JPS59109757A - Controller for cooling box for automobile - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention includes a cooling evaporator in a refrigerator equipped with an opening/closing member, and a refrigerant is supplied to the evaporator from a refrigeration cycle that also serves as an air conditioner driven by an automobile engine. The present invention relates to an automobile cooling storage control device configured.

Since this device is used in an automobile, which is a poor thermal environment, the temperature inside the refrigerator also changes, which causes a problem in that the time required to cool the refrigerator sufficiently changes.

In view of the above-mentioned problems, the present invention provides an automobile cooling refrigerator control device in which the time required for cooling the inside of the refrigerator to an appropriate temperature after starting cooling is not greatly affected by the original temperature inside the refrigerator. The purpose is to provide

Therefore, in the configuration described at the beginning, the present invention includes a temperature sensor that generates a signal corresponding to the temperature inside the refrigerator, and adjusts the flow resistance of the refrigerant passage connected to the air conditioner in response to the electric signal. The present invention is characterized in that it includes an adjustment device and a control circuit that controls the adjustment device and adjusts the flow resistance according to a signal from the temperature sensor.

According to the present invention, when the temperature inside the refrigerator is high, the amount of refrigerant supplied to the refrigerator evaporator can be increased, and when the temperature inside the refrigerator is low, the amount of refrigerant flowing into the refrigerator can be decreased. This has the advantage that when the temperature inside the refrigerator is low, the amount of refrigerant flowing into the refrigerator can be reduced and the air cooling capacity of the air conditioner can be increased. Furthermore, if a compressor that can change the refrigerant discharge capacity is used, it is effective in reducing the compressor working efficiency.

Although any type of temperature sensor may be used, it is easy to use a heat-sensitive resistance element such as a thermistor. Further, the temperature sensor can be of a type that detects the air temperature inside the refrigerator, and this temperature sensor can also be used to control the operation of the convection fan in the jW.

Hereinafter, the present invention will be explained in detail based on a practical example shown in the accompanying drawings.

FIG. 1 shows a schematic sectional view of the refrigerator 1, and FIG. 2 shows the entire system combined with peripheral devices.

As shown in more detail in FIG. 1, a convection blower motor 2 and an evaporator 3 are disposed inside the refrigerator 1, and an opening/closing member 4 that can be opened and closed by manual operation is provided in the refrigerator 1.
is provided. The evaporator 3 is supplied with refrigerant through pipes 3A and 3B from a refrigeration cycle 5 shown in FIG. 2, which is driven by an automobile.

This evaporator 3 passes the air flow from the blower motor 2 in the upper layer 1liI3C and cools the air flow at this time. This airflow, indicated by the white arrow, passes through the refrigerator section IA in the refrigerator, passes through the lower part of the evaporator 3, and is returned to the blower motor 2. IB indicates the contents stored in refrigerator section IA.

In the lower part 3D of the evaporator 3, a cooling compartment IC is formed in a section shielded from the air flow.

A suitable opening/closing member 6, such as a rotating type or a sliding type, is attached to this refrigerator section IC. ID is refrigerator section I
It shows an ice tray stored in C.

In the refrigerator 1, a heating element 7 that generates heat when energized is disposed in a passageway through which the airflow by the blower motor 2 reaches the refrigerator section IA, for example, between the blower motor 2 and the evaporator 3. As the heating element 7, a honeycomb structure called a ceramic heater or the like is applied. In this embodiment, a material having a particularly positive resistance-temperature coefficient is used.

A heating element with this characteristic, commonly called a PTC heater, exhibits a self-temperature regulating effect by increasing its own resistance value by 1 (6) when its own temperature reaches a predetermined value.

Therefore, the cooling action in the evaporator 3 is stopped,
When the heating element 7 is energized, the air flow is heated by the heating element 7, thereby warming the refrigerator section IA.

Therefore, as far as this embodiment is concerned, the refrigerator 1 can be said to be a freezer, refrigerator, and hot storage.

A temperature sensor, such as a thermistor, for detecting the air temperature inside the refrigerator is disposed in the refrigerator section IA, and is used for electrical control of the temperature inside the refrigerator, which will be described later.

As shown in FIG. 2, the borator 3 of the cooling Ml 1 is piped to be supplied with refrigerant from the refrigeration cycle 5 of the air conditioner. That is, in this embodiment, the evaporator 3 is the evaporator 9 of the air conditioner.
is connected in parallel with ζ.

The refrigeration cycle 5 has a compressor 7 10, and the compressor 10 is mechanically connected to a rotating system (not shown) of an automobile prime mover when an electromagnetic clutch 11 is electrically energized, so that the compressor 10 rotates. It is driven to compress and discharge the sucked refrigerant. The refrigerant compressed by the compressor 10 is
In the process of passing through the circulation path shown by the arrow, the two evaporators 3
．． 9 and from there back to Compre Nosa 10.

In order to enable selective use of the two evaporators 3.9, a solenoid operated valve 14 is provided at the inlet of the evaporator 3, and a constant pressure constant pressure expansion valve (not shown) is provided between the solenoid valve 14 and the evaporator 3. The evaporator 9 is provided with a solenoid valve 15 that opens when electrically energized. Note that a suitable pressure reducing means is also provided between the evaporator 9 and the solenoid valve 15. However, when the solenoid valve 15 is opened during the cooling operation of the air conditioner, the constant pressure expansion valves of the 14 evaporators do not open due to the difference in flow resistance. Cooling effect (
In other words, the refrigerating capacity of the refrigerator section IA or the freezing capacity of the freezer section IC) is extremely limited.

Therefore, if the flow resistance on the evaporator 9 side is increased by occasionally closing the solenoid valve 15, the amount of refrigerant passing through the evaporator lake 3 can be adjusted, thereby adjusting the cooling effect of the refrigerator 1. Therefore, in this embodiment, the solenoid valve 15 is closed intermittently, and the ratio between the closing time and the opening time (intermittent ratio or duty ratio) of the solenoid valve 15 is
By making it depend on the temperature inside the refrigerator detected by the temperature sensor 8, the cooling capacity of the refrigerator is changed according to the temperature inside the refrigerator.

FIG. 2 also shows in block form an electric control circuit for operating the refrigerator 1 and the refrigeration cycle 5 and for adjusting the operating state of the refrigerator 1. As shown in FIG.

Reference numeral 16 indicates an electric circuit section provided especially for controlling the operation of the refrigerator 1. Further, 17 indicates an electric circuit section for controlling the operation of the air conditioner including the evaporator 9.

Connected to the electric circuit section 16 are a switch group 18 serving as an operator for instructing the operation of the refrigerator, and a display device 19 for displaying the operating state of the refrigerator, and also instructing the electric circuit section 17 to operate the air conditioner. A switch group 20 as an operating device and a display device 21 that displays the operating state of the air conditioner are connected.

The electric circuit section 17 for the air conditioner includes an electromagnetic clutch 11 for operating the refrigeration cycle 5 and a means for supplying energizing current to the electromagnetic valve 15, although not shown in the drawings, similar to a known device. There is.

Further, the electric circuit section 17 includes an electric circuit section 16 for a refrigerator.
In order to close the electromagnetic valve 15 in response to an electric signal Sr from the gate circuit 22, a gate circuit 22 consisting of a suitable logic gate is provided. Therefore, although the gate circuit 22 permits the supply of the energizing current to the solenoid valve 15 when the electric signal Sc is at the energizing level in accordance with the request of the air conditioner, when the electric signal Sr reaches the energizing level, , prohibits the supply of energizing current to the solenoid valve 15 regardless of the level of the electric signal Sc.

The two electric circuit sections 16 and 17 operate in conjunction with each other, and in addition to being provided with an electric signal Sr from the electric circuit section 16 to the electric circuit section 17 requesting the closure of the electromagnetic valve 15 as described above. At the same time, an electric signal SO indicating the operation of the compressor 10 is applied from the electric circuit section 17 to the electric circuit section 16. The role of the electrical signal SO is as follows.

That is, the cooling effect of the refrigerator l and the cooling effect of the air conditioner are provided by the compressor 10 of the common refrigeration cycle 5, and when the refrigerator 1 is operated by operating the switch group 18, the operating state of the compressor 10 is must be taken into consideration. One method is to send an operation request signal for the compressor 10 from the electric circuit section 16 to the electric circuit section 17 when the switch group 18 issues a command to exert a cooling effect in the refrigerator 1. Can be done. However, in this embodiment, when the electric circuit section 17 is supplying the energizing current to the electromagnetic clutch 11, the actuation signal SO is sent to the electric circuit section 16, and when the electric circuit section 16 receives this, The cooling effect of the refrigerator 1 is adjusted by intermittently setting the electrical signal Sr to the energizing level.

The electric circuit section 16 is connected to the blower motor 2, which is a functional element of the refrigerator I, and the heating element 7 through electric wires. One end of these functional elements 2.7 is connected to a power supply positive terminal or a ground terminal, and the other end is connected to a switch element (described later) in the electric circuit section 16. In addition, the electric circuit section 1
6 is connected to the temperature sensor 8 inside the refrigerator, and the temperature sensor 8,
Input signals from switch group 18 etc. and electric circuit section 1
Based on the electrical signal SO from 7, an electrical signal Sr is generated which requires the activation and deactivation of the functional element 2.7 as well as the intermittent activation of the @magnetic valve 15.

The thick broken line in the figure indicates the electrical circuit section 16.1 from the on-board battery.
7 and the positive side power supply line to the blower motor 2, and this power supply line is connected to the electrical circuit shown in the figure by turning on the main switch 23, which is composed of a key switch and, if necessary, a dedicated switch (including a relay contact) connected in series. It is designed to supply power to the

Next, the arm configuration and operation of the electric circuit section 16 for controlling the refrigerator 1 will be explained with reference to FIG. 3.

The switch group 1st consists of two interlocking movable pieces 18A, 18.
The structure is such that B opens and closes the fixed contacts in each of the 3 positions, and the 3 positions C? Divided into riL storage (11), neutral (N), and cooling (C),
It is configured to selectively command operation as a freezer or refrigerator, and operation as a hot storage.

The display device 19 is connected to the movable piece 18B of the switch group 18. The display device 18 includes a red light emitting diode 19A connected to the hot storage contact of the movable piece 18B, and a movable piece 18A.
The current limiting resistor 19C consists of a blue light emitting diode 19B connected to the refrigerator contact and a current limiting resistor 19C.
It is connected to the circuit package 24 via.

Among the functional elements of the refrigerator 1, the heating element 7 is a movable piece 18A.
It is connected between the power supply lines through the hot storage contact and the normally open contact of the relay 25. When the switch group 18 selects the operation of the refrigerator, the circuit package 24 responds by energizing the excitation coil of the relay 25, closing the relay contact, and immediately supplying the energizing current to the heating element 7. and start to develop a fever.

The circuit package 24 is based on the cooling request signal Sc which becomes the energizing level when the switch group 18 selects the refrigerator operation, and the warming request signal sh which becomes the energizing level when the hot storage operation is selected. Operate.

This circuit package 24 includes a control circuit 2 for the blower motor 2.
6. An intermittent signal 5 generation circuit 27 that generates an electric signal Sr that intermittently energizes the solenoid valve 15; a drive circuit 2 for the display device 9;
8, a logic gate 29 for signal reception, and a logic gate 30 for signal transmission.

The logic gate 29 for signal reception is composed of an AND gate in this embodiment, and when the electric signal SO is at the activation level indicating the operation of the compressor 10 and the cooling request signal Sr from the switch group 18 is at the activation level, the logic gate 29 is an AND gate. , line 29A is the biasing level.

The blower control circuit 26 includes a relay 26A having a normally open relay contact connected in series with the blower motor 2, a drive transistor 26B1, an OR gate 26C, and an antagonal gate 1-1.
26D, and a high input impedance comparison circuit 26E connected to the temperature sensor 8.

In the ventilation control circuit 26, when the cooling request signal Si is at the energizing level, the line 29A is at the energizing level;
That is, based on the fact that the compressor 10 is in the operating state, the AND gate 26D is "opened". In this case, a logic signal having an energizing or deactivating level that matches the control signal sb appearing at the output end of the comparator circuit 26B is generated at the output end of the AND gate 26D. The output signal of this AN1' gate 26D is transmitted to the drive transistor 2 through an OR gate 26C.
6B is applied to the control input terminal. Transistor 26B
eventually becomes conductive or disconnected in accordance with the control signal Sb of the comparator circuit 26E, thereby closing or opening the contacts of the relay 26A.

The comparison circuit 26E turns off when the resistance value of the temperature sensor 8 having a negative temperature coefficient of resistance is larger than the predetermined value after Q'c jiil in terms of the temperature inside the refrigerator, that is, when the temperature is lower. If the temperature is higher than that, a control signal sb is generated which becomes the activation level. Note that an appropriate hysteresis is provided in this comparison circuit 26]E.

In other words, when the cooling request signal 3r is at the activation level, the blower control circuit 26 detects that the compressor 10 is in operation, and operates and stops the blower motor 2 according to the operation of the comparison circuit 26B. .

Here, the comparison circuit 26E determines that if the temperature inside the refrigerator becomes too cold,
By stopping the blower motor 2 and stopping agitation of the air inside the refrigerator, it has the role of preventing the temperature inside the refrigerator from becoming too cold.

In the ventilation control circuit 26, a warming request signal sh is applied to the other input terminal of the orgame 26C. Therefore, when the storage request signal sh reaches the energizing level, the transistor 26B immediately becomes conductive to energize the relay 26A and operate the blower morph 2.

The intermittent signal generation circuit 27 may have a clock pulse coefficient type digital circuit configuration, or may have an analog circuit configuration as exemplified in this embodiment. The illustrated intermittent signal generation circuit 27 includes a triangular wave oscillation circuit 27A that generates a triangular waveform voltage having a constant slope at a constant period, and compares this output waveform with a predetermined threshold voltage value from a reference voltage source 27B to output an output voltage. The comparison circuit 27C can be configured to generate a pulse train signal (intermittent signal) at the same time. In this configuration
C changes the threshold voltage value generated by the reference voltage source 27B according to the detection signal from the temperature sensor 8.
The on/off ratio of the intermittent signal can be adjusted in accordance with the temperature inside the refrigerator.

Here, the reference voltage source 26B can have the configuration example shown in FIG. 4. That is, in FIG. 4, the reference voltage source 27B includes a resistor 27a that supplies current to the temperature sensor 8, a high input impedance inverting amplifier circuit 27b, a resistor 27c and a constant voltage diode 27d forming a voltage clamp circuit. It is configured. As shown in FIG. 5, an output voltage V appears at the output terminal of the amplifier circuit 27b, which increases as the internal temperature T rises, but this voltage (2) is prevented from exceeding a certain voltage by a clamp circuit.

Thus, the intermittent signal generation circuit 27 can generate a pulse train signal that increases the intermittent ratio up to a certain upper limit as the temperature inside the refrigerator increases.

The intermittent pulse train signal generated by the intermittent signal generation circuit 27 is passed through a logic gate 3.0 consisting of an AND gate.
It is sent to the electric circuit section 17 as an electric signal Sr. Thus, the inflow of refrigerant from the refrigeration cycle to the evaporator 3 is interrupted and the cooling capacity of the freezer 1 is adjusted using the intermittent ratio of the intermittent signal generated by the intermittent signal generation circuit 27. The logic gate 30 has the role of sending out an intermittent signal only when the logic circuit 26 determines that the cooling request signal Sc is at the activation level and the activation signal So is at the activation level.

To summarize the operation of this device, switch group 18
When the cooling contact (C) is turned on at , if the compressor 10 is not operating and the electrical signal So at the energizing level is given from the electrical circuit section 17, the circuit package 2
In step 4, the cooling operation is electrically controlled and the light emitting diode 19A is turned on to display the information to the occupant.

As a method of controlling the cooling operation, the energizing circuit of the blower motor 2 is opened and closed based on a temperature signal indicating the degree of cooling inside the refrigerator detected by the temperature sensor 8, and if the inside of the refrigerator is excessively cooled, the refrigerator Stop stirring in Part IA and stir if not sufficiently cooled.

Further, in the intermittent signal generation circuit 27, an intermittent signal having an intermittent ratio according to the temperature inside the refrigerator is generated, and the electric circuit section 17
By sending the electric signal Sr to the evaporator 1, the electromagnetic valve 15 shown in FIG. Adjust accordingly.

On the other hand, in the switch group 18, when the warming contact (old) is turned on, it closes the energizing circuit of the blower motor 2 to agitate the air in the refrigerator, and also energizes the relay 25 to energizes to uniformly warm up the refrigerator section IA.

Further, the light emitting diode 19A is turned on to display the information to the occupant.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and the details of the implementation means can be changed and improved.

For example, the logic circuit 26 and the intermittent signal generation circuit 27 are
This can also be achieved by digital signal processing using a microcomputer.

As described above, according to the present invention, in a refrigerator connected to an automobile air conditioner, it is possible to intermittent the refrigerant supply to the evaporator depending on the temperature inside the refrigerator when the refrigerator is used. It is possible to suppress fluctuations in the cooling time within the refrigerator as much as possible, and to reduce the burden on the refrigeration cycle.

[Brief explanation of the drawing]

The attached drawings show an embodiment of the present invention, in which Fig. 1 is a schematic cross-sectional view of a refrigerator, Fig. 2 is an overall configuration diagram, Fig. 3 is an electrical wiring diagram of the electric circuit section, and Fig. 4 is a schematic cross-sectional view of a refrigerator. FIG. 5 is a detailed electrical wiring diagram of the reference voltage source in the electric circuit section, and FIG. 5 is a voltage generation characteristic diagram of the reference voltage source. 1... Refrigerator, IA... Refrigerator section, IC... Freezer section, 2... Ventilation morph, 3... Evaporator, 8
...Temperature sensor, 16...Electric circuit section, 27...
Intermittent signal generation circuit. Representative Patent Attorney Takashi Okabe

Claims (3)

[Claims] (1) A refrigerator for automobiles that is equipped with at least a cooling evaporator inside the refrigerator equipped with an opening/closing member, and is configured such that refrigerant is supplied to the evaporator from a refrigeration cycle that also serves as an air conditioner driven by the automobile engine. The control device includes: a temperature sensor that outputs a signal corresponding to the temperature inside the refrigerator; and an adjustment device that adjusts the flow resistance of the refrigerant passage connected to the air conditioner in response to the electrical signal; A control device for an automobile refrigerator, comprising: a control circuit that controls the adjustment device and adjusts the flow resistance according to a signal from the temperature sensor. (2) The automobile refrigerator control device according to claim 1, wherein the adjusting device is an electromagnetically operated valve whose open/closed state changes by energizing and deenergizing an electric signal. (3) The control circuit is adapted to adjust the conduction resistance within a range that does not exceed a predetermined upper limit value in response to a signal from the temperature sensor. The automobile cooling storage control device according to item 2.