JP2004225620A - Liquid discharging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely detect some failure generated at a discharging route or a discharging nozzle with a relatively simple structure. <P>SOLUTION: A force feed pump 3 consists of an air motor 4 and a plunger pump 5 connected with the air motor 4. The plunger 5 is connected with four discharging nozzles 15 through a high-pressure hose 13. The discharging nozzle 15 is opened and closed by a switching valve 14. The opening and closing operations of the switching valve 14 is detected by a pneumatic switch 17. The air motor 4 is provided with a pneumatic switch 32 for detecting the reciprocating movement of the piston rod 8. A controller 40 calculates the reciprocating time of the piston rod 8 on the basis of an output signal of the pneumatic switch 32 and makes a comparison with standard reciprocating time for diagnosis of failure. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a backward-acting pump for pumping and pumping a liquid and a liquid ejecting apparatus including a discharge nozzle for ejecting the liquid pumped by the pump, and more particularly, to a liquid ejecting apparatus having a function of detecting occurrence of an abnormality in an ejection path. Liquid ejecting apparatus.
[0002]
[Prior art]
As a liquid discharge device such as a high-pressure cleaning device or a two-liquid coating device, there is a device that pumps liquid from a liquid supply source by an air-driven backward-acting pump such as an airless pump or a diaphragm pump and supplies the liquid to a discharge nozzle at a constant rate. is there.
[0003]
In the liquid discharge device, if an abnormality such as leakage or clogging occurs in the path from the pump to the discharge nozzle or in the discharge nozzle, the discharge amount from the discharge nozzle becomes unstable, which may result in poor cleaning or poor painting. For this reason, some conventional liquid ejection devices have a function of monitoring the occurrence of abnormalities in the ejection path and ejection nozzles (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
JP-A-6-108964 (FIGS. 1 and 2)
[0005]
[Problems to be solved by the invention]
The liquid ejection device is provided with a number of magnetic sensors for detecting the piston position of the pump, and is configured to detect the occurrence of an abnormality by monitoring the operation of the piston. For this reason, there has been a problem that the configuration is complicated and the manufacturing cost is increased.
[0006]
In the air-driven pump, the operation of the piston is linked to the opening and closing operation of the discharge nozzle. However, the above-mentioned structure discharge device does not consider the opening and closing operation of the discharge nozzle. Therefore, for example, when the discharge nozzle is frequently opened and closed, there is a problem that a normal operation is erroneously recognized as an abnormality.
[0007]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid discharge apparatus that can accurately detect an abnormality occurring in a discharge path or a discharge nozzle with a relatively simple configuration. .
[0008]
[Means for Solving the Problems]
The liquid discharge device according to claim 1 of the present invention is an air-driven backward-acting pump that pumps up liquid from a liquid supply source and pumps the liquid by reciprocating operation of a piston provided in a cylinder, and discharges liquid discharged from the pump. A discharge nozzle for discharging, an operation signal output unit that outputs a signal corresponding to the reciprocating operation of the piston, a standard time storage unit that stores a standard reciprocating time of the piston, and an output signal of the operation signal output unit. An abnormality diagnosis means is provided for detecting a reciprocating time required for the piston to make one reciprocation, and performing abnormality diagnosis by comparing the detected reciprocating time with the standard reciprocating time.
[0009]
If leakage or clogging occurs in the discharge path or the discharge nozzle, the discharge flow rate of the pump changes, and the reciprocating time of the piston changes. According to the above configuration, the abnormality diagnosis means detects the time required for the piston to actually make one reciprocation based on the output signal of the operation signal output means, and compares the detected reciprocation time with the standard reciprocation time. Is used to diagnose the occurrence of an abnormality.
[0010]
When an on-off valve for opening and closing the discharge nozzle and on-off detection means for detecting the on-off operation of the on-off valve is provided, the time during which the on-off valve is opened while the piston makes one reciprocating operation is detected as the reciprocating time. Good (invention of claim 2). This makes it possible to detect the time during which the piston was actually operating, in other words, the time during which the pump actually performed the liquid discharging operation.
[0011]
The abnormality diagnosis means may diagnose that an abnormality has occurred when the difference between the detected round-trip time and the standard round-trip time is a predetermined value or more consecutively a plurality of times (the invention of claim 3). According to such a configuration, occurrence of an abnormal state can be diagnosed accurately and accurately.
[0012]
In addition, the liquid discharge device according to claim 4 of the present invention includes a plurality of discharge nozzles for discharging liquid pumped from the backward-acting pump, a plurality of on-off valves for opening and closing each of the discharge nozzles, A plurality of open / close detecting means for detecting each open / close operation, a standard time storage means for storing a standard reciprocating time of the piston when all combinations of one or more of the open / close valves are in an open state, A standard flow rate for calculating and storing a standard discharge flow rate per unit time of the pump when all combinations of one or more of the plurality of on-off valves are open based on a standard reciprocating time and a capacity of the cylinder. Storage means, operation signal output means for outputting a signal corresponding to the reciprocating operation of the piston, and the time during which the on-off valve is opened during the reciprocating operation of the piston and the opening time From the standard discharge flow rate corresponding to the combination of the on-off valves in the state, the discharge amount of the pump during one reciprocation of the piston is calculated, and the abnormality diagnosis is performed by comparing the discharge amount and the capacity of the pump. It is characterized by comprising abnormality diagnosis means for performing.
[0013]
According to the above configuration, the abnormality diagnosing means performs the abnormality diagnosis by comparing the displacement of the pump and the capacity of the cylinder during one reciprocation of the piston. Therefore, even if a plurality of discharge nozzles are opened and closed during one reciprocation of the piston, abnormality diagnosis can be performed. Moreover, the standard discharge flow rate is calculated from the standard reciprocating time of the piston and the capacity of the cylinder, and the discharge amount is calculated from the output signals of the operation signal output means and the open / close detection means and the standard discharge flow rate. For this reason, it is not necessary to install a flow meter, and abnormality diagnosis can be performed with a simple and inexpensive configuration.
[0014]
The abnormality diagnosis means may diagnose that an abnormality has occurred when the difference between the total discharge amount and the capacity of the pump is a predetermined value or more continuously plural times (the invention of claim 5). According to such a configuration, occurrence of an abnormal state can be diagnosed accurately and accurately.
[0015]
It is also a good configuration to include a standard time setting means for setting a standard round trip time based on the output signal of the operation signal output means (the invention of claim 6). According to the above configuration, for example, the standard reciprocating time is automatically set by, for example, driving the pump for a short time before starting the operation to output the operation signal.
[0016]
According to a seventh aspect of the present invention, there is provided a liquid discharging apparatus, wherein an air pressure adjusting means for adjusting the pressure of the pressurized air is provided in an air supply path for supplying pressurized air for driving to a pump, and the discharge pressure of the pump is substantially reduced. Control means for controlling the air pressure adjusting means so as to be constant.
[0017]
If the discharge pressure of the pump fluctuates, the reciprocating time and discharge flow rate of the piston fluctuate, so that accurate abnormality diagnosis cannot be performed. According to the above configuration, the discharge pressure of the pump can be kept substantially constant, so that the occurrence of an abnormal state can be diagnosed more accurately.
[0018]
In a case where the liquid discharging apparatus according to the eighth aspect of the present invention includes a plurality of backward-acting pumps, each of the plurality of air supply paths independently supplies pressurized air for driving to the plurality of pumps. A plurality of air pressure adjusting means for adjusting the pressure of the pressurized air are provided, and a control means for controlling the air pressure adjusting means so that the discharge pressure of the pump becomes substantially the same is provided.
[0019]
According to the above configuration, even when a plurality of backward-acting pumps are provided, the occurrence of an abnormal state can be accurately diagnosed.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment in which the present invention is applied to a high-pressure cleaning device as a liquid ejection device will be described with reference to FIGS. FIG. 1 shows the entire configuration of the high-pressure cleaning device 1. In FIG. 1, a solid line indicates a washing water path, a broken line indicates an air path, and a two-dot chain line indicates an electric control path.
[0021]
The high-pressure cleaning device 1 is mainly configured by a pump 3 for pumping and pumping cleaning water from a cleaning water tank 2 as a liquid supply source. The pressure pump 3 includes an air motor 4 and a plunger pump 5 connected to the air motor 4.
[0022]
The air motor 4 is configured such that a piston rod 8 moves up and down by pressurized air supplied from a pressurized air supply source 6 via an air supply hose 7. The plunger pump 5 includes a cylinder 9, a plunger 10 passing through the cylinder 9, and a piston 11 provided at a lower end of the plunger 10 located in the cylinder 9. The upper end of the plunger 10 is connected to a piston rod 8 and moves up and down integrally with the piston rod 8.
[0023]
A suction port 9 a is provided at a lower portion of the cylinder 9. The washing water tank 2 is connected to the suction port 9a via a water supply hose 12. A discharge port 9b to which a high-pressure hose 13 is connected is provided on a side surface of the cylinder 9. A discharge nozzle 15 is connected to an end of the high-pressure hose 13 via an on-off valve 14.
[0024]
The on-off valve 14 is of a pneumatic drive type, and pressurized air for driving is supplied from a not-shown pressurized air supply source through an air supply hose 16. The air supply hose 16 is provided with a pneumatic switch 17 that is turned on when pressurized air flows through the air supply hose 16.
[0025]
The on-off valve 14, the discharge nozzle 15, and the air supply hose 16 constitute a discharge unit 18 as discharge means. Although not shown in detail, in the present embodiment, the tip of the high-pressure hose 13 is branched into four branches, and the discharge unit 18 is connected to each branch. An air pressure switch 17 is provided on the air supply hose 16 of each discharge unit 18.
[0026]
In the plunger pump 5, the washing water in the cylinder 9 is pressurized and discharged from the discharge port 9 b during the descending stroke of the plunger 10 accompanying the advancement of the piston rod 8, and the plunger 10 rises as the piston rod 8 retreats. In the stroke, the cleaning water in the cylinder 9 is pressurized and discharged from the discharge port 9b, and the cleaning water in the cleaning water tank 13 is sucked from the suction port 9a. That is, the pressure feed pump 3 (plunger pump 5) is configured as a backward-acting pump that discharges the washing water in both the upward and downward strokes of the plunger 10.
[0027]
The water supply hose 12 is provided with a ball cock 19, a pneumatic automatic ball valve 20, and an accumulator 21. The high-pressure hose 13 is provided with an accumulator 22, first and second filter devices 23 and 24, and a ball cock 25. The first filter device 23 is for removing relatively large dust generated by abrasion of a friction component provided in the cleaning water passage, for example, a packing or an O-ring (both not shown) in the cylinder 9. , Filter 26, analog output pressure gauge 27, and ball cock 28.
[0028]
The second filter device 24 is for removing small dust such as metal dust that cannot be removed by the filter 26, and includes a ceramic filter 29 and pressure sensors 30 and 31 for detecting pressures around the filter 29. Have been.
[0029]
The air motor 4 is provided with a pneumatic switch 32 (corresponding to an operation signal output means) for outputting a signal corresponding to the reciprocating operation of the piston rod 8. The pneumatic switch 32 is configured to be turned on during the downward stroke of the piston rod 8 and turned off during the upward stroke.
[0030]
The air supply hose 7 is provided with a safety valve 33, a pressure gauge 34, an electropneumatic regulator 35, and a ball cock 36. An air supply hose 37 for supplying pressurized air for driving to the ball valve 20 is connected between the electropneumatic regulator 35 and the ball cock 36 in the air supply hose 7. The air supply hose 37 is provided with an air regulator 38 and a solenoid valve 39.
[0031]
The controller 40 is mainly configured by a microcomputer, and includes a RAM as a volatile memory and an EEPROM (both not shown) as a rewritable nonvolatile memory as storage means. The EEPROM stores a control program executed by the microcomputer and standard values used for abnormality diagnosis described later.
[0032]
The controller 40 is supplied with output signals of the pneumatic switches 17 and 32 and the pressure sensors 30 and 31. Further, the controller 40 controls the driving of the electropneumatic regulator 35, the solenoid valve 39, and the like. Further, various operation switches and indicators (not shown) are connected to the controller 40.
[0033]
The operation switch and the indicator are provided on an operation panel (not shown) of the cleaning device 1. The operation switch includes an ON / OFF switch for operating and stopping the pump 3, a switch for performing various settings, and a switch for switching an operation mode. The display is composed of a liquid crystal display (LCD), an indicator light (LED), and the like for displaying the setting contents and operation status of the cleaning device 1 and for reporting an abnormality.
[0034]
Next, the operation of the present embodiment will be described with reference to FIG.
After the pressure of the driving air for the pressure feed pump 3 (hereinafter referred to as primary air pressure) is set by operating the operation switch, when the start of the cleaning operation is instructed, the driving air is supplied from the pressurized air supply source 6 to the air motor 4. Supplied to
[0035]
Then, when the operator opens the on-off valve 14 of each discharge nozzle 15, the plunger 10 moves up and down together with the piston rod 8 repeatedly. As a result, the cleaning water is pumped from the cleaning water tank 2 by the plunger pump 5 and discharged from the discharge nozzle 15 through the high-pressure hose 13.
[0036]
At this time, the controller 40 controls the electropneumatic regulator 35 so that the set primary air pressure is set several seconds after the start of the work is instructed. This prevents the filters 26 and 29 from being damaged due to sudden pressurization. Further, the pressure pump 3 discharges the cleaning water at a secondary water pressure (discharge pressure) that is increased in proportion to the primary air pressure. The set primary air pressure and the pressure detected by the pressure sensor 31 are displayed on a display (LCD). The pressure detected by the pressure sensor 31 corresponds to the secondary water pressure of the pressure pump 3.
[0037]
Further, the controller 40 monitors the clogged state of the ceramic filter 29 based on the output signals of the pressure sensors 30 and 31. Thereby, the operator can know the replacement time of the ceramic filter 29 and the like.
[0038]
Further, the controller 40 detects the discharge nozzle 15 in the open state based on the output signal of the pneumatic switch 17. Further, the reciprocating time of the piston rod 8 and the rising / falling step time ratio are detected based on the output signal of the pneumatic switch 32. Then, the detected reciprocating time, the ascending / descending process time ratio is compared with the pre-stored standard reciprocating time, standard ascending / descending process time ratio, or the capacity counter is set according to the combination of the discharge nozzle 15 in the open state. An abnormality diagnosis of the cleaning device 1 is performed based on the result.
[0039]
The round-trip time corresponds to the time from the ON signal edge of the pneumatic switch 17 to the next ON signal edge, and the rise / fall process time ratio is the time from the ON signal edge to the OFF signal edge of the pneumatic switch 17 and the OFF signal. This corresponds to the time from the edge to the next ON signal edge.
[0040]
These values differ depending on the combination of the ejection nozzles 15 in the open state. Therefore, the operator sets the standard values of the reciprocating time and the ascent / descent process time ratio in the open state for all combinations of any one to four of the four discharge nozzles 15. For example, the controller 40 automatically sets and stores the information by, for example, opening the four discharge nozzles 15 sequentially and reciprocating the piston rod 8 of the pressure feed pump 3 several times before starting the cleaning operation.
[0041]
Note that the standard value differs depending on conditions such as a set value of the primary air pressure, a diameter of the discharge nozzle 15, and the like. Therefore, even when the primary air pressure is set or the discharge nozzle 15 is changed even during the work, it is necessary to update the standard value.
[0042]
Further, the controller 40 sets and stores a standard discharge flow rate per unit time (for example, 10 msec) of the pressure feed pump 3 based on the standard reciprocation time. The standard discharge flow rate is calculated from the standard reciprocating time and the capacity of the cylinder 9.
[0043]
If the number of the discharge nozzles 15 in the open state does not change during one reciprocation of the piston rod 8, the controller 40 determines the reciprocating time of the pump 3 detected from the output signal of the pneumatic switch 32 and the pneumatic pressure. A comparison is made between the standard reciprocating time corresponding to the combination of the ejection nozzles 15 that are detected to be in the open state based on the output signal of the switch 17. If the difference between the two exceeds a predetermined allowable value N consecutive times (N is an integer of 2 or more), it is determined that an abnormality such as clogging or leakage has occurred in the discharge path or the discharge nozzle 15 and that is reported. .
[0044]
If the number of the discharge nozzles 15 in the open state does not change during one reciprocating operation of the air motor 4, the controller 40 calculates the ratio of the ascending / descending process time detected from the output signal of the pneumatic switch 32 to the idle time. A comparison is made with a standard time ratio corresponding to the combination of the ejection nozzles 15 detected to be in the open state based on the output signal of the pressure switch 17. If the difference between the two exceeds a predetermined allowable value for M consecutive times (M is an integer of 2 or more), it is determined that an abnormality has occurred in the valve in the discharge path, and the fact is notified.
[0045]
On the other hand, when the discharge nozzle 15 is randomly opened and closed while the air motor 4 performs one reciprocating operation, the controller 40 performs an abnormality diagnosis using the capacity counter. The controller 40 sets the capacity counter to the capacity of the cylinder 9 at the ON signal edge of the pneumatic switch 32. Then, the standard discharge flow rate corresponding to the combination of the discharge nozzles 15 in the open state is sequentially subtracted from the capacity counter for each unit time, and the value of the capacity counter at the next ON signal edge of the pneumatic switch 32 is compared with the allowable value. I do.
[0046]
FIG. 2 is a diagram showing the output signal (a) of the pneumatic switch 32, the output signals (b) and (c) of the pneumatic switch 17, and the capacity counter (d) side by side. FIG. 2 shows output signals of the pneumatic switches 17 of the two discharge nozzles A and B for convenience. The capacity of the cylinder 9 is set to P (ml).
[0047]
As shown in FIG. 2, when the discharge nozzle 15 is opened and closed while the piston rod 8 makes one reciprocating operation, the reciprocating time is extended or shortened according to the number of the discharge nozzles in the open state. For this reason, the round trip time detected based on the output signal of the pneumatic switch 32 cannot be simply compared with the standard round trip time described above.
[0048]
Therefore, for example, in the period T1 in FIG. 2D, the capacity counter is subtracted by the standard discharge flow rate when the discharge nozzle A is in the open state, and in the period T3, the standard flow rate is reduced by the standard flow rate when the discharge nozzle B is in the open state Subtract the capacity counter. In the period T4, the capacity counter is decremented by the standard flow rate when both of the discharge nozzles A and B are in the open state. Note that, during the period T2, since the discharge nozzles A and B are both in the closed state, the capacity counter does not change.
[0049]
After the controller 40 starts subtracting the capacity counter, the absolute value of the capacity counter at the next ON signal edge of the pneumatic switch 32 continuously exceeds the predetermined value L times (L is an integer of 2 or more). At this time, it is determined that an abnormality has occurred, and the fact is notified. The abnormality of the capacity counter can diagnose the occurrence of clogging or leakage of the ejection path or the ejection nozzle 15 in the same manner as the abnormality of the round trip time.
In addition, the allowable value and the number of determinations (N, M, L) used for the abnormality determination can be appropriately set by an operator.
[0050]
As described above, according to the present embodiment, the controller 40 is configured to diagnose the occurrence of an abnormality in the high-pressure hose 13 and the discharge nozzle 15 based on the output signals of the pneumatic switches 17 and 32. Therefore, unlike the conventional apparatus in which a large number of magnetic sensors are provided to perform the abnormality diagnosis, the abnormality diagnosis can be performed with a relatively simple configuration.
[0051]
Further, when the number of the discharge nozzles 15 in the open state changes during one reciprocation of the piston rod 8, the controller 40 sets the discharge path based on the standard discharge flow rate and the capacity counter corresponding to the open / close valve 14 in the open state. Diagnosis of leaks and clogs is now performed. Therefore, even when the on-off valve 14 is frequently opened and closed, the abnormality diagnosis can be performed with high accuracy.
[0052]
In this case, the standard discharge flow rate is calculated from the standard reciprocating time corresponding to the open / close valve 14 and the capacity of the cylinder 9. Therefore, it is not necessary to provide a flow meter for abnormality diagnosis, and a simple and inexpensive configuration can be achieved.
[0053]
The controller 40 diagnoses that an abnormality has occurred when the difference between the round-trip time and the standard round-trip time, the difference between the rise / fall process time ratio and the standard time ratio, and the absolute value of the capacity counter exceeds a predetermined value a plurality of times. . This is because the signal of the pneumatic switch 17 and the signal of the pneumatic switch 32 do not match, for example, when the high-pressure hose 13 is long and the opening and closing operation of the on-off valve 14 and the reciprocating operation of the piston rod 8 are delayed. According to the above configuration, it is possible to prevent as much as possible from erroneously diagnosing a change in the reciprocating time or the like caused by the opening / closing of the on-off valve 14 as an abnormality.
[0054]
The controller 40 controls the electropneumatic regulator 35 to keep the primary air pressure of the pump 3 and thus the secondary water pressure substantially constant. Therefore, the ejection operation is stabilized and the accuracy of the abnormality diagnosis is improved.
[0055]
FIG. 3 shows a second embodiment of the present invention, and different points from the first embodiment will be described. The same parts as those in the first embodiment are denoted by the same reference numerals. That is, the high-pressure cleaning device 51 according to the present embodiment includes a plurality of, for example, three pumps 3 and three discharge units 52 connected to the pumps 3 via the high-pressure hose 13.
[0056]
Pressurized air is supplied from a common pressurized air supply source 6 to an air motor 4 of the pressure feed pump 3 via an air supply hose 7. Further, cleaning water is supplied to the cylinder 9 of the pressure pump 3 from the common cleaning water tank 2 via a water supply hose 12.
[0057]
The discharge section 52 includes the on-off valve 14 and a plurality of, for example, four discharge nozzles 15 connected to the on-off valve 14. The cleaning device 51 according to the present embodiment is configured such that the cleaning liquid is simultaneously discharged from the four discharge nozzles 15 by opening the on-off valve 14. The configuration other than the above is substantially the same as that of the first embodiment.
[0058]
In the above configuration, the controller 40 controls the electropneumatic regulator 35 so that the primary air pressures of all the pumps 3 have substantially the same value. Therefore, even in a configuration including a plurality of pressure pumps 3, the primary air pressure, and thus the secondary water pressure, can be made substantially the same.
[0059]
Therefore, the controller 40 can accurately detect which of the high-pressure hose 13 and the discharge nozzle 15 has an abnormality based on the output signals of the pneumatic switches 17 and 32.
[0060]
Note that the present invention is not limited to the above-described embodiment, and for example, the following modifications are possible.
The abnormality diagnosis may be performed based on the capacity counter even when the number of the discharge nozzles 15 in the open state does not change while the piston rod 8 makes one reciprocating operation. The standard value used for the abnormality diagnosis may be set by an operator.
[0061]
In the pressure-feed pump shown in the above embodiment, the secondary water pressure is also increased in proportion to the primary air pressure due to its structure. That is, if the primary air pressure corresponding to the secondary water pressure is set and the electropneumatic regulator 35 is controlled so as to have the set primary air pressure, a desired secondary water pressure can be obtained. However, the secondary hydraulic pressure may be detected based on the output signal of the pressure sensor 30 or 31, and the electropneumatic regulator 35 may be feedback-controlled in accordance with the detected secondary hydraulic pressure. According to such a configuration, the discharge pressure of the pump can be more accurately kept constant.
[0062]
The pressure pump may be constituted by a backward-acting diaphragm pump.
The liquid pumped by the pump is not limited to washing water, but may be paint or chemical.
The open / close detecting means may be constituted by, for example, a reed switch for directly detecting the open / close operation of the open / close valve. Further, the opening / closing valve may be constituted by an electromagnetic valve, and the opening / closing state may be detected based on a drive signal of the electromagnetic valve.
[0063]
【The invention's effect】
As is apparent from the above description, the liquid ejection device of the present invention is configured to perform abnormality diagnosis based on a signal corresponding to the reciprocating operation of the piston of the backward-acting pump output by the operation signal output means, so that it is relatively simple. With such a configuration, the occurrence of an abnormality can be detected with high accuracy.
[Brief description of the drawings]
FIG. 1 is a diagram showing the entire configuration of a high-pressure cleaning device according to a first embodiment of the present invention; FIG. 2 is an operation timing (a) of an air motor, opening and closing timings (b) and (c) of a discharge valve, and a capacity counter. FIG. 3 shows (d) FIG. 3 corresponds to FIG. 1 showing a second embodiment of the present invention.
1, 51 is a high-pressure washing device (liquid discharge device), 3 is a pressure feed pump (return type pump), 8 is a piston rod (piston), 9 is a cylinder, 14 is an on-off valve, 15 is a discharge nozzle, and 17 is pneumatic. Switch (open / close detection means), 32 is a pneumatic switch (operation signal output means), 35 is an electropneumatic regulator (pneumatic pressure adjustment means), 40 is a controller (control means, abnormality diagnosis means, standard time storage means, standard flow rate storage means) , Time setting means).

Claims (8)

An air-driven backward-acting pump that pumps up liquid from a liquid supply source by pumping the liquid by a reciprocating operation of a piston provided in the cylinder,
A discharge nozzle for discharging the liquid pumped from the pump,
Operation signal output means for outputting a signal corresponding to the reciprocating operation of the piston,
Standard time storage means for storing a standard reciprocating time of the piston,
Abnormality diagnosis means for detecting a reciprocating time required for the piston to make one reciprocation based on an output signal of the operation signal output means and comparing the detected reciprocation time with the standard reciprocation time to perform an abnormality diagnosis. A liquid ejection device comprising: An on-off valve for opening and closing the discharge nozzle, and on-off detection means for detecting the on-off operation of the on-off valve,
2. The liquid ejection apparatus according to claim 1, wherein the abnormality diagnosis unit detects a time when the on-off valve is opened while the piston makes one reciprocating operation as a reciprocating time. The abnormality diagnosis means diagnoses that an abnormality has occurred when a difference between the standard round-trip time and the detected round-trip time is a predetermined value or more consecutively a plurality of times. Liquid ejection device. An air-driven backward-acting pump that pumps up liquid from a liquid supply source by pumping the liquid by a reciprocating operation of a piston provided in the cylinder,
A plurality of discharge nozzles for discharging the liquid pumped from the pump,
A plurality of on-off valves for opening and closing each of the discharge nozzles,
A plurality of open / close detecting means for detecting the open / close operation of each of the open / close valves,
Standard time storage means for storing a standard reciprocating time of the piston when all combinations of one or more of the on-off valves are in an open state;
A standard for calculating and storing a standard discharge flow rate per unit time of the pump when all combinations of one or more of the plurality of on-off valves are open based on the standard reciprocating time and the capacity of the cylinder. Flow rate storage means,
Operation signal output means for outputting a signal corresponding to the reciprocating operation of the piston,
Calculate the discharge amount of the pump during one reciprocation of the piston from the time when the on-off valve is opened during the reciprocation of the piston and the standard discharge flow rate corresponding to the combination of the on-off valve in the open state. And a failure diagnosis means for performing failure diagnosis by comparing the discharge amount with the capacity of the pump. 5. The liquid discharge apparatus according to claim 4, wherein the abnormality diagnosis means diagnoses that an abnormality has occurred when a difference between the total discharge amount and the capacity of the pump is a predetermined value or more continuously. The liquid ejecting apparatus according to claim 1, further comprising a standard time setting unit that sets a standard round trip time based on an output signal of the operation signal output unit. An air supply path for supplying pressurized air for driving to the pump,
Air pressure adjusting means provided in the air supply path to adjust the pressure of the pressurized air,
5. The liquid discharging apparatus according to claim 1, further comprising control means for controlling the air pressure adjusting means so that a discharge pressure of the pump becomes substantially constant. A plurality of reversing pumps,
A plurality of air supply paths for independently supplying pressurized air for driving to the plurality of pumps,
A plurality of air pressure adjusting means provided in each of the air supply paths to adjust the pressure of the pressurized air,
5. The liquid discharging apparatus according to claim 1, further comprising control means for controlling the air pressure adjusting means so that discharge pressures of the plurality of pumps become substantially the same.

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