JPH0442703Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a show case equipped with a refrigerant circuit that can alternately perform cooling and defrosting using two evaporators.

(Prior art) Conventionally, this type of show case has two evaporators placed in the air passage provided on the back side of the show case body through a partition plate, and each evaporator performs cooling and defrosting alternately. It is designed to cool the inside of the refrigerator and keep products cold.

(Problem to be solved by the invention) By the way, in the above-mentioned conventional show case, when defrosting is performed in one of the evaporators before the power is turned on, the mode is changed to defrosting in the other evaporator when the power is turned on. If the transfer occurs, the liquid refrigerant filling the cooler on the defrosting side will flow into the compressor, causing the compressor to malfunction.
There are drawbacks that can cause destruction.

In addition, if the mode shifts to a mode in which both coolers perform cooling when the power is turned on, which has a larger heat load than during operation, a large load will be placed on the compressor, resulting in startup failures, or overcurrent will flow into the power circuit, resulting in failure. There are some drawbacks that may arise.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a show case that can start operation in an appropriate mode when the power is turned on.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes first and second evaporators arranged in the air passage in the case main body via a partition plate, and the first evaporator A first mode in which the evaporator is defrosted and the second evaporator is cooled; a second mode in which the first evaporator is cooled and the second evaporator is defrosted; In a case equipped with a refrigerant circuit that can be operated in the third mode for cooling the evaporator, if the first or second mode is in operation before the power is turned on, the first mode starts operation in the pre-power-on mode when the power is turned on. an initial operating means, and a second mode that starts operation in either the first or second mode when the power is turned on if the third mode is before the power is turned on;
An initial operating means is provided, and a normal operating means is provided which operates in the order of the first, third, second, third, . . . modes after the initial operation.

(Function) In the case according to the present invention, when the power is turned on in the first or second mode, operation is started in the pre-power-on mode when the power is turned on. Furthermore, if the power is in the third mode before the power is turned on, operation is started in either the first or second mode when the power is turned on.

(Embodiment) FIGS. 1 to 5 show an embodiment of the present invention.

First, the structure of the case body will be explained with reference to FIG. In the figure, reference numeral 1 denotes a case body, and heat insulating panels 10 are arranged on the top, back, bottom, and side surfaces of the case body, and upper wall portions 10a,
A back wall portion 10b, a bottom wall portion 10c, and a side wall portion 10d are formed.

Inside the case body 1, there are air passages 11 along the top wall 10a, the back wall 10b, and the bottom wall 10c.
An inner box 12 is provided to form a
Divided into layers.

Although not shown, the air passage 11 is located at the back wall portion 10b.
It is divided into three parts in the direction of the side wall portion 10d, and evaporators 22a, 22b and damper 23c, which will be described later, are arranged in the center of this three-part air passage (see, for example, Japanese Utility Model Publication No. 10853/1983).

An air outlet 14 and an inlet 15 are provided at the top and bottom of the front opening of the case body 1, respectively, and non-cooling air 16a is supplied from the air outlet 14 by a blower (not shown) as shown by the dashed-dotted line arrow in the figure. Inlet 15
The air is blown out towards the suction port 15 and the bottom wall portion 10.
It circulates through the air passage 11 on the lower side of c, the air passages (not shown) on both sides of the back wall part 10b, and the air passage 11 on the upper side of the upper wall part 10a.

Also, inside the non-cooling air 16a at the front opening, there is an evaporator 22 as shown by the solid arrow in the figure.
The cooling air 16b with which heat has been exchanged by the air blowers 16a and 22b is blown out from the air outlet 14 toward the suction port 15 by the blower 17.
The air circulates through the upper air passage 11, the central air passage 13 of the back wall 10b, and the lower air passage 11 of the upper wall 10a.

In other words, an air curtain 16 is formed at the front opening of the case body 1 by the two types of winds 16a and 16b.

There are a plurality of shelf boards 18 inside the storage case body 1.
and net plates 19 are arranged above and below so that products can be displayed.

The aforementioned air passage 13 is divided into two layers in the front-rear direction by providing a partition plate 20 in parallel between the back wall portion 10b and the inner box 12, and is divided into two layers, a first air passage 20a and a second air passage. A passage 20b is formed. Partition plate 2
0 is bent at the center and has a first air passage 20a.
is narrower below the center, and the second air passage 20b is narrower above the center.

Above the first air passage 20a, an inner box 12
A first evaporator 22a is fixedly arranged between a mounting plate 21 and a partition plate 20 provided in the
A first evaporator 22b is fixedly arranged between the first evaporator 22b and the first evaporator 22b.

Further, at the upper end of the partition plate 20, first and second
Damper 23 that opens and closes the air passages 20a and 20b of
A damper unit 23 containing the air conditioner c is attached, and above the damper unit 23, the above-mentioned blower 17 is arranged.

Next, the refrigerant circuit built into the above-mentioned show case body 1 will be explained with reference to FIG. The compressor 24 shown in the figure has an outlet side 24a connected to a condenser 25. Further, the outlet side of the condenser 25 is branched into three routes, and each branch part has a solenoid valve 26a,
26b and 26c are interposed.

The branch end where the solenoid valve 26a is installed is connected to the inlet side of the first evaporator 22a, and the solenoid valve 26c is connected to the inlet side of the first evaporator 22a.
The branch end where the evaporator 22b is interposed is connected to the inlet side of the second evaporator 22b.

Between the outlets of the solenoid valves 26a and 26b and the solenoid valve 26
Check valves 27a and 27b facing leftward and rightward, respectively, are provided between the outlets b and 26c.
Furthermore, expansion valves 28a and 28b are provided between the check valve 27a and the solenoid valve 26a, and between the check valve 27b and the solenoid valve 26c, respectively.

Further, the outlet sides of the first and second evaporators 22a and 22b are connected to the inlet side 24b of the compressor 24 via electromagnetic valves 26d and 26e, respectively. Further, the inlets of the electromagnetic valves 26d and 26e are connected via a pair of opposing check valves 27c and 27d, and the remaining branch end, in which the electromagnetic valve 26b is interposed, is connected to the intermediate point of the connection.

In the above refrigerant circuit, the solenoid valves 26b, 26c,
When the compressor 24 is operated with the solenoid valve 26d closed and the solenoid valves 26a and 26e open, the refrigerant discharged from the compressor 24 passes through the condenser 25 and the solenoid valve 26a in order and flows into the first evaporator 22a. The first evaporator 22a is defrosted, and the refrigerant from the first evaporator 22a flows through the check valves 27c and 27b.
and the expansion valve 28b in order to the second evaporator 22b.
and is cooled in the second evaporator 22b (first mode).

Also, close the solenoid valves 26a, 26b, 26e,
The compressor 24 is opened with the solenoid valves 26c and 26d open.
When the refrigerant is operated, the refrigerant discharged from the compressor 24 passes through the condenser 25 and the solenoid valve 26c in order and flows into the second evaporator 22b, defrosting the second evaporator 22b and defrosting the second evaporator 22b. The refrigerant from the evaporator 22b flows through the check valves 27d, 27a and the expansion valve 28a.
, and flows into the first evaporator 22a, where it is cooled (second mode).

Furthermore, the solenoid valves 26a and 26c are closed, and the solenoid valve 2
With 6b, 26d, and 26e open, compressor 24
When the refrigerant is activated, the refrigerant discharged from the compressor 24 passes through the condenser 25 and the solenoid valve 26b in order, and then the check valve 2
7a, 27b parts, one side is check valve 27a
and the expansion valve 28a in order to the first evaporator 22a.
and the other flows into the check valve 27b and the expansion valve 2.
8b and flows into the second evaporator 22b, where cooling is performed in both evaporators 22a, 22b (third mode).

The refrigerant circuit is operated in the following mode order according to the control program described below: 1st → 3rd → 2nd → 3rd → 1st → 3rd... However, from the first mode to the third mode. At the time of transition or when transitioning from the second mode to the third mode, the first evaporator 22a or the second evaporator 22b is full of liquid refrigerant, so the solenoid valve 26d or the solenoid valve 26e remains unchanged. When opened, the inlet side 24b of the compressor 24
There is a risk that liquid refrigerant may flow into the unit and cause malfunction or damage.

Therefore, when shifting from the first mode to the third mode, the solenoid valve 26a is closed and only the solenoid valve 26e remains open for a predetermined time, and the first evaporator 22
The liquid refrigerant in a is vaporized (fourth mode). Furthermore, when shifting from the second mode to the third mode, the solenoid valve 26c is closed and only the solenoid valve 26d remains open for a predetermined period of time to vaporize the liquid refrigerant in the second evaporator 22b (fifth mode). mode).

Next, referring to FIG. 3, the damper unit 2
3 will be explained. The damper unit 23 has a damper shaft 23b that is rotationally driven by a motor 23a via a belt, a pulley, etc., and a damper 23c is attached to the damper shaft 23b. This damper 23c can be stopped at positions A, B, and C in FIG. 1 by rotating a damper shaft 23b by a motor 23a.

Specifically, according to the control program described later, the damper 23c stops at position A in the first and fourth modes and opens only the second air passage 20b, and stops at position B in the second and fifth modes. In the third mode, it stops at position C and opens only the first air passage 20a, and in the third mode, it stops at position C and opens the first and second air passages 20a.
0a and 20b are both opened.

A cam 23d having a recess 23d' at one location is attached to the other end of the damper shaft 23b, and around the cam 23d there is a hinge roller lever shape for detecting the stop position of the damper 23c. 3 micro switches 29a, 29b, 29
c is installed.

The positional relationship between the damper 23c, the cam 23d, and each micro switch 29a, 29b, 29c is such that when the damper 23c is in position A, the lever of the micro switch 29a is in the recess 23 of the cam 23d.
d', and when the damper 23c is in position B, the lever of the micro switch 29b is engaged with the cam 23d.
Further, when the damper 23c is in position C, the lever of the micro switch 29c fits into the recess 23d' of the cam 23d, and the micro switches 29a, 29b, 29c
The position at which the damper 23c should stop can be detected depending on the on/off state.

Next, the configuration of the control system will be explained with reference to FIG. In the figure, numeral 30 is a control circuit composed of a microcomputer, and has a control program according to the flow shown in FIG. This control circuit 30 turns on/off the micro switches 29a, 29b, 29c.
The off state is detected, and the drive circuits 31a to 31e of the solenoid valves 26a to 26e and the motor 23a are activated.
Controls the cw direction drive circuit 33a and the ccw direction drive circuit 33b. Note that 34 in the figure is a clock circuit.

Next, the cooling operation of the above-mentioned case will be explained with reference to FIG.

First, micro switch 2 is activated based on power on.
The position of the damper 23c is checked from the on/off states of each of 9a, 29b, and 29c.

When the damper 23c is in position A, the drive circuits 31a and 31e are activated to open the solenoid valves 26a and 26.
e is opened to set the first mode, and when the damper 23c is in position B, the drive circuit 31
c and 31d to open the solenoid valves 26c and 26d to set the second mode, and operate the refrigerant circuit in each mode for 5 minutes.

On the other hand, when the damper 23c is in the position C, the drive circuit 33a or 33b is activated, the damper shaft 23b is rotated in the CW direction or the CCW direction by the motor 23a, and the damper 23c is placed in either the position A or B. In addition, the refrigerant circuit is operated in the first or second mode for 5 minutes in the same manner as above.

When the above setting is the first mode, the drive circuit 31e is operated to open only the solenoid valve 26e and the fourth
mode, and the refrigerant circuit is operated in the fourth mode for 5 minutes. After this, damper 23c
3rd (55 minutes) → 2nd (30 minutes) while switching the position of
) → 5th (5 minutes) → 3rd (55 minutes) → 1st (30 minutes)
The refrigerant circuit is operated in the following mode order: →Fourth (5 minutes)...

On the other hand, if the above settings are in the second mode,
The drive circuit 31d is operated to open only the solenoid valve 26d to set the fifth mode, and the refrigerant circuit is operated in the fifth mode for 5 minutes. After this, while switching the position of the damper 23c, the steps are as follows: 3rd (55 minutes) → 1st (30 minutes) → 4th (5 minutes) → 3rd (55 minutes) → 2nd (30 minutes)
The refrigerant circuit is operated in the following mode order: minute)→fifth (5 minutes)...

According to the above embodiment, when the power is turned on, the damper 2
If the damper 23c is at position A, the first mode is set, and if the damper 23c is at position B, the second mode is set. 22b is defrosted and the evaporator 22a or 22b is filled with liquid refrigerant, the electromagnetic valve 26d or 26e on the outlet side is not opened, and the liquid refrigerant is It is possible to suppress the liquid from flowing into the compressor 24, that is, from generating a liquid back-up, thereby reliably preventing its malfunction or destruction.

Also, even if the damper 23c is in position C when the power is turned on, the damper 23c can be moved to position A or B.
1st or 2nd in the same way as above
Since the mode is initially set, it is possible to reduce the load on the compressor 24, power supply circuit, etc. when the power is turned on, which has a large thermal load, and to reliably prevent startup failures and breakdowns.

Note that the power-on time mentioned in the above embodiments is not only when the show case starts to be used, but also when the power is cut off due to a power outage etc. during operation and is restored again.
This includes cases where the power is turned off and turned on again for some reason while driving.

(Effects of the invention) As detailed above, according to the invention, if the mode is the first or second mode before the power is turned on, operation is started in the pre-power-on mode when the power is turned on. Even when defrosting is performed in any of the evaporators and the evaporator is filled with liquid refrigerant, the liquid refrigerant is prevented from flowing into the compressor, thereby reliably preventing its failure or destruction.

In addition, if the power is in the third mode before the power is turned on, operation will start in either the first or second mode when the power is turned on, so the compressor, power supply circuit, etc. that have a large heat load when the power is turned on will be operated in either the first or second mode. This reduces the burden on customers and reliably prevents startup failures and breakdowns.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the present invention, in which Figure 1 is a sectional view of the show case, Figure 2 is a refrigerant circuit diagram, Figure 3 is a perspective view of the main parts of the damper unit, and Figure 4 is a perspective view of the main parts of the damper unit. The figure is a block diagram of the control system, and FIG. 5 is a flowchart of the control program. In the figure, 1... Showcase main body, 13... Air passage, 22a... First evaporator, 22b... Second evaporator, 30... Control circuit.

Claims (1)

[Claims for Utility Model Registration] A first evaporator and a second evaporator are arranged in the air passage inside the case body through a partition plate, and the first evaporator is defrosted and the second evaporator is cooled. a first mode in which
A show case equipped with a refrigerant circuit that can be operated in a second cooling mode that cools the first evaporator and defrosts the second evaporator, and a third mode that cools the first and second evaporators. , a first initial operation means that starts operation in the pre-power-on mode when the power is turned on if the power is in the first or second mode before the power is turned on; A second initial operation means that sometimes starts operation in either the first or second mode, and a normal operation that operates in the order of the first, third, second, third, etc. modes after the initial operation. A show case characterized in that it is provided with means.