JPH07232587A - Structure of refrigerating room of refrigerated vehicle - Google Patents

Abstract

PURPOSE:To prevent the freshness of refrigerated cargoes from being lost by controlling the temperature rise at the rear part of a refrigerating room every time a rear door of the refrigerating room of a refrigerated vehicle is opened/ closed. CONSTITUTION:A temperature control means 7 is constituted by providing a first evaporator 5A for a first half part of the roof where cooling coils 6A, 6B are separately formed and connected in parallel to a refrigerant piping 8 and a second evaporator 5B for a second half of the roof inside the roof 3 of a refrigerating room 2, and providing a control valve 9 to shut off the flow of the refrigerant when a rear door 3 is opened on a refrigerant introducing part of the first evaporator 5A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating room structure for a refrigerating vehicle used for transportation of frozen food.

[0002]

2. Description of the Related Art As is well known as a refrigeration system for a refrigerating room of a refrigerating vehicle, a unit cooler in which an evaporator and a cooling fan are integrally assembled is arranged at an appropriate position above the refrigerating room to form an evaporator. In general, a refrigerant is introduced to cool the air, and the cooling fan circulates the air in the freezing room to cool the inside of the freezing room.

[0003]

When transporting food frozen by a refrigerating vehicle over a long distance, the rear door is opened each time a load is loaded or unloaded during transportation, even if the inside of the freezing room is cooled to a predetermined low temperature. When the door is opened, the temperature at the back of the freezing room rises and the frozen state of the food changes, or the frost adhering to the inside of the freezing room melts due to the temperature rise, and when this drops directly onto the frozen food, close the rear door and reopen it. Even if it returns to the frozen state, the freshness of the frozen food may decrease and the commercial value may be impaired.

In order to avoid such a situation, the refrigerating capacity of the refrigerating room may be increased. However, in the air circulation system using the unit cooler as described above, the refrigerating capacity is increased. It is necessary to increase the output of the vehicle-mounted engine that drives the compressor, and there is no choice but to increase the size of the engine.

However, increasing the size of the engine mounted on the vehicle in order to improve the refrigerating capacity necessitates a drastic change in the vehicle body itself, which not only makes the vehicle body unnecessarily large, but also in terms of weight and cost. Will be very disadvantageous to.

Under these circumstances, the freezing capacity must be sacrificed to some extent, and it is not possible to transport foods that have been frozen over a long distance and a long time in an ultra-low temperature frozen state (for example, -50 ° C). It is difficult to make friends.

On the other hand, instead of such a cooling air circulation system using a unit cooler, liquefied nitrogen gas is directly sprayed into the freezing room to maintain the frozen food loaded in the freezing room in an ultra-low temperature frozen state. However, it is difficult to control the temperature in the freezing room with this method, and it is not possible to appropriately control the temperature according to the loading amount of frozen food.

Further, in order to spray the liquefied nitrogen gas, a cylinder of the liquefied nitrogen gas is mounted on the vehicle, but the capacity of the cylinder becomes unnecessarily large in consideration of the mounting space and weight on the vehicle. However, the capacity of the cylinder is limited by itself, and in the current situation where the supply base of liquefied nitrogen gas is limited and limited, it is not suitable for long-distance transportation, and the liquefied nitrogen gas itself is not suitable. Since it is expensive, it is disadvantageous in terms of cost.

Therefore, according to the present invention, the cooling temperature of the front and rear portions of the freezing room can be controlled, and even when the rear door of the freezing room is opened, the cooling temperature of the rear portion of the freezing room is kept low and the frozen food loaded is loaded. The present invention provides a refrigerating room structure for a refrigerating vehicle that does not cause a change in the frozen state or frost that has adhered to the inside of the freezing room is melted and dripped onto frozen food.

[0010]

According to a first aspect of the present invention, there is provided a cooling coil in which a pipe for conducting a refrigerant is formed in a meandering shape from a front portion to a rear portion inside a roof of a freezing room having a rear door formed at a rear portion of a vehicle body. Is provided to form an evaporator, and temperature control means for controlling the cooling temperature of the first half and the second half of the evaporator is provided.

According to a second aspect of the present invention, a first evaporator in the front half of the roof and a second evaporator in the rear half of the roof, in which cooling coils formed separately from the evaporator are connected in parallel to the refrigerant pipes, respectively.
The first evaporator is provided with a control valve for shutting off the flow of the refrigerant when the rear door is opened at the refrigerant introduction portion of the first evaporator.

According to a third aspect of the present invention, as the control valve,
It uses an expansion valve that is manually closed prior to opening the rear door.

According to a fourth aspect of the present invention, as the control valve,
A normally open type switching valve is provided which is provided in the refrigerant introducing portion of the first evaporator and which is closed by a detection signal of a door sensor which detects the opening of the rear door when the rear door is opened.

According to a fifth aspect of the present invention, the evaporator includes a first cooling coil portion formed in the latter half of the inside of the roof by a single refrigerant conducting pipe, and the inside of the roof following the first cooling coil portion. With the second cooling coil portion formed in the first half of the, the refrigerant introduction portion is set to the end portion of the first cooling coil portion, while the refrigerant lead portion is set to the end portion of the second cooling portion,
The refrigerant flow path is set to a series path from the first cooling coil section to the second cooling coil section.

[0015]

According to the present invention, the temperature control means controls the cooling temperature of the front half and the rear half of the evaporator disposed from the front to the rear inside the roof of the freezing room. Therefore, by lowering the cooling temperature of the latter half of the evaporator when the rear door is opened, the temperature rise in the rear part of the freezing room due to the opening of the rear door is suppressed, and the frost in the rear part of the freezing room is melted and the frozen state of frozen food loaded is frozen You can avoid making changes.

According to a second aspect of the present invention, the evaporator is composed of a first evaporator in the front half of the roof and a second evaporator in the rear half of the roof, in which cooling coils formed separately are connected in parallel to the refrigerant pipe. Since a control valve for shutting off the flow of the refrigerant is provided in the refrigerant introduction portion of the first evaporator when the rear door is opened, when the rear door is opened during the operation of the refrigeration cycle, the control valve operates by By shutting off the refrigerant introduction part of the first evaporator, the entire amount of the refrigerant can be supplied to the second evaporator in the latter half of the roof, so that the second evaporator in the latter half of the roof can be cooled without increasing the compressor output. By significantly lowering the temperature, it is possible to suppress the temperature rise in the rear part of the freezing room due to the opening of the rear door.

According to the third aspect of the invention, since the control valve is composed of the expansion valve, the temperature control can be easily performed by manually closing the expansion valve before opening the rear door. be able to.

According to a fourth aspect of the present invention, the control valve is a normally open type switching valve, and the switching valve is closed by a detection signal of a door sensor for detecting the opening of the rear door. When the rear door is opened, the refrigerant introduction section on the first evaporator side can be automatically shut off to reliably perform the temperature control.

According to the fifth aspect, the refrigerant flows in series from the first cooling coil section in the latter half of the roof to the second cooling coil section in the first half of the roof, and the cooling temperature of the latter half of the freezing room is the first half of the freezing room. Since the cooling temperature is controlled to be lower than the cooling temperature, the temperature rise in the rear part of the freezing room can be suppressed even when the rear door is opened.

[0020]

Embodiments of the present invention will now be described in detail with reference to the drawings.

1 to 3, reference numeral 1 denotes a vehicle body,
A closed box-shaped freezing room 2 having, for example, a double door type rear door 3 is provided at the rear part thereof.

Inside the roof 4 of the freezing room 2, a cooling coil 6 in which a pipe for conducting a refrigerant is formed in a meandering manner is arranged in a bare pipe state to form an evaporator 5, and the evaporator 5 is also provided. A temperature control means 7 is provided to control the cooling temperature of the first half and the second half.

In this embodiment, as the evaporator 5, cooling coils 6A and 6B, which are separately formed, are used.
The first evaporator 5A in the front half of the roof and the second evaporator 5B in the rear half of the roof are connected in parallel to the refrigerant pipe 8.

In addition, in the refrigerant introducing portion of the first evaporator 5A, specifically, in the branch pipe 8a of the refrigerant pipe 8, the freezing room 2 is provided.
Control valve 9 for shutting off the flow of the refrigerant when the rear door 3 of the vehicle is opened
In this embodiment, the evaporator 5 is thus divided into the first half 5A and the second half 5B of the roof front half and the roof rear half, and these are connected in parallel to the refrigerant pipe 8. In addition, the temperature control means 7 is configured by providing the control valve 9 in the refrigerant introduction part 8a of the first evaporator 5A.

The first evaporator 5A and the second evaporator 5B
Refrigerant introduction part, that is, the branch pipes 8a, 8 of the refrigerant pipe 8
Although expansion valves 10 and 11 are provided in b, respectively, in this embodiment, the expansion valve 10 of the first evaporator 5A is effectively used as a control valve 9 that is manually closed prior to opening the rear door 3. ing.

As the pipe for conducting the refrigerant forming the cooling coils 6A and 6B, a metal pipe having good heat conductivity and corrosion resistance is used, but it is arranged on the inner side of the roof 4 as a whole. In order to reduce the weight of the vehicle body and keep the weight of the vehicle low, a lightweight metal pipe such as titanium, titanium alloy, aluminum, or aluminum alloy is preferable. Among them, a pipe made of titanium or titanium alloy has good thermal conductivity and corrosion resistance. Since both are good, and are lightweight and have high hardness, damage resistance can be improved in consideration of interference with the cargo when wiring the cooling coils 6A and 6B in a bare pipe state as described above, which is the most preferable.

According to the structure of the above embodiment, the freezing room 2
When frozen food is loaded inside and the refrigeration cycle (not shown) is activated, the liquid refrigerant sent to the evaporator 5 is
Is branched by the branch pipes 8a, 8b and supplied to the first evaporator 5A and the second evaporator 5B side in substantially equal parts.
1 is expanded and gasified in the first evaporator 5A and the second evaporator 5B to perform a cooling action, and the first half and the second half of the freezing room 2 are cooled at the same cooling temperature by natural convection.

When the rear door 3 is opened for loading and unloading loads during the operation of such a refrigeration cycle, if the expansion valve 10 as the control valve 9 is manually closed prior to the opening of the rear door 3, Since the entire amount of the liquid refrigerant sent to the evaporator 5 is supplied to the second evaporator 5B in the latter half, the refrigerating action of the second evaporator 5B is enhanced without increasing the output of the compressor (not shown), and the freezing room The cooling temperature of the latter half of 2 is remarkably lowered.

Therefore, even if the rear door 3 is opened, the temperature rise in the rear part of the freezing room 2 can be suppressed, and the melting of frost in the rear part of the freezing room and the frozen state of the frozen food loaded can be changed. Can be avoided.

When the loading and unloading work of the load is completed and the rear door 3 is closed and the expansion valve 10 is manually returned to the original predetermined open state, the first evaporator 5A and the second evaporator 5 are
An equal amount of refrigerant is supplied to B, and the front half and the rear half of the freezing room 2 are cooled to a uniform low temperature.

FIG. 4 shows a different example of the temperature control means 7, in which the evaporator 5 is divided into a first evaporator 5A in the front half of the roof of the freezing room 2 and a second evaporator 5B in the rear half of the roof. The first evaporator 5A and the second evaporator 5B are connected in parallel to the refrigerant pipe 8 in the same manner as in the above embodiment, but the control valve 9 serves as the refrigerant introduction side of the first evaporator 5A. A normally open type electromagnetic switching valve 12 is provided in the branch pipe 8a in the upstream side of the expansion valve 10, and a door sensor 13 for detecting the opening of the rear door 3 is provided in a mounting portion of the rear door 3. The electromagnetic switching valve 12 is closed by the detection signal of 13.

According to this embodiment, when the rear door 3 is opened during the operation of the refrigerating cycle, the door sensor 13 detects it and immediately closes the electromagnetic switching valve 12 to activate the first evaporation of the front half of the roof. It is possible to cut off the supply of the refrigerant to the evaporator 5A, supply all the amount of the refrigerant sent to the evaporator 5 to the second evaporator 5B in the rear half of the roof, and automatically lower the cooling temperature in the rear half of the freezing room 2. it can.

When the rear door 3 is closed, the electromagnetic switching valve 12 is opened by the door sensor 13 and the first evaporator 5A is opened.
Then, the amount of refrigerant supplied to the second evaporator 5B is made uniform, and the first half and the second half of the freezing room 2 are cooled at a uniform low temperature.

Therefore, in this embodiment, unlike the case where the control valve 9 is manually operated every time the rear door 3 is opened and closed, the opening and closing of the control valve 9 is not forgotten, and the rear door 3 is not forgotten. When the door is opened, the cooling temperature of the second half of the freezing room 2 is automatically lowered to suppress the temperature rise.
When the door is closed, the inside of the freezing room 2 can be automatically cooled uniformly.

FIG. 5 shows a third embodiment of the present invention.

In this embodiment, the evaporator 20 provided inside the roof 4 of the freezing room 2 from the front part to the rear part is formed in the latter half part inside the roof by one refrigerant conducting pipe. The first cooling coil portion 21A having a large number of coil turns and the second cooling coil portion 21B having a small number of coil turns formed in the front half of the inside of the roof subsequent to the first cooling coil portion 21A, and The coolant introduction part 20a is set to the end of the first cooling coil part 21A, while the coolant derivation part 20b is set to the end of the second cooling coil part 21B to set the refrigerant circulation path to the first cooling coil part 21A.
To the second cooling coil unit 21B as a series path.

According to this embodiment, when the refrigerating cycle is operated, the liquid refrigerant is supplied to the refrigerant introducing portion 20a of the first cooling portion 21A in the rear half of the roof, passes through the expansion valve 22 and is gasified, After circulating through the first cooling coil portion 21A, after traveling around the second cooling coil portion 21B in the latter half of the roof, it is led out to the compressor (not shown) via the refrigerant outlet portion 20b.

Therefore, the refrigerant gas is transferred to the first cooling coil unit 2
The refrigerating capacity gradually decreases in the process of flowing from 1A to the second cooling coil portion 21B, and the cooling temperature of the second half of the freezing room 2 in which the first cooling coil portion 21A is arranged is the second cooling coil portion 21B. Since the cooling temperature is controlled to be lower than the cooling temperature of the first half of the freezing room 2, the temperature of the rear part of the freezing room 2 does not rise extremely even when the rear door 3 is opened, and the frost in the rear part of the freezing room 2 does not rise. It is possible to prevent the melted product from being melted or the frozen state of the frozen food to be changed.

Therefore, according to this embodiment, even if a special control valve is not used as the temperature control means or the operation control means of the control valve is not used, only the layout of the cooling coil 21 can be changed to easily achieve the desired result. The purpose of can be achieved, which is very advantageous in terms of cost.

In this embodiment, the first cooling coil section 2 is also used.
In 1A and the 2nd cooling coil part 21B, after flowing a refrigerant,
Although the cooling temperature is originally different in the downstream relationship, if the rear door 3 is closed, the cooling temperature in the freezing room 2 is substantially equalized due to natural convection in the front and rear parts of the freezing room 2,
There will be no problem in freezing the cargo.

[0041]

As described above, according to the present invention, the following effects can be obtained.

(1) An evaporator is constructed by arranging a cooling coil from the front part to the rear part inside the roof of the freezing room to control the cooling temperature of the first half and the second half of the evaporator. Since the temperature control means is provided, by lowering the cooling temperature of the latter half of the evaporator when the rear door is opened, it is possible to prevent the temperature of the rear part of the freezing room from rising above a certain level due to the opening of the rear door. .

As a result, the frost adhering to the evaporator at the rear of the freezing room or its surroundings is melted and dropped onto the cargo to reduce the freshness of the cargo, and the frozen state of the cargo is prevented from changing, and It is possible to prevent the loss of value.

(2) A first evaporator in the front half of the roof and a second evaporator in the rear half of the roof, in which cooling coils formed by separately molding the above-mentioned evaporators are connected in parallel to the refrigerant pipe, If a control valve that blocks the flow of the refrigerant when the rear door is opened is provided in the refrigerant introduction part of the first evaporator, the entire amount of the refrigerant is supplied to the second evaporator by the operation of the control valve when the rear door is opened. Thus, the temperature control described above can be easily performed, and the intended purpose can be achieved cost effectively without increasing the output of the compressor and its drive system.

(3) If the expansion valve attached to the first evaporator is effectively used as the control valve, and the expansion valve is manually closed before opening the rear door,
The cost can be advantageously obtained without increasing the number of parts.

(4) If a normally open type switching valve is used as the control valve and the switching valve is closed by a detection signal of a door sensor for detecting the opening of the rear door, the above-mentioned refrigerant supply can be achieved. The temperature control by the control can be automatically performed, and it is possible to avoid erroneous operation.

(5) A first cooling coil section having an evaporator provided inside the roof of the freezing room from the front part to the rear part and formed in the latter half of the roof by a single pipe for conducting refrigerant, and the first cooling A second cooling coil portion formed in the front half of the roof following the coil portion, the refrigerant introduction portion is set at the end portion of the first cooling coil portion, and the refrigerant discharge portion is formed at the end portion of the second cooling coil portion. Setting the refrigerant flow path to a serial path from the first cooling coil unit to the second cooling coil unit, the cooling temperature of the latter half of the freezing room by the first cooling coil unit is frozen by the second cooling coil unit. The cooling temperature can be controlled to be lower than the cooling temperature in the first half of the room, and the temperature control means can be easily configured only by changing the layout of the cooling coil.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing a main part of a refrigerant circuit according to a first embodiment of the present invention.

FIG. 2 is a schematic side view of a refrigeration vehicle adopting the same embodiment.

FIG. 3 is a schematic plan view of FIG.

FIG. 4 is an explanatory view similar to FIG. 1 showing a second embodiment of the present invention.

FIG. 5 is an explanatory view similar to FIG. 1, showing a third embodiment of the present invention.

[Explanation of symbols]

 1 Body Body 2 Freezing Room 3 Rear Door 4 Roof of Freezing Room 5 Evaporator 7 Temperature Control Means

Claims (5)

[Claims] 1. An evaporator is constructed by arranging a cooling coil having a meandering pipe for conducting a refrigerant from a front portion to a rear portion inside a roof of a freezing room having a rear door formed at a rear portion of a vehicle body. A refrigerating room structure for a refrigerating vehicle, comprising temperature control means for controlling a cooling temperature of a front half and a rear half of the evaporator. 2. The first half of the front half of the roof, wherein the cooling coils formed separately from the evaporator are connected in parallel to the refrigerant pipe.
It consists of an evaporator and a second evaporator in the latter half of the roof.
2. The refrigerating room structure for a refrigerating vehicle according to claim 1, wherein a control valve for cutting off the flow of the refrigerant when the rear door is opened is provided in the refrigerant introducing portion of the evaporator. 3. The refrigerating compartment structure for a refrigerating vehicle according to claim 2, wherein the control valve is an expansion valve which is manually closed prior to opening the rear door. 4. A normally open type switching valve, wherein the control valve is provided in a refrigerant introducing portion of the first evaporator and is closed when a rear door is opened by a detection signal of a door sensor for detecting the opening of the rear door. The refrigerating room structure of the refrigerating vehicle according to claim 2. 5. The evaporator is formed by a single refrigerant conducting pipe in a first cooling coil portion formed in a rear half portion inside the roof and in a front half portion inside the roof following the first cooling coil portion. The second cooling coil portion is provided, and the refrigerant introduction portion is set at the end portion of the first cooling coil portion, while the refrigerant lead-out portion is set at the end portion of the second cooling coil portion, and the refrigerant circulation path is set to the first cooling coil portion. The refrigerating room structure for a refrigerating vehicle according to claim 1, wherein a series path from the first cooling coil section to the second cooling coil section is set.