JP3270010B2 - Automatic drain discharge device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an automatic drain discharge device for an air compressor.

[0002]

2. Description of the Related Art FIG. 5 is a flow sheet of a conventional automatic drain discharge device for an air compressor. The air compressor 1 temporarily stores air compressed by an air compressor (not shown) in an air tank (not shown), and sends the compressed air from the air tank to a consumer of compressed air through a discharge pipe 2. Drain generated in the air tank is detected by a drain sensor 24, and a signal thereof is sent to an automatic drain control unit 26, and the automatic drain control unit 26 opens the discharge valve 5 for a predetermined time to discharge the drain. In the above, the automatic drain discharge device 2 includes the drain sensor 24, the discharge valve 5, and the drain automatic discharge control unit 26.
3.

FIG. 6 shows an example of a specific configuration of the automatic drain discharge device shown in FIG. A drain sensor 24 is provided in the drain sensor detection tank 29. An electrode 24 for detecting the upper limit liquid level is provided as a drain sensor 24 in a drain sensor detection tank 29.
H, and an electrode 24L located below the electrode 24H.

The drain from the air compressor 1 enters the drain sensor detection tank 29 from the direction of arrow a in the figure. One electrode 24H of the drain sensor is connected to a power supply (+ V) for applying a voltage, and the other electrode 24L is connected to the base of the transistor (TR1) 30.

When the drain reaches the position of the drain sensor 24H, a current flows between the electrodes 24H and 24L, and the drain is detected. This current turns on the transistor (TR1) 30. When the transistor 30 is turned “ON”, the time constant circuit 27 causes the solenoid valve driving unit 2 to operate for a certain period of time.
A command to open the discharge valve 5 is sent to 8. The solenoid valve driving unit 28 supplies electric power so as to open the solenoid valve 5 only for the time from the time constant circuit 27. As a result, the drain stored in the drain sensor detection tank 29 is discharged.

[0006]

In the above-mentioned conventional example, since a voltage (+ V) is constantly applied to the drain sensor, no consideration is given to explosion protection.

If conductive (metal, etc.) dust accumulates on the sensor unit (electrode), there is a risk that not only erroneous discharge but also continuous drain discharge operation may be performed.

[0008] If the water is continuously discharged by mistake, the pressure in the compressor will be greatly reduced.

When noise is superimposed on the electrode connected to the base of the transistor, the discharging operation is performed erroneously (which causes a pressure drop of the compressor).

Since it is not known when drain is detected, power must be supplied to the detection circuit at all times, and power consumption is not reduced.

Since a drain sensor detecting tank is required, the scale of the apparatus becomes large. For this reason, installation and installation are not easy.

Since the drain sensor is disposed in the drain sensor detecting tank in which compressed air is present, airtightness is required and the cost is increased.

Since the drain sensor is buried in the drain, there is a possibility that the drain sensor is corroded and the detection reliability is reduced.

As described above, it has been difficult to discharge drain with high reliability and efficiency.

It is an object of the present invention to provide an automatic drain discharge device which develops the above conventional technology and which can discharge drain with high reliability and efficiency.

[0016]

According to a first aspect of the present invention, there is provided an automatic drain discharge device attached to an air compressor which is operated continuously or intermittently, wherein the pressure of compressed air discharged from the air compressor is reduced. The pressure detection means to be detected and the pressure detection value detected by the pressure detection means are input at regular time intervals, and the current pressure detection value is compared with the previous pressure detection value. An accumulating means for accumulating the number of pressure rises when it is greater than a count value and operating a discharge timer when the count value reaches a preset number of times, and a discharge timer for opening a drain discharge valve for a predetermined time by a signal from the integrating means, A drain discharge valve controlled by a discharge timer.

According to a second aspect of the present invention, there is provided the automatic drain discharge device according to the first aspect, wherein the drain is discharged, the integrating means is reset, and the integrating means is started.

A third invention according to the present application is characterized in that the installation time of the integrating means and the discharge timer is variable.
Or the automatic drain discharge device according to the second invention.

In a fourth aspect of the present invention, a cycle timer for activating the discharge timer is added, and when either the cycle timer or the accumulating means reaches a set value, the discharge timer is activated and the drain discharge valve is activated. The automatic drain discharge device according to any one of the first to third inventions, wherein the valve is opened and the cycle timer and the integrating means are reset.

According to a fifth aspect of the present invention, there is provided an automatic drain discharge device attached to an air compressor which is operated continuously or intermittently, and a pressure detecting means for detecting a pressure of compressed air discharged from the air compressor. The pressure detection value detected by the pressure detection means is inputted at regular time intervals, the current pressure detection value is compared with the previous pressure detection value, and the pressure when the current pressure detection value is larger than the previous pressure detection value is Integrating means for accumulating the number of rises, and when the present pressure detection value is equal to or lower than the previous pressure detection value, an accumulation means for operating a discharge timer according to the number of pressure rises, and a drain discharge valve according to a signal from the accumulation means. , And a drain discharge valve controlled by the discharge timer.

According to a sixth aspect of the present invention, a cycle timer for energizing a discharge timer is added, and the present pressure detection value input to the integrating means when the cycle timer reaches a set value or the previous pressure detection value is used. The automatic drain discharge device according to the fifth invention, further comprising a discharge timer for opening a drain discharge valve when the value becomes equal to or lower than the value.

According to a seventh aspect of the present invention, a current pressure detection value is compared with a previous pressure detection value to calculate a pressure rise gradient, and the operation time of the drain discharge valve is made variable according to the pressure rise gradient. An automatic drain discharge device according to the fifth or sixth invention, characterized in that:

According to an eighth aspect of the present invention, there is provided an automatic drain discharge device attached to an air compressor which is operated continuously or intermittently, a pressure detecting means for detecting a pressure of compressed air discharged from an air compressor. A level comparator which receives the pressure detection value detected by the pressure detection means at regular time intervals and compares the current pressure detection value with the previous pressure detection value;
Integrating means for receiving the output from the level comparator, integrating the number of pressure rises when the current pressure detection value is greater than the previous pressure detection value, and outputting the count value to the discharge timer, and setting by the signal from the integration means A discharge timer that changes the valve opening time according to the count value and receives a signal from the level comparator when the current pressure value is equal to or lower than the previous pressure value, and a drain discharge valve controlled by the discharge timer; An automatic drain discharge device characterized by having:

[0024]

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

(Embodiment 1) In FIG. 1, an air compressor 1 includes an air compressor, an electric motor, an air tank and the like (not shown). The air tank has a pressure switch, and when the compressed air in the air tank detects the set lower limit pressure, the motor is driven to drive the air compressor driven by the motor. The air compressor sucks the atmosphere and pressurizes the air. When the pressure in the air tank detects the set upper limit pressure, the motor is stopped to stop the air compressor. Further, in an air compressor having an unloader device, when the set lower limit pressure is detected, unloading is released to set the air compressor in a pressurized state, and when the set upper limit pressure is detected, the air compressor is not stopped without stopping the motor. Pressure state.

The air compressor 1 sends the generated compressed air through the discharge pipe 2 to the compressed air demand side. On the other hand, drain generated in an air tank storing compressed air of the air compressor 1 is discharged through a drain discharge valve 5. This drain discharge valve 5 is a solenoid valve, an electric valve, or the like.

A pressure gauge 7 detects the pressure of the compressed air discharged from the air compressor 1 as pressure detecting means. The pressure gauge 7 may also serve as the pressure switch described above. In the following description, it is assumed that an A / D converter is added to the output of the pressure gauge to generate a digital signal assuming that the processing is performed digitally. May be used.
The compressed air pressure detected by the pressure gauge 7 is converted into a digital value by the A / D converter 3 and input to the sample and hold 8. The sample hold 8 receives a signal from the reference oscillator 10, holds the current compressed air pressure value input from the pressure gauge 7 via the A / D converter 3, and compresses the previous compressed air previously input. The pressure value of the air is input to the holding circuit 11. The reference oscillator 10 generates, for example, a pulse every one second. The sample board 8 sends the current compressed air pressure value to the level comparator 9, and the holding circuit 11 sends the previous compressed air pressure value to the level comparator 9.

The level comparator 9 which receives the current and previous compressed air pressure values from the sample hold 8 and the holding circuit 11 activates the counter 12 when the current compressed air pressure value is larger than the previous compressed air pressure value. Send a signal, do not send when small. The counter 12 receives the clock pulse from the reference oscillator 10, and counts the clock pulse from the reference oscillator 10 during the input capability signal. That is, the number of times that the current compressed air pressure value is higher than the previous compressed air pressure value is counted. The set value of the counter 12 is variable. When the set value is reached, a trigger pulse is sent to the discharge timer 13 so that the discharge timer 13 is operated.
2 to 0 and drain drain valve 5 to drain timer 13
Open and close for the set time.

FIG. 2 is a time chart showing the operation of the automatic drain discharge device having the above configuration.

At time t0, the power is turned on.

At the time t1, when the operation of the air compressor 1 is started as shown in FIG. 2A, the pressure gauge 7 detects the set lower limit pressure L as shown in FIG.
As shown in (c), the drain amount is zero. When the air compressor 1 is operated from time t1 to t2, the compressed air pressure reaches the set upper limit pressure H as shown in FIG. Then, as shown in FIG. 2e, the air compressor 1 is cut off and stopped. The pressure of the compressed air constantly rises from b to d in FIG. 2, and the drain amount increases as shown in FIGS. During this time, since the active signal is sent from the level comparator 9 to the counter 12, the counter 12 continues counting and counts (7).

From time t2 to time t3, the compressed air pressure detected by the pressure gauge 7 due to the use of the compressed air decreases as shown from d to g in FIG. During this time, the drain amount is substantially constant as shown by f to h in FIG. At time t3, when the pressure gauge 7 detects the set lower limit pressure L, the air compressor 1 is operated as shown in FIG.
As shown in FIG. 7, the pressure gauge 7 detects an increase in the compressed air pressure. At time t4 during which the pressure gauge 7 detects the increase in the compressed air pressure from g to j, the counter 12 counts the set value (8) due to the increase in the compressed air pressure. Between the time t3 and t4, the drain amount increases as shown by h to k in FIG. The counter 12 that has reached the set value (8) sends a discharge trigger signal to the discharge timer 13 and the discharge timer 13 sends a clear signal to the counter 12 to return the counter 12 and resets the counter 12 for a set time (from time t4 to t5). In FIG. 2, the drain discharge valve 5 is opened as shown from 1 (ell) to m, and as shown in k to n in FIG.

While the drain is being discharged, the air compressor 1
Is operating, and drain occurs from time t5 to t6 as shown from n to o in FIG. 2, and the counter 12 counts (2). When the pressure gauge 7 detects the set upper limit pressure as shown at j in FIG. 2 at time t6, the air compressor 1 stops as shown at p in FIG.

From time t6 to time t7, the compressed air is used and the pressure drops. At time t7, when the pressure gauge 7 detects the set lower limit pressure L of the compressed air as shown by q in FIG. It is operated like r.

When the compressed air pressure increases from time t7 to t8 and the counter 12 counts (8) at time t8, the counter 12 sends a discharge trigger signal to the discharge timer 13. The discharge timer 13 outputs a clear signal to the counter 1
2, the counter 12 is returned, and the drain discharge valve 5 is opened. Then, the drain which has increased from s to t in FIG. 2 is opened by the discharge timer 13 from time t8 to t9 as shown from u to v in FIG. 2, and the drain is changed from t to w in FIG. Is discharged as shown.

At time t9, when the pressure gauge 7 detects the set upper limit pressure x as shown by x in FIG. 2, the air compressor 1 stops as shown by y in FIG. From time t8 to t9, the counter 12 newly counts (1) in response to the rise of the compressed air.

From time t9 to t10, the air compressor 1 is stopped as shown from y to z in FIG. 2, and the compressed air pressure is reduced by the pressure gauge 7 from x to a1 in FIG. When the pressure gauge 7 detects the set lower limit pressure L of the compressed air at time t, the air compressor 1 is operated as shown by z in FIG. 2 and at time t11, the pressure gauge 7 is set by compressed pressure air as shown by b1 in FIG. Upper limit pressure H
Is detected, the air compressor 1 stops as shown by c1 in FIG.

From time t10 to t11, the drain is
The counter 12 counts from (2) to (6) during this time as shown by d1 to e1.

From time t11 to time t12, the compressed air pressure drops to the set lower limit pressure L as shown by b1 to f1 in FIG. In addition, the drain amount during this time is changed from e1 in FIG.
There is almost no change as in 1.

At time t12, the air compressor 1 is operated as indicated by g1 in FIG.
F1 to h1 as shown in FIG. The counter 12 counts (7) and (8) based on the signal sent from the pressure gauge 7 in response to the increase in the compressed air pressure, and at time t13 when the count value becomes (8), the counter 12 outputs the discharge trigger pulse. It is sent to the discharge timer 13, and the discharge timer 13 sends a clear signal to the counter 12 to restore the counter 12, and at the time t13 to t14, from i1 to j1 in FIG.
The drain discharge valve 5 is opened as shown in FIG. 3, and the drain discharge valve 5 discharges the drain and closes the drain as indicated by l (m) 1 to m1 in FIG.

The air compressor 1 is operated as shown from g1 to n1 in FIG. 2 while drain is being discharged from l (m) 1 to m1 in FIG. Rises from f1 to h1 in FIG. 2, the counter 12 counts (1).

According to the first embodiment, the following effects can be obtained. 1) With a simple circuit configuration, generation of drain can be predicted and drain can be reliably discharged. 2) Since no voltage is applied to a drain sensor or the like in the air compressor, explosion proof can be easily considered. 3) Since no drain sensor detection tank is required, the scale of the apparatus can be reduced. For this reason, attachment installation is easy. 4) In the method of detecting with a drain sensor, airtightness is required and the cost is increased because the air is disposed in a drain sensor detection tank where compressed air is present. However, in the case of this method, there is a merit in cost because the configuration is simple. . 5) In the method of detection by the drain sensor, the drain sensor is buried in the drain, so that the drain sensor may be corroded and the detection reliability may be reduced. There is no problem because it is detected by. 6) Since the integrating counter 12 and the discharge timer 13 are constituted by electronic circuits, the set time can be easily changed, so that the discharge can be controlled efficiently. 7) Since the pressure gauge 7 does not measure absolute pressure, only the pressure change is detected, so that "absolute accuracy" of the pressure gauge is not required (cost merit). 8) Since only the change in pressure is detected, a pressure gauge is not selected, so that the pressure gauge is inexpensive. 9) Applicable to various air compressors such as unloader type, pressure opening / closing type, and merging type. 10) There is no need to newly install a pressure gauge because it can also be used as a pressure gauge installed in the air compressor. 11) Since a change in pressure is detected, it can be installed at a piping point on the way.

(Embodiment 2) In Embodiment 2, a cycle timer 14 is added to Embodiment 1.

FIG. 3 is obtained by adding a cycle timer 14 to FIG. 1 of the first embodiment. Cycle timer 14
Sends a discharge trigger pulse to the discharge timer 13 at a set cycle, and the discharge timer 13 provided with the discharge trigger pulse sends a clear signal to the cycle timer 14 to return the cycle timer 14 and simultaneously open the drain discharge valve 5 for a set time. Give a valve. As shown in FIG. 3, the outputs of the counter 12 and the cycle timer 14 are output from the discharge timer 13 respectively.
(OR circuit), and the discharge timer 13 sends a clear signal for returning the counter 12 and the cycle timer 14 upon receiving any of the above inputs.

FIG. 4 is a time chart for explaining the operation of the second embodiment. Except for the operation of the cycle timer 14, the operation from time t0 to time t6 is the same as in the first embodiment, and the description of the first embodiment is cited. When the power is turned on at time t0, the cycle timer 14 starts. The cycle timer 14 is reset by the clear signal from the discharge timer 13 at the time t4.

From time t6 to t7, the compressed air pressure decreases as shown from j to q in FIG. 4 and when the pressure gauge 7 detects the set lower limit pressure of the compressed air at time t7, as shown in FIG. The compressor 1 is operated. From time t6 to time t7, the drain amount is substantially constant as shown from o to r in FIG. From time t7 to t8, the compressed air pressure increases as shown from q to s in FIG. 4, and when the pressure gauge 7 detects the set upper limit pressure of the compressed air at time t8, as shown in t in FIG. Stops. Time t
As the compressed air pressure increases from 7 to t8, the drain amount increases from r to u in FIG. Also, the counter 12 increases the count value from (t3) to (4) (5) during the period from time t7 to t8.

At time t9, the set time Tcycle of the cycle timer 14 restored at time t4 is reached, the cycle timer 14 activates the discharge timer 13, and the discharge timer 13 sends a clear signal to the counter 12 and the cycle timer 14. The discharge timer 13 and the counter 12 are reset, and the discharge timer 13 opens the drain discharge valve 5 from the time t9 to the time t10 as shown from v to w in FIG. 4 and the drain in the air tank becomes x in FIG.
Is discharged as shown in FIG. When the discharge timer 13 times out at time t10, the drain discharge valve 5
Is closed.

According to the second embodiment, the first embodiment
There are the following effects in addition to the effects of 1) Since the cycle timer is added in addition to the counter, the drain can be reliably discharged. 2) When the drain is discharged by the counter and when the drain is discharged by the cycle timer, the timer is returned and restarted, so that there is no unnecessary drain discharge operation and the discharge efficiency is improved. 3) Even if either the drain discharge function by the counter or the drain discharge function by the cycle timer is impaired, drain discharge is performed. Applies to equipment.

(Third Embodiment) In the third embodiment, the valve opening time of the drain discharge valve 5 in the first embodiment is determined in consideration of the pressure rising speed of the compressed air pressure.

FIG. 7 is a block diagram of the third embodiment, and the components denoted by the same reference numerals as those in FIG. 1 have the same functions.
The different parts will be described with reference to the description. The average pressure value calculator 15 receives the previous detected pressure value P0 input from the holding circuit 11 and the current detected pressure value P1 input from the sample board 8, and receives the pressure values P0, P0,
The ratio or difference of P1 is calculated at fixed time intervals, and the calculated result is sent to the discharge timer 13 where the discharge timer 13
The average value of the pressure gradient is calculated based on the set time of the pressure gauge 7 based on the pressure detected by the pressure gauge 7, and the operation time of the discharge timer 13 is varied according to the average value of the pressure gradient. In the third embodiment, the discharge timer 13 sends a clear signal to the counter 12 when the time is up so that the counter 12 returns. In the first and second embodiments, the counter 2 may be returned when the discharge timer 13 times out.

The time chart of the third embodiment is substantially the same as FIG. 2 in FIG.

In FIG. 8, the drain discharge valve 5 is 1 (ell).
To m, u to v, and i1 to j1 respectively. In the first embodiment, the valve opening times t4 to t5, t8 to t9, and t13 to t14 are times of the same length.

In the third embodiment, the operation time of the drain discharge timer 13 is changed for the following reason. The operation time of the counter 12 until the counter 12 reaches the set value is constant, and the compressed air pressure is increasing during this cumulative time. The greater the height at which the compressed air pressure rises over a certain period of time, the greater the amount of drain generated. In addition, the greater the gradient of the increase in the compressed air pressure at which the compressed air pressure increases during this fixed time, the greater the amount of drain generated. Accordingly, in the present invention, an average calculator 15 for the compressed air pressure gradient until the time when the counter 12 reaches the set value for the opening time of the drain discharge valve 5 is provided, and the set value of the discharge timer 13 is calculated by the calculator 15. It is always changed according to the average value of the obtained compressed air pressure gradient.

Further, since the compressed air pressure gradually decreases while the air compressor 1 is stopped, the generation of new drain is small.

In the third embodiment, when the average pressure rise in which the compressed air pressure rises is small, the amount of drain generated within a certain period of time is small. Therefore, the set time of the drain discharge timer 13 is shortened, and the average pressure rise gradient is large. In some cases, the amount of drain generated within a certain period of time is large.
The setting time of No. 3 is variable.

By doing so, there is no need to inject unnecessary compressed air from the drain discharge valve 5 or to close the drain discharge valve 5 while leaving a considerable amount of drain to be discharged.

It is needless to say that this embodiment can be applied to the second embodiment using a cycle timer.

FIG. 8 is a time chart showing the operation of the automatic drain discharge device having the above configuration. Power is turned on at time t0.

At the time t1, when the operation of the air compressor 1 is started as shown in FIG. 8A, the pressure gauge 7 detects the set lower limit pressure L as shown in FIG.
As shown in (c), the drain amount is zero. When the air compressor 1 is operated from time t1 to time t2, the compressed air pressure reaches the set upper limit pressure H as shown in FIG. Then, as shown in FIG. 8e, the air compressor 1 is cut off and stopped. The pressure of the compressed air constantly rises from b to d in FIG. 8, and the drain amount increases as shown in FIGS. 8c to 8f. During this time, since the active signal is sent from the level comparator 9 to the counter 12, the counter 12 continues counting and counts (7).

From time t2 to time t3, the compressed air pressure detected by the pressure gauge 7 due to the use of the compressed air decreases as shown from d to g in FIG. During this time, the drain amount is substantially constant as shown from f to h in FIG. At time t3, when the pressure gauge 7 detects the set lower limit pressure L, the air compressor 1 is operated as shown in FIG.
As shown in FIG. 7, the pressure gauge 7 detects an increase in the compressed air pressure. At time t4 during which the pressure gauge 7 detects the increase in the compressed air pressure from g to j, the counter 12 counts the set value (8) due to the increase in the compressed air pressure. Between the time t3 and t4, the drain amount increases as shown by h to k in FIG. When the counter 12 reaches the set value (8), the counter 12 sends a discharge trigger signal to the discharge timer 13, and the discharge timer 13 performs the set time (from time t4 to t5).
The drain discharge valve 5 is opened as shown from l (m) to m in FIG. 8, and the drain is discharged and opened again as shown from k to n in FIG. The discharge timer 13 sends a clear signal to the counter 12 at time t5 when the set time has elapsed, and causes the counter 12 to return.

Until the time t4 when the drain is discharged, the count value of the counter 12 is maintained by the pressure average gradient calculator 1
5, the pressure gradient average value calculator 15 calculates the pressure gradient value indicated by the pressure gauge 7 from the previous detection value of the pressure gauge 7 and the current detection value sent from the holding circuit 11 at fixed time intervals according to the count value. Then, the average value of the pressure gradient is calculated from the pressure gradient value of each count value, and the set time of the discharge timer 13 is changed according to the average value of the pressure gradient. That is, when the average value of the pressure gradient is large, the set time of the discharge timer 13 is lengthened, and when the average value of the pressure gradient is small, the set time of the discharge timer 13 is shortened.

The set value of the discharge timer 13 at this time t4 is the compressed air pressure between the times t1 and t2 when the counter 12 calculates (1) through (7) and the time t3 and t4 when (8) is calculated. Is changed according to the average value of the ascending slope. That is, when the average value is high, the set time of the discharge timer 13 is lengthened.
Shorten the setting time of.

During the drain discharge, the air compressor 1
Is operating, and drain occurs from time t5 to t6 as shown from n to o in FIG. 8, and the counter 12 counts (1). At time t6, when the pressure gauge 7 detects the set upper limit pressure as shown by j in FIG. 8, the air compressor 1 stops as shown by p in FIG.

From time t6 to time t7, the compressed air is used and the pressure drops. At time t7, when the pressure gauge 7 detects the set lower limit pressure L of the compressed air as shown by q in FIG. It is operated like r.

When the compressed air pressure increases from time t7 to t8 and the counter 12 counts (8) at time t8, the counter 12 sends a discharge trigger signal to the discharge timer 13. The discharge timer 13 opens the drain discharge valve 5. The drain which has increased from s to t in FIG. 8 is discharged by the drain timer 13 from time t8 to t9.
Is opened as shown from u to v in FIG. 8, and the drain is discharged as shown from t to w in FIG. At this time, the set time t8-t9 of the discharge timer 13 is changed in proportion to the average rising gradient of the compressed air pressure between the times t5 and t6 and between the times t7 and t8.

The discharge timer 13 closes the valve at the time t9, and at the same time, sends a clear signal to the counter 12 to reset the counter 12.

At time t9, when the pressure gauge 7 detects the set upper limit pressure x as shown by x in FIG. 8, the air compressor 1 stops as shown by y in FIG. At time t9, the counter 12 has been restored in response to the clear signal from the discharge timer 13.

From time t9 to t10, the air compressor 1 is stopped as shown from y to z in FIG. 8, the compressed air pressure is reduced by the pressure gauge 7 as shown from x to a1 in FIG. When the pressure gauge 7 detects the set lower limit pressure L of the compressed air at time t, the air compressor 1 is operated as shown in z of FIG. 8 and at time t11, the pressure gauge 7 sets the compressed air as shown at b1 of FIG. Upper limit pressure H
Is detected, the air compressor 1 stops as shown by c1 in FIG.

From time t10 to t11, the drain is
The counter 12 counts from (1) to (6) during this time as shown by d1 to e1.

From time t11 to time t12, the compressed air pressure drops to the set lower limit pressure L as shown by b1 to f1 in FIG. Further, the drain amount during this time is changed from e1 to k in FIG.
There is almost no change as in 1.

At time t12, the air compressor 1 is operated as shown by g1 in FIG.
F1 to h1 as shown in FIG. The counter 12 counts (7) and (8) based on the signal sent from the pressure gauge 7 in response to the increase in the compressed air pressure, and at time t13 when the count value becomes (8), the counter 12 outputs the discharge trigger pulse. The discharge timer 13 is sent to the discharge timer 13. The discharge timer 13 opens the drain discharge valve 5 from time t13 to t14 as shown from i1 to j1 in FIG. 8, and the drain discharge valve 5 is shown from l (m) 1 to m1 in FIG. Drain and close the valve. At this time, the set value of the drain discharge timer 13 is changed according to the average value of the rising gradient of the compressed air pressure from time t10 to t11 and from time t12 to t13.

While the drain is being discharged from l (m) to m1 in FIG. 8, the air compressor 1 is operated as shown from g1 to n1 in FIG. 8, and the compressed air pressure detected by the pressure gauge 7 is At time t14 when the signal rises from f1 to h1 in FIG. 8, the counter 12 that has returned after receiving the clear signal from the discharge timer 13 counts (1).

According to the third embodiment, the following effects can be obtained. 1) With a simple circuit configuration, generation of drain can be predicted and drain can be reliably discharged. 2) Since no voltage is applied to a drain sensor or the like in the air compressor, explosion proof can be easily considered. 3) Since no drain sensor detection tank is required, the scale of the apparatus can be reduced. For this reason, attachment installation is easy. 4) In the method of detecting with a drain sensor, airtightness is required and the cost is increased because the air is disposed in a drain sensor detection tank where compressed air is present. However, in the case of this method, there is a merit in cost because the configuration is simple. . 5) In the method of detection by the drain sensor, the drain sensor is buried in the drain, so that the drain sensor may be corroded and the detection reliability may be reduced. There is no problem because it is detected by. 6) Since the integrating counter 12 and the discharge timer 13 are constituted by electronic circuits, the set time can be easily changed, so that the discharge can be controlled efficiently. 7) Since the pressure gauge 7 does not measure absolute pressure, only the pressure change is detected, so that "absolute accuracy" of the pressure gauge is not required (cost merit). 8) Since only the change in pressure is detected, a pressure gauge is not selected, so that the pressure gauge is inexpensive. 9) Applicable to various air compressors such as unloader type, pressure opening / closing type, and merging type. 10) There is no need to newly install a pressure gauge because it can also be used as a pressure gauge installed in the air compressor. 11) By detecting not only the pressure rising direction but also the rising gradient (slope), fine control can be performed, and the efficiency of drain discharge can be further improved without escaping compressed air. 12) Since a change in pressure is detected, it can be installed at a piping point on the way.

In the third embodiment, the second embodiment
Similarly, a cycle timer may be added.

(Embodiment 4) In this embodiment, a counter value in the rising direction of the pressure gradient of the compressed air is detected, and when the pressure gradient becomes "0" or "falling direction", the discharge time according to the counter value is detected. Drain immediately. Reset the cycle timer (if equipped with a cycle timer) and counter simultaneously with draining.

FIG. 9 is a block diagram of the fourth embodiment, and the components denoted by the same reference numerals as those in FIG. 1 have the same functions.
The different parts will be described with reference to the description.

The level comparator 9 sends an active signal to the counter 12 when the pressure gradient of the compressed air pressure is rising. When the pressure gradient compared by the level comparator 9 is “0” or “downward direction”, the discharge timer 13 is activated without activating the counter 12. The time during which the discharge timer 13 is energized is variable so as to change in proportion to the counter value output from the counter 12.

FIG. 10 is a time chart of this embodiment.

FIG. 10 is a time chart showing the operation of the automatic drain discharge device having the above configuration.

At time t0, the power is turned on.

At the time t1, when the operation of the air compressor 1 is started as shown in FIG. 10A, the pressure gauge 7 detects the set lower limit pressure L as shown in FIG.
As shown in FIG. 10C, the drain amount is zero. Time t
When the air compressor 1 is operated from 1 to t2, FIG.
The compressed air pressure reaches the set upper limit pressure H as shown in (d). Then, as shown in FIG.
Is cut off and stops. This compressed air pressure is
10 to d, and the drain amount increases as shown in FIGS. During this time, since the active signal is sent from the level comparator 9 to the counter 12, the counter 12 continues counting and counts (7). Time t
When the level comparator 9 detects that the compressed air pressure goes from d to g in FIG. 10 in 2, the level comparator 9 sends a signal to the discharge timer 13 to activate the discharge timer 13.

From the time t1 to the time t2, the counter 12 counts (7), and this value is counted by the drain discharge timer 1
3 and the set valve opening time of the drain discharge timer 13 is increased in proportion to the counter value.

At time t2, the discharge timer 13
Sends a clear signal to the counter 12 to reset the counter 12 and for a set time (from time t2 to t3, which is proportional to the counter value (7)), as shown in FIG. 5 is opened, and f to h in FIG.
The drain is discharged and the valve is closed as shown in (1). At this time, the valve opening time t2-t3 of the drain discharge valve 5 is proportional to the counter value (7) of the counter 12, so that almost all of the drain liquid generated from the drain discharge valve 5 is discharged and the compressed air leaks. It is also possible to prevent it from happening.

At time t4 in FIG.
Detects the set lower limit pressure L as shown in FIG. 10g, the air compressor 1 is operated as shown in FIG. 10i, and the pressure gauge 7 increases the compressed air pressure as shown in FIGS. Is detected. The counter 12 counts (3) when the pressure gauge 7 detects an increase in the compressed air pressure from g to j. From time t4 to time t5, the drain amount increases as shown from k to o in FIG. At time t5, the compressor 1 stops as shown by p in FIG. After the compressor 1 is stopped, the pressure of the compressed air decreases slightly at time t6 from q to s in FIG. 10 after a slight pressure rise as shown from j to n in FIG. 10 in relation to the discharge piping system and the compressed air load. In response to this, the level comparator 9 activates the discharge timer 13, and the discharge timer 13 performs a time t6 to t7 proportional to the count value (3) received from the counter 12, as shown in t to w in FIG. The drain discharge valve 5 is opened.

Thereafter, at time t9, the drain discharge valve 5 is opened as shown from u to v in FIG. 10 for a time t9 to t10 proportional to the count number (8). At time t13, a time t13 proportional to the count number (7)
During -t14, the discharge valve 5 is opened as shown from i1 to j1 in FIG. At time t16, time t16-t17 proportional to the count number (4), the discharge valve 5 is opened as shown from m1 to n1 in FIG.

According to the fourth embodiment, the following effects can be obtained. 1) With a simple circuit configuration, generation of drain can be predicted and drain can be reliably discharged. 2) Since no voltage is applied to a drain sensor or the like in the air compressor, explosion proof can be easily considered. 3) Since no drain sensor detection tank is required, the scale of the apparatus can be reduced. For this reason, attachment installation is easy. 4) In the method of detecting with a drain sensor, airtightness is required and the cost is increased because the air is disposed in a drain sensor detection tank where compressed air is present. However, in the case of this method, there is a merit in cost because the configuration is simple. . 5) In the method of detecting with the drain sensor, the drain sensor is buried in the drain, so that the drain sensor may be corroded and the detection reliability may be reduced. There is no problem because it is detected. 6) Since the integrating counter 12 and the discharge timer 13 are constituted by electronic circuits, the set time can be easily changed, so that the discharge can be controlled efficiently. 7) Since the absolute pressure is not measured by the pressure gauge, only the pressure change is detected, so that "absolute accuracy" of the pressure gauge is not required (cost merit). 8) Since only the change in pressure is detected, a pressure gauge is not selected, so that the pressure gauge is inexpensive. 9) Applicable to various air compressors such as unloader type, pressure opening / closing type, and merging type. 10) Since it can also be used as a pressure gauge installed in the air compressor, it is not necessary to newly install a pressure gauge. 11) By detecting not only the pressure rising direction but also the rising gradient (slope), fine control can be performed, and the efficiency of drain discharge can be further improved without escaping compressed air. 12) Since a change in pressure is detected, it can be installed at a piping point on the way.

In the fourth embodiment, the second embodiment
Similarly, a cycle timer may be added.

[0088]

According to the present invention, 1) With a simple circuit configuration, generation of drain can be predicted and drain can be reliably discharged. 2) Since there is no member for applying a voltage such as a drain sensor in the air compressor, explosion proof can be easily considered. 3) Since no drain sensor detection tank is required, the scale of the apparatus can be reduced. For this reason, attachment installation is easy. (It is only necessary to wire the air compressor 1.) 4) In the method of detecting with a drain sensor, the airtightness is required because the compressed air is disposed in a drain sensor detection tank, which increases the cost. In this case, there is a cost advantage because the configuration is simple. 5) In the method of detecting with the drain sensor, the sensor is buried in the drain, so that the drain sensor may be corroded and the detection reliability may be reduced. Is no problem at all. 6) Since the integration counter and the discharge timer are constituted by electronic circuits, the set time can be easily changed, so that the discharge can be controlled efficiently. 7) When the amount of drain detected in the above 5) reaches a predetermined pressure rise integrated value by the integration counter, the drain discharge valve is opened, so that drain can be reliably discharged. Do not open the discharge valve.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment.

FIG. 2 is a time chart showing the operation of FIG.

FIG. 3 is a block diagram of a second embodiment.

FIG. 4 is a time chart showing the operation of FIG. 3;

FIG. 5 is a block diagram of a conventional example.

FIG. 6 shows a conventional drain discharge device.

FIG. 7 is a block diagram of a third embodiment.

FIG. 8 is a time chart showing the operation of FIG. 7;

FIG. 9 is a block diagram of a fourth embodiment.

FIG. 10 is a time chart showing the operation of FIG. 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Air compressor 2 ... Discharge piping 3 ... A / D converter 5 ... Drain discharge valve 7 ... Pressure gauge 8 ... Sample hold 9 ... Level comparator 10 ... Reference oscillator 11 ... Holding circuit 12 ... Integration counter 13 ... Discharge timer 14 Cycle timer 15 Pressure rise gradient calculator 23 Automatic drain discharge device 24 Drain sensors 24H, 24L Electrodes 26 Drain automatic discharge control unit 27 Time constant circuit 28 Solenoid valve drive unit 29 Drain sensor detection tank 30 ... TR1

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16T 1/00

Claims (8)

(57) [Claims] An automatic drain discharge device attached to an air compressor which is operated continuously or intermittently, wherein a pressure detecting means for detecting a pressure of compressed air discharged from the air compressor, and a pressure detecting means for detecting a pressure of the compressed air discharged from the air compressor. The pressure detection value is input at regular intervals and the current pressure detection value is compared with the previous pressure detection value.
Integrating means for accumulating the number of pressure rises when the current pressure detection value is greater than the previous pressure detection value and activating the discharge timer when the count value reaches a preset number of times, and for a predetermined time by a signal from the integrating means. An automatic drain discharge device comprising: a discharge timer for opening a drain discharge valve; and a drain discharge valve controlled by the discharge timer. 2. The automatic drain discharge device according to claim 1, wherein the drain is discharged, the integrating means is reset, and the integrating means is started. 3. The automatic drain discharge device according to claim 1, wherein the installation time of the integrating means and the discharge timer is variable. 4. A cycle timer for energizing a discharge timer is added, and when one of the cycle timer and the integrating means reaches a set value, the discharge timer is energized to open a drain discharge valve and a cycle timer. And resetting the integrating means.
Automatic drain discharge device according to one of the above. 5. An automatic drain discharge device attached to an air compressor which is operated continuously or intermittently, wherein the pressure detecting means detects the pressure of compressed air discharged from the air compressor, and the pressure detecting means detects the pressure. The pressure detection value is input at regular intervals and the current pressure detection value is compared with the previous pressure detection value.
Accumulates the number of pressure rises when the current pressure detection value is greater than the previous pressure detection value, and discharges according to the number of pressure rises when the current pressure detection value is equal to or lower than the previous pressure detection value An automatic drain discharge device, comprising: integrating means for operating a timer; a discharge timer for opening a drain discharge valve in response to a signal from the integrating means; and a drain discharge valve controlled by the discharge timer. 6. A cycle timer for energizing a discharge timer is added, and when the cycle timer reaches a set value or the current pressure detection value input to the integrating means becomes equal to or lower than the previous pressure detection value. 6. The automatic drain discharge device according to claim 5, further comprising a discharge timer for opening a drain discharge valve when the drain valve is opened. 7. The system according to claim 5, wherein a current pressure detection value is compared with a previous pressure detection value to calculate a pressure rise gradient, and the operating time of the drain discharge valve is made variable in accordance with the pressure rise gradient. Or the automatic drain discharge device according to 6. 8. An automatic drain discharge device attached to an air compressor that is operated continuously or intermittently, wherein the pressure detecting means detects the pressure of compressed air discharged from the air compressor, and the pressure detecting means detects the pressure. A level comparator that inputs pressure detection values at regular intervals and compares the current pressure detection value with the previous pressure detection value, and receives the output from the level comparator and changes the current pressure detection value to the previous pressure detection value An integration means for integrating the number of pressure rises when the pressure is greater than and outputting a count value to a discharge timer, and changing the set valve opening time according to the count value by a signal from the integration means, and also using the level comparator to determine whether the current pressure value is the last time. A drain timer that operates in response to a signal when the pressure value is equal to or lower than the pressure value of the pressure value, and a drain discharge valve that is controlled by the discharge timer. Output device.