JPS6114720Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a drain discharge device using a thermistor.

A drain discharge device installs a thermistor in the air tank of the compressor and detects the change in resistance of the thermistor that occurs when the thermistor is immersed in the drain generated in the tank to discharge the drain in the tank. The difference between the heat radiation coefficient and the heat radiation coefficient in the drain atmosphere is utilized. Therefore, when the thermistor is placed in an air atmosphere, it is preferable that the thermistor itself be sufficiently heated to prevent malfunction.
By the way, if an air flow occurs in the tank and this air flow hits the thermistor directly, a relatively large amount of heat will be taken away from the thermistor, making it difficult to set the thermistor itself to a sufficiently heated state, and as a result, the drain It may become like a thermistor is placed in the atmosphere, resulting in malfunction. This tendency becomes more pronounced as the compressor becomes larger and the thermistor is closer to the compressed air supply port.

This invention was made in view of the above points,
The purpose of this is to prevent air from being blown directly onto the thermistor, allowing the thermistor to be placed in a substantially static air atmosphere, thereby preventing malfunctions and increasing flexibility in the installation position of the thermistor. An object of the present invention is to provide a drain discharge device that can be expanded.

The purpose is to provide a tank connected to the air compressor to be supplied with compressed air from the air compressor according to the present invention, a support attached to the tank, and a tank that collects a predetermined amount or more of drain in the tank. a first thermistor attached to one end of the support so as to be immersed directly in the drain;
a second thermistor installed inside the support so as not to be directly immersed in the drain;
a case attached to the support to surround the outside of a portion of the support to which the first thermistor is attached; and a case formed at one end of the case;
a first opening for allowing the drain to flow in and out of the case; and a second opening formed at the other end of the case for allowing the air in the tank to flow into and out of the case. , a discharge valve connected to the tank for discharging condensate in the tank to the outside of the tank, and the second thermistor detecting the difference in resistance between the first thermistor in the air and in the condensate. This can be achieved by a drain discharge device comprising a control circuit which compensates for and detects the temperature inside the tank and opens and closes the discharge valve based on the detection result.

Next, a preferred specific example of the present invention will be explained based on the drawings.

In the figure, a detection unit 3 is provided in an air tank 2 of an air compressor 1, and a compressor main body 4 that generates compressed air and a motor 5 that operates the main body 4 are installed in the upper part of the tank 2. is attached, and the compressed air generated in the main body 4 is supplied into the tank 2 through the compressed air supply port 6, and
The compressed air stored inside is discharged from the discharge port 7 as necessary.
It is discharged through and used. A pipe 8 communicating with the inside of the tank 2 is attached to the lower part of the tank 2, and the drain generated in the tank 2 is transferred to the pipe 8,
Strainer 9 and solenoid valve 1 as drain discharge valve
can be ejected via 0. The detection unit 3 includes a case 1 having a drain inlet/outlet 11 and an air outlet/outlet 12.
3 and a thermistor 15 supported by the support body 14,
16, the thermistor 15 functions as a detection thermistor that detects that a certain amount of drainage has occurred in the tank 2, and the thermistor 16
The thermistor 1 detects the temperature inside and compensates the thermistor 15 according to the detected temperature.
5. Further, the thermistor 15 is arranged at one end of the support body 14 so as to be substantially directly immersed in the drain when a certain amount of drain is generated in the tank 2, and the thermistor 16
is not directly immersed in the drain even if a certain amount of drain is generated, but is attached inside the support body 14 so as to detect the temperature inside the tank 2. A direct current supplied by a control circuit 17 is passed through the thermistors 15 and 16. As shown in FIG. 3, the current I-voltage V characteristic of the thermistor 15 is as shown in curve 18. As shown in
In the liquid, that is, in the drain, the heat radiation coefficient increases, the temperature of the thermistor 15 decreases, and the resistance of the thermistor increases, as shown by a curve 19. The control circuit 17 detects the difference in the characteristics of the thermistor 15 in the air and in the liquid, that is, the difference in resistance of the thermistor 15 in the air and in the liquid, and opens and closes the electromagnetic valve 10. For example, the thermistor 15 is attached to the tip of the support 14 in such a way that it is easily affected by the environmental temperature, so when the thermistor 15 is not immersed in drain and is exposed to compressed air, the thermistor 15 dissipates heat. Since the coefficient becomes smaller and exhibits the resistance shown by the characteristic curve 18 as described above, the control circuit 17
detects this and closes the solenoid valve 10. On the other hand, when the thermistor 15 is immersed in the drain, the heat dissipation coefficient of the thermistor 15 becomes large and the control circuit 17
detects this and opens the solenoid valve 10.
The drain generated in the tank 2 is discharged through the tank 2.

Meanwhile, the thermistor 16 is installed inside the support 14 in a position that is not susceptible to fluctuations in the heat radiation coefficient, so it can detect the environmental temperature regardless of the presence or absence of the drain, and depending on the detected temperature. Temperature compensation may be provided for thermistor 15.

In the drain discharge device configured in this way, the thermistor 15 is surrounded by the case 13 and is provided within the case 13, so even if an air flow exists in the tank 2, the area around the thermistor 15 is substantially blocked. In a static air atmosphere, thermistor 15 exhibits a resistance shown by curve 18. Note that when the thermistor 15 is further cooled by the airflow, the resistance becomes as shown by curve 20 between curves 18 and 19, and as is clear from this, curve 1
9 and the curve 20 becomes smaller, that is, there is no difference between the resistance of the thermistor 15 in the air and the resistance in the liquid, which may cause malfunction. On the other hand, during use, when condensate is generated in the tank 2 and the liquid level 21 of the condensate rises, the condensate flows into the case 13 through the inlet 11, while the compressed air in the case 13 flows through the inlet 12. leaks through. Therefore, when the liquid level 21 of the drain rises by a certain amount or more, the thermistor 15 is substantially immersed in the drain, resulting in the resistance shown by the curve 19. In addition, the detection unit 3
is preferably provided at a position within the tank 2 where the least amount of airflow is generated, for example at a position away from the supply port 6 and the discharge port 7.

By the way, in the specific example described above, a solenoid valve was used as the drain discharge valve, but the present invention is not limited to this.
Other general valves may also be used. In addition, the present invention is not limited to a device for discharging condensate generated in a tank integrated with a compressor main body, but can also be applied to a general gas tank.

As described above, according to the present invention, since the thermistor is surrounded by the case, a static atmosphere can be established around the thermistor, which can prevent malfunctions and increase the degree of freedom in the installation position. obtain.

In addition, even if the temperature inside the tank fluctuates, the difference in the resistance values of the first thermistor in the air and in the drain can be compensated for by the second thermistor, and the first thermistor Therefore, the state in which the first thermistor is immersed in the drain and the state in which it is placed in the air in the tank can be reliably discriminated even if the environmental temperature changes; Control the discharge valve without malfunction, i.e.
The drain inside the tank can be discharged reliably.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a preferred specific example according to the present invention, FIG. 2 is a detailed diagram of the detection section shown in FIG. 1, and FIG.
The figure is a characteristic curve diagram of a thermistor. 2... Air tank, 3... Detection unit, 10... Solenoid valve, 11... Drain inlet/outlet, 12... Air inlet/outlet, 13... Case, 15... Thermistor,
17...Control circuit.

Claims (1)

[Scope of utility model registration request] A tank connected to the air compressor to receive compressed air from the air compressor, a support attached to the tank, and a tank connected directly to the drain when a predetermined amount or more of drain accumulates in the tank. a first thermistor attached to one end of the support so as to be immersed in the drain; a second thermistor attached inside the support so as not to be directly immersed in the drain; a case attached to the support body to surround the outside of the part where the first thermistor is attached; and a first case formed at one end of the case for allowing the drain to flow in and out of the case. a second opening formed at the other end of the case for allowing air in the tank to flow in and out of the case; and a discharge valve connected to the first thermistor, the difference in resistance value in the air and in the drain is compensated and detected by the temperature in the tank detected by the second thermistor, and A drain discharge device comprising a control circuit that opens and closes the discharge valve based on a detection result.