JP2019116963A - Drain trap - Google Patents

Abstract

To provide a drain trap applied at a compression pneumatic circuit and capable of detecting each of both states of opening failure and closing failure.SOLUTION: A drain trap 1 comprises: discharge detection means 30 installed at a secondary side of a valve main body 12b of the drain trap 1 to inform that either a pressure or flow rate exceeds a predetermined set value; a first timer 40 and a second timer 50 having a longer time counting than that of the first timer 40 each of which is a count-up timer; time delay means 41 for resetting the first timer 40 after either delaying or smoothing of a detected signal sent by the discharge detection means 30; denial means 51 for denying (NOT) a signal of the discharge detection means 30 and finally resetting either the first timer 40 or the second timer 50. The drain trap applies a constitution that when either the first timer 40 or the second timer 50 shows a predetermined time counting-up completion, an alarm output ALM is performed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a drain trap connected to a pneumatic circuit.

  In the compressed air pressure circuit, a drain, which is condensed water, is generated due to pressure changes and temperature changes. The drain must be properly drained from the circuit as it causes degradation of the compressed air by causing failure of the connected equipment or polluting others at the end of the circuit. A drain trap is a device connected to drain the drain from the circuit.

  The drain trap is a valve dedicated to draining, provided at a point where the circuit communicates with the outside of the circuit. When the drain trap performs the valve opening operation, the pressure energy of the fluid drains the drain toward the outside of the circuit. In a compressed pneumatic circuit, the fluid is, of course, compressed air. Therefore, the drain trap connected to the compressed pneumatic circuit discharges the drain out of the circuit using the energy of the compressed air.

  As described above, since the nature of the drain trap is a valve, whatever the system is, mechanical operation such as moving the valve body is necessary for draining the drain. And since the mechanical malfunction of the drain trap impairs the normality of the fluid circuit, it is desirable that the occurrence is immediately detected and an alarm can be issued to the device or person.

  By the way, in a drain trap, particularly one using a solenoid valve, what is often seen as a mechanical malfunction includes adhesion or sticking of foreign matter to a movable mechanism of a valve body or a valve body or a valve seat.

  As a first example of operation failure due to foreign matter, foreign matter bites into (is caught in) the valve body or the valve seat portion, and the valve body is constantly separated from the valve seat, that is, valve closing failure.

  Also, as a second example, in spite of the presence of the valve opening command, any of the valve opening mechanisms has grease adhesion or foreign matter in the way of the valve opening mechanism, and the valve body can not be moved for valve opening. That is, there is an open valve failure.

  The valve closing failure of the first example causes the fluid in the circuit to be lost. The valve opening failure of the second example causes the drain to be a discharge failure. As such, there is a need for a drain trap that can prevent both.

  As a technique for confirming that the drainage operation of the drain trap has been performed mechanically correct, Patent Document 1 takes into consideration the duration of rush current (rush current) flowing to the solenoid valve, and the coil of the solenoid valve Propose a technique to judge that the movable iron core with the valve part has malfunctioned (open valve failure) due to the adhesion of grease etc. if it does not reach the normal current amount even after passing a predetermined time after energization. There is.

However, in the technical proposal according to Patent Document 1, if the solenoid valve is not energized, it can not be determined that the solenoid valve is abnormal.
Therefore, since it is not possible to detect the valve closing failure (loss of fluid) due to the foreign matter biting into the valve seat or the valve body as described above, an alarm is not issued even if such a situation occurs.

Moreover, in the technical proposal concerning patent document 1, it can not detect between valve-opening and valve-opening.
Therefore, no warning is issued about the possibility that the drain of dangerous water is stored in the circuit between the valve opening and the valve opening.

JP, 2015-86791, A

  Then, this invention makes it a subject to be used for a compression pneumatic circuit, and to provide the drain trap which can detect both an valve opening defect and a valve closing defect, respectively.

  In order to solve the above problems, the present invention relates to a drain trap which is connected to a place where gas and liquid can be mixed by compressed air and drain and which performs an opening / closing valve operation of a valve body by an electrical valve opening command signal. Discharge detection means disposed on the secondary side of the valve main body of the trap for notifying that the pressure or flow rate has exceeded a predetermined set value, and the first timer, which is a count-up timer, and the first timer whose counting time is longer than the first timer (2) timer, time delay means for delaying or smoothing the detection signal sent from the discharge detection means and then resetting the first timer, and negating the signal from the discharge detection means, finally the first timer or the first timer And n negative means for resetting one of the two timers, and the first timer or the second timer counts up for a predetermined time. To adopt a configuration in which the alarm output when it becomes complete.

  Preferably, the discharge apparatus includes a first orifice closed by the valve body, and a second orifice disposed inside a pipe line downstream of the first orifice and smaller in diameter than the first orifice, the discharge The detection means adopts a configuration disposed at a predetermined intermediate position between the first orifice and the second orifice.

  Preferably, the first timer and / or the second timer perform an AND operation on any one of the detection signal, the signal transmitted by the time delay means, and the signal transmitted by the negation means, and the valve opening command signal. It adopts a configuration to be (AND) and reset.

  Preferably, pressure detection means is provided on the primary side of the valve body, and the alarm output is not performed if the pressure detection means does not exceed a predetermined set value.

According to the present invention, a drain trap having the following effects can be provided. Even when the drain and the compressed air are mixed and neither liquid nor gas phase, both the valve opening failure and the valve closing failure can be detected.
Even if the secondary side is open to the atmosphere, a slight pressure is generated by the first orifice and the second orifice, so that means for detecting the pressure can be employed as confirmation of fluid discharge.
(3) Since the valve opening command signal and the signal of the discharge detection means are finally ANDed with each other, it can be confirmed that the valve opening command signal is correctly sent within the time until the alarm is issued.
4 Since the pressure on the primary side of the valve body is monitored, false alarms will not be issued when the air compressor is shut down or the circuit is not in use.

  Problems, configurations, and effects other than those described above will be described in detail in the following embodiments.

It is a block diagram of the drain trap concerning this invention. It is a structural example of the valve | bulb main body of the drain trap concerning this invention. It is a structural example of secondary side piping of the drain trap concerning this invention. It is a hardware configuration example of control of the drain trap concerning the present invention. It is a hardware configuration example of control of the drain trap concerning the present invention. It is an ideal signal detection example of the drain trap concerning this invention. It is an example of signal detection of the drain trap concerning the present invention. It is an example of signal detection of the drain trap concerning the present invention. It is an example of signal detection of the drain trap concerning the present invention. It is an example of alarm output of the drain trap concerning the present invention. It is an example of alarm output of the drain trap concerning the present invention.

The drain trap 1 according to the present invention is a drain trap 1 connected to a location where gas and liquid can be mixed by compressed air and drain, and performing an on-off valve operation of the valve main body 10 by an electrical valve open command signal 61. Discharge detection means 30 disposed on the secondary side of the valve main body 12b of the drain trap 1 to notify that the pressure or flow rate has exceeded a predetermined set value, a first timer 40 which is a count-up timer, and the first timer A second timer 50 with a longer counting time, time delay means 41 for delaying or smoothing the detection signal sent from the discharge detection means 30 and then resetting the first timer 40, and negating the signal from the discharge detection means 30 ( NOT means 51 for not resetting one of the first timer 40 or the second timer 50 finally Comprising, first timer 40 or the second timer 50 is the largest, characterized in that employs a configuration in which an alarm output ALM when a predetermined time count-up completion.
Hereinafter, an embodiment of a drain trap 1 according to the present invention will be described based on the drawings.

  The drain trap 1 according to the present invention is not particularly limited to the embodiments described below, and devices within the scope of the technical idea of the present invention, that is, devices that can exhibit the same effects, materials of the devices or The shape can be changed as appropriate.

  Compressed air is compressed by an air compressor. In many cases, compressed air is naturally cooled or cooled and dehumidified by a refrigeration air dryer or the like to generate a drain, which is the condensed water. The drain trap 1 is a dedicated valve for discharging the drain from the circuit.

  As a basic operation of the drain trap 1, the valve body 10 is opened from the inlet 13 on the primary side to which the circuit piping is connected, so that the drain trap 1 is connected via the outlet 14 and the secondary piping 20. Drain the drain out of the circuit. The valve body 10 mainly comprises a valve seat 11 forming a first orifice 11b and a valve body movable means 12 having a valve body 12b. In response to the valve opening command signal 61, the valve body movable means 12 moves electromagnetically to perform the on-off valve operation. In this mode, the valve body 12 b is separated from the valve seat 11 (open valve) or pressed against the valve seat 11 and closed (closed valve). In general, a valve that performs an electromagnetic on-off valve operation is called a "magnetic valve". The solenoid valve causes the movable iron core to perform a suction operation by energizing the coil according to the valve opening command signal 61 sent from the control means 60, and gives the moving energy to the valve main body moving means 12.

  Note that, for the valve opening command signal 61, various delivery control methods can be adopted. What is sent out for a predetermined time every predetermined time is "Timer control method", the upper limit and the lower limit water level sensors are arranged in the drain reservoir, and when the drain detects the upper limit, it sends out the valve open command signal 61 to detect the lower limit. Those that stop sending the same signal when they are lost are called "upper limit / lower limit method" or the like. Some of them are used in combination.

  The discharge detection means 30 disposed at a predetermined intermediate position of the secondary side piping path 20 provided on the secondary side of the outlet 14 detects that the valve main body 10 has released the compressed air and the drain by opening and closing the valve. Be done. As the discharge detection means 30, a flow rate sensor, a pressure sensor, a pressure switch or the like can be considered. In addition, they do not send numerical values in analog quantities, and it is easier to control digital signals that can send on / off digital signals that send signals when the flow rate or pressure exceeds a predetermined value as the state of the circuit. Desirable because However, in order to detect a fluid leak due to a valve closing failure, it is desirable to set the threshold for signal transmission indicating that reaction has been made as low as possible.

  In the case where a pressure sensor or a pressure switch is used as the discharge detection means 30, there is usually little pressure in the secondary side piping path 20 in which the discharge detection means 30 is disposed, so It is necessary to provide in the next side piping route 20. However, the pressure may be a slight pressure that can be detected by the discharge detection means 30.

It is conceivable to provide a second orifice 21 having a smaller hole diameter than the first orifice 11 b as a means for generating pressure in the secondary side piping passage 20. In that case, the second orifice 21 is required to be disposed inside the pipe line at the rear stage (secondary side) of the first orifice 11 b. The attachment portion 22 for attaching the discharge detection means 30 is also required to be disposed at a predetermined intermediate position between the first orifice 11 b and the second orifice 21 of the valve body 10. With such a configuration, a slight pressure is generated as a differential pressure in the secondary side piping path 20, so a pressure sensor or a pressure switch can be employed as the discharge detection means 30.
In such a case, it should be noted that the amount of fluid that can be drained per unit time as a drain trap depends mostly on the diameter of the second orifice 21.

As described above, the detection signal 31 sent out by the discharge detection means 30 is sent by detecting the flow rate and pressure exceeding a predetermined amount although it is a minute amount. It is a signal which shows that it is. The signal waveform can be considered in at least three cases as described later.
Usually, although the flow sensor, pressure sensor, and pressure switch are similar in principle, their structures and adjustments are partially different between those for the gas phase and those for the liquid phase, and the gas and liquid are mixed. If this is the case, the value may not be accurately indicated.
In the case of discharging the drain from the compressed air circuit, the compressed air and the drain often discharge the gas-liquid mixed fluid mixed in a mist form.

As the first example, there is a waveform shown in FIG.
This is a signal waveform indicating that only the gas, i.e. compressed air, is discharged, or the liquid, i.e. only the drain is discharged. Since it is ideally ideal to drain only the drain, the valve body 10 is opened in response to the valve opening command signal 61, and if only the drain is drained, it will open about 100 to 500 msec. After the valve delay td, the flow rate and pressure possessed by the drain are detected by the discharge detection means 30, and a detection signal 31 free of waveform distortion is sent out. Then, when the valve body 10 is closed, the detection signal 31 is stopped to be sent out after the valve closing delay time td.

As the second example, there is a waveform shown in FIG.
This is a signal waveform indicating that all of the mixture of compressed air and drain is discharged while the valve body 10 is open. As described above, the discharge detection means 30 does not indicate exactly when the gas and liquid are mixed, and a signal that continues to be disturbed in this way is observed. In this case, the time for each rise of the signal is often observed for several milliseconds to several hundreds of milliseconds. It is considered that the reason for such a waveform is that, even in the flow of drain mixed gas and liquid, there is a time in which at least the periphery of the discharge detection means 30 is in either the liquid phase or the gas phase. .

As the third example, there is a waveform shown in FIG.
This is because the drain, which is in a gas-liquid mixed state at the timing of opening / closing of the valve main body 10, is recalled and stored in any place in the circuit during discharging, and as a liquid for a while Is a waveform showing that only the Therefore, the detection signal 31 disturbed at the timing of the on-off valve of the valve main body 10 has a waveform having no disturbance in the middle.

  The control means 60 firstly has no abnormality in the length of time during which the drain is being discharged (discharge time) based on one detection signal 31 where such a waveform can be disturbed, and secondly, the drain Monitor that there is no problem and discharge regularly (discharge cycle), and if they are abnormal, that is, if the discharge time and discharge cycle exceed the specified alarm time, alarm output ALM It is necessary to send it out. Therefore, the time counting timer required for control is a count up timer, and at least two channels are required. In addition, in the timer that clocks at least the alarm discharge time tdc, means for correcting the disturbance of the detection signal 31 is also required. Since the discharge cycle is usually longer than the discharge time, it is also necessary to set the timer for clocking the alarm discharge cycle tcc to be longer than the timer for clocking the alarm discharge time tdc. Furthermore, if the valve opening command signal 61 continues for a predetermined time by a predetermined time by setting, it is also necessary to set the set time according to the alarm of the respective count-up timers to be equal to or longer than those times.

  As an example satisfying such requirements, there is an example of implementation of the control means 60 shown in FIG. The hardware of the first timer 40, the time delay means 41, the second timer 50, the negation means 51, and the control means 60 are provided as an embodiment of the control means 60 shown in FIG.

Since two channels of the clocking timer are required, the alarm discharge time tdc is clocked by the first timer 40 and the alarm discharge cycle tcc is clocked by the second timer 50 in the embodiment shown in FIG. Therefore, the second timer 50 has a longer counting time than the first timer 40. Also, each time counting method is a count up timer, and if it is not reset to a predetermined time, an alarm output ALM is sent out. In the alarm output operation shown in FIG. 10 and FIG. 11, the alarm output ALM is sent out when the alarm discharge time tdc (first timer 40) and the alarm discharge cycle tcc (second timer 50) count up is completed. In FIG. 10, when the discharge detection signal 31 is not detected after the alarm discharge time tdc has once counted up, in FIG. 11, the discharge detection signal 31 is detected after the alarm discharge cycle tcc has once counted up. In this example, the alarm output ALM is set to be stopped when the respective abnormal conditions of "when" have ended once. In other words, when the first timer 40 and the second timer 50 are respectively reset, the transmission of the alarm output ALM is stopped. Conversely, the alarm output ALM continues to be delivered as long as the abnormal condition continues.
Note that the alarm output ALM may adopt a configuration that once an abnormality is detected, the alarm output ALM is maintained (self-holding) unless there is another special control such as manual reset.

  Here, at least the first timer 40 is finally reset because the first timer 40 has to measure the length of the discharging time while the signal waveform sent out of the detection signal 31 can be disturbed as shown in FIG. As the signal, it is necessary to use a signal sent from the time delay means 41 for delaying / smoothing the detection signal 31 for a predetermined time to correct the signal disturbance. The predetermined time may be several msec to several hundreds msec, which is the time for each rise of the signal of the disturbed detection signal 31 described above. In addition, if a delay by CR is performed, it is necessary to provide hysteresis on the receiver side of the signal as shown in FIG. 9 in view of preventing malfunction of an IC or the like. Further, the second timer 50 is sufficient if it is possible to determine whether there is drain discharge, that is, the presence or absence of a “duration” (discharge cycle) between valve opening and valve opening, so even if it is reset by a disturbed signal, it is sufficient. Although the time delaying means 41 is not necessarily required, since longer time counting is performed, there is no problem in operation even when the time delaying means 41 is provided also on the second timer 50 side.

  Furthermore, as a rough operation, the drain trap 1 performs only two operations: when draining (during a draining time) and when draining (during a draining cycle). Therefore, it is not necessary to simultaneously put timers of 2 ch in clocking state, and it is sufficient if only the timer (first timer 40) that clocks the discharge time during the discharge time is sufficient, and the timer that counts the discharge cycle (No. 2) The timer 50) may be in a reset state, and vice versa. Therefore, if one timer is in time-counting operation, the other timer may be reset. There is no particular question as to which of the first timer 40 and the second timer 50 performs the timing operation first. In the configuration in which the valve opening command signal 61 is sent immediately after the power is turned on, the second timer 50 is first reset, otherwise the first timer 40 is first reset.

Negative means 51 is disposed to realize the control described above.
Regardless of whether the logic of reset is negative logic or positive logic, if the first timer 40 and the second timer 50 are reset by the same logic, one is clocked by the negation means 51 arranged on either side During operation, it is feasible that the other is in the reset state. In other words, the negation means 51 is disposed only in one or the other.

  Since it is such an operation, it is also sufficient to switch and use the roles of the first timer 40 and the second timer 50 with the same timer by the detection signal 31 and the negation means 51 for sending out a signal that is negated. Is assumed. In that case, for example, as shown in FIG. 5, the negation means 51 is connected to the subsequent stage of the time delay means 41, and is connected to a general purpose timer (TMR) through some interface (I / F). Good. Then, for example, it may be used as the first timer 40 when the signal sent from the time delay means 41 is 1, and as the second timer 50 when the signal sent from the negative means 51 is 1. If the timer is reset at the time of switching, if one is clocking, the other can be similarly realized to be in a reset state. Although the configuration is partially different, the configuration shown in FIG. 5 is the same as drawing the same time chart as in FIGS. 10 and 11. Also, the alarm output ALM that has been sent once may be held as long as there is no other special control.

  Here, in order to improve the accuracy of the alarm output ALM, the second timer 50 outputs either the detection signal 31, the signal sent from the time delay means 41, or the signal sent from the pre-notification means and the valve open command signal 61. A configuration in which the logical product (AND) is reset is also conceivable. In such a configuration, since the valve opening command signal 61 and the signal of the discharge detecting means 30 are finally ANDed, the control means 60 outputs the valve opening command signal 61 within the time until the alarm is issued. It can also be confirmed at the same time that it is correctly delivered. In the case where a fluid leakage is detected for a long time due to a valve closing failure or the like, the first timer 40 sends out the alarm output ALM after a predetermined alarm time has elapsed, so that the logical product (AND) In the embodiment where the drain is detected by the water level sensor etc. and discharged, there is a possibility that the sensor may malfunction or the abnormal water amount in addition to the fluid leak due to the valve closing failure. Configuration.

  Furthermore, in order to improve the accuracy of the alarm output ALM, pressure detection means (not shown) is provided on the primary side, and when the pressure detection means does not exceed a predetermined set value, the alarm output ALM is not sent out. A configuration is also conceivable. In such a configuration, since the primary side pressure can also be monitored, the drain trap 1 does not issue a false alarm when the operation of the air compressor is stopped or the like. This is mainly because the circuit pressure is not applied to the primary side of the drain trap 1 when the air compressor is not performing the discharge operation or when the circuit is not in use, so the second timer 50 (for discharge cycle monitoring) is mainly used. ) Is provided for the purpose of preventing occurrence of an alarm (false alarm) without detecting flow rate or pressure even though the circuit is not used.

  The control means 60 is sufficient if the above control mode is possible, and it is considered that CPU, MPU, MCU, FPGA, PLD, control logic circuit by IC etc., PLC, relay circuit, or the like are considered. Be

  Also, the alarm output ALM may be output independently of each of the first timer 40 and the second timer 50, or may be output by ORing (OR) ing them. Also, as an output mode of the alarm output ALM, it is sufficient if human or other control device can be discriminated, an optical one, a buzzer, an electronic or electrical contact, one described in any electronic network protocol or Those similar to them are conceivable.

The present invention can monitor both the valve opening failure and the valve closing failure, and as described in "Effects of the Invention", exhibits many excellent effects.
Therefore, the industrial applicability of the "drain trap" in the present invention is considered to be great.

DESCRIPTION OF SYMBOLS 1 drain trap 10 valve main body 11 valve seat 11b 1st orifice 12 valve main body movable means 12b valve main body 13 inlet (primary side)
14 outlet (secondary side)
Reference Signs List 20 secondary side piping path 21 second orifice 22 mounting portion 30 discharge detection means 31 detection signal 40 first timer 41 time delay means 50 second timer 51 negative means 60 control means 61 valve opening command signal td valve opening delay / valve closing Delay tdc alarm discharge time tcc alarm discharge cycle ALM alarm output

Claims (4)

In a drain trap which is connected to a place where gas and liquid can be mixed by compressed air and drain and which opens and closes the valve body by an electric valve opening command signal,
Discharge detection means disposed on the secondary side of the valve body of the drain trap to indicate that the pressure or flow rate has exceeded a predetermined set value;
A first timer which is a count-up timer and a second timer whose counting time is longer than the first timer;
Time delay means for resetting the first timer after delaying or smoothing the detection signal sent from the discharge detection means;
And negative means for ultimately resetting any one of the first timer and the second timer by noting the signal of the discharge detection means.
An alarm output is performed when the first timer or the second timer has counted up for a predetermined time. A first orifice closed by the valve body;
And a second orifice disposed inside the pipe after the first orifice and having a smaller diameter than the first orifice,
The drain trap according to claim 1, wherein the discharge detection means is disposed at a predetermined intermediate position between the first orifice and the second orifice.   The first timer and / or the second timer are ANDed with any one of the detection signal, the signal transmitted by the time delay means, and the signal transmitted by the negation means with the valve opening command signal. The drain trap according to claim 1 or 2, which is reset. A pressure detection means provided on the primary side of the valve body;
4. The drain trap according to any one of claims 1 to 3, wherein the alarm output is not performed when the pressure detection means does not exceed a predetermined set value.