KR100464888B1 - Manifold gauge for refrigerating cycle, and trouble shooting methdo thereby - Google Patents

Abstract

The present invention relates to a fault diagnosis manifold gauge for a refrigeration cycle for a vehicle and a fault diagnosis method using the same, comprising: a pressure detecting unit for detecting a low pressure side operating pressure or a high pressure side operating pressure; A present pressure display section indicating a present operating pressure detected by the pressure detecting section; And an effective pressure display portion indicating a standard operating pressure for the current ambient temperature and an effective pressure range including the standard operating pressure; If the current operating pressure displayed on the present pressure display portion is within the effective pressure range for the current atmospheric temperature shown on the effective pressure display portion, it is determined to be normal, and when it is out of the effective pressure range, it is determined to be abnormal. . According to this, it is possible to provide a simple configuration at a low cost and to easily and accurately diagnose the failure of the refrigeration cycle and the corresponding failure part to measure the measures.

Description

MANIFOLD GAUGE FOR REFRIGERATING CYCLE, AND TROUBLE SHOOTING METHDO THEREBY}

The present invention relates to a fault diagnosis manifold gauge for a vehicle refrigeration cycle and a failure diagnosis method using the same. In particular, after measuring the low pressure side or the high pressure side operating pressure and the standard operating pressure of the refrigerant in the refrigeration cycle according to the atmospheric temperature In comparison, the present invention relates to an apparatus and a method for accurately diagnosing a failure of a refrigeration cycle and a failure thereof.

R-134a or R-12 is commonly used as an operating refrigerant of an automotive air conditioner. Referring to the operation of the refrigeration cycle using this working refrigerant schematically, the high-temperature, high-pressure gaseous refrigerant compressed by the compressor flows into the condenser, liquefied by heat to the surroundings, and then passes through a dryer to the evaporator from the expansion valve Sprayed. The refrigerant in the evaporator absorbs heat from the outside air while evaporating. At this time, the outside air of which the temperature is lowered is blown to keep the interior of the vehicle comfortable.

By the way, when there is an error in the operation of the car air conditioner, the low pressure side and the high pressure side operating pressure are measured through the pressure measuring service ports installed on the low pressure and high pressure side of the refrigeration cycle, and these measured pressure values are standard values. Compared with the experience value without any experience, it was judged whether there was any more according to the experience side. However, the operating pressure of the refrigerant in the refrigeration cycle changes very sensitively in proportion to the outside temperature, and it is impossible to accurately diagnose the failure according to the operator's experience without considering these conditions. Causes problems.

Therefore, when diagnosing or repairing the failure of the refrigeration cycle, it is recommended to know the standard operating pressure and the effective pressure value of the refrigerant according to the atmospheric temperature at the time of operation, and then perform the failure diagnosis based on this. Not only have not been proposed yet, in particular, a variety of devices and methods for accurately diagnosing the failure of the refrigeration cycle is not provided.

On the other hand, in recent years, the refrigerant gas pressure measurement and injection gauge has been disclosed, but this gauge does not present the standard operating pressure of the refrigerant according to the ambient temperature, in particular, only the high pressure side operating pressure can be measured, it is easy for operators and self-operators It is difficult to conveniently measure the condition of the air conditioner, and thus there is a problem in that its performance or failure cannot be diagnosed accurately and efficiently.

Accordingly, an object of the present invention is to provide a relatively low price in consideration of the problems of the prior art, so that not only the worker of the repair shop but also the self-driver can easily diagnose the failure and the failure part of the vehicle. It is to provide a troubleshooting manifold gauge and a diagnostic method using the same.

Still another object of the present invention is to easily and conveniently check whether there is a shortage or excess of refrigerant gas in a vehicle refrigeration cycle, and when it is insufficient, it is possible to simply and conveniently replenish by applying a compensation value according to atmospheric temperature. It is to provide a failure checker and a method of inspecting a vehicle refrigeration cycle.

1 is a front view of a troubleshooting manifold gauge for a vehicle refrigeration cycle according to the present invention,

2 is an exploded perspective view of FIG. 1;

3 is a flow chart illustrating a method of diagnosing a failure of a refrigeration cycle for a vehicle using the fault diagnosis manifold gauge;

Figure 4 is a front view showing a fault diagnosis manifold gauge of the refrigeration cycle for automobiles according to another embodiment of the present invention, a low pressure side manifold gauge, a high pressure side manifold gauge, and a refrigerant gas injection unit in detail, and

5 is a flowchart illustrating a method of diagnosing a failure of a refrigeration cycle for a vehicle using a failure diagnosis manifold gauge according to another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

1, 50: Manifold gauge for troubleshooting of refrigeration cycle for automobile

10: Bourdon tube 20, 70: fixed instrument substrate

30, 80: rotation setting plate 40, 63: needle

90: refrigerant gas injection unit

The object is, according to the present invention, the pressure detecting unit for detecting the low pressure side operating pressure of the refrigeration cycle for automobiles; A low pressure side current pressure display unit indicating a current low pressure side operating pressure detected by the pressure detecting unit; And an effective pressure display portion indicating an effective pressure range including the low pressure side standard operating pressure and the low pressure side standard operating pressure with respect to the current ambient temperature; When the current low pressure side operating pressure displayed on the low pressure side current pressure display part is within the effective pressure range for the current atmospheric temperature shown on the effective pressure display part, it is determined to be normal, and when it is out of the effective pressure range, it is determined to be abnormal. It is achieved by a fault diagnosis manifold gauge of the refrigeration cycle for automobiles.

Here, the present pressure display unit, a fixed instrument substrate in which a plurality of temperature scales indicating an atmospheric temperature and a plurality of pressure scales indicating the standard operating pressure of the low pressure side with respect to the temperature scale are displayed correspondingly in an arc shape, and the fixed Simply configurable, including a needle that rotates between the scales of the instrument panel and indicates the current low pressure working pressure; The effective pressure display portion may be rotatable with respect to the fixed instrument substrate, and may be configured as a rotation setting plate in which the low pressure side effective pressure ranges for the respective atmospheric temperatures are partitioned.

And, the high-pressure side pressure measurement unit for measuring the current high-pressure side operating pressure of the vehicle refrigeration cycle, and can be compared with the high-pressure standard operating pressure value for the current ambient temperature; And a refrigerant gas injection unit capable of injecting refrigerant gas into the refrigeration cycle, it is possible to more accurately diagnose the failure of the refrigeration cycle for the vehicle and its failure portion.

On the other hand, according to another field of the present invention, the object, the step of providing information on the effective pressure range including the standard operating pressure of the low pressure side of the vehicle refrigeration cycle for each ambient temperature and the standard operating pressure; Measuring a current ambient temperature; Measuring a current low pressure working pressure of the vehicle refrigeration cycle; And determining that it is normal when the measured current low pressure side operating pressure is within the effective pressure range corresponding to the current ambient temperature, and determining that it is abnormal when out of the range. Achievable by the method.

In the preparing of the information, the information on the high pressure side standard operating pressure with respect to the air temperature is further provided; Measuring the high pressure side working pressure; And if the measured high-pressure side operating pressure is within the tolerance range of the high-pressure side standard operating pressure is determined to be normal, it is preferable to further include the step of determining more than the tolerance range.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail.

1 is a front view of a fault diagnosis manifold gauge of a vehicle refrigeration cycle according to the present invention, Figure 2 is an exploded perspective view of FIG. As can be seen from these figures, the fault diagnosis manifold gauge 1 includes a cylindrical upper and lower casing 3 and 5, a Bourdon tube 10 mounted in the casing 3 and 5, It is installed on the upper surface of the lower casing (3) includes a fixed base plate 20 to block the Bourdon tube 10, and a rotation setting plate 30 is rotatably installed on the inner plate surface of the upper casing (5).

The upper casing 3 is formed of a transparent material and is detachably coupled to the lower casing 5. In the upper and lower casings 3 and 5, the needle 40 is rotatably provided in the upper central region of the fixed substrate 20. The needle 40 is installed to elastically rotate in response to the deformation of the bourdon tube 10. The Bourdon tube 10 is a hollow flat tube made of a resilient metal plate that is bent in an arc shape to seal the end, and flows into the coupling tube 13 exposed to the outside. The displacement is proportional to the magnitude of the pressure of the refrigerant gas.

On the other hand, the fixed instrument substrate 20 is provided with a plurality of arc-shaped pressure scales 21 representing the operating pressure in the low-pressure side refrigerant pipe. In addition, inside the pressure scales 21, temperature scales 25 corresponding to atmospheric temperatures of 15 ° C. to 40 ° C. are provided. The temperature scales 25 are provided to correspond to the pressure scales 21, based on the standard operating pressure values of the following experimental data I. The low pressure standard operating pressure for ambient temperature is proposed by the applicant as follows.

Experimental Data I

Table of low pressure side standard operating pressure and effective pressure range for each ambient temperature

Unit ㎏ / ㎠

Air temperature Low Pressure Standard Operating Pressure Effective pressure range MIN MAX 15 1.070 0.962 1.184 16 1.160 1.040 1.280 17 1.250 1.118 1.376 18 1.334 1.196 1.472 19 1.421 1.274 1.568 20 1.510 1.352 1.664 21 1.595 1.430 1,760 22 1.680 1.508 1.856 23 1.769 1.586 1.952 24 1.856 1.664 2.048 25 1.940 1.742 2.144 26 2.030 1.820 2.240 27 2.120 1.898 2.336 28 2.204 1.976 2.432 29 2.291 2.054 2.528 30 2.380 2.132 2.624 31 2.472 2.217 2.728 32 2.570 2.301 2.832 33 2.661 2.386 2.936 34 2.755 2.470 3.040 35 2.850 2.555 3.144 36 2.944 2.639 3.248 37 3.040 2.724 3.352 38 3.132 2.808 3.456 39 3.227 2.893 3.560 40 3.320 2.977 3.664

(Measurement conditions: RPM 1500 to 2000 in the door open state, and 4 air conditioners)

According to this, as can be seen in the fixed substrate 20, for example, the temperature scale 15 ℃ is provided to correspond to the pressure scale corresponding to the low pressure side standard operating pressure 1.07 kg / ㎠, 40 ℃ is 3.32 kg / It is provided corresponding to 2 cm 2. In the figure, it can be seen that the temperature scales of 15 ° C. to 40 ° C. are also provided correspondingly to the pressure scales of 1.07 kg / cm 2 to 3.32 kg / cm 2, respectively.

Here, the experimental data I is based on the refrigeration cycle for vehicles applied to the various vehicles currently produced, if there is no abnormal operation, the refrigerant gas flowing in the low-pressure side refrigerant pipe, that is, the inlet pipe of the compressor It is a table that shows the standard operating pressure of the low pressure side after repeatedly measuring the actual pressure change according to the change temperature and calculating the average of each of them.

And, MIN and MAX are the lowest valid working pressure value and the highest working pressure value including the low pressure standard operating pressure corresponding to each ambient temperature when there is no abnormality in the operation of the automotive refrigeration cycle, respectively. According to this, when the atmospheric temperature is 17 ℃, as shown in the experimental data I, the minimum effective operating pressure (MIN) is 1.118 kg / ㎠ and the maximum effective operating pressure (MAX) is 1.376 kg / ㎠, low pressure When the needle 20 is located within these effective pressure ranges when the side working pressure is measured, it can be diagnosed as normal.

On the other hand, the rotation setting plate 30 is provided with a plurality of setting scales 31 arranged radially at regular intervals with respect to the rotation center thereof. The setting scales 31 represent 17 ° C, 22 ° C, 27 ° C, 32 ° C, and 37.5 ° C, respectively, among temperature values between 15 ° C and 40 ° C. On both sides of each of the set graduations 31, the effective pressure ranges 31, 32, 33, 34, 35 and 36 of the low pressure side of the normal refrigerating cycle are provided on both sides. Each section is divided.

Each effective pressure range 31, 32, 33, 34, 35, 36 has a MIN of 1.118 kg / cm &lt; 2 &gt;, for example, when the set scale 31 is 17 deg. The MAX is partitioned at intervals of 1.376 kg / cm 2, that is, 0.258 kg / cm 2, and at 22 ° C., 27 ° C., 32 ° C., and 37.5 ° C., respectively. At both ends of the effective pressure ranges 31, 32, 33, 34, 35, and 36, the atmospheric temperatures to which the corresponding effective pressure ranges can be applied are indicated. That is, at 17 ° C. of the set scale 31 having a low pressure side standard operating pressure of 1.250 kg / cm 2, the effective pressure range 32 partitioned at intervals of 0.258 kg / cm 2 on both sides is provided, and the effective partitioned in this manner is provided. The pressure range 32 is applied as it is when the atmospheric temperature is 15 ℃ to 19 ℃.

The rotation setting plate 30 is rotatable by using the operation knob 45 protruding from the center outer surface of the upper casing 3. The user grips the operation knob 45 and simply rotates the setting knob 31 corresponding to the current atmospheric temperature to the temperature scale 25 of the fixed instrument substrate 20.

Hereinafter, a method for diagnosing a failure of a refrigeration cycle for a vehicle by using the fault diagnosis manifold gauge 1 will be described in detail with reference to the flowchart of FIG. 3.

Before diagnosing failure, it is important to first provide information on the low pressure side standard operating pressure and effective pressure range for ambient temperature, as seen in Experimental Data I (S1). In addition, the present manifold gauge 1 can be provided based on such information, and the driver and the air conditioner can easily and accurately freeze the manifold gauge 1 as described below by purchasing the present manifold gauge 1 which is inexpensive with a simple configuration. Diagnosis of cycle failure is possible.

In order to diagnose the failure, the present air temperature is first measured (S2). For ease of explanation and understanding below, the current ambient temperature is assumed to be 30 ° C. Then, the rotation setting plate 30 is rotated so that the setting scale 31 of the effective pressure range 35 of 30 ° C. to 34 ° C. including the current atmospheric temperature 30 ° C. is fixed. The temperature scale 25 of the instrument panel 20 is to be designated 30 ℃ (S3). Then, both ends of the effective pressure range 35 partitioned around the set graduation 31 designating 30 ° C. of the fixed gauge substrate 20 are 2.132 kg / cm 2 and 2.624 kg / cm 2, respectively. Specifies.

As such, when the setting of the rotation setting plate 30 for the current air temperature is completed, the measurement port of the manifold gauge 1, that is, the coupling pipe 13, is a service port formed in the low pressure side refrigerant pipe of the refrigeration cycle. To (S4). Then, the Bourdon tube 10 is deformed by the pressure of the refrigerant gas flowing into the coupling tube 13, that is, the operating pressure. Accordingly, the needle 40 is rotated to designate the current low pressure side operating pressure (S5). ). At this time, when the needle is located in the effective pressure range of 2.132 kg / cm 2 to 2.624 kg / cm 2 (S6), it is determined that there is no abnormality in the operation of the vehicle refrigeration cycle (S7).

However, when the needle 40 is not located within the pressure scale of 2.132 kg / cm 2 to 2.624 kg / cm 2, it is possible to determine that the freezing cycle is abnormal, that is, failure (S9, S12). Here, when the needle 40 indicates a pressure scale of 2.132 kg / cm 2 or less, that is, a value less than or equal to the minimum effective operating pressure value MIN (S8), or the needle 40 has a pressure scale of 2.624 kg / cm 2, that is, the highest effective value. In the case of indicating a value greater than or equal to the operating pressure value (MAX) (S11), the failure part is identified and corrected based on the following failure factor determination table I (S10, S13).

[Failure Element Decision Table I]

Effective pressure range Fault factor MAX or more Excess refrigerant, condenser cooling failure, air inflow, expansion valve open Defective compressor, insufficient refrigeration oil Insufficient refrigerant or poor cooling of condenser MIN or less Expansion valve open in condenser defective state Lack of refrigerant, expansion blockage, expansion blockage due to internal moisture inflow, high-voltage circuit blockage, evaporation freezing Excessive gas injection when the expansion valve is clogged, clogging the expansion valve when the condenser is bad

Based on the failure factor diagnosis table I, the manifold gauge 1 can be used to easily and accurately diagnose the failure of the refrigeration cycle for automobiles. And, furthermore, the fixed part can be determined and appropriate action can be taken.

On the other hand, the failure of the refrigeration cycle for automobiles can be accurately diagnosed even by measuring only the low pressure side operating pressure described above, but can be diagnosed comprehensively and more specifically based on the operating pressures of both the low pressure side and the high pressure side. Figure 4 is a front view showing a manifold gauge according to another embodiment of the present invention capable of diagnosing the failure by measuring the operating pressure of the low and high pressure side of the refrigeration cycle. As can be seen from this figure, the manifold gauge 50 of this embodiment includes a high pressure side manifold gauge 60 and a refrigerant gas in addition to the low pressure side manifold gauge 1 described with reference to FIGS. 1 and 2. The injection unit 90 further includes. Here, the description of the low pressure side manifold gauge 1 is replaced by the above.

The high pressure side manifold gauge 60 is installed on the front of the cylindrical upper and lower casing 61, the bourdon tube 10 mounted in the casing 61, and the lower casing, similarly to the low pressure side manifold gauge 1. And a fixed instrument substrate 70 for blocking the Bourdon tube, and a rotation setting plate 80 rotatably installed on the inner plate surface of the upper casing. And the needle 63 which rotates corresponding to the elastic deformation of the bourdon tube 10 is also provided.

The fixed gauge substrate 70 is provided with pressure arcs 71 which represent the operating pressure in the refrigerant pipe of the high pressure side of the refrigeration cycle in an arc shape. The temperature reference point 65 is displayed below the pressure division section.

The rotation setting plate 80 is provided with temperature intervals 81 that indicate the atmospheric temperature partly along the outer circumference at regular intervals. On the other side facing these temperature scales 81, the normal range 75 showing the tolerance value centered on the high pressure side standard operating pressure with respect to the atmospheric temperature, and on both sides around the normal range 75, respectively. A compartmentalized lack of pressure and excess pressure ranges 77 and 78 are provided.

The rotation setting plate 80 can also be rotated by gripping the knob exposed to the upper portion of the upper casing. At this time, the standard operating pressure and the tolerance value of the high pressure side for the current atmospheric temperature are shown in Experiment Table II below. As can be seen, it is proposed.

Experimental Data II

Table of High Pressure Standard Operating Pressure and its Tolerance for Ambient Temperature

Unit ㎏ / ㎠

Air temperature High Pressure Standard Operating Pressure Normal operating error Usable error 15 7.40 ± 5% ± 10% 16 8.00 ± 5% ± 10% 17 8.60 ± 5% ± 10% 18 9.20 ± 5% ± 10% 19 9.80 ± 5% ± 10% 20 10.40 ± 5% ± 10% 21 11.00 ± 5% ± 10% 22 11.60 ± 5% ± 10% 23 12.20 ± 5% ± 10% 24 12.80 ± 5% ± 10% 25 13.40 ± 5% ± 10% 26 14.00 ± 5% ± 10% 27 14.60 ± 5% ± 10% 28 15.20 ± 5% ± 10% 29 15.80 ± 5% ± 10% 30 16.40 ± 5% ± 10% 31 17.05 ± 5% ± 10% 32 17.70 ± 5% ± 10% 33 18.35 ± 5% ± 10% 34 19.00 ± 5% ± 10% 35 19.65 ± 5% ± 10% 36 20.30 ± 5% ± 10% 37 20.95 ± 5% ± 10% 38 21.60 ± 5% ± 10% 39 22.25 ± 5% ± 10% 40 22.90 ± 5% ± 10%

(Measurement conditions: RPM 1500 to 2000 in the door open state, and 4 air conditioners)

In the experiment table II, if there is no abnormality in the operation of the vehicle refrigeration cycle applied to the various vehicles currently produced, the actual temperature according to the atmospheric change temperature of the refrigerant gas flowing in the high-pressure side refrigerant pipe, that is, the outlet pipe of the condenser After measuring the degree of pressure change repeatedly, the average value of each is set to the standard operating pressure on the high pressure side. In addition, the normal operating error indicates a desirable effective value of the standard operating pressure that appears according to each vehicle model, the usable error represents the effective value of the standard operating pressure that may be used without any action, but it is necessary to check sooner or later.

The refrigerant gas injection unit 90 includes an injection pipe 91, a low pressure side refrigerant hose 94, a high pressure side refrigerant hose 92, and a gas injection hose which are coupled to communicate with the lower portion of the injection pipe 91, respectively. 93 and a pair of valves 95 and 96 capable of blocking the flow paths of the low pressure side refrigerant hose 94 and the high pressure side refrigerant hose 92, respectively. The low pressure side manifold gauge 1 is coupled to the injection tube 91 at the upper side to which the low pressure side refrigerant hose 94 is coupled, and the high pressure side manifold gauge 60 is coupled to the upper side to which the high pressure side refrigerant hose 92 is coupled. Is combined.

Hereinafter, a method of inspecting whether a refrigeration cycle has failed using the failure diagnosis manifold gauge of the present embodiment having such a configuration will be described with reference to the flowchart of FIG. 5.

Before diagnosing the failure of the refrigeration cycle, it is important to provide information on the low pressure standard operating pressure and its effective pressure range for the ambient temperature and the high pressure standard operating pressure (P1). Based on this information, the low pressure side manifold gauge 1 and the high pressure side manifold gauge 60 can be manufactured, respectively.

In order to diagnose the failure of the refrigeration cycle, the current atmospheric temperature is first measured (P2). Then, the low and high pressure side manifold gauges 1 and 60 are set based on the measured atmospheric temperature (P3). Here, the setting of the low pressure side manifold gauge 1 is omitted in the description with respect to FIGS. 1 to 3, and it is also assumed that the air temperature is 30 ° C. below. On the other hand, in order to set the high pressure side manifold gauge 60, the rotation setting plate 80 is rotated, and the temperature scale 81 corresponding to the current atmospheric temperature is set at the temperature reference point 65. Then, the normal pressure range 75 of the rotation setting plate 80 is disposed between 15.58 kg / cm 2 and 17.20 kg / cm 2 with a pressure scale 71 of 16.40 kg / cm 2.

In this state, the valves 95 and 96 of the refrigerant gas injection unit 90 are closed, and the high pressure side refrigerant hose 92 and the low pressure side refrigerant hose 94 are respectively connected to the high pressure side refrigerant pipe and the low pressure side refrigerant pipe of the refrigeration cycle. To (P4). Then, the needle 40 of the low pressure side manifold gauge 1 rotates to indicate the low pressure side operating pressure, while the needle 63 of the high pressure side manifold gauge 60 also rotates to indicate the high pressure side operating pressure. (P5).

At this time, it is checked whether the low pressure side needle 63 is located within the effective pressure range with respect to the current atmospheric temperature (P6). Therefore, when it is located within the effective pressure range, it is again checked whether the high pressure side needle 63 is located within the normal range (P11). Here, when the high pressure side needle 63 is located within the normal range, it is determined that the refrigeration cycle is operating normally (P12). However, when the high pressure side needle 63 is not located within the normal range, that is, when it is disposed at a position below the corresponding lower limit normal operating error value (P13) or above the upper limit normal operating error value (P14), a failure occurs. It can determine (P15). In such a case, the fault can be repaired by checking the fault based on the fault factor determination table II below (P16).

On the other hand, when the low pressure side needle 40 is not located within the effective pressure range with respect to the atmospheric temperature (P6), it is checked whether it is below the minimum effective working pressure value (P7). At this time, if the minimum effective operating pressure is less than or equal to the high-pressure side needle 63 is checked again within the normal range (P21). Therefore, when the high pressure side needle 63 is located within the normal range, it is determined as a failure (P15), and the check is made (P16). However, when the high pressure side needle 63 is not located within the normal range, as described above, it is sequentially located below the lower limit normal operating error value (P13) or above the upper limit normal operating error value (P14). After confirming the test, take appropriate action accordingly (P15, P16).

And if the low pressure side needle 40 is not located below the minimum effective working pressure value (P7), it is checked whether it is located above the maximum effective working pressure value (P8). At this time, if it is located above the maximum effective working pressure value, check the position of the high-pressure side needle 63 (P21), and check the corresponding matter in the above-described order and then take action.

On the other hand, the method of determining whether or not the failure of the refrigeration cycle for vehicles and its failure is as follows. For reference, the following failure factor determination table II shows the low pressure side operating pressure and the high pressure operating pressure measured in the refrigeration cycle, and the standard pressure and effective pressure range of the low pressure side with respect to the present atmospheric temperature which can be seen in the experiment tables I and II. And, compare the information of the standard operating pressure and the normal range of the high-pressure side, and describe in detail the failure parts in the refrigeration cycle for vehicles that can occur according to the height and difference and the matters to be referred to when determining such failure parts. It is.

[Failure Element Decision Table Ⅱ]

1. When the measured low pressure operating pressure is higher than the minimum effective operating pressure

High pressure Fault Reference for judging fault Remarks High pressure Over refrigerant injection Excessive dew condensation, such as frost and dew, on the low-pressure pipe on the evaporator. Knocking noise generated by the compressor when the injection volume is large and the compressor is damaged. Repair is required even under normal discharge temperature Poor condenser cooling, external contaminants (dust, etc.), excessive amount of foreign substances such as oil sludge inside condenser, condenser fan and motor failure There is no or small temperature difference between condenser inlet and outlet.The condenser and the high pressure pipe are very hot.In case of refrigerant injection, the operating pressure of the air conditioner is excessively high. Air inflow inside the air conditioner No cold feeling after touching the low pressure pipe.When the compressor clutch is turned off, the high pressure side pressure decreases rapidly. Excessive expansion valve open, expansion valve open state Low pressure pipe temperature is higher than expansion valve temperatureFocus on frost and condensation on low pressure pipe Increases frost and condensation on door and window closing High pressure Compressor internal defect · High pressure drop is fast when compressor clutch is off. Lack of freezing When the low / high pressure is out of the error range of the standard air pressure. High pressure Excessive gas injection and poor cooling of condenser in compressor failure

2. When the measured low pressure working pressure is lower than the minimum effective working pressure

High pressure Fault Reference for judging fault Remarks High pressure Partially closed expansion valve with low condenser cooling or low condenser capacity Condenser inlet and outlet pipe temperature difference is small or small. When the amount of refrigerant injected is very high when the expansion valve is partially closed High pressure Low refrigerant injection The low pressure pipe is a little cold and the high pressure pipe is not hot. Expansion valve clogging When the pressure on the low pressure side is near atmospheric pressure or when the vacuum is indicated Expansion valve freezes due to moisture and moisture in the air system The low pressure side pressure is near atmospheric or vacuum (sometimes normal). Clogging of the high pressure side (condenser, high pressure pipe, dryer, etc.) Dew condensation or cold part of high-pressure side components. Evaporator freezing Cold wind comes out The wind volume decreases significantly or there is no wind. High pressure When the gas injection volume is too high when the expansion valve is partially closed Partial closure of expansion valve in condenser cooling state

3. When the measured low pressure operating pressure is within the effective pressure range

High pressure Fault Reference for judging fault Remarks High pressure Gas injection volume is too high when the expansion valve is partially closed. Excessive cooling of the condenser with some expansion valves closed High pressure Very low refrigerant injection in compressor failure Blockage of expansion valve in compressor failure High pressure in normal operation Air conditioner normal at outlet temperature below 6 ℃ If the discharge temperature is abnormal, the refrigerant is insufficient when air is introduced into the air conditioner. High pressure drop quickly after compressor clutch off.

The failure diagnosis method using the failure diagnosis manifold gauge 50 of the vehicle refrigeration cycle according to the present embodiment as described above, compared to the above-described and illustrated embodiment (1), the measured low pressure side and high pressure side operating pressure Based on the above, since it is possible to diagnose the abnormality in a comprehensive and parallel manner, there is an advantage in that it is more accurate and can respond quickly to the trouble part. When the amount of refrigerant gas in the refrigeration cycle is insufficient, the refrigerant gas can be accurately injected into the refrigeration cycle through the refrigerant gas injection unit 90.

On the other hand, in the above-described and illustrated embodiment 50 has been described a method for diagnosing the failure of the refrigeration cycle for vehicles using the low pressure side manifold gauge (1) and the high pressure side manifold gauge (60), the high pressure side Using only the manifold gauge 60, it is a matter of course that can be easily inspected and corrected according to the flow chart of FIG.

In the above-described and illustrated embodiments (1, 50), the configuration for measuring the low pressure side and the high pressure side operating pressure has also been described as including the Bourdon tube 10, but the present invention is not limited to this configuration, Digitally configurable, whereby the same purpose and effect can be achieved.

As described in detail above, according to the present invention, a refrigeration cycle for automobiles that can be manufactured at a relatively low price, which enables the operator as well as the driver of the repair shop to easily diagnose the fault and the corresponding fault part, and to correct the problem. Diagnostic manifold gauges and methods of troubleshooting using the same are provided.

The fault diagnosis manifold gauge for the refrigeration cycle for automobiles and the fault diagnosis method using the same can also easily and conveniently check whether there is a shortage or excess of refrigerant gas. It can be supplemented conveniently.

Claims (5)

delete A fixed instrument substrate 20 in which a plurality of temperature scales 25 indicating a current atmospheric temperature and a plurality of pressure scales 21 indicating the low pressure side standard operating pressure with respect to the temperature scale are displayed correspondingly in an arc shape; and In the fault diagnosis manifold gauge of a refrigeration cycle for a vehicle comprising a needle (40) rotating between the scales of the fixed instrument substrate and pointing to the current low pressure operating pressure, Rotatable with respect to the fixed substrate 20, And a rotation setting plate 30 in which effective pressure ranges 31 to 36 including the low pressure side standard operating pressure for the current atmospheric temperature are partitioned. When the needle 40 indicating the current low pressure side operating pressure is within the effective pressure range indicated on the rotation setting plate for the current atmospheric temperature, it is determined to be normal, and when it is out of the range, it is determined to be a failure. Fault manifold gauge for vehicle refrigeration cycle. The method of claim 2, A high pressure side pressure measuring unit capable of measuring a current high pressure side operating pressure of the vehicle refrigeration cycle and comparing the high pressure side standard operating pressure value with respect to the current atmospheric temperature; And And a refrigerant gas injector (90) capable of injecting refrigerant gas into the refrigeration cycle. delete delete