JP2010048738A - Dispensing device and method for removing clogging in the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dispensing device capable of removing clogging with a convenient and low cost structure in dispensing operation subjected to a liquid likely to clog, and a method for removing clogging in this dispensing device. <P>SOLUTION: The dispensing device 1 for discharging a liquid 12 stored in a liquid-feeding section 10 with a discharging nozzle attached to the nozzle section 7 of a dispensing head 6, includes a main passage valve 15 and a pump mechanism 16 on a main passage 9 from the liquid-feeding section 10 through the dispensing head 6 to the liquid-feeding section 10, and includes the steps of closing the main passage valve 15 and operating the pump mechanism 16 under the state that individual passage valves provided on each discharging nozzle are open in the discharging controller 8 of the dispensing head 6, making the pressure in the individual passages with the individual passage valves opened and in the discharging nozzle attached to the individual passages a negative pressure against atmosphere, and absorbing a material clogged by the negative pressure in the main passage 9 to remove it. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a dispensing device that discharges liquid by a discharge nozzle and a clogging removal method in the dispensing device.

  In the field of biomedical research such as genomic drug discovery, there are dispensing devices for dispensing various liquids such as samples to be tested and reagents used in the test process into test containers such as microplates. Used. In the test, it is required to accurately discharge a fixed amount of liquid as needed. However, if the amount of liquid required is very small, liquid is used in the discharge nozzle used in the dispensing device and the discharge nozzle. The liquid feed flow path for feeding is used with a small diameter.

  Liquids to be dispensed include various types of liquids, such as cell buffers, suspensions containing magnetic beads used as probe carriers, and highly viscous liquids that are easy to discharge. In some cases, different properties may be discharged. When such a liquid is discharged using a discharge nozzle with a small diameter, suspended components and high-viscosity substances in the liquid stay in the discharge nozzle and the flow path, so-called “clogging” that prevents the normal flow of the liquid. Is likely to occur. For this reason, what is equipped with the washing | cleaning function of the discharge nozzle is known as a dispensing equipment used for such a use (refer patent document 1).

In the example shown in Patent Document 1, an air pump is connected to a discharge piping system for discharging a liquid so that air can be discharged from the discharge nozzle. When necessary, the discharge nozzle is placed in a liquid tank containing cleaning liquid. The liquid remaining inside the discharge nozzle is removed by performing air flushing in which air is discharged in a state where the liquid is immersed. Also, the fluid used for flushing is something other than air, such as a cleaning solution, and the clogging in the discharge nozzle and flow path is removed by the flow of the cleaning solution, or the discharge piping system is connected to a vacuum circuit and the inside is evacuated. Various prior arts exist, such as a method for removing clogging. Furthermore, a method in which the discharge nozzle is removed from the dispensing head when clogging occurs and the operator manually cleans it is widely used as a countermeasure against clogging.
JP-A-7-103986

  However, the prior art including the example shown in Patent Document 1 has the following difficulties. First, both the method of flushing the inside of the discharge piping system with air and fluid and the method of removing clogging by vacuum suction of the inside require that a dedicated circuit be attached to the discharge piping system. This complicates the equipment size and costs. Moreover, in the method of removing the discharge nozzle and performing cleaning, it is necessary to repeatedly perform a complicated and troublesome work every time clogging occurs frequently, and it is inevitable that the efficiency of the test work is reduced. As described above, the conventional dispensing apparatus has a problem that it is difficult to remove clogging with a simple and low-cost configuration in a dispensing operation for a liquid that easily causes clogging.

  Accordingly, the present invention provides a dispensing apparatus capable of removing clogging with a simple and low-cost configuration and a clogging removing method in this dispensing apparatus in a dispensing operation for a liquid that easily causes clogging. The purpose is to provide.

  The dispensing device of the present invention is a dispensing device that discharges the liquid stored in the liquid supply unit by a discharge nozzle attached to the dispensing head, and is based on the liquid supply unit and passes through the dispensing head. A return flow path that forms a circulation channel that returns to the liquid supply section, a suction opening that is one open end is disposed in the liquid stored in the liquid supply section, and the other open end is A main flow path disposed at a position higher than the liquid level of the liquid in the liquid supply section, and a plurality of individual flow paths that are branched from the main flow path and in which the discharge nozzles are respectively attached to the end portions And a pressurizing device that discharges the liquid from the discharge nozzle through the main flow path and the individual flow paths by pressurizing the liquid supply unit, and the individual flow paths provided for each of the individual flow paths. Individual flow valve that opens and closes individually, and front A main flow path valve that opens and closes the main flow path provided between a branch section where the individual flow path branches in the main flow path and the suction opening section, and between the branch section and the return opening section in the main flow path. A pump mechanism for returning the liquid in the main flow path to the liquid supply section through the return opening, and a controller for controlling the pressurizing device, the pump mechanism, the individual flow path valve, and the main flow path valve. A negative pressure is generated in the main flow path by operating the pump mechanism with the main flow path valve closed and the individual flow path valve open. The inside of the individual flow path in which the valve is opened and the discharge nozzle attached to the individual flow path are sucked in the direction opposite to the liquid discharge direction.

  The clogging removal method in the dispensing apparatus of the present invention forms a circulation flow path that returns to the liquid supply section from the liquid supply section as a base point through a dispensing head equipped with a discharge nozzle. A suction opening which is one opening end is disposed in the stored liquid, and a return opening which is the other opening end is disposed at a position higher than the liquid level of the liquid in the liquid supply unit. A main flow path, a plurality of individual flow paths that are branched from the main flow path, and each of which has the discharge nozzle attached to an end thereof, and the inside of the liquid supply section is pressurized to pass through the main flow path and the individual flow paths. A pressure device for discharging the liquid from the discharge nozzle, an individual flow valve provided for each of the individual flow paths to individually open and close these individual flow paths, and the individual flow path branching in the main flow path Branching section and the suction opening A main flow path valve that opens and closes the main flow path, and is provided between the branching section and the return opening in the main flow path to allow the liquid in the main flow path to return to the return opening. And a clogging generated in the discharge nozzle and / or the individual flow path in the dispensing device that discharges the liquid stored in the liquid supply portion by the discharge nozzle. A method for removing clogging in a dispensing apparatus for removing a negative pressure in the main flow path by operating the pump mechanism with the main flow path valve closed and the individual flow path valve open. The clogged portion is sucked in the direction opposite to the liquid discharge direction in the individual flow path in which the individual flow path valve is opened by this negative pressure and in the discharge nozzle attached to the individual flow path. The causing material removal by suction into the main channel.

  According to the present invention, by operating the pump mechanism with the main channel valve closed and the individual channel valve opened, the individual channel valve is opened and the individual channel is opened. A simple and low-cost configuration by adopting a method in which the pressure in the discharge nozzle attached to the cylinder is negative with respect to atmospheric pressure, and the negative pressure causes suction of substances that cause clogging into the main flow path. Can remove clogging.

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating the configuration of a dispensing device according to one embodiment of the present invention, FIG. 2 is a diagram illustrating the configuration of a dispensing head in the dispensing device according to one embodiment of the present invention, and FIG. 3 is a diagram illustrating one embodiment of the present invention. 4 is a block diagram showing the configuration of the control system of the dispensing apparatus in the form of FIG. 4, FIG. 4 is a flowchart showing the liquid discharge processing by the dispensing apparatus of one embodiment of the present invention, and FIG. 5 is one embodiment of the present invention. FIG. 6 is a flowchart of liquid discharge state determination in liquid discharge processing by the dispensing device.
These are the flowcharts of the clogging removal operation | movement in the liquid discharge process by the dispensing apparatus of one embodiment of this invention.

  First, the configuration of the dispensing apparatus 1 will be described with reference to FIG. In the biomedical research field such as genome drug discovery, the dispensing apparatus 1 divides and discharges various liquids such as a sample to be tested and a reagent used in a test process into a test container such as a microplate. It is used for this purpose. In the present embodiment, the liquid stored in the liquid supply unit is discharged by a discharge nozzle attached to the dispensing head.

  In FIG. 1, the positioning device 2 includes a container mounting table 3 that is movable in the horizontal direction. A microplate 4 that is a test container is placed on the container placement table 3, and the microplate 4 is provided with a plurality of wells 4 a that store liquid. Further, a waste liquid recovery unit 5 is disposed on the upper surface of the container mounting table 3. A dispensing head 6 is disposed above the container mounting table 3 so as to be movable up and down by a head lifting mechanism (not shown).

  On the lower surface of the dispensing head 6, there is provided a nozzle portion 7 having a configuration in which a plurality (here, 5) of discharge nozzles (see discharge nozzles 71 to 75 shown in FIG. 2) protrude downward. The dispensing head 6 is a discharge control unit including a plurality of individual flow path valves (see the individual flow path valves 81 to 85 shown in FIG. 2) for individually turning on and off the liquid discharge from the discharge nozzles 71 to 75. 8 is built-in. By controlling the discharge control unit 8, each of the discharge nozzles 71 to 75 of the nozzle unit 7 discharges a predetermined amount of liquid.

  By driving the positioning device 2, the container mounting table 3 moves horizontally (arrow a), whereby each well 4 a of the microplate 4 is aligned with the nozzle portion 7 of the dispensing head 6. By lowering the dispensing head 6 in this state, each of the discharge nozzles 71 to 75 of the nozzle portion 7 is positioned in each well 4a. By discharging liquid from the discharge nozzles 71 to 75 in this state, a predetermined amount of liquid is dispensed to each well 4 a of the microplate 4.

  The waste liquid recovery unit 5 recovers the liquid that is discarded without being discharged into the well 4 a from among the liquids discharged from the nozzle unit 7. That is, the positioning device 2 is driven to move the container mounting table 3, the waste liquid recovery unit 5 is aligned with the discharge nozzles 71 to 75 to be recovered, and liquid is discharged from the discharge nozzles. The liquid to be discarded can be recovered by the waste liquid recovery unit 5.

  The liquid discharged from the nozzle part 7 of the dispensing head 6 is supplied via the main flow path 9 by the liquid supply part 10. The main flow path 9 forms a circulation flow path that returns to the liquid supply section 10 via the dispensing head 6 with the liquid supply section 10 as a base point. The liquid supply unit 10 includes a liquid supply bottle 11 that stores the liquid 12 to be dispensed, and a suction opening 9 a that is one open end of the main flow path 9 is provided in the liquid supply bottle 11 of the liquid supply unit 10. It arrange | positions so that it may be located in the stored liquid 12. FIG. In addition, the return opening 9 b which is the other opening end is disposed at a position higher than the liquid level 12 a of the liquid 12 in the liquid supply bottle 11.

  The liquid 12 to be dispensed is a sample or a reagent to be tested. Examples of the liquid 12 include a cell buffer, a suspension containing magnetic beads used as a probe carrier, a viscous material having a high viscosity, and the like. Is included. Unlike a general liquid, such a liquid has a characteristic that clogging in a flow path is likely to occur due to a change in properties such as an increase in viscosity or aggregation over time. In the dispensing device 1 shown in the present embodiment, even when the liquid 12 having such a characteristic that clogging is likely to occur is targeted, a problem due to clogging is prevented by the configuration described later. I have to.

  The liquid supply unit 10 includes a pressurizing device 13 for pressurizing the inside of the liquid supply bottle 11. By operating the pressurizing device 13, the liquid 12 in the liquid supply bottle 11 is pressurized. By this pressurization, the liquid 12 is pushed into the main channel 9 from the suction opening 9a, and is pumped through the main channel 9 toward the dispensing head 6 (arrow b). Of the liquid 12 pumped in the main flow path 9, the undischarged liquid 12 that has not been discharged from the dispensing head 6 returns to the liquid supply unit 10 via the main flow path 9.

  Next, the configuration of the dispensing head 6 will be described with reference to FIG. The main flow path 9 introduced into the dispensing head 6 is connected to the branching section 90 in the dispensing head 6, and the liquid 12 is sent from the supply direction (arrow d direction) to the branching section 90 via the main flow path 9. Be paid. A plurality of individual channels 91 to 95 are branched from the branching unit 90. That is, the individual flow paths 91 to 95 are configured to be branched from the main flow path 9. Discharge nozzles 71 to 75 are detachably attached to the ends of the individual flow paths 91 to 95, respectively.

  The individual channels 91 to 95 include a first individual channel valve 81, a second individual channel valve 82, and a third individual channel that individually open and close these individual channels for each individual channel. A flow path valve 83, a fourth individual flow path valve 84, and a fifth individual flow path valve 85 are provided. In the following description, these individual flow valves are referred to as individual flow valve # 1, individual flow valve # 2, individual flow valve # 3, individual flow valve # 4, and individual flow valve # 5. (Refer to FIG. 3). Each of the individual flow valve # 1 to the individual flow valve # 5 has a structure that is electromagnetically driven by a solenoid valve, and can open and close at a high speed.

  By pressurizing the inside of the liquid supply bottle 11 by the pressurizing device 13, the liquid 12 is sent in the discharge direction (arrow f direction) via the main flow path 9 and the individual flow paths 91 to 95, and the discharge nozzle 71. -It discharges from the lower end part of the discharge nozzle 75. The discharge nozzles 71 to 75 are thin nozzles having a minimum inner diameter of about 0.2 mm, and discharge the liquid 12 with a minute discharge amount in the range of 0.1 μl to 50 μl. In this liquid discharge operation, the individual flow path valve # 1 to the individual flow path valve # 5 are individually controlled to open and close, thereby individually controlling the discharge timing and the discharge amount of the liquid 12 from the discharge nozzles 71 to 75. be able to. The discharge amount adjustment is performed by controlling the opening time of the individual flow path valve # 1 to the individual flow path valve # 5 and the pressurization pressure by the pressurization device 13. Of the liquid 12 supplied through the main flow path 9, the liquid 12 that has not been discharged from the discharge nozzles 71 to 75 is sent through the main flow path 9 in the return direction (arrow e direction).

  In the main flow path 9, a flow rate sensor 14 and a main flow path valve 15 are provided in a path from the liquid supply unit 10 to the dispensing head 6. The flow rate sensor 14 measures the flow rate of the liquid 12 fed toward the dispensing head 6 in the main flow path 9. The main flow path valve 15 is a two-port open / close valve, and is provided between the branch portion 90 where the individual flow paths 91 to 95 branch in the main flow path 9 and the suction opening 9a. 9 has a function of opening and closing. By closing the main flow path valve 15, the path from the liquid supply unit 10 to the dispensing head 6 is blocked.

A pump mechanism 16 is interposed in the middle of a path along which the main flow path 9 returns from the dispensing head 6 to the liquid supply unit 10. The main flow path 9 is a tube made of a flexible material, and a peristaltic pump is used for the pump mechanism 16. The peristaltic pump has a function of feeding the liquid 12 inside the tube in a certain direction from the dispensing head 6 to the liquid supply unit 10 by exerting a squeezing action in one direction on the tube. That is, by operating the pump mechanism 16, the liquid 12 in the main flow path 9 is sent in a direction to return to the liquid supply unit 10 (arrow c) and returned to the liquid supply bottle 11. That is, the pump mechanism 16 is provided between the branching portion 90 and the return opening 9b in the main channel 9, and has a function of returning the liquid 12 in the main channel 9 to the liquid supply unit 10 through the return opening 9b. Have. By adopting such a configuration, the liquid 12 can always be circulated in the main flow path 9. Therefore, even when the liquid 12 having the characteristic that clogging is likely to occur is targeted, the liquid 12 does not stay in the main flow path 9, thereby preventing problems due to the liquid 12 stagnation such as clogging. Can do.

  Next, the configuration of the control system will be described with reference to FIG. The measurement result of the flow sensor 14 is fed back to the control unit 20. The control unit 20 controls the opening / closing operations of the individual flow valve # 1 to the individual flow valve # 5 constituting the discharge control unit 8, the opening / closing operation of the main flow valve 15 and the operation of the pump mechanism 16. Further, the control unit 20 controls the positioning operation of the microplate 4 by the positioning device 2 and the pressurizing operation in the liquid supply bottle 11 by the pressurizing device 13. Based on the measurement result of the flow sensor 14, the control unit 20 controls the pressurizing device 13, whereby the flow rate of the liquid 12 supplied to the dispensing head 6 through the main flow path 9 is appropriately controlled. Further, the control unit 20 controls the opening time of the individual flow path valve # 1 to the individual flow path valve # 2, whereby the discharge amount of the liquid 12 from the discharge nozzle 71 to the discharge nozzle 75 is controlled.

  Next, with reference to FIG. 4, the liquid discharge operation performed by the dispensing apparatus 1 executing the liquid discharge program will be described. First, it is determined whether or not the liquid in the nozzle needs to be discarded (ST1). In-nozzle liquid disposal requires execution of so-called “discarding” in which the liquid 12 existing in the ejection nozzles 71 to 75 is discarded in advance prior to the ejection of the liquid to the microplate 4 to be dispensed. Whether or not. This determination is made by an operator who operates the dispensing apparatus 1 and performing an operation input to that effect on the control unit 20.

  If it is determined that it is necessary, a liquid disposal operation is executed (ST2). In this liquid disposal operation, the positioning device 2 is driven to sequentially position the waste liquid collection unit 5 below the discharge nozzles 71 to 75. Next, the individual flow path valve # 1 to the individual flow path valve # 5 are opened, and the liquid 12 to be discarded is discharged from the discharge nozzles 71 to 75 into the waste liquid collection unit 5. If it is determined that it is unnecessary in (ST1), the process proceeds to the next step without executing (ST2).

  In the next step, the pump mechanism 16 is stopped prior to the discharge operation of the liquid 12 (ST3). Thereby, the circulation of the liquid 12 in the main flow path 9 is interrupted. Next, the container is positioned for the top well (ST4). That is, the container mounting table 3 is driven to move the microplate 4, and the microplate 4 is positioned with respect to the dispensing head 6 with the leading well 4 a as a reference. As a result, the plurality of wells 4 a of the microplate 4 are positioned below the discharge nozzles 71 to 75.

  Next, in a state where the dispensing head 6 is lowered and the lower ends of the discharge nozzles 71 to 75 are positioned in the respective wells 4a, all the individual flow path valves # 1 to # 5 are opened. (ST5). Thereby, the liquid 12 is discharged from the discharge nozzles 71 to 75 to each target well 4a. At this time, the flow rate is read by the flow rate sensor 14 (ST6), and after confirming that normal liquid supply is performed, all the individual flow path valves # 1 to # 5 are closed (ST7). ). Thereafter, the presence / absence of the next well 4a to be dispensed is determined (ST8). If the next well 4a is present, the container positioning for positioning the next well 4a is performed (ST9), and thereafter, the same step is repeatedly executed by returning to (ST5). If the next well 4a is not present in (ST8), the process proceeds to the next step.

  In the next step, liquid discharge state determination is performed to determine whether or not the discharge amount of the actually discharged liquid 12 is normal (ST10). This process will be described with reference to FIG. Here, based on the error with respect to the set value of the output value of the measurement result obtained by the flow sensor 14 (a reference value preset as an appropriate value), it is determined whether or not it is normal. That is, the absolute value of the difference between the output value and the set value is divided by the set value, and a percentage obtained by multiplying this by 100 is obtained as the error E (ST20). Next, the obtained error E is compared with an allowable value Tc indicating a predetermined allowable range (ST21). Here, if the error E does not exceed the allowable value Tc, it is determined to be normal (ST22), and if the error E exceeds the allowable value Tc, it is determined to be abnormal (ST23).

  When returning to the main flow, whether or not the next clogging removal operation (ST12) is necessary is determined based on the determination results of (ST22) and (ST23) (ST11). That is, if it is normal, the liquid ejection operation is terminated as it is, and if it is abnormal, the clogging removal operation (ST12) described below is executed. This clogging removing operation is performed for the purpose of removing foreign matters remaining in the discharge nozzles 71 to 75 and the individual flow paths 91 to 95 and the aggregates of the liquid 12. Hereinafter, the details of the clogging removing operation will be described with reference to FIG.

  In the nozzle clogging removal operation, since the plurality of discharge nozzles 71 to 75 are individually operated sequentially, the counter value j is set as an index for specifying the operation processing that is sequentially executed. First, since the first discharge nozzle 71 is targeted, the counter value j is set to 1 (ST30). Thereafter, pressurization by the pressurizer 13 is stopped (ST31), and then the main flow path valve 15 is closed (ST32). In this state, the pump mechanism 16 is driven (ST33). As a result, the liquid 12 present in the main flow path 9 is sent in the return direction to the liquid supply unit 10 by the pump mechanism 16. As a result of the feeding operation of the liquid 12 in the main flow path 9 in a state where one side is closed in this way, the path from the main flow path valve 15 through the main flow path 9 to the pump mechanism 16 in the main flow path 9 is at atmospheric pressure. A lower negative pressure is generated.

  The clogging is removed by using the negative pressure generated in this way. That is, in this state, the individual flow path valve #j is opened (ST34). Here, first, the individual flow path valve # 1 is opened, so that the flow path from the discharge nozzle 71 to the branching section 90 via the individual flow path 91 is the discharge direction of the liquid 12 (arrow shown in FIG. 2). Vacuum suction is performed in the opposite direction to that shown in f). In this state, a predetermined time set as a sufficient suction time for removing clogging is awaited (ST35). As a result, a substance that causes clogging by remaining in these flow paths, that is, a foreign matter mixed in the liquid 12 or a coagulated substance that has become a high viscosity by agglomeration of the liquid 12, etc. To the main flow path 9 side, and the clogged state is eliminated. When the predetermined time has elapsed, the individual flow path valve #j (in this case, the individual flow path valve # 1) is closed (ST36).

  Thereafter, the same operation process is repeatedly executed for the remaining discharge nozzles 72 to 75. That is, in the process of sequentially executing the processes (ST34) to (ST36) for each nozzle, it is determined whether or not the count value j has reached 5 which is equal to the number of ejection nozzles (ST37). If it has not reached 5, the count value j is incremented by 1 (ST38), then the process returns to (ST34), and thereafter the same processing is repeatedly executed. If it is confirmed in (ST37) that the count value j has reached 5, the main flow path valve 15 is opened (ST39). As a result, the path from the liquid supply unit 10 to the dispensing head 6 in the main channel 9 is opened. Next, the pressurizing device 13 is driven to return to the state where the liquid supply bottle 11 is pressurized (ST40). As a result, the liquid 12 can be supplied from the liquid supply unit 10 to the dispensing head 6, and thereafter, the liquid discharge operation shown in FIG. 4 is repeatedly executed.

  That is, in the dispensing apparatus 1 shown in the present embodiment, negative pressure is generated in the main flow path 9 by operating the pump mechanism 16 with the main flow path valve 15 closed and the individual flow path valve opened. I try to let them. The negative pressure causes the individual flow path valve to be opened and the discharge nozzle attached to the individual flow path to be sucked in the direction opposite to the liquid 12 discharge direction, causing clogging. A substance to be removed is sucked into the main flow path 9 and removed.

  By adopting such a configuration, the following excellent effects are obtained as compared with the prior art. Compared to the method of flushing the inside of the discharge piping system with air or fluid, or the method of removing clogging by vacuum suction inside the discharge piping system, it is not necessary to attach a dedicated circuit to the discharge piping system. There is no increase in equipment size or cost due to the complicated equipment configuration. Compared with the method of cleaning by removing the discharge nozzle, clogging can be easily performed without the need to repeat complicated and time-consuming work every time clogging occurs frequently. Removal can be performed. That is, the configuration of the present invention makes it possible to remove clogging with a simple and low-cost configuration.

  According to the dispensing device and the clogging removal method of the dispensing device of the present invention, clogging can be removed with a simple and low-cost configuration in a dispensing operation for a liquid that easily causes clogging. It has an effect and is useful for a dispensing apparatus used in the biomedical research field.

Structure explanatory drawing of the dispensing apparatus of one embodiment of this invention Structure explanatory drawing of the dispensing head in the dispensing apparatus of one embodiment of this invention The block diagram which shows the structure of the control system of the dispensing apparatus of one embodiment of this invention The flowchart which shows the liquid discharge process by the dispensing apparatus of one embodiment of this invention Flow chart of liquid discharge state determination in liquid discharge processing by the dispensing device of one embodiment of the present invention Flow chart of clogging removal operation in liquid discharge processing by the dispensing device of one embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dispensing apparatus 4 Microplate 4a Well 6 Dispensing head 7 Nozzle part 8 Discharge control part 9 Main flow path 9a Suction opening part 9b Return opening part 10 Liquid supply part 11 Liquid supply bottle 12 Liquid 13 Pressurization apparatus 14 Flow rate sensor 15 Main flow Road valve 16 Pump mechanism 71, 72, 73, 74, 75 Discharge nozzle 81 First individual flow path valve (individual flow path valve # 1)
82 Second individual flow valve (individual flow valve # 2)
83 Third individual flow valve (individual flow valve # 3)
84 Fourth individual flow path valve (individual flow path valve # 4)
85 Fifth individual flow path valve (individual flow path valve # 5)
91, 92, 93, 94, 95 Individual flow path

Claims (3)

A dispensing device that discharges liquid stored in a liquid supply unit by means of a discharge nozzle attached to a dispensing head,
A suction opening that forms a circulation flow path that starts from the liquid supply unit and returns to the liquid supply unit via the dispensing head and that is one opening end in the liquid stored in the liquid supply unit Is disposed, and the return channel that is the other opening end is disposed at a position higher than the liquid level of the liquid in the liquid supply unit, and
A plurality of individual flow paths that are branched from the main flow path and are respectively mounted with the discharge nozzles at the ends,
A pressurizing device that discharges the liquid from the discharge nozzle through the main flow path and the individual flow path by pressurizing the liquid supply unit;
An individual flow path valve provided for each of the individual flow paths to individually open and close these individual flow paths;
A main flow path valve that opens and closes the main flow path, provided between the branch portion where the individual flow path branches in the main flow path and the suction opening;
A pump mechanism provided between the branch portion and the return opening in the main flow path to return the liquid in the main flow path to the liquid supply section via the return opening;
A controller for controlling the pressurizing device, the pump mechanism, the individual flow path valve, and the main flow path valve;
A negative pressure is generated in the main channel by operating the pump mechanism with the main channel valve closed and the individual channel valve open, and the individual channel valve is opened by the negative pressure. A dispensing device that sucks in the individual flow path and the discharge nozzle mounted in the individual flow path in a direction opposite to the liquid discharge direction.   The main flow path is a tube made of a flexible material, and the pump mechanism is a peristal pump that feeds liquid in the tube in the predetermined direction by exerting a squeezing action in one direction on the tube. The dispensing device according to claim 1. A circulation channel that returns to the liquid supply unit via a dispensing head on which a discharge nozzle is mounted with the liquid supply unit as a base point is formed, and at one opening end portion in the liquid stored in the liquid supply unit A suction opening is disposed, and a return opening which is the other opening end is disposed at a position higher than the liquid level of the liquid in the liquid supply section, and is branched from the main flow path. A plurality of individual flow paths each having the discharge nozzle mounted on each end thereof, and a pressurizing device that discharges the liquid from the discharge nozzles via the main flow path and the individual flow paths by pressurizing the inside of the liquid supply unit An individual flow path valve that is provided for each of the individual flow paths and that individually opens and closes the individual flow paths, and is provided between the branch portion where the individual flow paths branch in the main flow path and the suction opening. The main channel that opens and closes this main channel A path valve, and a pump mechanism provided between the branch portion and the return opening in the main flow path to return the liquid in the main flow path to the liquid supply section through the return opening, In the dispensing device that discharges the liquid stored in the liquid supply unit by the discharge nozzle, a clogging removal method in the dispensing device that removes clogging generated in the discharge nozzle and / or the individual flow path,
A negative pressure is generated in the main channel by operating the pump mechanism with the main channel valve closed and the individual channel valve open, and the individual channel valve is opened by the negative pressure. The inside of the individual flow path and the discharge nozzle attached to the individual flow path are sucked in the direction opposite to the liquid discharge direction, and the substance causing the clogging is sucked into the main flow path and removed. The clogging removal method in the dispensing apparatus characterized by the above-mentioned.

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