KR20190136910A - Plunger pump and fixed-volume liquid dispenser - Google Patents

Abstract

The present invention provides a plunger pump and a fixed-volume liquid dispenser which dispense a fixed amount at satisfactory precision. The plunger pump (20) comprises a pump body (24) having a pump chamber (25) formed therein, and a plunger to move forwards and backwards with respect to the pump chamber (25). The pump body (24) includes: an introduction path (21) to introduce a liquid to the pump chamber (25); an extraction path (22) to extract a liquid from the pump chamber (25); and an exit passage (51) to communicate with the pump chamber (25) to be installed on one end in a moving direction of the plunger to discharge the plunger from the pump chamber (25). The exit passage (51) allows the plunger to reciprocate, has a passage width almost identical to the outer diameter of the plunger, and includes an opened air vent mechanism (52a) arranged on a passage wall and opened and closed by a reciprocating motion of the plunger.

Description

Plunger Pump and Liquid Dispenser {PLUNGER PUMP AND FIXED-VOLUME LIQUID DISPENSER}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plunger pump and a liquid metered discharge device, and more particularly, to a plunger pump and a liquid metered discharge device for performing a metered discharge with high precision.

Conventionally, the plunger pump which has the pump main body in which the pump chamber was formed inside, and the plunger which moves forward and backward with respect to a pump chamber is proposed (for example, patent document 1). The plunger pump is provided with an introduction passage for introducing liquid into the pump chamber and a discharge passage for extracting liquid from the pump chamber, and a liquid containing container containing liquid is connected to the introduction passage. By closing the inlet passage, opening the outlet passage and advancing the plunger while the liquid is filled in the pump chamber, the liquid of the volume of the plunger inserted into the pump chamber is drawn out of the pump chamber, and Quantitative discharge is performed. The liquid is sucked out of the introduction passage by closing the draw passage, opening the introduction passage, and retracting the plunger with respect to the pump chamber.

In such a plunger pump, when air (air) is mixed in the pump chamber, when the plunger is moved forward in the pump chamber, the pressure is applied to the air and the volume is reduced, so that a predetermined amount of liquid is not discharged from the pump chamber. have. In particular, the mixing of air occurs a lot when the liquid container connected to the introduction path of the plunger pump is replaced. When the liquid container is replaced, the liquid container is removed once, so that a lot of air is introduced into the pump chamber from the discharge furnace. In addition, after cleaning the inside of the plunger pump by maintenance or the like, air is introduced even when the pump chamber is filled with liquid.

In order to extract the air mixed in the pump chamber, for example, the plunger pump shown in FIG. 9 is provided with an air bleed 3 for communicating the inside and the outside of the pump chamber 2 of the pump main body 1. . When the plunger pump is operated, the air bleeding operation is performed by using the air bleeding air (3) prior to the metered discharge operation. In the air bleeding operation, first, the stopper 6 closing the air bleeding path 3 is removed and the air vent 3 is brought into an open state in communication with the outside. ) To the closed state. Then, the valve 5a of the inlet passage 5 is opened to introduce liquid from the liquid container (not shown) connected to the inlet passage 5, and the liquid is drawn out of the air vent 3 through the pump chamber 2. Let's do it. At this time, the air in the pump chamber 2, the introduction passage 5, and the discharge passage 4 exits the pump chamber together with the liquid. When the operator visually confirms that air is not mixed with the liquid coming out of the opening of the air vent (3), the introduction of the liquid is stopped to bring the liquid introduction passage (5) to a closed state, and the air vent (3) The opening on the outside of the plug is plugged with a stopper (6).

JP 2003-139073 A

As described above, upon completion of the air bleeding operation, the air bleeding passage 3 is closed from the outside by a stopper 6. However, there is a problem that air flows into the air bleeding air 3 when the cap 6 is closed, so that a predetermined amount of liquid is not discharged from the pump chamber, resulting in poor accuracy of metered discharge.

This invention is made | formed in view of the said problem, and makes it a subject to provide the plunger pump and the liquid metered-discharge apparatus which perform quantitative discharge with high precision.

The plunger pump according to the present invention includes a pump main body having a pump chamber formed therein, a plunger that moves forward and backward with respect to the pump chamber, and the pump main body includes an introduction passage for introducing liquid into the pump chamber, A discharge passage for leading liquid from the pump chamber, and a discharge passage provided at one end of the plunger in a retracting direction in communication with the pump chamber to withdraw the plunger from the pump chamber; The plunger is capable of reciprocating movement and has a passage width substantially the same as the outer diameter of the plunger, and an air bleed mechanism opening and closing by the reciprocating operation of the plunger is opened in the passage wall.

According to the above configuration, in the air bleeding operation, the plunger is moved in the discharge direction to open the air bleeding mechanism of the discharge passage, and the discharge passage is closed and the introduction passage is opened. Then, liquid is injected from the introduction passage and passed through the pump chamber to lead it out of the air vent. At this time, the air remaining in the pump chamber or the introduction furnace and the discharge passage exits the air discharge mechanism together with the liquid. When the air has sufficiently exited the pump chamber, the plunger is advanced to the position at which the air bleeding mechanism is closed, and at the same time, the air bleeding operation is terminated with the introduction passage in the closed state.

In the quantitative discharging operation, the plunger is moved forward with respect to the pump chamber from the position where the air vent mechanism is closed, with the lead-out passage in the open state and the introduction passage in the closed state. Then, the liquid of the volume fraction of the plunger inserted into the pump chamber is drawn out from the pumping path of the pump chamber, and the quantitative discharge of the liquid is performed. When the liquid is discharged, the plunger is retracted from the pump chamber to the position where the air vent mechanism is closed, with the discharge passage closed and the introduction passage opened. The operation is repeated as many times as desired.

The outer diameter of the plunger is almost equal to the exit passage passage width, and at the end of the air draining operation, the air draining mechanism is closed by the plunger from the exit passage side. For this reason, air does not mix in a pump chamber at the time of closing of an air vent mechanism. In addition, even if the air bleed hole communicating with the air bleeding mechanism is closed from the outside with a stopper and air is left between the air bleeding mechanism and the cap, the air bleeding mechanism is closed by the plunger from the exit passage side, so that the remaining air is fixed. It does not affect the discharge operation. For this reason, quantitative discharge can be performed with high precision.

In a preferred embodiment, the pump main body is provided with the pump chamber having an inner diameter larger than the outer diameter of the plunger and a chamber having an inner diameter that is continuously provided at the one end side of the pump chamber and larger than the inner diameter of the pump chamber, An attachment block having the discharge passage and the air bleed mechanism is fitted into the chamber such that the discharge passage communicates with the pump chamber.

In this embodiment, the said pump main body is provided with the air vent which communicates with the said chamber, The said attachment block is provided with the air vent hole which has the said air vent mechanism, The said air vent hole is said air vent It is fitted to communicate with.

In this embodiment, the said attachment block has the outer periphery which makes the outer peripheral surface turn around the circumferential direction, The said discharge path and the said outer periphery are communicated by the said air vent hole, The said outer periphery the said air vent You may be in communication with the furnace.

In this embodiment, the air vent mechanism may be provided in plural in the circumferential direction of the attachment block.

In this embodiment, in the exit passage of the attachment block, preferably, a tapered portion is formed at the end of the pump chamber side, the passage width of which is increased toward the end.

In this embodiment, the said air vent may be closed by the stopper which can be removed from the outer side of the said pump main body.

In this embodiment, the said chamber may be provided with the sealing member by which the said plunger closely fits so that the plunger can slide.

The liquid metering-discharge device of the present invention includes any one of the plunger pumps described above, a first valve for opening and closing the introduction passage of the plunger pump, a second valve for opening and closing the outlet passage of the plunger pump, and the plunger reciprocating. A plunger drive mechanism for moving, and a control device for controlling the reciprocating movement of the plunger by the plunger drive mechanism and opening / closing operations of the first valve and the second valve, wherein the control device is configured to carry out The first valve is controlled to open the inlet passage, the second valve is controlled to close the outlet passage, and the plunger drive mechanism is controlled to retract the plunger from the air bleed mechanism of the discharge passage. When the air bleeding mechanism is opened and the metered discharge operation is performed, the first valve is controlled to close the introduction passage, and the second valve is controlled to control the drawing. Open to, and by controlling the plunger drive mechanism is operated to advance the plunger in the pump chamber.

According to the above arrangement, when performing the air bleeding operation, the control device controls the first valve to open the inlet passage, controls the second valve to close the outlet passage, controls the plunger drive mechanism to control the plunger to evacuate the passage passage. Retract the air to release the air vent. And liquid is inject | poured from an introduction furnace, and it is led out from an air vent mechanism through a pump chamber. At this time, the air remaining in the pump chamber or the introduction furnace and the discharge passage exits the air discharge mechanism together with the liquid. When the air has sufficiently exited the pump chamber, the plunger is advanced to the position at which the air bleeding mechanism is closed, and at the same time, the air bleeding operation is terminated with the introduction passage in the closed state.

In the fixed-quantity discharge operation, the control device controls the first valve to close the inlet passage, controls the second valve to open the outlet passage, controls the plunger drive mechanism to move the plunger forward in the pump chamber. The liquid of the volume of the plunger inserted into the pump chamber is drawn out of the pump chamber, and the liquid is discharged quantitatively. When the liquid is discharged, the second valve is controlled to close the discharge passage, the first valve is controlled to open the introduction passage, the plunger drive mechanism is controlled to retract the plunger from the pump chamber to the position where the air bleed mechanism is closed. Operate. The above operation is repeated a desired number of times.

The outer diameter of the plunger is almost equal to the exit passage passage width, and at the end of the air draining operation, the air draining mechanism is closed by the plunger from the exit passage side. For this reason, air does not flow into a pump chamber at the time of closing of an air vent mechanism. In addition, even when the air bleeding hole communicating with the air bleeding mechanism is closed from the outside with a stopper and air is left between the air bleeding mechanism and the stopper, the air bleeding hole is closed by the plunger from the exit passage side. It does not affect the metered discharge operation. For this reason, quantitative discharge can be performed with high precision.

According to the present invention, quantitative discharge can be performed with high accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the whole structure of the liquid quantitative discharge apparatus which concerns on one Embodiment of this invention.
2 is an enlarged cross-sectional view showing the main portion of the liquid metering discharge device.
3 is a perspective view of the attachment block.
4 is a block diagram showing the circuit configuration of the liquid metering discharge device.
5 is a flow chart showing the flow of air bleeding operation.
6A to 6F are explanatory views of the air bleeding operation.
7 is a flowchart showing the flow of the quantitative discharging operation.
8A to 8F are explanatory views of the quantitative discharging operation.
9 is an explanatory diagram showing a prior art.

Embodiments of the present invention will be described with reference to the drawings. In addition, in the following description, the advancing direction of the plunger 23 is made into the up-down direction in FIG. 1, and an advancing direction is also called a downward direction, and an exiting direction is also called an upward direction.

1 to 4 show a liquid metering discharge device 10 according to one embodiment of the present invention. As shown in FIGS. 1 and 2, the liquid metering discharge device 10 includes a valve 12 (“first valve”) that opens and closes the plunger pump 20 and the introduction passage 21 of the plunger pump 20. And a valve 13 (also referred to as a "second valve") for opening and closing the outlet passage 22 of the plunger pump 20, a plunger drive mechanism 40 for reciprocating the plunger 23, The control device 11 (FIG. 4) which controls the reciprocation of the plunger 23 by the plunger drive mechanism 40, and the opening / closing operation | movement of the 1st valve 12 and the 2nd valve 13 is provided. In addition, the kind of the liquid which the liquid metering-discharge apparatus 10 discharges is not specifically limited. The liquid also includes a liquid in which solids are dispersed in the liquid.

The plunger pump 20 is provided with the pump main body 24 in which the pump chamber 25 was formed inside, and the plunger 23 which moves forward and backward with respect to the pump chamber 25. The pump main body 24 includes a pump chamber 25 having an inner diameter larger than the outer diameter of the plunger 23, an introduction passage 21 for introducing liquid into the pump chamber 25, and an introduction passage 21. Continuously provided in the pump chamber 25 at the discharge path 22 for drawing liquid from the pump chamber 25 at an upper position, and at one end side of the pump chamber 25 and above in FIG. A chamber 26 having an inner diameter larger than the inner diameter of the chamber 25 and an air vent 27 communicating with the chamber 26 are provided. The introduction passage 21, the evacuation passage 22, and the air vent 27 are provided in the pump main body 24, respectively.

The upper end of the chamber 26 is opened, and the substantially cylindrical attachment block 50 shown in FIG. 3 is inserted from the opening. The attachment block 50 has a hollow portion that penetrates from one end portion to the other end portion, that is, penetrates up and down in FIG. 1, and the hollow portion communicates with the pump chamber 25 to connect the plunger 23 to the pump chamber ( The exit passage 51 which exits from 25 is comprised. The exit passage 51 has a passage width in which the plunger 23 can reciprocate and is substantially equal to the outer diameter of the plunger 23. In the passage wall of the exit passage 51, the air vent mechanism 52a is opened at the central portion in the axial direction. The air bleed mechanism 52a communicates with the air bleed hole 52, and the exit passage 51 and the outer circumferential path 54 described later communicate with the air bleed hole 52. The air vent mechanism 52a is opened and closed by the reciprocating operation of the plunger 23.

In the present embodiment, four air vent holes 52 are provided at positions at equal intervals in the circumferential direction. The number of the air vent holes 52 is not limited to four, but may be one, two or three, or five or more.

On the outer circumferential surface 50a of the attachment block 50, two blade-shaped protruding members 53 protruding in the radial direction over one wheel are provided. The space between the protruding members 53 constitutes an outer circumferential path 54, and the air bleed hole 52 is opened in the outer circumferential surface 50a between the protruding members 53, and the exit passage ( 51 and the outer periphery 54 are in communication. In the state where the attachment block 50 is fitted into the chamber 26, the outer circumferential path 54 communicates with the air vent 27 of the pump main body 24. The air moved from the pump chamber 25 to the exit passage 51 moves from the exit passage 51 to the outer circumferential path 54 via the plurality of air bleed holes 52, and passes through the outer circumferential path 54. Then, the air is exhausted from the pump main body 24 to the outside 27.

At both ends in the axial direction of the outer circumferential surface 50a of the attachment block 50, there is formed a blade-shaped member 55 which protrudes in the radial direction over one wheel. In each of the spaces between the blade member 55 and the protruding member 53, the displacement of the attachment block 50 is prevented, and liquid leaks from the gap between the attachment block 50 and the inner wall of the chamber 26. O-ring 56 for preventing is mounted.

The protruding member 53 and the blade member 55 have a diameter slightly smaller than the inner diameter of the chamber 26, and the attachment block 50 can be fitted into the chamber 26.

At the end portion of the pump chamber 25 side of the exit passage 51 of the attachment block 50, a tapered portion 57 is formed in which the passage width of the exit passage 51 increases toward the end, and the tapered portion 57 is formed. The inner wall of the exit passage 51 is continuous with the inner wall of the pump chamber 25 via. The attachment block 50 is formed integrally with synthetic resin.

In the chamber 26 of the pump main body 24, with the sealing member which has the through-hole 28c which the plunger 23 slidably penetrates to the attachment block 50 above the attachment block 50, and slidably penetrates. Block 28 is fitted. The sealing member attaching block 28 is fitted with an annular sealing member 28b in which the plunger 23 is fitted in a sliding manner. Although the sealing member 28b is spring packing, for example, it is not limited to this, either sealing member 28b as long as it can prevent a liquid from leaking to the exterior between the through-hole 28c and the plunger 23. ) May be used. The sealing member attaching block 28 is provided with an o-ring 28a for preventing the leakage of liquid between the sealing member attaching block 28b and the inner wall of the chamber 26.

Above the sealing member attachment block 28, the sealing member 29 in which the opening of the upper end of the chamber 26 of the pump main body 24 is sealed, and the through-hole 29a through which the plunger 23 slidably penetrates is formed. ) Is attached by a screw or the like not shown.

The plunger 23 reciprocates through the through-hole 29a of the blocking member 29, the through-hole 28c of the sealing member attachment block 28, and the exit passage 51 of the attachment block 50, By this reciprocating movement, the tip of the plunger 23 moves forward and backward with respect to the pump chamber 25.

The stopper attachment member 30 which has the stopper 31 which is removable is attached to the site | part corresponding to the air vent 27 on the outer peripheral surface of the pump main body 24 by attachment means, such as a screw clamp which is not shown in figure. The stopper mounting member 30 is formed with a stopper mounting hole 32 in communication with the air bleeding passage 27, and by inserting the stopper 31 from the outside into the spigot mounting hole 32, Is closed. An O-ring 30a is provided between the plug installation member 30 and the outer circumferential surface 50a of the pump main body 24.

The 1st valve 12 is attached to the site | part corresponding to the introduction path 21 of the outer peripheral surface of the pump main body 24, and opens and closes the introduction path 21. As shown in FIG. The 1st valve 12 is the 1st valve member 12a which opens and closes the channel | path 12c which communicates with the introduction path 21, and the 1st valve drive part 12b which drives the 1st valve member 12a ( 4). Although the 1st valve 12 is a needle valve provided with actuators (not shown), such as a needle and a solenoid, for example, it is not limited to this, Any structure may be sufficient as long as the introduction path 21 can be opened and closed. do. Although not shown, a liquid container is connected to the inlet of the passage 12c of the first valve 12, and the liquid is the passage 12c of the first valve 12 and the pump body 24 from the liquid container. Is introduced into the pump chamber 25 through the introduction passage 21.

The 2nd valve 13 is attached to the site | part corresponding to the outflow path 22 of the outer peripheral surface of the pump main body 24. As shown in FIG. The 2nd valve 13 is the 2nd valve member 13a which opens and closes the channel | path 13c which communicates with the draw path 22, and the 2nd valve drive part 13b which drives the 2nd valve member 13a ( 4). Although the 2nd valve 13 is a needle valve provided with actuators (not shown), such as a needle and a solenoid, for example, it is not limited to this, Any structure may be sufficient as long as the introduction path 21 can be opened and closed. . Although not shown, a nozzle portion for discharging liquid is connected to the outlet of the passage 13c of the second valve 13.

The plunger drive mechanism 40 includes a plunger drive portion 41 made of a servomotor and a ball screw mechanism 43 connected to the plunger drive portion 41 via a power transmission mechanism 42. The ball screw mechanism 43 includes a ball screw through which the rotation of the plunger drive portion 41 is transmitted via the power transmission mechanism 42, a bearing for rotatably supporting the ball screw, a nut member screwed into the ball screw, and the like. When the ball screw is rotated in either the forward or reverse direction by the plunger drive part 41, the plunger 23 is reciprocally moved integrally with the nut member in accordance with the rotation direction.

The power transmission mechanism 42 is for transmitting the rotation of the servomotor to the ball screw, the first pulley 42a provided on the output shaft of the servomotor, the first pulley 42b provided on the ball screw 43a, It consists of the belt 42c laid between the 1st pulley 42a and the 2nd pulley 42b.

As shown in FIG. 2, the plunger drive mechanism 40 has the tip of the plunger 23 at any one of a home position P1, an air bleeding start position P2, and a discharge completion position P3. The plunger 23 is driven to position. The home position P1 is a position at which the tip of the plunger 23 is positioned at the start and end of the air bleeding operation of the liquid metering discharge device 10 at the start and end of the quantitative discharging operation. ) Is positioned at the home position P1, the air venting mechanism 52a of the exit passage 51 is closed. In this embodiment, the groove position P1 is set at the same position as the lower end of the attachment block 50, but any position may be sufficient as long as the air vent mechanism 52a can be closed.

The air bleeding start position P2 is a position that opens the air bleeding mechanism 52a of the exit passage 51 and is a position above the air bleed mechanism 52a of the outlet passage 51. The discharge completion position P3 is a predetermined position in the pump chamber 25. The discharge completion position P3 is determined according to the type of liquid discharged by the liquid metering discharge device 10, the desired discharge amount, the diameter of the plunger 23, and the like, and the discharge completion position P3 is completed from the home position P1 of the plunger 23. The predetermined distance L to the position P3 is stored in advance in the storage unit of the control device 11 shown in FIG. 4.

Although not shown, the control device 11 includes a control unit, a storage unit, and an interface unit. The control unit is configured of, for example, a CPU or a memory serving as a work area, and executes a program stored in the storage unit, whereby the plunger drive unit 41, the first valve drive unit 12b, and the second valve which are servomotors are executed. The operation of the driver 13b is controlled. The storage unit is composed of, for example, a storage device such as a flash memory or a nonvolatile memory, and stores a program to be executed by the control unit. The storage unit also stores the number of times of quantitative discharging operation and the distance L for moving the plunger 23 from the home position P1 to the discharge completion position P3 during the quantitative discharging operation. The interface unit includes an input port for receiving a signal, an output port for transmitting a signal, an A / D conversion circuit, and the like, and controls the plunger driver 41, the first valve driver 12b, and the second valve driver 13b. It is for connecting the device 11. Although the control apparatus 11, each part of the plunger drive part 41, the 1st valve drive part 12b, and the 2nd valve drive part 13b is connected by the cable and performs transmission and reception of a control signal, the control device 11 Each of the plunger driver 41, the first valve driver 12b, and the second valve driver 13b may include a communication unit to wirelessly transmit and receive control signals.

The input device 14 which consists of a touch panel etc. is connected to the control apparatus 11, for example, and an operator can input an instruction | indication to the control apparatus 11 via the input apparatus 14. In addition, when the input device 14 also serves as a display device such as a monitor, the driving situation of the plunger drive part 41 controlled by the control device 11, the first valve 12, the second valve 13, and so on. Can be displayed.

Next, the operation of the liquid metering device 10 of the present embodiment will be described with reference to FIGS. 5 to 8. Although the liquid metering-discharge device 10 performs the metering-discharging operation of the liquid, after cleaning the inside of the liquid metering-discharging device 10 by maintenance or the like, or after replacing the liquid container, the liquid metering-discharging device ( Since air is present inside 10), the air bleeding operation is performed prior to the quantitative discharging operation of the liquid.

FIG. 5 is a flowchart illustrating the operation of the control device 11 during the air bleeding operation, and FIGS. 6A to 6F show the position of the plunger 23, the first valve 12 and the second valve. It is explanatory drawing which showed the opening / closing state of (13), and the installation state of the stopper 31. As shown in FIG. In FIG. 6, the liquid quantity dispensing apparatus 10 is simplified and shown for description.

The air bleeding operation starts from the state in which the 1st valve 12 is open, the 2nd valve 13 is closed, and the plunger 23 is in the home position P1. However, after cleaning the inside of the liquid metering device 10 due to maintenance or the like, or after replacing the liquid container, the first valve 12, the second valve 13, and the plunger 23 are used as the air. It may not be the state at the start of the subtraction operation. For this reason, when an operator inputs the start instruction of air bleeding operation from the input apparatus 14, in ST10 of FIG. 5, the control apparatus 11 opens the 1st valve 12, and the 2nd valve 13 in ST10 of FIG. Is closed, and whether the plunger 23 is in each state of the home position P1 is checked, and when it is not in this state, the 1st valve drive part 12b is controlled to open the 1st valve 12, The second valve 13 is controlled to close the second valve 13, and the plunger 23 is controlled to move the plunger 23 to the home position P1 (FIG. 6A). . Next, the operator removes the stopper 31 of the stopper mounting member 30 (FIG. 6B), and inputs the removal completion instruction of the stopper 31 from the input device 14 to the control device 11. In ST11, when the control apparatus 11 receives the removal completion instruction of the stopper 31, it progresses to ST12. If the stopper 31 is not instructed to complete removal, ST11 is repeated until the instruction is received. In addition, the sensor which detects whether the stopper 31 is affixed to the stopper installation member 30 may be attached. In this case, when the control apparatus 11 receives the signal which shows that the stopper 31 was removed from the stopper installation member 30 from the sensor, it progresses to ST12.

In ST12, the control apparatus 11 drives the plunger drive part 41 to retract the plunger 23 to the air bleed start position P2 (FIG. 6C). Then, the liquid is introduced from the liquid container through the first valve 12 into the pump chamber 25, passes through the exit passage 51 of the attachment block 50, and is provided in the exit passage 51. It passes through the air circumference 54 of the attachment block 50 from the air bleed hole 52, and passes through the air bleed 27 of the pump main body 24 and the plug installation hole 32 of the plug installation member 30. Go outside. At this time, the air also goes out together with the liquid. In the vicinity of the opening of the plug mounting hole 32, a liquid receiving means such as a liquid receiving container (not shown) is disposed, and the liquid receiving container receives the liquid coming out of the outside. As the liquid receiving means, a tube and a container attached to one end of the tube may be used. In this case, by attaching the other end of the tube to the opening of the plug mounting hole 32, the liquid that comes out is interposed through the tube. To accommodate.

When the operator visually confirms that air is not mixed with the liquid from the air bleeding machine 27, the operator inputs an instruction to end the air bleeding operation from the input device 14 to the control device 11. In ST13, the control apparatus 11 advances to ST14, when the instruction | indication of completion | finish of air drain operation | movement is received. If the instruction to end the air bleed operation is not received, the control device 11 repeats ST13.

In ST14, the control apparatus 11 controls the plunger drive part 41 to move the plunger 23 to the home position P1 (FIG. 6D). The operator attaches the stopper 31 of the stopper installation member 30 (FIG. 6E), and inputs the installation completion instruction of the stopper 31 from the input device 14 to the control device 11. In ST15, when the control apparatus 11 receives the instruction | indication of completion of installation of the stopper 31, it progresses to ST16. If the instruction to complete installation of the stopper 31 is not received, ST15 is repeated until the instruction is received. Moreover, you may attach the sensor which detects whether the stopper 31 is attached to the stopper installation member 30. FIG. In this case, when the control apparatus 11 receives the signal which shows that the stopper 31 was attached from the stopper installation member 30 from the sensor, it progresses to ST16.

In ST16, the control apparatus 11 drives the 1st valve drive part 12b, closes the 1st valve 12 (FIG. 6 (F)), and completes the air bleeding operation.

Next, the operation of the control device 11 during the quantitative discharging operation of the liquid in the liquid quantitative discharging device 10 will be described. FIG. 7 is a flowchart for explaining the metered discharge operation, and FIGS. 8A to 8F show the position of the plunger 23 during the metered discharge operation, the first valve 12 (valve member 12a), and It is explanatory drawing which showed the opening / closing state of the 2nd valve 13 (valve member 13a), and the installation state of the stopper 31. As shown in FIG. In FIG. 8, the liquid quantity dispensing apparatus 10 is simplified and shown for the purpose of description.

In ST31 of FIG. 7, the control apparatus 11 confirms that the 1st valve 12 and the 2nd valve 13 are closed, and the plunger 23 is in the home position P1 (FIG. 8). (A)). When the 1st valve 12 and the 2nd valve 13 are not in the closed state, respectively, or when the plunger 23 is not in the home position P1, the control apparatus 11 is the 1st valve drive part 12b. , The second valve driver 13b is controlled to close the first valve 12 and the second valve 13, and the plunger driver 41 is controlled to move the plunger 23 to the home position P1.

In ST32, the control apparatus 11 controls the 2nd valve drive part 13b, and opens the 2nd valve 13 (FIG. 8 (B)). In ST33, the control apparatus 11 advances the plunger 23 by the predetermined distance L, and moves the tip of the plunger 23 to the discharge completion position P3 (FIG. 8C). The volume of liquid which the plunger 23 entered the pump chamber 25 discharges from the nozzle part not shown in figure from the discharge path 22 via the passage 13c of the 2nd valve 13. In ST34, the control apparatus 11 controls the 2nd valve drive part 13b, and closes the 2nd valve 13 (FIG. 8D). In ST35, the control apparatus 11 controls the 1st valve drive part 12b, and opens the 1st valve 12 (FIG. 8E). In ST36, the control apparatus 11 controls the plunger drive part 41 to move the plunger to the home position P1 (FIG. 8F). As a result, the liquid passes through the first valve 12 and is sucked into the pump chamber 25. In ST37, the control apparatus 11 controls the 1st valve drive part 12b, and closes the 1st valve 12 (FIG. 8A). In ST38, the control device 11 determines whether or not the quantitative discharging operation has been performed a predetermined number of times. If not, the process returns to ST32. In this case, the quantitative discharging operation is terminated.

According to the embodiment described above, even when air is drawn in when attaching the stopper 31 in the air bleeding operation and air remains between the stopper 31 and the air bleed mechanism 52a, the air is discharged when the quantitative discharge operation is performed. Since the withdrawal hole 52 is always closed by the plunger 23 and does not communicate with the pump chamber 25, the remaining air can be quantitatively discharged with high accuracy without affecting the discharge amount.

Further, according to the above embodiment, since the attachment block 50 forming the exit passage 51 and the air venting mechanism 52a is fitted into the pump main body 24, the attachment block 50 is used during maintenance. In this way, maintenance is easier than in the case where the exit passage 51 and the air venting mechanism 52a are formed in the pump main body 24.

The attachment block 50 is formed with an outer circumferential path 54 through which air can pass through the outer circumferential surface 50a, and the air bleed hole 52 of the attachment block 50 is drawn into the air bleed 27 of the pump body 24. Even though the air vent 27 and the air vent hole 52 communicate with each other via the outer circumferential path 54 without being disposed at a position corresponding to the air vent, the air is discharged from the exit passage 51 of the attachment block 50. The air can be removed from the pump main body 24 by passing through the releasing hole 52 and the outer peripheral path 54, and moving to the air bleeding 27 of the pump main body 24.

Since the air vent mechanism 52a is provided in plural in the circumferential direction of the attachment block 50, the air is easily released from the exit passage 51 of the attachment block 50.

In addition, when a plurality of air vents 27 are directly installed in the pump main body 24 without using the attachment block 50, the stopper installation member 30 is provided for each air vent 27, and each It is necessary to arrange | position liquid receiving means, such as a liquid receiving container, in the vicinity of the plug installation member 30, and to receive a liquid. However, valves 12, 13 and the like are provided on the outer circumferential surface of the pump main body 24, and there is not enough space to arrange a plurality of liquid receiving means. However, in the present embodiment, a plurality of air bleeding mechanisms 52a are provided in the attachment block 50, and one air bleeding 27 is provided in the pump main body 24, which is located in the exit passage 51. Since the air exits the exit passage 51 from the plurality of air vent holes 52 and passes through the outer circumferential path 54, the air exits from the air drain passage 27 of the pump main body 24 to the outside. Air can be easily released from the 51, and a plurality of liquid receiving means need not be provided on the outer circumferential surface of the pump main body 24, thereby saving space. In addition, since one air vent 27 is formed in the pump main body 24, the structure of the pump main body 24 is simple compared with the case where a plurality of air vents 27 are provided.

In the exit passage 51 of the attachment block 50, a tapered portion 57 is formed at the end of the pump chamber 25 side toward the end thereof so that the attachment block 50 and the pump chamber ( 25) A step can be created between the two to prevent air from remaining in the step.

Since the air bleeding air 27 of the pump main body 24 is closed by the stopper 31 which can be removed from the outside of the pump main body 24, the liquid can be prevented from flowing out during the metered-out discharge operation.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning of this invention.

10: liquid metering discharge device 11: controller
12: first valve 13: second valve
20: plunger pump 21: introduction furnace
22: drawer 23: plunger
24: pump body 25: pump chamber
26: chamber 27: air bleeding
28: sealing member 31: stopper
40: plunger drive mechanism 50: attachment block
50a: outer peripheral surface 51: exit passage
52: air bleed mechanism 52: air bleed hole
56: O ring 54: outskirts
57: tapered portion

Claims (9)

As a plunger pump,
A pump body having a pump chamber formed therein; And
Including a plunger which moves forward and backward with respect to the pump chamber,
The pump body,
An introduction passage for introducing a liquid into the pump chamber,
A drawing furnace for drawing liquid from the pump chamber,
A discharge passage provided in one end side of the plunger in a retracting direction in communication with the pump chamber to retract the plunger from the pump chamber,
The exit passage is a plunger pump in which the plunger is capable of reciprocating and has a passage width substantially the same as the outer diameter of the plunger, and an air bleeding mechanism opening and closing by the reciprocating operation of the plunger is opened in the passage wall. The said pump main body is provided with the said pump chamber of the inner diameter larger than the outer diameter of the said plunger, and the chamber of the inner diameter which is provided continuously in the said one end side of the said pump chamber, and is larger than the inner diameter of the said pump chamber,
A plunger pump, in which the attachment block having the discharge passage and the air bleed mechanism is fitted in the chamber such that the discharge passage communicates with the pump chamber. According to claim 2, The pump body is provided with an air vent to communicate with the chamber,
The attachment block is formed with an air bleeding hole having the air bleeding mechanism, and is fitted into the air bleeding hole so as to communicate with the air bleed. According to claim 3, wherein said attachment block has a circumference of the outer circumferential surface in a circumferential direction, wherein said exit passage and said outer circumference communicate with each other by said air bleed hole. Plunger pump in communication with the furnace. The plunger pump according to claim 2, wherein a plurality of air bleeding mechanisms and air bleeding holes are provided in a circumferential direction of the attachment block. The plunger pump according to claim 2, wherein a tapered portion is formed in the exit passage of the attachment block at an end portion on the pump chamber side, the passage width of which is increased toward the end. The plunger pump according to claim 2, wherein the air bleeding is closed by a stopper removable from the outside of the pump body. The plunger pump according to claim 2, wherein the chamber is provided with a sealing member in which the plunger is fitted in a slidingly close contact with the attachment block. As a liquid metering discharge device,
The plunger pump according to any one of claims 1 to 8;
A first valve for opening and closing the introduction passage of the plunger pump;
A second valve for opening and closing the outlet passage of the plunger pump;
A plunger drive mechanism for reciprocating the plunger; And
It includes a control device for controlling the reciprocating movement of the plunger by the plunger drive mechanism, the opening and closing operation of the first valve and the second valve,
The control device,
In the air bleeding operation, the first valve is controlled to open the inlet passage, the second valve is controlled to close the outlet passage, and the plunger drive mechanism is controlled to remove the plunger from the air outlet of the discharge passage. By retreating from a sphere, the air vent mechanism is opened,
In the metered-discharge operation, the first valve is controlled to close the inlet passage, the second valve is controlled to open the outlet passage, and the plunger drive mechanism is controlled to advance the plunger to the pump chamber. Liquid discharge device.

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