lower the temperature in the adiabatic room; (d-3) and when the temperature in the adiabatic room detected by the temperature detecting means is lower than a set temperature, A low-temperature maintenance device comprising: a control device including a temperature increasing unit configured to operate a blower to increase a temperature in the heat-insulated chamber.