JP2864852B2 - Liquid level sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid level sensor used in an air conditioner having a heat storage tank, and more particularly to a seal structure.

[0002]

2. Description of the Related Art An air conditioner is disclosed in Japanese Unexamined Patent Publication No.
As disclosed in Japanese Patent Publication No. 37, there is a type that cools or heats a refrigerant by using heat storage stored in a heat storage tank. As shown in FIG. A liquid level sensor for detecting the liquid level of the medium is provided.

As shown in FIG. 6, the capacitance type liquid level sensor comprises a main body case a, a storage case b, and a detection cylinder portion c which is suspended from the storage case b and immersed in stored water. , The storage case b is formed so as to be openable, while a signal processing unit d is disposed inside the storage case b.
Is formed with a lower mold part e filled with polyurethane and an upper mold part f filled with epoxy resin. The signal processing section d is connected to a lead g that extends through the lower mold section e and the upper mold section f and extends to the outside.

An electrode plate h is provided on the inner peripheral surface of the detection cylinder c.
However, an electrode rod i is provided therein, and an electrode plate h and an electrode rod i are provided.
Is connected to the liquid level detection circuit on the signal processing unit d, and is configured to convert the capacitance between the electrode plate h and the electrode rod i into a liquid level signal and output it to the outside.

[0005]

However, in the above liquid level sensor, the adhesion between the lower mold part e or the upper mold part f and the storage case b is not sufficient, so that the water vapor and the storage in the space in the ice storage tank are not sufficient. There is a problem that water invades the inside along the inner surface of the storage case b and short-circuits the liquid level detection circuit of the signal processing unit d to cause malfunction. Therefore, the liquid level sensor has to be replaced frequently.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a liquid level sensor having a structure in which it is difficult for water to enter a signal processing unit.

[0007]

Means for Solving the Problems In order to achieve the above-mentioned object, the means according to the first aspect of the present invention is that the first mold part is formed by the first molding material which is in close contact with the storage case.
The mold portions are each formed of a second mold material that is in close contact with the lead wire.

Specifically, as shown in FIG. 3, the means adopted by the invention according to claim 1 includes a storage case (31) having an open upper part, and a physical quantity that changes with a change in the liquid level. (48) and (49) for detecting the

Further, in the storage case (31),
A signal processing unit (42) for receiving the output signals from the detection units (48) and (49) and converting the output signals into a liquid level signal is provided, and the signal processing unit (42) includes the storage unit. A lead wire (23) extending from the upper opening (37) of the case (31) to the outside is connected.

In addition, in the storage case (31),
A sealed portion (41) for enclosing the signal processing portion (42) is formed, and a first mold portion is provided above the sealed portion (41) in contact with the storage case (31) and the lead wire (23). (44) and the second mold part (45) are laminated.

Furthermore, a first mold part (44)
Is made of a first molding material having close contact with the storage case (31), while a second molding part (45)
Is made of a second molding material having an adhesive property with the lead wire (23).

A second aspect of the present invention provides a waterproof wall that extends a water infiltration path along a wall surface from an inner surface of the side wall to an inner sealing portion.

More specifically, as shown in FIG. 4, the means taken by the invention according to claim 2 includes a storage case (31) having an open upper part and a physical quantity that changes with a change in the liquid level. (48) and (49) for detecting the

Further, a waterproof wall (61) is provided on the bottom wall (32) of the storage case (31).
Is formed in a circulating manner with a predetermined distance from the side wall (33).

In addition, inside the waterproof wall (61), a signal processing unit (42) for receiving an output signal from the detection units (48) and (49) and converting the output signal into a liquid level signal. A lead wire (23) extending from the upper opening (37) of the storage case (31) to the outside is connected to the signal processing unit (42), while the waterproof wall (61) is connected to the signal processing unit (42). The inside of the inner sealing section (4) enclosing the signal processing section (42)
1) is formed.

Furthermore, the storage case (31) has an inner surface of the side wall (33), a bottom wall (32) and a waterproof wall (6).
The first contacting the at least part of the inner and outer surfaces of 1) in a circular manner.
A mold part (44) is formed, and a second mold part (45) is formed by lamination in contact with the storage case (31) and the lead wire (23).

Further, the first mold part (44) is made of a first mold material having an adhesive property to the storage case (31), while the second mold part (45) is made of the lead wire (23). And a second mold material having adhesiveness to the second mold material.

[0018] The means according to the third aspect of the present invention is to prevent the inside from being flooded by covering the entire storage case with an external mold portion.

Specifically, as shown in FIG. 5, the means adopted by the invention according to claim 3 includes a storage case (31) having an open upper part, and a physical quantity that changes with a change in the liquid level. (48) and (49) for detecting the

Further, a signal processing section (42) for receiving the output signals from the detection sections (48) and (49) and converting the output signals into a liquid level signal is provided in the storage case (31). The signal processing unit (42) includes the storage case (3).
The configuration is such that a lead wire (23) extending to the outside from the upper opening (37) of 1) is connected.

Furthermore, in the storage case (31),
An enclosed portion (41) for enclosing the signal processing portion (42) and a molded portion (67) in contact with the storage case (31) and the lead wire (23) are formed above the enclosed portion (41). Configuration.

Further, the storage case (31) is formed with an external mold portion (69) for covering the outside and sealing the storage case (31) and the external atmosphere.

Further, the means taken by the invention according to claim 4 is to set the molding material corresponding to the material of the storage case and the lead wire.

Specifically, the means taken by the invention according to claim 4 is, as shown in FIG.
In the liquid level sensor according to the present invention, the storage case (31)
Is a polyacetal resin, the lead wire (23) is covered with vinyl chloride resin, the first mold material of the first mold portion (44) is silicone gel, and the second mold material of the second mold portion (45) is silicone. It is configured to be formed by RTV, respectively.

[0025]

According to the first aspect of the present invention, the detectors (48) and (49) detect the physical quantity corresponding to the change in the liquid level, and the detectors (48) and (49) detect the physical quantity corresponding to the change in the liquid level. Is received by the signal processing unit (42), converted into a liquid level signal, and output to the outside via the lead wire (23). From the upper opening (37) of the storage case (31), the vapor of the stored liquid or the like tends to enter the inside along the inner surface of the storage case (31) or the lead wire (23).

On the other hand, the first mold part (44) formed above the inner sealing part (41) is in close contact with the inner surface of the storage case (31) due to the first molding material being in close contact with the inner surface of the storage case (31). Prevent intrusion. Also, the second mold part (45)
The molding material comes into close contact with the lead wire (23) and prevents water from flowing from the lead wire (23). As a result, the infiltration of the inner sealing portion (41) from the outside is prevented.

According to the invention of claim 2, the waterproof wall (6
1), the intrusion path along the wall surface from the inner surface of the side wall (33) to the inner sealing portion (41) becomes longer, and even if the vapor of the stored liquid (W) invades along the inner surface of the storage case (31). Even so, the time to reach the inner sealing portion (41) becomes longer.

According to the invention of claim 3, by covering the entire storage case (31) with the external mold portion (69), invasion of steam or the like into the storage case (31) is prevented.

According to the fourth aspect of the present invention, the first molding material is made of a silicone gel having good adhesion to the storage case (31) made of polyacetal resin, and the second molding material is made of a vinyl chloride resin having a covering portion. The use of a silicone RTV having good adhesion to the lead wire (23) ensures the ability to block invasion of vapor and the like.

[0030]

As described above, according to the first aspect of the present invention, the first mold portion (44) is formed by the first mold material which is in close contact with the inner surface of the storage case (31) serving as a flood path. (2) By forming the mold part (45) from the second mold material that is in close contact with the lead wire (23), the material of the mold part is selected according to the material of the storage case (31) and the lead wire (23). Inundation can be reliably prevented. As a result, a short circuit of the signal processing unit (42) can be reliably prevented.

According to the invention of claim 2, the waterproof wall (6
According to 1), even if steam or the like is flooded along the inner surface of the storage case (31), the time to reach the inner sealing portion (41) can be lengthened, and the life of the sensor can be further lengthened. it can.

According to the third aspect of the present invention, since the entire storage case (31) is covered with the external mold portion (69), it is possible to prevent water from entering the storage case (31), and the life of the sensor is reduced. Can be lengthened.

According to the fourth aspect of the present invention, the first molding material is made of silicone gel having good adhesion to the polyacetal resin, and the second molding material is made to adhere to the lead wire (23) made of vinyl chloride resin. By using a silicone RTV having good properties, it is possible to secure the barrier property against invasion of vapor or the like when using a polyacetal resin for the storage case (31).

[0034]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show a first embodiment in which the liquid level sensor according to the first and fourth aspects of the present invention is applied to a water level sensor of an ice storage tank of an air conditioner. FIG. 1 shows an overall configuration of an air conditioner, which is a so-called multi-type air conditioner in which a plurality of indoor units (A), (B),... Are connected to an outdoor unit (X).

The outdoor unit (X) includes a compressor (1) and a four-way switching valve (2) that switches as shown by a solid line in the cooling operation and switches as shown by a broken line in the heating operation. An outdoor heat exchanger (3) as a heat source side heat exchanger that functions as an evaporator during a heating operation as a condenser during a cooling operation, and adjusts a refrigerant flow rate during a cooling operation and reduces a refrigerant pressure during a heating operation. An outdoor electric expansion valve (4) functioning as a pressure reducing mechanism, a receiver (5) for storing condensed liquid refrigerant, and an accumulator (8) for removing liquid components in the suction refrigerant are provided. ing.

On the other hand, each indoor unit (A), (B),.
In addition, the indoor electric expansion valve (6), which functions as a pressure reducing mechanism during the cooling operation and adjusts the refrigerant flow rate during the heating operation,
(6), an indoor heat exchanger (7) that functions as an evaporator during cooling operation and as a condenser during heating operation.
(7),... Are provided.

The compressor (1), four-way switching valve (2), outdoor heat exchanger (3), outdoor electric expansion valve (4), receiver (5), indoor electric expansion valve (6),
, The indoor heat exchangers (7), (7),... And the accumulator (8) are sequentially connected by a refrigerant pipe (9) so that the refrigerant can flow therethrough, and the heat with the outdoor air is transmitted. A main refrigerant circuit (10) having a heat pump function of releasing heat obtained by the exchange to room air is configured.

In the air conditioner, heat is exchanged with the refrigerant flowing through the main refrigerant circuit (10) to perform cold storage heat and heat storage, or heat storage for utilizing the cold storage heat and heat storage. A unit (Y) is provided.

The heat storage unit (Y) includes a heat storage tank (11), which is a tank, in which stored water (W) as a heat storage medium capable of storing cold and warm heat, and the heat storage tank (11). And a heat storage heat exchanger (12) for performing heat exchange with the stored water (W).
The heat storage heat exchanger (12) is connected to the first bypass passage (13).
a) and the second bypass path (13b), the liquid line (9a) between the outdoor electric expansion valve (4) and the indoor electric expansion valves (6), (6),... of the main refrigerant circuit (10). The refrigerant is connected to the indoor electric expansion valves (6), (6),... In order from the side. Then, the first bypass path (13
a) a heat storage electric expansion valve (14) as a cold storage heat decompression mechanism for decompressing a refrigerant when cold water is stored in the stored water (W);
On the other hand, a first on-off valve (15) for opening and closing the second bypass passage (13b) is interposed in the second bypass passage (13b).

The space between the first on-off valve (15) of the second bypass passage (13b) and the heat storage heat exchanger (12) and the gas line (9b) of the main refrigerant circuit (10) are connected to the The refrigerant is circulated through a third bypass passage (13c), and a second on-off valve (16) for opening and closing the third bypass passage (13c) is interposed in the third bypass passage (13c). Have been.

The liquid line (9a) of the main refrigerant circuit (10) between the first bypass path (13a) and the second bypass path (13b) is used for variably adjusting the flow rate of the refrigerant. A flow control valve (17) is interposed.

The four-way switching valve (2), the outdoor electric expansion valve (4), the indoor electric expansion valves (6), (6),.
By opening or closing or adjusting the opening degree of the heat storage electric expansion valve (14), the first opening / closing valve (15), the second opening / closing valve (16), and the flow control valve (17), the refrigerant according to the operation mode described below. Switching means for switching the circulating path.
Furthermore, the flow of the refrigerant during the cold storage heat recovery cooling operation is controlled by the flow control valve, the first opening / closing valve (15), and the heat storage electric expansion valve (14) to the second bypass passage (13b) side and the main refrigerant circuit ( 10) There is provided a flow dividing means for dividing the flow to the side.

Next, an operation mode of the air conditioner will be described. In normal cooling operation, the four-way switching valve (2) switches as shown by the solid line in the figure, and the outdoor electric expansion valve (4), the flow control valve (17), and the indoor electric expansion valves (6) and (6) ),
Are opened and the other valves are closed, and the refrigerant condensed in the outdoor heat exchanger (3) circulates only through the main refrigerant circuit (10), and the indoor heat exchangers (7), (7) ), ... and return to the compressor (1).

The regenerative heat operation includes an outdoor electric expansion valve (4),
The flow control valve (17), the heat storage electric expansion valve (14), and the second on-off valve (16) are opened to operate the indoor electric expansion valves (6), (6),... And the first on-off valve (15). ) Is closed, the liquid refrigerant condensed in the outdoor heat exchanger (3) flows into the first bypass passage (13a), and the heat storage electric expansion valve (14).
, And is evaporated in the heat storage heat exchanger (12) and returned to the compressor (1).

At this time, the stored water (W) serving as a heat storage medium is made into ice by exchanging heat with the refrigerant in the heat storage heat exchanger (12) to store cold heat.

Normal cooling and regenerative heat simultaneous operation are performed by the outdoor electric expansion valve (4), the flow control valve (17), the indoor electric expansion valves (6), (6),. ) And the second on-off valve (16) are opened to open the first on-off valve (15).
Is closed. By these operation controls, part of the cold heat condensed in the outdoor heat exchanger (3) flows through the main cooling circuit and is reduced in pressure by the indoor electric expansion valves (6), (6),. While evaporating in the exchangers (7), (7),..., The remaining liquid cooling heat flows into the first bypass passage (13a) and is decompressed by the heat storage electric expansion valve (14) to be stored in the heat storage heat exchanger (12). To evaporate. Then, the refrigerant that has been evaporated to a gaseous state is circulated so as to merge in the gas line (9b) and return to the compressor (1).

In the cold storage heat recovery operation utilizing the cold energy stored in the cold storage operation, the outdoor electric expansion valve (4), the flow control valve (17), and the indoor electric expansion valves (6), (6),. The heat storage electric expansion valve (14) and the first opening / closing valve (15) are opened, the second opening / closing valve (16) is closed, and a part of the liquid refrigerant condensed in the outdoor heat exchanger (3) is removed. Second from main refrigerant circuit (10)
After flowing into the bypass passage (13b), the heat storage heat exchanger (1
In step 2), the liquid refrigerant is supercooled by heat exchange with water (or ice) and returns from the first bypass passage (13a) to the main refrigerant circuit (10), while the remaining liquid refrigerant passes through the flow control valve (17) and remains as it is. The liquid flows through the liquid line (9a) of the refrigerant circuit (10).
After the merging, they are circulated so as to evaporate in the indoor heat exchangers (7), (7),... And return to the compressor (1).

In the normal heating operation, the four-way switching valve (2) switches as shown by a broken line in the figure, and each indoor electric expansion valve (6),
(6), ... open and other valves close, discharge gas is condensed in each indoor heat exchanger (7), (7), ... and decompressed by the outdoor electric expansion valve (4). It is circulated to return to the compressor (1) after being evaporated in the outdoor heat exchanger (3).

In the heating / heating operation, the second opening / closing valve (16), the heat-storage electric expansion valve (14), the flow control valve (17) and the outdoor electric expansion valve (4) are opened to operate each indoor electric motor. The expansion valves (6), (6),... And the first on-off valve (15) are closed, and the discharged gas flows from the main refrigerant circuit (10) into the third bypass path (13c), and the heat storage heat exchanger. After being condensed in (12), the main refrigerant circuit (1) passes through the first bypass passage (13a).
0), the pressure is reduced by the outdoor electric expansion valve (4), evaporated in the outdoor heat exchanger (3), and then circulated back to the compressor (1).

At this time, the stored water (W) in the heat storage tank (11) is warmed by heat exchange with the refrigerant in the heat storage heat exchanger (12), and the warm heat is stored.

The normal heating and the heat storage / heating simultaneous operation are performed by the indoor expansion valves (6), (6),... And the second on-off valve (16).
The heat storage electric expansion valve (14), the flow control valve (17) and the outdoor electric expansion valve (4) are opened, and the first on-off valve (1) is opened.
5) is closed, and a part of the discharge gas is changed to the main refrigerant circuit (10).
Flows into the third bypass passage (13c), and is condensed in the heat storage heat exchanger (12), while the remaining discharged gas flows through the main refrigerant circuit (10) and passes through the indoor heat exchangers (7), ( 7),
... condensed. Then, after the two refrigerants join, the pressure is reduced by the outdoor electric expansion valve (4), the refrigerant is evaporated by the outdoor heat exchanger (3), and then circulated to return to the compressor (1).

Further, in the defrosting operation for storing and recovering heat and heat, the four-way switching valve (2) is switched to the solid line side in the drawing, and the outdoor electric expansion valve (4), the flow control valve (17), and the indoor electric expansion are controlled. Valves (6), (6),..., A heat storage electric expansion valve (14),
The second on-off valve (16) is opened and the first on-off valve (15) is opened.
Is closed, the discharged gas is condensed in the outdoor heat exchanger (3), and a part of the condensed liquid refrigerant flows from the main refrigerant circuit (10) into the first bypass passage (13a), and the heat storage electric expansion valve While the pressure is reduced in (14) and evaporated in the heat storage heat exchanger (12), the remaining liquid refrigerant is reduced in each indoor electric expansion valve (6), (6),... Of the main refrigerant circuit (10). Evaporates in the indoor heat exchangers (7), (7), .... Then, they are circulated so as to join each other in the gas line (9b) and return to the compressor (1).

At this time, the outdoor gas exchanger (3) is defrosted by the discharged gas, and the condensation capacity of the outdoor heat exchanger (3) is increased by utilizing the heat storage and heating of the heat storage tank (11). Thus, the defrost operation time is shortened.

Next, a water level sensor (22) is provided on the inner surface of the heat storage tank (11) via a mounting bracket (21), and the water level sensor (22) is controlled by a lead wire (23). It is connected to the board and is configured to output the detected water level signal to a microcomputer in the control board.

The water level sensor (22) is of a capacitance type, and as shown in FIG. 2, the main body case (27) includes a storage case (31) and a bottom wall (3) of the storage case (31).
2) and a cylindrical detection cylinder (36) immersed in stored water (W). As a material of the main body case (27), a water-repellent material such as polyacetal or polyethylene is used.

As shown in FIG. 3, the lid (38) of the storage case (31) is removably attached to the upper opening (37) with bolts and nuts, and the inside is filled with an inner sealing material. A sealed portion (41) is formed, and a signal processing portion (42) in which a semiconductor element or the like is mounted on a printed circuit board is sealed in the sealed portion (41). The inner sealing part (41) isolates the signal processing unit (42) from air contact by enclosing the signal processing unit (42).

As the inner sealing material, a material having a water-repellent property, such as paraffin, which is easily deformed to easily enclose the signal processing portion (42), is used. Further, the lead wire (23) is connected to the signal processing unit (42).
The other end of the lead wire (23) extends from the upper opening (37) and is connected to a control board outside the heat storage tank (11). The lead wire (23) has a configuration in which a copper wire is covered with a vinyl chloride resin.

Above the inner sealing portion (41), a first molding material is filled to form a first molding portion (44). The first mold part (44) is provided in the storage case (3).
1) closely contacting the inner surface of the side wall (33);
It is configured to block a flood path along the wall surface from the inner surface to the inner sealing portion (41). As the first molding material, one that easily adheres to the main body case (27), specifically, silicone gel is used.

Further, a second molding material (45) is formed by filling a second molding material above the first molding portion (44), and the second molding portion (45) is connected to the lead wire (45). 23) and lead wires (2
It blocks the entry of water vapor and the like along 3). As the second molding material, a material that easily adheres to the coating portion of the lead wire (23), specifically, a silicone RTV (Room Temperature Vul) that cures at room temperature.
canning, an epoxy resin, or the like, and preferably, a silicone RTV.

Further, an electrode plate (48) and an electrode rod (49) are provided in the detection cylinder portion (36) as a detection portion. The electrode plate (48) is provided around the inner surface of the detection cylinder (36), while the electrode rod (49) is spaced apart from the electrode plate (48) by a predetermined distance from the bottom of the signal processing unit (42). It is suspended in the part (36). The electrode plate (48) and the electrode rod (49) constitute a detection unit (28), and both are connected to the signal processing unit (42). The detection cylinder (36) is immersed in the stored water (W) of the heat storage tank (11), and the electrode plate (4) is
8) and the electrode rod (49) are immersed in the stored water (W). Further, the inside of the detection cylinder (36) communicates with the space in the heat storage tank (11) by a communication pipe (51) vertically penetrating the inside of the storage case (31). Of water can be changed in accordance with a change in the water level of the heat storage tank (11).

The upper and lower two O-rings (52) and (52) are fitted into the lead wire (23) and the communication pipe (51), respectively, in the second mold part (45). It is configured to further enhance the sealing between the portion (45) and the lead wire (23).

The signal processing section (42) includes an electrode plate (4
8) and the electrode rod (49), and a voltage is applied to the electrode plate (48) and the electrode rod (49) by utilizing the difference in dielectric constant between air and water.
Is configured to detect an amount of change in capacitance that occurs when water is covered with water, convert the change into a liquid level signal, and output the water level signal to a microcomputer in the control board via a lead wire (23). ing.

Next, the sealing function of the water level sensor (22) will be described.

During the heat storage / heating operation, the space in the heat storage tank (11) rises to about 40 ° C., and the steam becomes supersaturated. The upper part of the sensor body (26) is disposed above the liquid level in the heat storage tank (11), and the opening (3) of the storage case (31) is provided.
Water and water vapor tend to enter the inside of the storage case (31) through the gap between the cover (7) and the lid (38) and along the lead wire (23).

On the other hand, in the first mold part (44) formed above the inner sealing part (41), the first molding material is in close contact with the inner surface of the storage case (31), and the water vapor from the inner surface is formed. Is prevented. In addition, the second mold part (4
In 5), the second molding material is in close contact with the lead wire (23), and the intrusion of water vapor or the like from the lead wire (23) is prevented. As a result, intrusion of water vapor or the like into the inner sealing portion (41) is prevented.

Further, by using a water-repellent polyacetal resin for the material of the storage case (31),
Adhesion of water vapor or the like is reduced, and the amount of water vapor or the like entering the storage case (31) is reduced. In addition, since water-repellent paraffin is used for the material of the inner sealing portion (41), water vapor and the like are not attracted to the signal processing portion (42),
Circuit short circuit is prevented.

On the other hand, the first mold material is made of a silicone gel having good adhesion with the storage case (31) made of polyacetal resin, and the second mold material is made of the adhesion with the lead wire (23) made of vinyl chloride. By using a good silicone RTV, it is possible to secure the barrier property against invasion of water vapor and the like.

As described above, according to the present embodiment, the first mold part (44) is formed by the first mold material that is in close contact with the inner surface of the storage case (31) that serves as a vapor intrusion path.
The second part in which the mold part (45) is in close contact with the lead wire (23)
By using a mold material, the storage case (3
Since the material of the mold portion is selected according to 1) and the material of the lead wire (23), it is possible to reliably prevent water from entering. As a result, a short circuit of the signal processing unit (42) can be reliably prevented.

Further, a silicone gel having good adhesion to the polyacetal resin is used for the first molding material, and a silicone RTV having good adhesion to the lead wire (23) whose covering portion is made of vinyl chloride is used for the second molding material. When using a polyacetal resin for the storage case (31),
It is possible to secure the barrier property against invasion of water vapor and the like.

Next, FIG. 4 shows a second embodiment of the present invention. In this embodiment, the waterproof wall (61) provided in the storage case (31) makes the intrusion path along the wall surface from the inner surface of the side wall (33) of the storage case (31) to the sealed portion (41) longer. Then, even if water vapor or the like invades, the time to reach the inner sealing portion (41) is lengthened.

Specifically, in the storage case (31), a waterproof wall (61) is erected on the bottom wall (32) at a predetermined interval from the side wall (33), and is surrounded by the waterproof wall (61). A sealed portion (41) is formed in the closed space (space inside the waterproof wall), and a signal processing portion (42) is sealed in the sealed portion (41).

The storage case (3) above the inner sealing portion (41)
1) A first molding material is filled in an annular space (62) inside and between the side wall (33) of the storage case (31) and the waterproof wall (61) to form a first molding portion (44). ,
The first mold part (44) is provided with the inner surface and the bottom wall (32) of the side wall (33) of the storage case (31) and the waterproof wall (6).
1), the inner sealing portion (4) passes through the inner surface of the side wall (33), the inner surface of the bottom wall (32) and the inner and outer surfaces of the waterproof wall (61).
It is configured to block the infiltration path of water vapor or the like along the wall surface up to 1).

Further, a second mold material is filled above the second mold portion (44) to fill the second mold portion (4).
5) is formed, and the second mold portion (45) is in close contact with the lead wire (23) to prevent water vapor and the like from entering the signal processing portion (42) from the outside along the lead wire (23). doing.

According to the present embodiment, the waterproof wall (61) lengthens the flood path along the wall surface from the inner surface of the side wall (33) of the storage case (31) to the inner sealing portion (41). Even if water vapor or the like enters along the inner surface of (31), the time to reach the inner sealing portion (41) becomes longer.

As a result, even if water vapor or the like intrudes along the inner surface of the storage case (31), the waterproof wall (61) can extend the time to reach the inner sealing portion (41), Further, the life of the sensor can be extended.

FIG. 5 shows a third embodiment of the present invention. In the present embodiment, the entire storage case (31) to which the lid (38) is not attached is covered with the external mold part (69), so that water vapor and the like can be stored in the storage case (3).
1) to prevent intrusion.

Specifically, in the storage case (31),
It has the same configuration as the conventional water level sensor (22) of FIG.
Upper mold part (65) filled with epoxy resin
And a lower mold section (6) enclosing the signal processing section (42).
6) and an internal mold part (67) formed by laminating
Are formed.

Then, the entire storage case (31) without the lid (38) is attached to the external mold part (69).
And is sealed from the outside atmosphere, thereby blocking invasion of water vapor and the like into the storage case (31). As the outer mold part (69), polyurethane containing filler such as short carbon fiber, which is excellent in impact resistance, is used to prevent damage during mounting and use. Further, a fixture (21) attached to the side wall (33) of the storage case (31) is configured to protrude outside from the external mold part (69).

According to the present embodiment, by covering the entire storage case (31) with the external mold portion (69), it is possible to prevent water vapor or the like from entering the storage case (31), and the life of the sensor is reduced. Can be lengthened.

The liquid level sensor of the present invention may be used for other than the heat storage tank (11) of the air conditioner, and the liquid may be other than water.

In the first and second embodiments, the first mold part (44) and the second mold part (45) may be arranged upside down.

The first mold portion (44) in the second embodiment extends from the inner surface of the side wall (33) to the inner sealing portion (41) through the bottom wall (32) and the inner and outer surfaces of the waterproof wall (61). If it blocks the flood path along the wall of
It may be formed in a portion other than the embodiment. For example, the inner sealing portion (41) and the first mold portion (44) are vertically stacked in the space inside the waterproof wall, and the first mold portion (44) is attached to the waterproof wall (6).
The inner surface of 1) may be adhered to block the entry of water vapor or the like at the inner surface.

The water level sensor (22) is not limited to the capacitance type.

[Brief description of the drawings]

FIG. 1 is a refrigerant piping system diagram of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the water level sensor according to the first embodiment of the present invention.

FIG. 3 is an enlarged sectional view of a main part of FIG. 2;

FIG. 4 is an enlarged sectional view of a main part of a water level sensor according to a second embodiment of the present invention.

FIG. 5 is an enlarged sectional view of a main part of a water level sensor according to a third embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of a conventional water level sensor.

[Explanation of symbols]

 23 Lead wire 31 Storage case 32 Bottom wall 33 Side wall 41 Enclosure section 42 Signal processing section 44 First mold section 45 Second mold section 48 Electrode plate (detection section) 49 Electrode bar (detection section) 61 Waterproof wall 67 Internal mold section 69 External mold part

Claims (4)

(57) [Claims] A storage case (3) having an open upper part.
1) and detection units (48) and (49) for detecting a physical quantity that changes with a change in the liquid level, while the storage case (31) includes the detection units (48) and (49) in the storage case (31).
A signal processing unit (42) for receiving the output signal from (49) and converting the output signal into a liquid level signal is provided, and the signal processing unit (42) includes an upper opening of the storage case (31). While the lead wire (23) extending from (37) to the outside is connected, the signal processing unit (42) is provided in the storage case (31).
And a first mold part (44) and a second mold (44) in contact with the storage case (31) and the lead wire (23) above the inner seal part (41). The first mold part (44) is made of a first mold material having an adhesive property with the storage case (31).
The liquid level sensor, wherein the second mold part (45) is made of a second mold material having an adhesive property to the lead wire (23). 2. A storage case (3) having an open upper part.
1) and detection units (48) and (49) for detecting a physical quantity that changes with a change in the liquid level. On the bottom wall (32) of the storage case (31), a waterproof wall (61) is provided. ) Is erected around the side wall (33) of the storage case (31) at a predetermined interval, and is provided inside the waterproof wall (61).
A signal processing unit (42) for receiving the output signal from (49) and converting the output signal into a liquid level signal is provided, and the signal processing unit (42) includes an upper opening of the storage case (31). While a lead wire (23) extending from (37) to the outside is connected, an inner sealing part (41) for enclosing the signal processing part (42) is formed inside the waterproof wall (61), The storage case (31) is provided with a first mold portion (44) that is in contact with at least a part of the inner surface of the side wall (33), the bottom wall (32), and the inner and outer surfaces of the waterproof wall (61). And a storage case (31) and a lead wire (23).
The second mold part (45) is formed in a laminated manner in contact with
The mold part (44) is made of a first mold material having close contact with the storage case (31), while the second mold part (4)
5) A liquid level sensor comprising a second molding material having an adhesive property to the lead wire (23). 3. A storage case (3) having an open upper part.
1) and detection units (48) and (49) for detecting a physical quantity that changes with a change in the liquid level, while the storage case (31) includes the detection units (48) and (49) in the storage case (31).
A signal processing unit (42) for receiving the output signal from (49) and converting the output signal into a liquid level signal is provided, and the signal processing unit (42) includes an upper opening of the storage case (31). While the lead wire (23) extending from (37) to the outside is connected, the signal processing unit (42) is provided in the storage case (31).
And a mold part (67) in contact with the storage case (31) and the lead wire (23) are formed above the inner seal part (41), and the storage case (31) is formed. A liquid level sensor, wherein an external mold part (69) is formed to cover the outside and seal the storage case (31) and the outside atmosphere. 4. The liquid level sensor according to claim 1 or 2, wherein the storage case (31) is made of polyacetal resin, the lead wire (23) is covered with a vinyl chloride resin, and the first mold part (44). Wherein the first molding material is formed of silicone gel and the second molding material of the second molding portion is formed of silicone RTV.