JPH04103574U - Refrigerant condition detection device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent stagnation due to the refrigerant from occurring at the sensor part in the refrigerant flow path, and to prevent dirt from adhering to the glass surface on the refrigerant flow path side, and to check the state of the refrigerant. Perform accurate detection. [Structure] A glass tube 27 forming a part of the refrigerant flow path between each joint part 23 of the casing 22 is attached to the glass holder 2.
4 and each O-ring 28, and each joint portion 23 is integrally fixed by each fixing plate 25. Moreover, a glass tube 2 is provided between the glass holder 24 and each fixing plate 25.
A pair of element holders 2 sandwich 7 from the radial direction.
9 and 29 are provided, and a light emitting element 3 is provided in each element holder 29.
0, Insert and install the light receiving element 31, each element 30, 31
are arranged to face each other in the radial direction of the glass tube 27.

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. 2 to 4 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 pipe 2 forming a refrigerant flow path through which a refrigerant such as gas circulates, and a refrigerant circulating in the middle of the pipe 2. A compressor 3 and a condenser 4 are provided sequentially along the ring direction (direction of arrow A in the figure). and an evaporator 5, and the evaporator 5 has an endothermic surface facing toward the operator's cabin (not shown). It is designed to look inward. Then, the refrigerant is compressed by the compressor 3. After that, while passing through the condenser 4 and evaporator 5, the gas changes from high pressure gas to high pressure liquid to low pressure gas. At the same time, when the phase transition from liquid to gas occurs in the evaporator 5, The interior of the driver's cabin is cooled by removing heat from the inside of the driver's cabin.

[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 that has become 6A is provided, and the liquefaction status of the refrigerant can be visually observed through the viewing window 6A. Ru.

[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 composed of a pressure reducing valve, etc., and the liquid phase is removed from the receiver tank 6. The refrigerant that is drawn out is reduced to a predetermined pressure and is circulated in the direction of arrow A. Ru. The refrigerant whose pressure has been reduced by the expansion valve 7 evaporates while flowing through the evaporator 5, It 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 The refrigerant inside is prevented from entering into each element holder 12 through each O-ring 11. It looks like this.

[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 flowing in the direction of arrow A from leaking to the outside from each through hole 9B. Ru.

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 The light emitting element 13 and the light receiving element 14 are positioned in each element holder 12. ing.

[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 corresponding to the state of the refrigerant flowing in the direction of arrow A in the casing 9 is generated. The detected voltage V as shown in FIG. 4 is output.

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

[0014] While flowing through the condenser 4, this refrigerant is condensed and becomes a gas-liquid mixture. After being separated into gas and liquid in the receiver tank 6, the refrigerant in the liquid phase is passed through the expansion valve 7. The heat flows into the evaporator 5, and while it evaporates (vaporizes) in the evaporator 5, the heat inside the driver's room is absorbed. By depriving the air, the inside of the driver's cabin is cooled, and it becomes a gas phase state, which is then reheated by the compressor 3. Compressed.

[0015] Here, the refrigerant sensor 8 detects that the refrigerant flowing in the direction of arrow A in the pipe 2 is normally in a liquid phase. It is arranged between the receiver tank 6 and the expansion valve 7, and emits light from the light emitting element 13. When the light receiving element 14 receives light through the coolant, it moves inside the casing 9 in the direction of arrow A. The control circuit uses a detection signal corresponding to the state of the refrigerant flowing through the control circuit as a detection voltage V as shown in Fig. 4. (not shown).

[0016] When the refrigerant filled in the pipe 2 reaches the appropriate amount, the The refrigerant flowing inside the housing 9 is completely in a liquid phase, and the light from the light emitting element 13 is emitted from the housing 9. Does the light pass through the refrigerant in the housing 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. Based on the detected voltage V from the refrigerant sensor 8, the control circuit activates an alarm such as an alarm lamp. (not shown) to notify the operator etc. when it is time to fill properly. Ru.

[0017] In addition, if the refrigerant in piping 2 leaks to the outside and there is a shortage of refrigerant, The refrigerant flowing through the housing 9 becomes a gas-liquid mixture and bubbles are generated, causing the light emitting element 1 Since the light from 3 is blocked by the air bubbles and the amount of light received by the light receiving element 14 decreases, The detected voltage V from the medium sensor 8 falls below the predetermined voltage Vi. This allows The control circuit stops the operation of the alarm, indicating that there is a refrigerant shortage due to a refrigerant leak, etc. The system is designed to notify the operator, etc.

[0018]

[Problem that the idea aims to solve]

By the way, in the prior art described above, the casing 9 of the refrigerant sensor 8 is provided with a refrigerant flow path. Since each through hole 9B is bored in orthogonal directions, each through hole 9B and each sight group are connected to each other. A stagnation of the refrigerant F flowing in the direction of the arrow A occurs between the These stagnation areas B allow impurities, lubricating oil, etc. in the refrigerant F to It adheres to the refrigerant flow path side surface of the sight glass 10 as the refrigerant sensor 8 is used for a long time. Sometimes. For this reason, each sight glass 10 is damaged by the adhesion of impurities, etc. The transmittance of the light emitted from the light receiving element 14 is reduced, and the light received by the light receiving element 14 is reduced. The amount of light received by the refrigerant sensor 8 also decreases, making it difficult for the refrigerant sensor 8 to accurately detect the refrigerant state. There is an unresolved problem.

[0019] The present invention was devised in view of the problems of the prior art mentioned above. Effectively prevents stagnation of the refrigerant and enables accurate detection of refrigerant status over a long period of time. Our objective is to provide a refrigerant condition detection device that can improve reliability. It has been the target.

[0020]

[Means to solve the problem]

The configuration adopted by the present invention in order to solve the problems of the prior art described above is that the refrigerant flow path a casing forming a part of the It is made of a light-transmitting material that is installed inside the cooling chamber through a sealing member, and through which the refrigerant flows. a transparent tube, and the case by sandwiching the transparent tube from the radial direction. A pair of element holders attached to the thing, and a pair of element holders inserted into each element holder. light-emitting elements mounted on the translucent tube and facing each other across the refrigerant flow path in the radial direction of the transparent tube; and a light receiving element.

[0021]

[Effect]

With the above configuration, the refrigerant is streamed in the transparent tube that communicates with the refrigerant flow path of the casing. It is possible to prevent the occurrence of stagnation areas due to the smooth distribution of light, and the light emitted from the light emitting element and the light receiving element. To compensate for the light received by the tube to pass through the transparent tube with high transmittance. I can do that.

[0022]

【Example】

Hereinafter, an embodiment of the present invention will be described based on FIG. 1. In addition, in the example, the above-mentioned Components that are the same as those in the prior art are given the same reference numerals, and their explanations will be omitted.

[0023] In the figure, 21 indicates a refrigerant sensor as a refrigerant state detection device of this embodiment, and the refrigerant The sensor 21 is connected to the middle of the pipe 2, and is attached to a casing (described later) that forms part of the refrigerant flow path. 22, and a glass tube installed inside the casing 22, through which a refrigerant flows. 27 and the casing 2 so as to sandwich the glass tube 27 from the radial direction. A pair of element holders 29 attached to It is generally composed of a light emitting element 30 and a light receiving element 31.

[0024] Reference numeral 22 indicates a casing, and the casing 22 has a pair of joint parts 23, which will be described later. The casing 22 consists of a lath holder 24 and a pair of fixing plates 25, and the casing 22 is It forms the outer shape of the sensor 21 and is provided in the middle of the piping 2.

[0025] Reference numerals 23 and 23 indicate a pair of rectangular parallelepiped joints made of a metal material or the like; Each joint 23 has an inner diameter that is substantially the same as the inner diameter of the pipe 2. A communication hole 23A constituting a part of the refrigerant flow path is formed, and one side of the communication hole 23A The end 2A of the pipe 2 is fitted into the pipe fitting hole 23B, and the other side is a glass tube. This is a glass tube insertion hole 23C into which the tube 27 is fitted. In addition, each joint The opening side of the glass tube insertion hole 23C is expanded in two stages in the part 23. The glass holder fitting step is formed into a stepped cylindrical shape and the glass holder 24 fits therein. A portion 23D is formed on the outer surface side of each joint portion 23, and upper, lower, left, and right portions are spaced apart from each other on the outer surface side of each joint portion 23. Screw holes 23E, 23E, . . . extending downward are formed. And each joint After fitting the end 2A of the pipe 2 into the pipe fitting hole 23B, the part 23 It is integrated with the piping 2 by being fixed to the piping 2 by means such as brazing. It looks like this.

[0026] 24 indicates a glass holder formed of a resin material into a stepped cylindrical shape; The holder 24 has a stepped shape on both the left and right ends corresponding to the stepped portion 23D of each joint 23. , the inner peripheral surface is formed as a cylindrical surface corresponding to the outer peripheral surface of the glass tube 27. . Further, the glass holder 24 has a position facing outward in the radial direction from the middle part in the axial direction. radial through holes 24A, 24A that protrude and into which each element holder 29 is inserted; Cylindrical protrusions 24B, 24B are formed. Here, each protrusion The portion 24B may be formed into a rectangular tube shape so as to be held between the end faces of each joint portion 23, or may be formed into a cylindrical shape. It may be formed into When each protrusion 24B is formed into a cylindrical shape, each A concave curved concave corresponding to the outer circumferential surface of each protrusion 24B is provided on the opposing end surface side of the joint portion 23. (not shown).

[0027] 25, 25 surround each joint part 23 from the outside and connect each joint part 23 integrally. The element holder 29 is inserted into the center of each fixing plate 25. In order to insert the bolts 26, 26, etc. into the element holder fixing hole 25A, which is fixed by Bolt insertion holes 25 drilled at positions corresponding to each bolt hole 23E of each joint part 23 B, 25B, . . . are formed. Each fixing plate 25 has a fixing member for the element holder. The element holder 29 is inserted into the fixed hole 25A in advance and fixed by means such as brazing. It is now possible to

[0028] Here, the casing 22 inserts the glass tube 27 into the glass holder 24. In this state, insert the left and right ends into each glass tube insertion hole of the joint parts 23, 23. 23C and each stepped portion 23D, and a glass holder 24 etc. is inserted between each joint portion 23. After positioning, insert each bolt 26 into each bolt insertion hole 25B of each fixed plate 25. by screwing each bolt 26 into each screw hole 23E of each joint part 23. , each joint part 23 is integrated with each fixing plate 25, and the glass tube 27 and The casing 22 is assembled with the glass holder 24 sandwiched therebetween.

[0029] 27 has an inner diameter dimension that is substantially the same as the inner diameter dimension of the pipe 2, e.g. For example, as a transparent tube formed into a cylindrical shape from a transparent material such as transparent glass. The left and right ends of the glass tube 27 are connected to each joint 23. is inserted into the glass tube insertion hole 23C of each joint part 23 and the glass holder. 24 is sealed via O-rings 28, 28 as sealing members. . Each O-ring 28 is connected to the refrigerant flowing in the direction of arrow A within the casing 22. This prevents leakage to the outside from both ends of the glass tube 27.

[0030] Reference numerals 29 and 29 indicate element holders formed in a cylindrical shape from a metal material, and each element holder is One end of the holder 29 is inserted into each through hole 24A of the glass holder 24, and the other end The sides protrude from each of the fixing plates 25 to the outside through the element holder fixing holes 25A, and It is fixed to each fixed plate 25. Each element holder 29 is a glass tube. 27 from the radial direction, and insert the glass between each joint part 23 of the casing 22. It is positioned via the space holder 24. Each element holder 29 also has a shaft. an element insertion hole 29A extending in the direction; and an element insertion hole 29A located on the inner circumference of the protruding end An annular step portion 29B having a larger diameter than A is formed, and each step portion 29B is a light emitting element. The element 30 and the light receiving element 31 are positioned in each element holder 29.

[0031] 30 and 31 are inserted into each element holder 29, and cylinders are inserted into each element holder 29. A light-emitting element and a light-receiving element are shown fixed via mounting bolts 32, 32 of the shape, The light emitting element 30 and the light receiving element 31 have annular flanges 30A and 31A and a pair of terminal pins. The collar portions 30A, 31A are located inside the protruding end of each element holder 29. By screwing each mounting bolt 32 around the circumference, the tip surface of each mounting bolt 32 and each It is held between the step part 29B of the element holder 29. Then, the light emitting element 30 The light-receiving element 31 is arranged to face the glass tube 27 in the radial direction, and the light-emitting element The light from the child 30 passes through the glass tube 27 and is received by the light receiving element 31. It looks like this.

[0032] The refrigerant sensor 21 according to this embodiment has the above-mentioned configuration, and its basic There is no particular difference in operation from that of the prior art.

[0033] However, in this embodiment, the refrigerant sensor 21 is connected in the middle of the pipe 2, and the refrigerant flow is controlled by the refrigerant sensor 21. Consists of joint parts 23, glass holders 24, fixing plates 25, etc. that form part of the road. The casing 22 and the glass holder 24 of the casing 22 are fitted and attached. a glass tube 27 through which a refrigerant flows; The glass holder 24 of the casing 22 and each fixing plate 2 are sandwiched from the opposite direction. A pair of element holders 29, 29 attached to 5 and inserted into each element holder 29. Since it is composed of a light emitting element 30 and a light receiving element 31 which are attached as shown in FIG. The refrigerant flowing through the refrigerant sensor 21 from the end 2A of the pipe 2 is From the communication hole 23A to the communication hole 23A of the other joint part 23 via the glass tube 27. The stagnation area of the refrigerant as mentioned in the prior art can be smoothly distributed to It is possible to reliably prevent this from occurring in the middle of the glass tube 27.

[0034] Therefore, according to this embodiment, the inner surface of the glass tube 27 is It can reliably prevent dirt such as pure substances and lubricating oil from adhering to the glass screen. The light transmittance of the tube 27 can be ensured for a long period of time, and the refrigerant It is possible to accurately detect the condition over a long period of time, and the lifespan of the refrigerant sensor 21 can be extended. It can significantly extend your life.

[0035] Furthermore, a glass holder 24 made of resin material is attached to the outer circumferential side of the glass tube 27. Insert the glass holder 24 and the glass tube 27 into each joint part 23 on both ends. A pair of O-rings 28 are inserted into the glass tube insertion hole 23C and the stepped portion 23D. Since they are fitted, there is no gas between each joint 23 and the glass tube 27. The glass tube 27 can be effectively protected by interposing the glass holder 24. For example, ensure a small gap between the glass tube 27 and each insertion hole 23C. However, if both ends of the glass holder 24 are tightly fitted into each stepped portion 23D, , it is possible to more reliably prevent damage or destruction of the glass tube 27 over a long period of time, and it is durable. In addition to improving performance, each O-ring 28 can reliably prevent refrigerant leakage. etc., various effects can be achieved.

[0036] In the above embodiment, each element holder 29 is fixed to each fixing plate 25 for the element holder. Although it has been described that it is fixed to the hole 25A by means such as brazing, instead of this, each A threaded portion is formed on the outer peripheral surface of the element holder 29, and the periphery of each element holder fixing hole 25A is A female thread portion is formed on the surface so that each element holder 29 is fixed by screwing. It's okay. Also, the connection between each joint 23 and the end 2A of the pipe 2 is sealed. It may be fixed by screwing through a member or the like.

[0037] Further, in the embodiment described above, each joint portion 23 of the casing 22 is formed into a rectangular parallelepiped shape. However, instead of this, each joint portion 23 is formed into a short cylindrical shape, and A communication hole 23A, a pipe insertion hole 23B, a glass tube insertion hole 23C and a In this case, each fixing plate 25 is connected to each joint. Formed by a half body having a semi-cylindrical shape with an arc corresponding to the outer peripheral surface of the hand part 23 When assembling the casing 22, these half bodies are attached to the outer periphery of each joint part 23 in the radial direction. They may also be fitted from the sides.

[0038] Furthermore, in the embodiment, each element holder 29 includes a light emitting element 30 and a light receiving element 31. has been described as being fixed using each mounting bolt 32, but the present invention is not limited to this. For example, a substantially cylindrical shape whose diameter can be contracted and expanded through a slit extending in the axial direction. Place the light emitting element 30 and light receiving element 31 into each element holder 29 using a setting ring or the like. It may be fixed.

[0039]

[Effect of the idea]

As detailed above, according to the present invention, the refrigerant state detection device a casing, and a casing inside the casing so as to communicate with the refrigerant flow path of the casing. A light-transmitting device made of a light-transmitting material that is installed through a sealing member and through which a refrigerant flows. The tube and the transparent tube are sandwiched in the casing from the radial direction. A pair of attached element holders and each element holder is inserted and installed. and a light emitting element and a receiver facing each other across the coolant flow path in the radial direction of the transparent tube. Since it is composed of optical elements, the refrigerant is It can effectively prevent the occurrence of stagnation areas, and prevent impurities in the refrigerant and lubricating oil. It is possible to reliably prevent the inner surface of the light-transmitting tube from becoming dirty. and, Reliably prevents the light transmittance of the light-transmitting tube from decreasing due to long-term use. The refrigerant condition can be detected with high precision over a long period of time, and the refrigerant condition detection device It can effectively extend the life of the equipment.

[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 circuit diagram showing an air conditioner according to the prior art;

FIG. 3 is a longitudinal cross-sectional view of a refrigerant sensor according to the prior art;

FIG. 4 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 Joint part 24 Glass holder 25 Fixed plate 27 Glass tube (transparent tube) 28 O-ring (sealing member) 29 Element holder 30 Light emitting element 31 Light receiving element F Refrigerant

Claims (1)

[Scope of utility model registration request] Claim 1: A casing that forms part of a refrigerant flow path, and a light-transmitting material that is provided within the casing via a sealing member so as to communicate with the refrigerant flow path of the casing, and through which the refrigerant flows. a pair of element holders attached to the casing so as to sandwich the translucent tube in the radial direction; A refrigerant state detection device comprising a light emitting element and a light receiving element facing each other across a refrigerant flow path.