JP2002090212A - Liquid level detection mechanism for refrigeration cycle tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To connect a tank to a pole without taking labor and cost and without relying upon such thermal works as welding, soldering, etc. SOLUTION: The liquid level detection mechanism 12 for refrigeration cycle tanks comprises a float 6 floating on the surface of a liquid refrigerant or refrigerator oil stored in a tank 1 forming a part of the refrigeration cycle, a hollow pole 8 set in the tank 1 for guiding the float 6 according to the positional variation of the liquid surface, and a float position detector 9 disposed in a hollow 8a of the pole 8 for detecting the height position of the float 6. The top of the pole 8 is connected to an opening 1a formed on the topside of the tank 1, and this mechanism adopts a structure of engaging a first engaging part 13 provided at the opening 1a of the tank 1 with a second engaging part 14 provided at a connection 8b of the pole 8, thereby fixing the pole 8 to the tank 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid surface position detecting mechanism for detecting the liquid surface position of a liquid refrigerant or a refrigerating machine oil in a tank constituting a part of a refrigeration cycle using a float floating on the liquid surface. It is.

[0002]

2. Description of the Related Art FIG. 5 shows a configuration diagram of a mechanism for detecting a liquid level in a tank in a conventional refrigeration cycle. In FIG.
Reference numeral 1 denotes a tank which is installed on the suction side of the compressor in the refrigerating cycle and stores the refrigerant or refrigerating machine oil 5 and 2 denotes a tank 1
Of refrigerant or refrigeration oil 5 into the tank 3 and tank 1
Gas outflow pipe from the tank 4, liquid outflow pipe from the tank 1,
6 is a float that floats on the liquid surface of the liquid refrigerant or the refrigerating machine oil 5, 7 is a magnet built in the float 6, 8 is a hollow portion, and is formed of a material that does not block a magnetic field formed by the magnet 7. The pole 16 is a reed switch that closes when the magnetic field formed by the magnet 6 approaches within a predetermined distance and opens when the magnetic field formed by the magnet 6 exceeds a predetermined distance, 10a is a connection between the tank 1 and the pole 8, and 11 is a reed switch. 16
12a is a float 6, a magnet 7, a pole 8,
The liquid level detection mechanism includes the reed switch 16, the connecting portion 10a, and the lead wire 11 as components.

Next, the operation of the liquid level detection mechanism 12a shown in FIG. 5 will be described. When the liquid refrigerant or the refrigerating machine oil 5 flows into the tank 1 from the inflow pipe 2, the liquid level of the liquid refrigerant or the refrigerating machine oil 5 in the tank 1 rises, and accordingly, the float 6 and the magnet 7 rise along the pole 8. . If the liquid refrigerant or the refrigerating machine oil 5 flows out of the tank 1 from the liquid outflow pipe 4, the liquid refrigerant or the refrigerating machine oil 5
, The float 6 and the magnet 7 descend along the pole 8. Therefore, the position of the magnetic field formed by the magnet 7 is detected by opening and closing the reed switch 16, and the position of the magnetic field, that is, the height position of the float 6 is determined via a lead wire 11 to an external control device represented by a microcomputer. By transmitting, the level position of the liquid refrigerant in the tank 1 or the liquid level of the refrigerating machine oil 5 is detected.

[0004]

In the above-mentioned conventional refrigerating cycle, in the liquid level detecting mechanism 12a of the tank 1, the connecting portion 10a between the tank 1 and the pole 8 is connected by heat processing such as welding or brazing. Therefore, there is a problem that it takes time and cost to protect the low heat-resistant component constituting the liquid level position detection mechanism 12a from the heat caused by the thermal processing. In addition, the connecting portion 1 between the tank 1 and the pole 8
The diameter of the opening at 0a was smaller than the diameter of the float 6, and it was impossible to remove the float 6 from the opening or to insert the float 6 into the opening.
Therefore, when some trouble occurs in the liquid level position detecting mechanism 12a, the liquid level position detecting mechanism 12a is replaced.
Alternatively, there is a problem that it is difficult to repair a failed portion of the liquid level detection mechanism 12a. Since the hollow portion of the pole 8 is open to the outside air, the boundary surface between the hollow portion of the pole 8 and the hollow portion falls below the dew point temperature of the outside air due to cold heat conduction from the tank 1, the liquid refrigerant or the refrigerating machine oil 5. However, there is a problem in that dew condensation occurs on the boundary surface, and water droplets generated by the dew condensation adhere to the reed switch 16, causing erroneous detection of the reed switch 16 or deteriorating the material constituting the reed switch 16 due to the water droplet. Was. Furthermore, after the water drops accumulate in the hollow portion of the pole 8 and the hollow portion is filled with water, when the temperature in the hollow portion falls below the freezing point due to the above-described cold conduction, the water collected in the hollow portion is removed. There was a possibility that the pole 8 or the reed switch 16 would be broken due to freezing and expansion. Further, since the reed switch 16 is directly connected by the lead wire 11, the inside of the pole 8 is complicated by the lead wire 11 to reduce workability and reliability. There is a problem that it is difficult to fix to the position.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a liquid surface position detecting mechanism for a refrigeration cycle tank according to the present invention comprises a liquid refrigerant stored in a tank constituting a part of a refrigeration cycle. Alternatively, a float that floats on the liquid surface of the refrigerating machine oil, a hollow pole that is installed in the tank and guides the float along the position change of the liquid surface, and a float that is installed in the hollow portion of the pole and adjusts the height position of the float A liquid level position detecting mechanism having a float position detecting device for detecting, wherein an upper portion of the pole is connected to an opening formed on the upper surface of the tank, wherein a first engaging portion provided at the opening of the tank; A structure is employed in which the pawl is fixed to the tank by engaging a second engaging portion provided at the connecting portion of the pawl.

In the above structure, the inside diameter of the opening of the tank is larger than the outside diameter of the float.

Further, in each of the above-described structures, the hollow portion of the pole in which the float position detecting device is installed is configured to have an airtight structure with respect to outside air.

In each of the above-described configurations, a magnet is integrally attached to the float, and a reed switch that operates when the magnet approaches within a predetermined distance is used as the float position detecting device. A board made of a conductive wiring pattern formed on a board is formed so as to be accommodated in the hollow portion of the pole, and when the board is housed in the pole, the reed switch is positioned at a predetermined height in the pole. Thus, the reed switch is arranged at a predetermined position on the substrate, and the reed switch and the wiring pattern are electrically connected.

Further, the wiring pattern in the above configuration is covered with a resin material having an electrical insulating property to form a sealed structure.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of the Invention FIG. 1 is a configuration diagram showing a tank liquid level detection mechanism in a refrigeration cycle according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes a part of a refrigeration cycle, which is provided on a suction side of the compressor and stores a refrigerant or refrigerating machine oil 5;
Is an inflow pipe for introducing the refrigerant or the refrigeration oil 5 into the tank 1, 3 is a gas outflow pipe from the tank 1, 4 is a liquid outflow pipe from the tank 1, 6 is a float that floats on the liquid surface of the liquid refrigerant or the refrigeration oil 5. , 7 are magnets integrally attached to the float 6, 8 is a material having a hollow portion 8 a (see FIG. 2) which is kept airtight from the inside of the tank 1 and which does not block the magnetic field formed by the magnet 7. A hollow pole formed,
Reference numeral 9 denotes a magnetic sensor (an example of a float position detecting device) which is installed in the hollow portion 8a of the pole 8 and detects the position of a magnetic field.
0 is the connection between the tank 1 and the pole 8, 11 is the magnetic sensor 9
The reference numeral 12 denotes a float 6, a magnet 7, a pole 8, a magnetic sensor 9, a connecting portion 10, and a liquid level detection mechanism including the lead 11 as a component. The float 6 can be freely moved up and down along the pole 8.

Next, the operation of the liquid level detecting mechanism 12 shown in FIG. 1 will be described. When the liquid refrigerant or the refrigerating machine oil 5 flows into the tank 1 from the inflow pipe 2, the liquid level of the liquid refrigerant or the refrigerating machine oil 5 in the tank 1 rises, and accordingly, the float 6 and the magnet 7 rise along the pole 8. . On the other hand, if the liquid refrigerant or the refrigerating machine oil 5 flows out of the tank 1 from the liquid outflow pipe 4, the liquid refrigerant or the refrigerating machine oil 5 in the tank 1
, The float 6 and the magnet 7 descend along the pole 8. The position of the magnetic field formed by the magnet 7 is detected by the magnetic sensor 9, and the position of the magnetic field, that is, the height position of the float 6 is transmitted to an external control device represented by a microcomputer via the lead wire 11. The height position of the liquid level of the liquid refrigerant or the refrigerating machine oil 5 in the tank 1 is detected.

Next, the structure of the connecting portion 10 between the tank 1 and the pole 8 shown in FIG. 1 will be described in detail with reference to FIG. FIG.
The same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. 2, reference numeral 13 denotes an opening 1 on the upper surface of the tank 1.
a, which has a cylindrical hollow portion inside, and a screw portion (female screw) on the inner peripheral surface of the hollow portion.
(A first engagement portion) on which is formed a pole 8
Is provided so as to keep airtight with the pole 8 at the connecting portion 8b of
Further, a pedestal (second engaging portion) having a hole for allowing the lead wire 11 to penetrate and having a threaded portion (male screw) formed on the outer peripheral surface of a cylindrical shape, 15 is a lead of the pedestal 14. It represents a filler such as resin or silicon for sealing a hole for penetrating the line 11. Also, in FIG.
Represents the outer diameter of the float 6, and the symbol b represents the inner diameter of the cylindrical hollow portion of the pedestal 13, and the relationship between a and b is a <b.
In this embodiment, the screw portion of the pedestal 13 and the pedestal 1
The pawl 8 is fixed to the tank 1 by engaging (in this case, screwing) with the screw portion of the tank 4. However, the first and second engagement portions of the present invention are not limited to the above-mentioned screw portions, and may be, for example, those in which fitting portions for detachably sealingly fitting are provided on both the tank 1 and the pole 8.

As shown in FIG. 2, the structure for connecting the tank 1 and the pole 8 is screwed through the pedestal 13 and the pedestal 14, so that the tank 1 and the pole 8 can be connected to each other by heat or brazing. Since there is no need to heat as in the case of connection by processing, in order to ensure the reliability of the components of the liquid level position detection mechanism 12 against heating accompanying thermal processing, high heat-resistant parts must be used. Conventional problems such as high cost can be avoided. Further, at the time of thermal processing, it is possible to save labor and cost required for a cooling operation required for protecting low heat resistant components constituting the liquid level position detection mechanism 12 from heat. Furthermore, after connecting the pole 8 to the tank 1 in advance by thermal processing, the other components of the liquid level detection mechanism 12 are replaced by the thermal processing so that the low heat-resistant component is not affected by the heating accompanying the thermal processing. There is no need to take the conventional method of incorporating. Thus, it is possible to avoid the conventional problem that the painting step and the washing step of the tank 1 that need to be performed after the thermal processing become difficult due to the pole 8 connected in advance. Alternatively, it is possible to avoid the conventional problem that the workability is deteriorated because other components of the liquid level detection mechanism 12 have to be incorporated in a state where the pole 8 is fixed to the tank 1.

Further, as shown in FIG.
a is larger than the outer diameter a of the float 6 (a <
b) If this is done, the entire liquid level position detection mechanism 12 can be removed from the tank 1 by simply removing the screw portion connecting the pedestal 13 and the pedestal 14 without performing processing such as cutting of the tank 1 or fusing of a welded portion. Can be removed from. Further, by screwing the screw portion of the pedestal 13 and the screw portion of the pedestal 14 after the liquid level detection mechanism 12 is inserted into the tank 1, the liquid can be cut into the tank 1 without performing processing such as cutting or welding of a welded portion. Since the entire surface position detection mechanism 12 can be connected to the tank 1, the liquid surface position detection mechanism 12 can be replaced when some trouble occurs in the liquid surface position detection mechanism 12. Further, it is easy to repair a failed portion of the liquid level position detection mechanism 12 and the like. The labor and cost required for repair can be reduced.

Further, as shown in FIG. 2, a hole for penetrating the lead wire 11 provided on the pedestal 14 is sealed with a filler 15 so that the hollow portion of the pole 8 in which the magnetic sensor 9 is installed is formed. Since the air 8a is made airtight with respect to the outside air, it is possible to prevent the outside air from entering the hollow portion 8a of the pole 8. Accordingly, it is possible to prevent dew condensation on the boundary surface which occurs when the boundary surface between the pole 8 and the hollow portion 8a is lower than the dew point temperature of the outside air due to heat conduction from the tank 1, the liquid refrigerant, or the refrigerating machine oil 5. it can. Therefore,
It is possible to avoid a problem that water droplets generated by dew condensation adhere to the magnetic sensor 9 to cause erroneous detection of the magnetic sensor 9 or that the material forming the magnetic sensor 9 is deteriorated by the water droplet. Further, after the hollow portion 8a is filled with water due to the accumulation of water droplets in the hollow portion 8a, when the temperature in the hollow portion 8a falls below the freezing point due to the above-mentioned cold conduction, the inside of the hollow portion 8a is generated. The problem that the accumulated water freezes and expands and breaks the pole 8 or the magnetic sensor 9 can be avoided.

Embodiment 2 of the Invention FIG. 3 is a configuration diagram of a liquid level detection mechanism according to Embodiment 2 of the present invention.
In FIG. 3, the same parts as those in FIG. 1 or FIG. 2 are denoted by the same reference numerals, and detailed description is omitted. In FIG. 3, reference numeral 16 denotes a reed switch (another example of a float position detecting device), which is closed when the magnet 7 of the float 6 approaches within a predetermined distance, and opens when the magnet 7 is separated by a predetermined distance or more, and 17 is a reed switch 1.
6 and the reed switch 16 and the lead 1
1 represents a substrate that is electrically connected.

Next, the detailed structure of the substrate 17 of FIG. 3 will be described with reference to FIG. In FIG. 4, reference numeral 18 denotes a resin plate having electrical insulating properties (an example of a resin material), and 19 denotes two resin plates 1.
A wiring pattern having a structure sandwiched between 8, 18 and having conductivity. The substrate 17 is a resin plate 1
8 and 18 and a wiring pattern 19.
The substrate 17 is formed in a shape and size that can be accommodated in the hollow portion 8a of the pole 8. The reed switch 16 is disposed at a predetermined position on the substrate 17 so that the reed switch 16 is positioned at a predetermined height in the hollow portion 8a when the substrate 17 is accommodated in the pole 8. The reed switch 16 is electrically connected to the wiring pattern 19.

If the board 17 is used to support the reed switch 16 in the pole 8 as shown in FIG. 3, the reed switch 16 is electrically connected to the board 17 and fixed at a predetermined position, and then the board 17 is attached. By using a method of inserting into the hollow portion 8a of the pole 8 and fixing it at a predetermined position,
It is possible to easily and accurately install the reed switch 16 at an intended position in the hollow portion 8a of the pole 8. The substrate 17 is a reed switch 16
And the lead 11 are electrically connected to each other. Therefore, when the conventional method of directly connecting the reed switch 16 to the lead 11 is employed, the inside of the pole 8 is complicated by the lead 11. As a result, the problem that workability and reliability are reduced can be avoided. Also, the increase in the space required when increasing the number of the wiring patterns 19 is extremely smaller than the increase in the space required when increasing the number of the lead wires 11, so that the number of the reed switches 16 is increased. The amount of increase in the diameter of the pole 8 required for this operation can be reduced as compared with the amount of increase in the conventional method of directly connecting the reed switch 16 to the lead wire 11, thereby reducing the cost. It has the advantage of being connected.

Further, as shown in FIG. 4, if a sealing structure is adopted in which the wiring pattern 19 is sandwiched between two resin plates 18 and 18 having electrical insulation properties, the conductive wiring pattern 19 Will not appear on the surface,
The wiring pattern 19 is not short-circuited when water droplets or dust adheres to the surface of the substrate 7, so that the reliability is improved. In addition, since it is possible to eliminate the need for an insulating desiccant applied to the surface of the substrate 17 in order to prevent the short circuit of the wiring pattern 19 described above, it is possible to reduce cost and labor for processing.

[0020]

As described in detail above, according to the first aspect, the pole is fixed to the tank by engaging the first engagement portion of the tank opening with the second engagement portion of the pole connection portion. With such a structure, there is no need for heat processing such as the case of connecting a tank and a pole by welding or brazing. Therefore,
In order to ensure the reliability of the components of the liquid level detection mechanism with respect to the heating caused by the thermal processing, it is possible to avoid the problem of increasing the cost by using components having high heat resistance. In addition, it is possible to reduce the labor and cost required for a cooling operation required to protect components having low heat resistance from heat when thermal processing is performed. Furthermore, there is no need to take a method of connecting the pole to the tank in advance by thermal processing and then incorporating other components so that the component having low heat resistance is not affected by the heating accompanying the thermal processing. This makes it difficult to paint and clean the tank, which must be performed after thermal processing, due to the poles that are connected in advance, and other components with the poles fixed to the tank. It is possible to avoid the problem that workability is deteriorated due to the inevitable incorporation of.

According to the second aspect of the present invention, the inner diameter of the opening of the tank is made larger than the outer diameter of the float. The entire liquid surface position detection mechanism can be removed from the tank without performing processing such as cutting or fusing of a welded portion. Conversely, after inserting the liquid level detection mechanism into the tank, just engage the engagement part between the tank and the pole,
The entire liquid level detection mechanism can be connected to the tank without performing processing such as cutting or welding of the welded portion on the tank. Therefore, it is possible to easily replace the liquid level position detecting mechanism when a failure occurs in the liquid level position detecting mechanism, or to repair a failed portion of the liquid level position detecting mechanism. This can reduce the labor and cost required for repairing a failed part, as compared with a case where the above-described processing such as cutting or welding of a welded part is performed on the tank, or a case where the entire tank is replaced.

According to the third aspect of the present invention, the hollow portion of the pole, in which the float position detecting device is installed, has an airtight structure with respect to the outside air, so that the boundary surface between the hollow portion of the pole and the outside world has a tank. The dew point on the boundary surface, which is generated when the temperature drops below the dew point temperature of the outside air due to heat conduction from the liquid refrigerant or the refrigerating machine oil or the like, can be prevented. Therefore, it is possible to avoid a problem that water droplets generated by dew condensation adhere to the magnetic sensor and cause the magnetic sensor to perform erroneous detection, or the water droplets deteriorate the material of the magnetic sensor. Furthermore, after the water drops accumulate and fill in the hollow portion of the pole, the temperature in the hollow portion falls below the freezing point due to the aforementioned thermal conduction, and the water in the hollow portion freezes, expands, and destroys the pole or the magnetic sensor. Problems can be avoided.

According to the fourth invention, the reed switch is arranged at a predetermined position on the board so that the reed switch is located at a predetermined height in the pole when the board having the wiring pattern is accommodated in the pole. In addition, by electrically connecting the reed switch and the wiring pattern,
The reed switch can be easily and accurately installed at an intended position in the pole. Further, it is possible to avoid the problem that the inside of the pole becomes complicated due to the lead wire and the workability and the reliability are reduced, which occurs when the method of directly connecting the reed switch by the lead wire is adopted. In addition, the amount of space required to increase the number of wiring patterns is extremely small compared to the amount of space required to increase the number of lead wires. The required increase in the diameter of the pole can be reduced as compared with the increase in the case where the method of directly connecting the reed switch with the lead wire is used, and there is an advantage that the cost is reduced.

According to the fifth aspect of the present invention, since the wiring pattern is covered with the resin material having electrical insulation to form a sealed structure, the conductive wiring pattern does not appear on the surface of the substrate. The wiring pattern is not short-circuited when water droplets or dust adheres to the surface of the substrate, thereby improving reliability. Further, since a moistureproofing agent having an electric insulating property, which is applied to the surface of the substrate in order to prevent the short circuit of the wiring pattern described above, becomes unnecessary, the cost and the processing labor can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a tank liquid level detection mechanism in a refrigeration cycle according to Embodiment 1 of the present invention.

FIG. 2 is a diagram illustrating a structure of a connection portion between a tank and a pole according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram illustrating a liquid level detection mechanism according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a substrate according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram showing a liquid level detection mechanism of a tank in a conventional refrigeration cycle.

[Explanation of symbols]

Reference Signs List 1 tank, 1a opening, 5 liquid refrigerant or refrigerating machine oil, 6 float, 7 magnet, 8 pole, 8a hollow, 8b connection, 9 magnetic sensor (float position detecting device), 10 connection, 11 lead wire, 12 Liquid level position detecting mechanism, 12A liquid level position detecting mechanism, 13 pedestals (first engaging portion), 14 pedestals (second engaging portion), 15 filler, 16 reed switch (float position detecting device), 17 substrate, 18 resin plate (resin material), 19
Wiring pattern, a outside diameter, b inside diameter.

Continued on the front page (72) Inventor Takuya Inoue 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation F-term (reference) 2F013 AA05 AA06 BC02 CA12 CB10 2F014 AA11 AA14 AA16 AB01 AB04 AC02

Claims (5)

[Claims] 1. A float floating on a liquid surface of a liquid refrigerant or refrigerating machine oil stored in a tank constituting a part of a refrigeration cycle, and a float installed in the tank to change the position of the liquid surface. A hollow pole that guides along,
A liquid having a float position detecting device installed in a hollow portion in the pole to detect a height position of the float, wherein an upper portion of the pole is connected to an opening formed in an upper surface of the tank. In the surface position detection mechanism, a structure in which a first engagement portion provided at an opening of the tank and a second engagement portion provided at a connection portion of the pole are engaged to fix the pole to the tank. A liquid level position detection mechanism for a refrigeration cycle tank. 2. The liquid level position detecting mechanism for a refrigeration cycle tank according to claim 1, wherein the inner diameter of the opening of the tank is larger than the outer diameter of the float. 3. The refrigeration cycle tank according to claim 1, wherein the hollow portion of the pole in which the float position detecting device is installed has an airtight structure with respect to outside air. Liquid level position detection mechanism. 4. A resin plate having electrical insulation and formed on the resin plate using a reed switch which is mounted integrally with the float and which operates when the magnet approaches within a predetermined distance as a float position detecting device. And a wiring pattern having electrical conductivity formed in the pole, the reed switch is formed at a predetermined height in the pole when the substrate is accommodated in the pole. 4. The device according to claim 1, wherein the reed switch is arranged at a predetermined position on the substrate, and the reed switch is electrically connected to the wiring pattern. A liquid level position detection mechanism for a refrigeration cycle tank according to claim 1. 5. The liquid level position detecting mechanism for a refrigeration cycle tank according to claim 4, wherein the wiring pattern is covered with a resin material having electrical insulation to form a sealed structure.