JPH0126471B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to measuring the amount of refrigerant in a car cooler.

Users have traditionally requested a dealer to repair a malfunctioning car cooler compressor.

In this case, the dealer will check the refrigerant level to find out what caused the compressor failure.

Hereinafter, a conventional method for checking the amount of refrigerant will be explained with reference to FIG. 1, which shows an outline of a car cooler cycle.

The arrow A side indicates the engine compartment, and the arrow B side indicates the interior side of the automobile. The condenser 1 cools and liquefies the high-pressure, high-temperature gaseous refrigerant sent from the compressor 4, and at the outlet of the condenser 1 it becomes a medium-temperature, high-pressure liquid. The refrigerant condensed in condenser 1 is sent to liquid tank 2. The flow state of the refrigerant is observed through a side glass 3 provided at the top of the liquid tank 2. By rotating the compressor 4, the liquid refrigerant passes through the side glass 3,
By observing whether the liquid refrigerant is cloudy, has intermittent bubbles, or is clear, it is possible to know whether the amount of refrigerant is appropriate. In other words, if there is cloudiness or bubbles, it means that there is either too much or too little refrigerant, and when it is clear, the refrigerant is judged to be appropriate. The expansion valve 5 shown in the figure is installed at the inlet of the evaporator 6, and converts the high-pressure liquid refrigerant sent from the liquid tank 2 into a mist of low-pressure liquid refrigerant by a throttling action to the evaporator 6.
send to In the evaporator 6, air inside the vehicle is sent between the fins by a blower, so the low-pressure mist of refrigerant flowing inside the tube evaporates and becomes gas. At this time, the tube and fins are cooled by the heat of vaporization, so the blowing air is cooled. This refrigerant is then sent to the compressor 4 through the suction slot valve 9. In FIG. 1, the first piping connection part 7,
The hatched parts such as the second pipe connection part 8 indicate "0" ring type pipe connection parts.

Generally, the appropriate total amount of refrigerant in the car cooler cycle is 0.9-1.1Kg. If the amount of refrigerant is greater than the appropriate amount, a portion of the cooler cycle that should normally be in a gas state becomes liquid, causing a liquid back phenomenon, and it is determined that the compressor is damaged.

If it is determined that there is too much refrigerant, the repair can be completed by filling the car cooler cycle with the appropriate amount of refrigerant and replacing the failed compressor. Therefore, there is no need to disassemble and check all the parts of the car cooler cycle.

If the amount of refrigerant is less than the appropriate amount, it is determined that the compressor has seized up due to insufficient lubrication and insufficient cooling by the refrigerant.

If the compressor seizes up due to a low amount of refrigerant, it can be easily identified because if the amount of refrigerant was low from the beginning, the cooling function would not be fully utilized from the beginning. Therefore, the repair can be completed by filling the car cooler cycle with the appropriate amount of refrigerant and replacing the failed compressor.

However, if the cooling function initially exhibits proper cooling function, but then the cooling function deteriorates and the compressor seizes up, it is assumed that refrigerant has leaked from somewhere within the cooler cycle. The cooler cycle must be disassembled to find the leak. Repairs are then completed by replacing the leaking parts and replacing the failed compressor.

However, in the conventional method of checking the amount of refrigerant in a car cooler using side glasses, it is impossible to check the amount of refrigerant by observation unless the compressor is rotated to flow the refrigerant.

If the compressor seizes up due to an accidental refrigerant leak or becomes stuck (a phenomenon in which the inside of the compressor is damaged and becomes unable to rotate when a liquid backlash occurs) and the compressor cannot be rotated to flow the refrigerant, check the amount of refrigerant. Since I couldn't do it, I disassembled the cooler cycle and checked all the parts, even if it was pointless. Furthermore, even when the compressor rotates, the side glass is visually inspected, which causes individual differences and makes it difficult to make accurate judgments.

The present invention was made in view of such conventional problems, and provides a method for accurately measuring the amount of refrigerant without rotating the compressor of a car cooler cycle, and a refrigerant discharge device used in the method. It is an object.

Hereinafter, the present invention will be explained based on examples.

FIG. 2 is a diagram showing a refrigerant discharge device according to an embodiment of the present invention. First, to explain the configuration, the service valve and high pressure valve 10 provided in the first piping connection part 7 of the car cooler cycle, and the service valve and low pressure valve 11 provided in the second piping connection part 8, respectively. and introduce the refrigerant in the cooler cycle into the refrigerant discharge device. The refrigerant that has entered the high pressure valve 10 and the low pressure valve 11 join together at the three-way connector 12, and the mist separator 13
The oil, moisture, etc. in the refrigerant are removed, and the first
It enters the next pressure control valve 14 and the second pressure control valve 15, is adjusted to a predetermined pressure, and is discharged from the orifice 16 to the outside. By measuring the release time at this predetermined pressure, the amount of refrigerant sealed in the cooler cycle can be measured.

In addition, to measure the total amount of refrigerant in the cycle, it would be simple to put the entire amount into a bag and measure its volume, but the total amount of refrigerant would be approximately 500 when released and cannot actually be measured. Therefore, as in this embodiment, the amount of refrigerant is estimated by measuring the refrigerant release time.

In the figure, 24 is a first pressure head that detects the cycle pressure _P1 from the three-way connector 12 to the mist separator and converts it into an electrical signal, and 17 is a
The discharge pressure is the same as the first pressure head 24.
A second pressure head detects P ₂ and converts it into an electrical signal.

Also, 28 and 29 are the cycle pressure P ₁ and the discharge pressure
These are meters that each indicate P ₂ .

18 is a strain meter that amplifies the electrical signals sent from the first and second pressure heads 24 and 17 via cords 25 and 26;
9 is a pen recorder that records and displays the electrical signal sent from the strain meter 18 via the cord 27 at a speed of Cm per minute or Cm per hour. 18 and 19 both require 100V, so the device of this embodiment must be installed in a location where it can be connected to a commercial power source.

Next, the operation of this embodiment will be explained.

The service valve provided in the first piping connection 7 of the car cooler cycle and the high pressure valve 10 of the device of this embodiment, and the service valve provided in the second piping connection 8 and the low pressure valve 11 of the device of this embodiment. and connect them respectively. This connection may be made to either a high or low pressure valve. The refrigerant flowing from the high and low pressure valves 10 and 11 joins at the three-way connector 12 and flows into the mist separator 13. Then, the mist separator 13 removes oil and moisture from the refrigerant.
Dust etc. are removed. Next, the refrigerant flows into the primary pressure control valve 14 and is controlled to a relatively stable pressure (0.5 to 1.0 Kg/cm ² in this device), and flows into the secondary pressure control valve 15 to improve accuracy. The pressure is controlled to a high and stable predetermined pressure. The refrigerant thus clean and adjusted to a predetermined pressure is discharged from the fixed orifice 16. By measuring the discharge time at this predetermined pressure, the total amount of refrigerant remaining in the cycle can be determined. Note that since the specific volume of the discharged gaseous refrigerant changes depending on the temperature, correction for the temperature is required. (Refer to Figure 4) In Figure 4, lines A, B, and C indicate the outside temperature at the time of measurement of 10℃ and 20℃, respectively.
℃, shows the relationship between the remaining amount of refrigerant and the release time at 30℃.

How to use this relationship table between refrigerant amount and discharge time is as follows. As shown in FIG. 3, data of cycle pressure P ₁ (arbitrary value) and discharge pressure P ₂ (certified value) indicating the relationship between discharge time and pressure are written on the pen recorder recording paper 50, and refrigerant discharge starts. from the drop point which is the intersection of this cycle pressure P ₁ and the discharge pressure P ₂
Read the release time until P ₀ . That is, the descent point P ₀
Until then, the pressure applied to the orifice 16 can be maintained constant by the pressure control valve 15, and from the start of discharge to the drop point
During the time until P ₀ , the refrigerant is released from the orifice at a predetermined pressure, so the amount of refrigerant released during this time is proportional to the time, and if the release pressure P ₂ is selected appropriately, the remaining amount of refrigerant in the suspension can be ignored. It is possible to roughly estimate the amount of refrigerant sealed in the cooler from the previous period. For example, if the release time is 95 minutes, the outside temperature at that time is 20℃.
In this case, the amount of refrigerant (Kg) can be read as approximately 1.2Kg by following line B of the diagram of the relationship between the amount of refrigerant and refrigerant gas release time of 95 minutes in Figure 4, which was created by experiment or calculation in advance. In other words, the amount of refrigerant in the car cooler cycle is 1.2Kg, which is the appropriate amount (0.9Kg).
~1.1Kg).

Therefore, from this data result, it is clear that the amount of refrigerant needs to be adjusted to the appropriate amount, and there is no need to inspect other car cooler cycle parts, and the repair can be completed by immediately replacing only the malfunctioning compressor.

Also, if the release time is 55 minutes, for example, and the outside temperature at that time is 20°C, follow line B for 55 minutes of the refrigerant release time in the diagram of the relationship between the amount of refrigerant and the refrigerant gas release time in Figure 4. The amount of refrigerant (Kg) is approximately
It becomes 0.65Kg. That is, it can be seen that the amount of refrigerant in the car cooler cycle is 0.65 kg, which is less than the appropriate amount.

Therefore, in this case, based on this data result, disassemble the parts of the clarar cycle and find the leakage point.
Plug leaks or replace parts, and replace failed compressors.

FIG. 5 shows another embodiment.

In this second embodiment, the first pressure control valve and the second pressure control valve in the first embodiment are changed to one, recording of cycle pressure is stopped, and the discharge pressure is
ON when 0.3Kg/cm ² or more and less than 0.3Kg/cm ²
Timer 2 is activated by pressure switch 20 which turns OFF.
1, measure the release time of refrigerant gas,
The entire device is made small and lightweight, and is portable, unlike the first embodiment, which has to be installed in a place with a commercial power source. 1st in the diagram
The same numbers as those in the embodiments indicate the same or corresponding parts, and redundant explanation will be omitted.

As explained above, according to this invention,
The refrigerant in the car cooler cycle is extracted from the service valve, oil, moisture, dust, etc. are removed, the pressure is set to a specified level, and the refrigerant is released from the orifice to the outside. Even if the refrigerant cannot flow due to problems such as seizure, the refrigerant amount in the car cooler cycle can be determined.

In addition, it is possible to clearly distinguish whether the cause of damage to the compressor is seizure due to insufficient refrigerant amount, or whether the damage occurs due to other causes even though there is sufficient refrigerant in the compressor.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of a car cooler cycle, Figure 2
The figure is a schematic diagram of the refrigerant discharge device of the first embodiment, Figure 3 is a data diagram of the pen recorder, Figure 4 is a diagram showing the relationship between the amount of refrigerant and the refrigerant gas discharge time, and Figure 5 is the diagram of the second embodiment. FIG. 3 is a block diagram showing an example. 7...First piping connection part, 8...Second piping connection part, 10...High pressure valve, 11...Low pressure valve, 13...Mist separator, 14...Primary pressure control valve, 15... ...Secondary pressure control valve, 16...
...Orifice, 19...Pen recorder, 21...
timer.

Claims (1)

[Claims] 1. A refrigerant is extracted from a service valve of a cooler cycle, oil, water, etc. are removed from the refrigerant, and the refrigerant is turned into a gas at a predetermined pressure and released to the outside. Measure the time taken,
A method for measuring the amount of refrigerant in a car cooler, characterized by estimating the amount of refrigerant from the time. 2 Consisting of a mist separator connected to the service valve of the cooler cycle, a pressure control valve connected to the mist separator to turn refrigerant into a gas at a predetermined pressure, and an orifice connected to the pressure control valve, from which the refrigerant is 1. A refrigerant discharge device used for measuring the amount of refrigerant in a car cooler, characterized in that the refrigerant discharge device is configured to be able to discharge the refrigerant to the outside.