JPS5871213A - Automobile's cooler - Google Patents

Abstract

PURPOSE:To prevent a secondary failure in a car's room air conditioner by discriminating whether the ratio of an engine rpm. and a revolution number of a cooling compressor has a certain relation or not and by indicating the engagement and disengagement control of a solenoid clutch disposed between the engine and the compressor. CONSTITUTION:By turning a switch 8 on, a discrimination circuit 3 maintains its output at L level in a certain interval so that a relay circuit 4 has one terminal of a clutch 5 grounded for electrification thereof. On the other hand, a lamp 7 is continuously lit via a lamp actuation circuit 6. After the lapse of said interval the discrimination circuit 3 estimates the ratio between both speeds of an engine and a compressor on the basis of respective output signals from an engine rpm. detection means 1A and a compressor revolution speed detection means 2A and if the ratio is estimated to be 0.8 or more, the discrimination circuit 3 maintains the L level, energizing the clutch 5 and lighting the lamp 7. If the speed ratio is reduced to below 0.8 because of a trouble of the compressor during driving, the discrimination circuit 3 is turned to H level, whereby the clutch 5 is deenergized to interrupt the compressor and the lamp 7 is made to flicker. A secondary failure may be thus prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for air conditioning a passenger cabin of an automobile, and particularly to a portion that cools air, that is, a cooling device.

In general, in an air conditioner dedicated to cooling or an air conditioner that also has a reheating section for cooling air (1), a refrigerant compressor is operated by receiving rotational drive from an automobile engine, thereby controlling the circulating refrigerant. The cooling heat exchanger is configured to have an endothermic effect.

However, if the effect of the lubricating oil mixed in with the gas is weakened due to a lack of cold 8 gas in the compressor, or if the compressor locks and stops due to damage to parts, etc., the automobile engine or electromagnetic A large load is applied to connecting parts such as a clutch, and there is a risk of secondary failure.

In order to prevent the above-mentioned secondary failure, the present invention provides an automobile cooling system that stops driving the compressor when the compressor is locked, and displays a simple and easily recognized abnormal state to inform the occupants. The purpose is to provide.

For this reason, the present invention compares the rotational speed of an automobile engine with the rotational speed of a compressor driven by the motor through an electromagnetic clutch, and when the specific rotational speed of the compressor (2) has significantly decreased, an electrical determination means is made. A judgment output is generated, and the judgment output disconnects the electromagnetic clutch, and also serves as a means to display whether the cooling system is operating or stopped, indicating whether the cooling system is operating normally or has stopped abnormally. It is made distinguishable by changing the aspect.

To explain the illustrated embodiment of the present invention, in FIG. 1, IA is a first timing sensor 2A that generates a pulse signal in synchronization with the rotation of the output shaft of an automobile engine;
is a second timing sensor that generates a pulse signal in synchronization with the rotation of the central shaft of the compressor, which transmits the rotational torque generated on the output shaft of the engine through a pulley (not shown), a belt (not shown), and an electromagnetic clutch 5. be. The frequency of the pulse signals generated by each of these sensors is proportional to the shaft rotational speed of the engine and compressor, respectively.

1 and 2 are r;-v conversion circuits that convert pulse signals from the first and second timing sensors into frequency and voltage;
The value of the DC (3) pressure produced at the output of each conversion circuit corresponds to the frequency of the input pulse signal and, therefore, to the engine rotational speed or combination engine rotational speed.

3 is an abnormality determination circuit, which includes two converter circuits 1 and 1-1.
．． It consists of an Ichikawa comparison circuit that compares the two output voltages. While the speed ratio of compressor rotation speed/engine rotation speed is normally 14'1 degree, when the compressor is locked, it becomes significantly (It'''F. Therefore, in this comparison circuit, (, I above speed) is set to generate an H level signal when, for example, is 0.8 or less.

For example, if the output voltage of the engine side conversion circuit 1σ1 path 1 is divided into 415 voltages to be used as the human power for one side of the comparator circuit, and the output voltage of the compressor side conversion circuit 2 is used as the human power for the other side of the comparison circuit, then 1. Then, in the judgment time Uδ3, the speed ratio is 0.
．． If the level is 8 or more, 1 is generated, and if the level is 0.8 or less, an H level output signal is generated.

3A is a delay amount jIh that causes the output of the determination circuit 11h3 to be at L level for a certain period of time at the start of power supply.

Reference numeral 4 designates a relay (4) circuit that responds to the output signal from the determination circuit 3 and is constructed using a contact relay, the contact of which is connected to the ground side energizing path of the electromagnetic clutch 5.

6 is a lamp drive circuit with a built-in oscillation circuit, and judgment circuit 3
In response to the output signal from the display device, a continuous lighting signal and a blinking signal are selectively given to the lamp 7, which is a display element.

8 is a main switch provided on the power supply path from the vehicle battery, and is a switch called an air conditioner switch.

In the above configuration, when the switch 8 is turned on, the output of the determination circuit 3 is at the L level for a certain period of time, so the relay circuit 4
One end of the electromagnetic clutch 5 is grounded, and the electromagnetic clutch 5 is energized. On the other hand, the output terminal of the lamp drive circuit 6 also becomes the ground potential, that is, a continuous lighting signal is generated, and the lamp 7 is continuously lit.

Eventually, after a certain period of time has passed, the determination circuit 3 compares and determines the speed ratio of the two input terminals. If the speed ratio is 0.8 or more, the output of the determination circuit 3 continues to be at level 2, the electromagnetic clutch 5 is energized, and the lamp 7 is also lit. Therefore, the compressor operates as a cooling device with (5) rotations.

However, if the rotation of the two-liter compressor is disturbed for some reason, the rotational speed of the compressor decreases compared to the engine rotational speed, and this may cause distortion. At this time, when the speed ratio becomes smaller than 0.8, the determination circuit 3 generates an H level output.

Therefore, the relay circuit 4 opens the relay point B to cut off the current to the electromagnetic clutch 5 and put it in a deenergized state. Therefore, the compressor is stopped and secondary failures no longer occur. On the other hand, in response to the output signal of the determination circuit 3 becoming level I, the built-in oscillation circuit of the lamp drive circuit 6 is activated, and the potential of the output terminal is intermittently set to the ground level, causing the lamp 7 to blink. Ru.

FIG. 2 shows a detailed example of the lamp drive circuit 7 described above. 9 is a comparator which converts the output voltage of the constant voltage power supply 10 into the resistor 11.
．． When the output of the judgment circuit 3 is at the level, the transistor 13 that drives the lamp 7 is turned on, and when the output of the judgment circuit 3 is at the level 11, the voltage divided using The capacitor 14, the resistor 15, and the positive feedback resistor 16 form an oscillation circuit that turns on and off the transistor 13 at a determined period.

In this series of devices, when the main switch 8 is opened, the power to all circuits is cut off, so the operation as a cooling device is stopped and the lamp 7 is also turned off.

In the second embodiment, lighting and blinking of the lamp is changed depending on the speed ratio determination output, but the light emitting color of the light emitting diodes provided with the same display frame may be changed.

In addition, the speed ratio can be determined by comparing the period or frequency of the pulse signals generated by the first and second timing sensors IA and 2A using not only an analog circuit as in the second example but also a digital processing circuit. You may also do so. In addition, a digital computer (micro=1 pumper) with a software program can be used for this purpose.
In that case, it can also serve as creating an oscillation signal used when driving the lamp.

As described above, the present invention can prevent secondary failure by interrupting the electromagnetic clutch when the compressor rotation becomes abnormal (7), and also prevents the rotation of the engine nozzle from stopping when the main switch is turned off or from abnormal stop. Since the display is switched between the two cases on the same display unit, it has the excellent effect of making it easier for the user to recognize the information.

[Brief explanation of the drawing]

FIG. 1 is an electrical wiring diagram showing one embodiment of the present invention, and FIG. 2 is an electrical wiring diagram showing details of the lamp drive circuit () in FIG. 1. IA...first timing sensor (detection means), 2A
...Second timing sensor (detection means), 3...
Abnormality determination circuit, 4... Relay circuit, 5... Electromagnetic clutch, 6... Lamp drive circuit, 7... Lamp (display means), 8... Main switch. Representative Patent Attorney Takashi Okabe (8)

Claims (1)

[Claims] a first detection means responsive to the rotational speed of an automobile engine; a second detection means responsive to the rotational speed of a cooling compressor driven by the engine via an electromagnetic clutch; and the eleventh second detection means. electrical determination means for determining whether the rotation speed of the engine has a predetermined ratio relationship with respect to the rotation speed of the compressor based on a detection signal from the determination means; and energization of the electromagnetic clutch based on a determination output from the determination means. 1. A cooling device for an automobile, comprising a relay means for switching de-energization, and a display means for switching a display mode between normal operation and abnormal stop according to a judgment output from the judgment means.