JPS595199B2 - Automatic drain discharge device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention periodically discharges the drain in the air tank and air piping for a short time while the air compressor is in operation, and continuously discharges the drain after the power supply circuit of the air compressor drive motor is cut off. This invention relates to an automatic drain discharge device capable of discharging compressed air.

Inventions related to this include, for example, providing a float and discharging a drain when the float floats above a certain water level;
There are some that stop discharging when the float sinks below a certain water level.

Therefore, since drains below a certain water level cannot be discharged, there is always a drain below a certain water level.

In addition, a repeat timer allows the normally closed solenoid valve (the valve is always closed,
Some drains are periodically discharged for short periods of time by opening a valve (electromagnetic valve) when current flows.

In this case, the drain can be discharged while the air compressor is in operation, but after the power supply circuit of the air compressor driving motor is cut off and the air compressor is stopped, the drain cannot be discharged because power cannot be transmitted to the solenoid valve.

Therefore, after the air compressor is stopped, the compressed air in the air tank cools and the drain generated remains in the air tank.

Due to improvements in piping technology in recent years, there is less leakage of compressed air.
After the work was completed, the air compressor was stopped and when the air compressor was started the next morning, the residual pressure of the compressed air in the air tank was high, and since the measurement was taken after the air compressor had been stopped for a long time, the sliding parts were covered with oil. It's out.

When an air compressor is started under the load of this lack of oil and high residual pressure, the sliding parts will wear out and electrical equipment will often be damaged.

In addition, during the cold season, the residual drain freezes, damaging the pipes and blocking the inside of the pipes, making it difficult to use compressed air the next morning.

In order to eliminate the above-mentioned can center point, the present invention uses an economical repeating bimetallic thermal timer suitable for unloader type air compressors and a limited-time normally open bimetallic thermal timer to operate a normally open solenoid valve (the valve is always open and current flows through it). When the air compressor is in operation, the drain inside the air tank is automatically discharged periodically for a short period of time, keeping the inside of the air tank highly clean at all times. At the same time, the power circuit of the machine drive motor is cut off to stop the air compressor, and at the same time, the normally open solenoid valve is left open to release the drain and compressed air in the air tank, and then start the next air compressor. To obtain an automatic drain discharging device which has both the effect of being able to carry out the process without any load and the effect of not causing any billing due to freezing during the cold season because there is no drain.

This will be explained below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a circuit breaker for an electric motor 2 that drives an air compressor 3. As shown in FIG.

5 is an air tank connected to the air compressor 3 via piping 4.

8 is a solenoid valve that always opens the valve and closes the valve when current flows;
That is, it is a normally open solenoid valve, and the pipe 6 for discharging the drain
It is connected to the bottom of the air tank 5 by.

7 is a discharge pipe through which the normally open solenoid valve 8 discharges the drain to the outside.

9 is an air pipe that sends compressed air to the outside.

Discharging the drain in the air pipe 9 is exactly the same as the present explanation of discharging the drain in the air tank, so the explanation will be omitted.

The electrical circuit diagram for controlling the normally open solenoid valve 8 is shown at the top of FIG.

The normally open solenoid valve 8 is connected to the power supply circuit of the motor 2 through the time-limited normally open contact 22 and the common terminal 11.

We will call this electric circuit or circuit.

In addition, the normally open solenoid valve 8 has a normally open contact 14 and a time limited movable contact 1.
3 (indicated by the dotted line).

It is connected to the power source of the electric motor 2 through the common terminal 11.

This electric circuit will be called a circuit.

Reference numeral 10 denotes a repeating bimetal thermal timer, which includes a common terminal 11, a normally closed contact 12, a time-limited movable contact 13, a normally open contact 14, and a heater 15.

20 is a time-limited normally open bimetal thermal timer consisting of a time-limited normally open contact 22 and a heater 24.

The heaters 15 and 24 share the normally closed contact 12 and are connected in parallel to the power supply.

The operation will be explained with reference to the drawings.

When the power supply circuit of the electric motor 2 is closed, the electric motor 2 drives the air compressor 3, and the air compressor 3 supplies compressed air to the air tank 5.

At the same time, current flows through the common terminal 11, the time-limited movable contact 13, and the normally closed contact 12, heating the heaters 15 and 24.

On the other hand, in circuit 8, since the time-limited normally open contact 22 is open, no current flows, so the normally open solenoid valve 8 opens and the drain in the air tank 5 is discharged from the discharge pipe I.

When the scheduled time has elapsed, first, the time-limited normally open contact 22 is heated by the heater 24 and closed, so that current flows from the circuit 8 to the normally open solenoid valve 8, and the normally open solenoid valve 8 closes the valve, stopping drain discharge.

Next, the time-limited movable contact 1 heated by the heater 15
3 opens the normally closed contact 12 and closes the normally open contact 14, so
Since the current flows from the circuit to the normally open solenoid valve 8, the normally open solenoid valve 8 remains closed.

On the other hand, the heater 15.24 is powered off and cooled down, and first the time-limited normally open contact 22 is opened, but since current flows from circuit A, the normally open solenoid valve 8 remains closed.

After a further appropriate period of time has elapsed, the time-limited movable contact 13 returns to the normally closed contact 12, both circuits A and B are opened, and the normally open solenoid valve 8 is opened again to discharge the drain.

Next, the point that the normally open solenoid valve 8 is periodically opened and closed to repeatedly discharge the drain will be explained in detail.

The repeating bimetal thermal timer 10 has a time-limited movable contact 13 and a heater 15, and the time-limited normally open bimetal thermal timer 20 has a time-limited normally open contact 22 and a heater 2.
I have 4.

When the operating time of the time-limited movable contact 13 is 11 seconds and the return time is 12 seconds, and the operating time of the time-limited normally open contact 22 is t1 seconds and the return time is t2 seconds, the following relationship is established: T1, T2, T2. It is.

Next, the opening/closing cycle of the normally open solenoid valve 8 will be explained.

At the same time as the electric motor 2 is started, current flows to the common terminal 11, the time-limited movable contact 13, and the normally closed contact 12, but since the time-limited normally open contact 22 is open, the current does not flow to the normally open solenoid valve 8, so the current does not flow to the normally open solenoid valve 8. The open solenoid valve 8 opens the valve to discharge the drain.

On the other hand, the current flows through the heaters 15 and 24 to heat them, and due to the relationship of operation time Tl>tl, the time-limited normally open contact 22 closes t1 seconds after startup, and the current flows from the 8 circuits to the normally open solenoid valve 8. Since the drain is flowing, the normally open solenoid valve 8° stops the drain discharge.

Next, 11 seconds after startup, the time-limited movable contact 13 is heated by the heater 15, opens the normally closed contact 12, and closes the normally open contact 14, so that current flows from both circuits A and B to the normally open solenoid valve. 8, so drain discharge remains stopped.

On the other hand, the heaters 15 and 24 are cooled by the power supply Z cut off, and due to the relationship between T2 and t2, the time-limited normally open contact 22 returns to open and opens the 8 circuits, but the current flows from the A circuit to the normally open solenoid valve 8. The drain discharge remains stopped.

(Tl + Tz) seconds after startup, time-limited movable contact 13
Since A returns to the normally closed contact 12, the 8 circuits A and 8 become open, and the normally open solenoid valve 8 is powered off and discharges the drain.

Therefore, while the air compressor 3 is being driven by the electric motor 2, the normally open solenoid valve 8 can repeatedly automatically discharge the drain for tl seconds, with (T1+T2) seconds being one cycle.

This relationship is shown in FIG.

At the end of the day's work, when the circuit switch 1 is opened to stop the air compressor, no current flows in both circuits A and B, so the normally open solenoid valve 8 remains open, and there is no drain or compressed air. The air compressor can be started with no load the next morning because the air is discharged until it reaches 100 mL, and it does not freeze at night during the cold season because there are no drains.

operating times T1 and tl of the repeating bimetallic thermal timer 10 and the time-limited normally open bimetallic thermal timer 20;
Since recovery times T2 and t2 can be manufactured with appropriate values, if the optimal values are selected for the drain discharge cycle (T1 + T2) and drain discharge time t1 according to the capacity of the air compressor, the air tank will be drained. It also prevents leaving too much drain in the tank and unnecessarily releasing compressed air to the outside.

According to the experimental results, (T-work + T2) is 200 seconds to 6
00 seconds, tl from 5 seconds to 30 seconds, and t2 within 90 seconds, and manufacturing is possible.

Therefore, the present invention controls a normally open solenoid valve based on an economical repeating bimetal thermal timer and a time-limited normally open bimetal thermal timer suitable for an unloader type air compressor, so that the air inside the air tank is controlled while the empty compressor is in operation. The drain is automatically discharged periodically for a short period of time to keep the inside of the air tank highly clean at all times, and when the air compressor operating body stops, the drain and compressed air are discharged, eliminating the need for the next air compressor. It has the effect of starting without any load, preventing wear and tear on sliding parts such as cylinders and wear and tear on electrical equipment, and since there is no drain, there is no need to worry about freezing even at night during the cold season. It is very useful as an automatic drain discharge device for unloader type air compressors.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an automatic drain discharge device according to the present invention attached to an air tank of an unloader type air compressor. FIG. 2 illustrates the relationship between the drain discharge cycle and the drain time. 00-

Claims (1)

[Claims] 1 Power supply circuit of motor 2, common terminal 11, normally closed contact 1
2. A repeating bimetallic thermal timer 10 including a timed movable contact 13, a normally open contact 14 and a heater 15, a timed normally open bimetallic thermal timer 20 including a timed normally open contact 22 and a heater 24, and an air compressor driven by an electric motor 2. It consists of a normally open solenoid valve 8 connected to an air tank 5 to which compressed air is supplied from 3, a time-limited normally open contact 22 and a common terminal 1.
A normally open solenoid valve 8 that can be connected to the power supply circuit of the motor 2 through 1
The electrical circuit of the normally open solenoid valve 8 is connected to the power supply circuit of the motor 2 through the normally open contact 14, the time limited movable contact 13, and the common terminal 11, and the electrical circuit of the normally open solenoid valve 8 is connected to the power supply circuit of the motor 2 through the normally open contact 14, the time limited movable contact 13, and the common terminal 11. The normally closed contact 12 is shared, and the electric circuit of the heaters 15 and 24 connected in parallel, as well as the electric circuit of the motor 2 constitute a circuit that controls the normally open solenoid valve 8, and the operation of the time-limited movable contact 13. Time T1, return time T2
and an operating time t1s of the time-limited normally open contact 22 and a return time t2 such that the relationship T1 > tl *T2 n t2 is established.