JPH04136479U - Refrigerant condition detection device - Google Patents

Abstract

(57) [Summary] [Purpose] By using a rod-shaped optical path member, the amount of bubbles generated when refrigerant is insufficient can be quantitatively detected, and the amount of refrigerant filling can be detected with high precision. [Structure] A glass rod 23 made of a translucent material is provided in the radial direction of the casing 22 so as to extend in the radial direction. In addition, a light emitting element 27 and a light receiving element 2 are provided on both ends of the glass rod 23 in the axial direction.
8. The light from the light emitting element 27 is transmitted to the glass rod 23
The light is divided into light that is transmitted in the axial direction and light that is diffused to the sides. The light diffused to this side surface is reflected by bubbles generated when there is a shortage of refrigerant, and this reflected light is detected by the light receiving element 28 together with the light transmitted in the axial direction of the glass shaft 23.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is installed in, for example, an automobile air conditioner, and detects the state of the refrigerant in the refrigerant flow path. The present invention relates to a refrigerant state detection device suitable for use in discharging the refrigerant.

0002

[Conventional technology]

The present applicant previously disclosed in Japanese Patent Application No. 2-411494 (hereinafter referred to as prior art) We proposed an air conditioner equipped with an optical refrigerant condition detection device.

0003 Therefore, FIGS. 6 to 8 show an optical refrigerant state detection device according to this type of prior art. This shows an air conditioner equipped with

0004 In the figure, 1 indicates a cooling cycle, and the cooling cycle 1 includes ammonia, freon gas, A piping 2 forming a refrigerant flow path through which refrigerant F such as gas circulates, and a refrigerant F Compressors 3, condensing The evaporator 5 has an endothermic surface facing toward the operator's cabin (not shown). z) facing inward. After the refrigerant F is compressed by the compressor 3, , while passing through the condenser 4 and evaporator 5, the phase changes sequentially from high pressure gas → high pressure liquid → low pressure gas. At the same time, when the phase transition from liquid to gas occurs in the evaporator 5, the operation is started. The interior of the driver's compartment can be cooled by removing heat from the interior.

[0005] 6 is located between the condenser 4 and the evaporator 5 and is provided in the middle of the pipe 2, and is in a liquid state. This is a receiver tank that temporarily stores the refrigerant F that has become A window 6A is provided, through which the liquefaction status of the refrigerant F can be visually observed. ing.

[0006] 7 is located between the receiver tank 6 and the evaporator 5 and is provided in the middle of the pipe 2. The expansion valve 7 is constituted by a pressure reducing valve or the like, and the expansion valve 7 is composed of a pressure reducing valve or the like, and The refrigerant F, which is brought out in a liquid phase, is depressurized to a predetermined pressure and flows in the direction of arrow A. Let it pass. Then, while the refrigerant F whose pressure has been reduced by the expansion valve 7 flows through the evaporator 5, It evaporates, becomes a gaseous state, and is compressed again by the compressor 3.

[0007] 8 is located between the receiver tank 6 and the expansion valve 7 and is provided in the middle of the piping 2. A refrigerant sensor as an optical refrigerant state detection device is shown in FIG. As shown, a cylindrical casing is connected in the middle of the pipe 2 and forms part of the refrigerant flow path. The casing 9 includes a light emitting element 13, a light receiving element 14, etc., which will be described later. A pair of cylindrical mounting portions 9A, 9A facing each other in the radial direction protrudes outward in the radial direction. has been done. Further, the casing 9 is provided with a A radial direction that is coaxial with the section 9A, has a smaller diameter than each of the mounting sections 9A, and communicates with the inside of the refrigerant flow path. Through-holes 9B, 9B are formed on the bottom side of each mounting portion 9A coaxially with each through-hole 9B. Annular seal grooves 9C and 9C are provided.

[0008] 10, 10 is an O-ring 1 as a sealing member in each mounting portion 9A of the casing 9. 1 and 11, each sight glass 10 is transparent. It is formed into a thick disk shape from a glass material, etc., and one part of each element holder 12 described later Each O-ring 11 is held between the end face and the casing 9 via each O-ring 11 . stop Each sight glass 10 closes one end side of each element holder 12, and the casing 9 to prevent the refrigerant F from entering into each element holder 12 via each O-ring 11. It has become so.

[0009] Further, each O-ring 11 is installed in each seal groove 9C of the casing 9, and By sealing between the thing 9 and each sight glass 10, the inside of the casing 9 can be sealed. This prevents the refrigerant F flowing in the direction of arrow A from leaking to the outside from each through hole 9B. There is.

0010 12, 12, one end side is screwed to each mounting part 9A of the casing 9, and the other end side is screwed to each mounting part 9A of the casing 9. Element holders radially protruding from the thing 9 are shown, and each element holder 12 is made of a metal material. It is formed into a cylindrical shape made of material, and has a male threaded portion screwed into the mounting portion 9A on the outer periphery of one end thereof. 12A is formed. An element is provided on the inner periphery of the protruding end of each element holder 12. An annular step portion 12C having a larger diameter than the insertion hole 12B is formed, and each step portion 12C A light emitting element 13 and a light receiving element 14 are positioned within each element holder 12.

[0011] 13 and 14 are inserted into each element holder 12, and a cylindrical tube is inserted into each element holder 12. A light-emitting element and a light-receiving element are shown fixed via mounting bolts 15, 15, and the light-emitting element and light-receiving element are The optical element 13 and the light receiving element 14 have annular collars 13A and 14A and a pair of terminal pins 1. 3B and 14B, and the flanges 13A and 14A are attached to the inner periphery of the protruding end of each element holder 12. By screwing each mounting bolt 15, the tip surface of each mounting bolt 15 and each element It is held between the step part 12C of the holder 12. Then, the light emitting element 13 and The light receiving elements 14 are attached to each attachment part 9A of the casing 9 via each element holder 12. and are arranged facing each other in the radial direction of the casing 9 with each sight glass 10 interposed therebetween. Ru.

0012 Thus, the refrigerant sensor 8 ensures that the light receiving element 14 receives the light from the light emitting element 13. As a result, a detection signal is generated according to the state of the refrigerant F flowing in the direction of arrow A within the casing 9. The detected voltage V as a signal is output as shown in FIG.

[0013] In the prior art configured in this way, for example, the cooling cycle 1 is installed in a car. At this stage, refrigerant F such as Freon gas containing lubricating oil is filled into pipe 2, and the air conditioner is turned on. By turning on a switch (not shown), the compressor 3 changes to the rotational output from the engine. The compressor 3 compresses the refrigerant F in the pipe 2 while moving in the direction of arrow A. be distributed in the direction of

[0014] This refrigerant F is condensed while flowing through the condenser 4 and becomes a gas-liquid mixture. After being separated into gas and liquid in the receiver tank 6, the refrigerant F in the liquid phase passes through the expansion valve 7. It flows into the evaporator 5 through the evaporator 5, and while it evaporates (vaporizes) in the evaporator 5, the By removing the heat, the inside of the driver's cabin is cooled, and the gas phase is returned to the compressor 3. more compressed.

[0015] Here, the refrigerant sensor 8 detects that the refrigerant F flowing in the direction of arrow A in the pipe 2 is normally in a liquid phase. The light emitting element 13 is arranged between the receiver tank 6 and the expansion valve 7. When the light receiving element 14 receives the light through the coolant F, the inside of the casing 9 is shown by the arrow A. A detection signal corresponding to the state of the refrigerant F flowing in the direction is set as a detection voltage V as shown in FIG. Output to a control circuit (not shown).

[0016] When the refrigerant F filled in the pipe 2 reaches the appropriate filling amount, The refrigerant F flowing inside the casing 9 is completely in a liquid state, and light from the light emitting element 13 is emitted. The light passes through the refrigerant F in the casing 9 and is received by the light receiving element 14 with a high amount of light. Therefore, the detected voltage V from the refrigerant sensor 8 is at a higher level than the predetermined voltage Vi shown in FIG. The control circuit turns on the alarm lamp etc. based on the detected voltage V from the refrigerant sensor 8. An alarm (not shown) can be activated to notify workers etc. of proper filling time. .

[0017] In addition, when refrigerant F in piping 2 leaks to the outside and there is a refrigerant shortage, When the refrigerant F does not reach the proper level of filling, the refrigerant flows through the casing 9. The refrigerant F becomes a gas-liquid mixture and bubbles are generated, and the light from the light emitting element 13 hits the bubbles. Therefore, the amount of light received by the light receiving element 14 decreases, so that the detection from the refrigerant sensor 8 is The output voltage V is lower than the predetermined voltage Vi as shown in FIG. This allows the control The circuit stops the operation of the alarm and detects a lack of refrigerant due to a refrigerant leak or proper filling. It is possible to notify workers etc. that the target has not been reached.

[0018]

[Problem that the idea aims to solve]

By the way, the refrigerant sensor 8 in the above-mentioned prior art detects an insufficient amount of refrigerant F. By blocking the light from the light emitting element 13 by the bubbles generated by the The amount of light received by the optical element 14 decreases, and the detection voltage V decreases, thereby changing the state of the refrigerant. Since it is a detection device, it is possible to determine whether the filling amount of refrigerant F is appropriate. As shown in FIG. 8, the detected voltage V from the refrigerant sensor 8 changes due to the charging of the refrigerant F. Refrigerant leakage occurs because the filling amount changes rapidly after reaching 90% or more of the proper filling amount. Detection of subtle leakage of refrigerant F charge amount after leakage occurs, and when refilling refrigerant F There is a problem that it is not possible to detect how much refrigerant F is filled in the Ru.

[0019] The present invention was developed in view of the problems of the prior art described above. A refrigerant-type device that allows quantitative detection of the amount of refrigerant in the refrigerant flow path. The purpose is to provide a state detection device.

[0020]

[Means to solve the problem]

The refrigerant state detection device adopted by the present invention to solve the above-mentioned problems detects the refrigerant flow. A casing that forms part of the road, and a rod-shaped casing made of a translucent material. an optical path member extending in the radial direction and provided in the casing; and both ends of the optical path member. A light emitting element located on the side and emitting light into the optical path member, and a light emitting element that emits light into the optical path member. It consists of a light-receiving element that receives light.

[0021]

[Effect]

With the above configuration, light from the light emitting element passes through the optical path member and is received by the light receiving element. The light is divided into light that is diffused to the side of the optical path member, and light that is diffused to the side of the optical path member. The diffused light is reflected by the bubbles, and the light receiving element separates this reflected light and the transmitted light. Can receive light.

[0022]

【Example】

Embodiments of the present invention will be described below with reference to FIGS. 1 to 5. In addition, in the example The same reference numerals are given to the same components as in the prior art described above, and their explanations are omitted. shall be taken as a thing.

[0023] In the figure, 21 indicates a refrigerant sensor as a refrigerant state detection device of this embodiment, and the refrigerant The sensor 21 includes a casing 22, which will be described later, and extends in the radial direction of the casing 22. A cylindrical glass rod 23 is provided, and the case is located at both ends of the glass rod 23. Element holders 24 and 25 screwed onto the shing 22 and inserted into the element holder 24. There is a large distance between the vertical light emitting element 27 and the light receiving element 28 inserted into the element holder 25. It is roughly structured.

[0024] 22 indicates a casing formed in a long cylindrical shape and provided in the middle of the pipe 2; The casing 22 has a pair of cylindrical mounting portions 22A, 22 facing each other in the radial direction. A protrudes outward in the radial direction and is located at the bottom of each mounting portion 22A. Radial through holes 22B, 22B are drilled coaxially with A and communicate with the inside of the refrigerant flow path. Ru. Further, female threaded portions 22C, 22C are formed on the inner peripheral surface of the protruding side of each of the mounting portions 22A. has been completed.

[0025] Reference numeral 23 indicates a glass rod as an optical path member formed in a cylindrical shape, and the glass rod 23 are each through hole of the casing 22 so as to extend in the radial direction of the casing 22. 22B, and glass rod fixing recesses 24E, 25 of the element holders 24, 25. It is sandwiched between E.

[0026] 24 and 25 have one end screwed onto each mounting portion 22A of the casing 22, and the other end Element holders radially protruding from the casing 22 are shown, and each element holder 24, 25 is screwed into the female threaded portion 22C of the mounting portion 22A formed on the outer peripheral surface of one end thereof. The male threads 24A, 25A and the O-rings 26, 26 formed on the outer peripheral surface of the other end are installed. O-ring grooves 24B, 25B to be attached, element insertion hole 24C drilled in the axial direction, 25C, and stepped portions 24D, 25D having a larger diameter than the element insertion holes 24C, 25C. and a diameter smaller than the outer diameter of the stepped portions 24D, 25D, and element insertion holes 24C, 25C. ring insertion holes 24E and 25E formed with a larger diameter than the A glass rod fixing recess 2 formed to communicate with the element insertion holes 24C and 25C. It consists of 4F and 25F. Of the element holders 24 and 25, The element insertion hole 24C of the element holder 24 to which the light emitting element 27 is attached is provided with a glass rod 23. It is formed so as to be inclined with respect to the axial direction.

[0027] 27 and 28 are inserted into the element holders 24 and 25, and are inserted into the element insertion holes 24C and 2 Stepped cylindrical set ring that can be contracted and expanded within the positioning step portions 24D and 25D of 5C A light emitting element and a light receiving element are shown fixed via 29, 29, and the light emitting element 27 , the light receiving element 28 has annular collars 27A, 28A and a pair of terminal pins 27B, 28. B, and the flanges 27A and 28A are arranged on the inner periphery of the protruding end of each element holder 26. By inserting the ring 29 into each ring insertion hole 24E, 25E, each set reset is completed. sandwiched between the tip end surface of the ring 29 and the stepped portions 24D, 25D of the element holders 24, 25. It is. The light emitting element 27 is arranged obliquely to the axis of the glass rod 23. The light receiving element 28 is disposed on the same axis as the glass rod 23.

[0028] The refrigerant sensor 21 according to this embodiment has the above-mentioned configuration. A diagram of the optical path of light from the light emitting element 27 in the glass rod 23, which is a feature of 21. 3 and FIG. 4.

[0029] Generally, since light has a diffusion effect, the light from the light emitting element 27 is centered around the glass rod 23. It can be divided into light B, which is transmitted in the direction, and light C, which is diffused in the side. Here, cold When the filling amount of medium F has reached the appropriate filling amount, as shown in Figure 3, the glass rod Since there are no bubbles around 23, the glass emitted light from the light emitting element 27. The light C diffused on the side surface of the glass rod 23 is diffused to the outside from the side surface of the glass rod 23. child Therefore, the amount of light received by the light receiving element 28 is equal to the amount of light transmitted in the axial direction of the glass rod 23. B only, and the detection voltage V output from the light receiving element 28 has a low voltage value.

[0030] On the other hand, when the charging amount of refrigerant F has not reached the appropriate charging amount or due to refrigerant leakage. When there is a shortage of refrigerant, as shown in FIG. Bubbles corresponding to the insufficient filling amount of the medium F appear on the outer peripheral surface of the glass rod 23, so that light is not emitted. The light C diffused onto the side surface of the glass rod 23 from the element 27 is transmitted to the outer peripheral surface of the glass rod 23. The light is reflected by the bubbles and returned into the glass rod 23. For this reason, the light receiving element 2 The amount of light received at 8 increases, and the detection voltage V output from the light receiving element 28 becomes This results in a high voltage value.

[0031] Thus, the refrigerant sensor 21 in this embodiment includes the casing 22 and the casing. A glass rod 23 extending in the radial direction of the glass rod 22 and both end sides of the glass rod 23 A light emitting element 27 provided at one end and a light receiving element 2 provided at the other end. 8, the light from the light emitting element 27 is transmitted in the axial direction of the glass rod 23. It is divided into light B, which diffuses to the sides, and light C, which diffuses to the sides. This diffused light C is the refrigerant. The light is reflected by air bubbles that occur when F is insufficiently filled, and the air is detected by the light receiving element 28. The amount of light received corresponding to the amount of bubbles generated can be detected, and the detection from the light receiving element 28 A detection voltage V corresponding to the amount of bubbles generated is output to the control circuit.

[0032] That is, at the time of proper filling, the refrigerant F in the pipe 2 is in a completely liquid phase state. , no bubbles are generated, and the light C diffused on the side surface of the glass rod 23 is diffused into the pipe 2. , the amount of light received by the light receiving element 28 is the light B transmitted in the axial direction of the glass rod 23. The refrigerant sensor 21 controls the low detection voltage V corresponding to the amount of light received. output to the control circuit.

[0033] On the other hand, when there is a shortage of refrigerant F due to a refrigerant leak, or when the refrigerant is being refilled, When proper charging is not achieved, refrigerant F is in a gas-liquid mixed state (bubble generation state). Therefore, the light C diffused to the side of the glass rod 23 by this bubble is The light is reflected by the glass rod 23, returned to the glass rod 23, and received by the light receiving element 28. The amount of light increases, and the refrigerant sensor 21 outputs a high detection voltage V corresponding to the amount of light received. Output to control circuit.

[0034] Furthermore, the occurrence of bubbles due to a lack of refrigerant (leakage) is caused by an insufficient amount of refrigerant F (decreased amount). ), the more bubbles will be generated, so the number of bubbles around the glass rod 23 will also increase. As a result, the amount of light C diffused on the side surface of the glass rod 23 is reflected. This allows the cooling It becomes possible to quantitatively measure the insufficient filling amount of the medium F.

[0035] Therefore, in the control circuit, as shown in FIG. 5, the detected voltage V from the refrigerant sensor 21 is The charging amount of refrigerant F can be accurately determined by determining whether the voltage is smaller than a predetermined voltage Vi. It is possible to notify the driver and workers of this using an alarm. Also, At this time, the alarm connected to the control circuit should be equipped with a level meter or meter. If a refrigerant status indicator that can display the refrigerant status is added, it can be detected by the prior art. What is the amount of insufficient filling (leakage) of refrigerant F that was not possible? You can know what is going on.

[0036] In the above embodiment, the cylindrical glass rod 23 was used as the optical path member, but the present invention is not limited to this, but can also be used to emit light in the lateral and axial directions, such as a prismatic glass rod or fiber. A member capable of emitting light may also be used. In addition, when using a cylindrical member, You may also use one that seals a liquid with the same refractive index as the cylindrical member on the inner circumference. stomach. Furthermore, the light emitting element 27 is configured to be inclined with respect to the axial direction of the glass rod 23. However, if the light emitting element 27 with high diffusivity is used, the light emitting element can be used without tilting. Good too. Furthermore, by using an inverting circuit, the detection voltage characteristics can be improved compared to the prior art. They can have similar characteristics.

[0037]

[Effect of the idea]

As detailed above, according to the present invention, the refrigerant state detection device a casing extending in the radial direction of the casing and made of a translucent material; An optical path member formed in the shape of a rod, and an optical path member located at both ends of the optical path member, Consists of a light emitting element that emits light and a light receiving element that receives light from the light emitting element. Therefore, the light diffused to the side surface of the optical path member causes the generation of air bubbles around the optical path member. amount can be detected. In other words, when the refrigerant is slightly reduced from the proper charging amount. Since the amount of bubbles generated is small, the light diffused from the side of the optical path member is reflected. The amount of light returned to the optical path member decreases, and as the refrigerant decreases, air bubbles The amount of light generated increases, and the amount of light that diffuses from the sides is reflected and returned to the optical path member. will increase. This amount of light is detected by the light receiving element, so detection corresponds to the amount of refrigerant charged. Voltage can be output from the refrigerant condition detection device, making it possible to quantitatively and accurately determine the amount of refrigerant charged. can be detected.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a refrigerant sensor according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along arrow II-II in FIG. 1;

FIG. 3 is an explanatory diagram showing the optical path of light from a light emitting element within a glass rod when refrigerant is properly filled.

FIG. 4 is an explanatory diagram showing the optical path of light from a light emitting element within a glass rod when refrigerant is insufficient (leakage).

FIG. 5 is a characteristic line diagram showing the detection voltage of the refrigerant sensor according to the example.

FIG. 6 is a circuit diagram showing an air conditioner according to the prior art.

FIG. 7 is a longitudinal cross-sectional view of a refrigerant sensor according to the prior art;

FIG. 8 is a characteristic line diagram showing a detection voltage of a refrigerant sensor.

[Explanation of symbols]

1 Cooling cycle 2 Piping 21 Refrigerant sensor (refrigerant state detection device) 22 Casing 23 Glass rod (light path member) 24, 25 Element holder 27 Light emitting element 28 Light receiving element F Refrigerant

Claims (1)

[Scope of utility model registration request] 1. A casing forming a part of a refrigerant flow path, an optical path member formed in a rod shape from a translucent material and provided on the casing to extend in the radial direction within the casing, and the optical path member of the optical path member. A refrigerant state detection device comprising a light emitting element that emits light into the optical path member and a light receiving element that receives light from the light emitting element, which are located at both ends.