JP7249069B1 - Liquid supply device and liquid ejection device - Google Patents

Abstract

A liquid supply device is provided that prevents air from entering the interior when liquid is introduced into the interior, thereby reducing waste of the liquid. A liquid supply device (10) includes a pump main body (11) having a pump chamber (12) formed therein, a plunger (13) which advances and retreats with respect to the pump chamber (12), a plunger driving means (14), and a plunger driving means (14). and an opening 16 a communicating with the pump chamber 12 on the other end side of the outlet passage 15 , and an inlet passage for introducing the liquid into the pump chamber 12 . 16, between a second position P2 where the plunger 13 is closest to one end and the opening 16a of the introduction passage 16 at the start of the operation of introducing the liquid from the opening 16a of the introduction passage 16 into the pump chamber 12; The distance L2 is one-third or less of the distance L1 between the second position P2 and the first position P1 when the plunger 13 is on the farthest other end side of the pump chamber 12 . [Selection drawing] Fig. 1

Description

The present invention relates to a liquid supply device and a liquid ejection device for ejecting liquid.

2. Description of the Related Art Conventionally, various liquid supply devices have been proposed that use a reciprocating plunger to eject a small amount of liquid from a liquid port. For example, as shown in FIG. 8, the liquid supply device 200 of Cited Document 1 has a syringe 201 that presses out a liquid from a liquid agent ejection portion and a liquid agent flow path 202 that connects to the liquid agent ejection portion of the syringe 201. A casing 205 having a member 203 and an opening 202a of a liquid agent channel 202 on its inner wall, and a vertically extending cylindrical channel 204 into which the liquid sent from the syringe 201 through the liquid agent channel 202 flows. a plunger 206 provided in the cylindrical passage 204 of the casing 205, and plunger driving means 208 for reciprocating the plunger 206 in the cylindrical passage 204 of the casing 205 to discharge the liquid from the nozzle portion 207 at the lower end of the casing 205. and

At the time of liquid ejection, the plunger 206 is driven downward by the plunger driving means 208 while the liquid is flowing into the tubular passage 204 . As a result, the liquid receives pressure from the plunger 206 and the liquid in the tubular passage 204 is sent downward through the nozzle portion 207 .

When the lower end of the plunger 206 has moved to the lower end of the tubular passage 204 and the liquid in the tubular passage 204 has been almost discharged, the operation of supplying the liquid into the tubular passage 204 is performed. At the start of the liquid supply operation, the lower end of the plunger 206 is in the vicinity of the nozzle section 207 and the opening 202a of the liquid agent channel 202 is blocked by the outer peripheral surface of the plunger 206 . The plunger 206 moves upward from the vicinity of the nozzle portion 207 of the cylindrical passage 204 to at least a position above the opening 202a. When the opening 202 a communicates with the tubular passage 204 , a positive pressure is supplied to the syringe 201 and liquid is supplied from the syringe 201 through the liquid agent flow path 202 into the tubular passage 204 .

JP 2013-107035 A

In the liquid supply device of Cited Document 1, since the plunger 206 is pulled up while the opening 202a of the liquid agent channel 202 is blocked by the outer peripheral surface of the plunger 206 during the operation of supplying the liquid to the tubular passage 204, The air is sucked in and mixed with the liquid remaining in the tubular passage 204 and the nozzle portion 207 . In particular, since the opening 202a is located in the center of the cylindrical passage 204 in the vertical direction, the plunger 206 moves over a long distance and sucks in a large amount of air. After the plunger 206 is positioned above the opening 202 a of the liquid agent channel 202 , the liquid contained in the syringe 201 is pressurized and flows into the cylindrical channel 204 from the opening 202 a of the liquid agent channel 202 . At this time, the liquid flows into the tubular passage 204 while pushing out the air in the tubular passage 204, but there is already a large amount of air in the tubular passage 204, and part of the air enters the liquid as bubbles. . Therefore, before the liquid is discharged onto the discharge target (work), it is necessary to perform a discarding operation in which the liquid containing air bubbles is previously discharged and discarded, which wastes the liquid.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a liquid supply device and a liquid ejection device which prevent air from entering the interior when liquid is introduced into the interior and reduce waste of liquid due to the disposal operation. The purpose is to provide an apparatus.

To achieve the above objectives, the present invention includes the subject matter described in the following sections.

Item 1: The liquid supply device of the present invention comprises a pump body having a pump chamber formed therein, a plunger that advances and retreats with respect to the pump chamber, plunger drive means that advances and retreats the plunger, and the pump chamber. A lead-out passage provided on one end side for drawing out the liquid in the pump chamber, and an opening communicating with the pump chamber on the other end side of the lead-out passage, and an introduction for introducing the liquid into the pump chamber. and a distance between a second position where the plunger is at the most one end side and the opening of the introduction path at the start of the operation of introducing liquid from the opening of the introduction path into the pump chamber is It is one-third or less of the distance between the second position and the first position on the farthest other end side.

According to the above configuration, in the operation of introducing the liquid into the pump chamber (initial liquid introduction operation) when the pump chamber does not contain the liquid, such as at the beginning of use of the liquid supply device or after cleaning, the plunger is positioned below the pump chamber and the plunger is moved upward, the liquid is introduced into the pump chamber through the introduction passage by the suction force of the plunger and the pressure applied to the liquid in the introduction passage. At this time, the air in the pump chamber is pushed out from the lead-out passage by the liquid introduced into the pump chamber. In this way, the air is pushed downward by at least the weight of the liquid and is pushed out of the lead-out path, so that the air is less likely to mix with the liquid. In the present invention, the distance between the second position where the plunger is closest to one end and the opening of the liquid introduction path is the first distance between the second position and the plunger when the plunger is closest to the other end of the pump chamber. is set to be one-third or less of the distance between the positions of That is, the volume of the space between the introduction path and the second position is small, and the amount of air contained in the space is small. Therefore, when the liquid pushes out the air, the amount of air to be pushed out is small, the air can be reliably pushed out from the pump chamber, and air bubbles are less likely to mix into the liquid introduced into the pump chamber. Therefore, the amount of liquid mixed with air bubbles before the liquid ejection operation is reduced, and the liquid is not wasted.

Item 2: The liquid supply device according to Item 1, wherein the opening of the introduction path is formed on the inner surface of the pump chamber on the other end side of the lead-out path.

Item 3: further comprising a valve that opens and closes the introduction path,
In the operation of drawing out the liquid from the lead-out path, the introduction path is closed by the valve, and the plunger is positioned between the first position and the third position located on the other end side of the opening of the introduction path. Item 3. The liquid supply device according to Item 1 or 2, which is movable between.

Item 4: In the operation of introducing liquid into the pump chamber from a state in which the pump chamber contains no liquid, the plunger is positioned in the first position and in the fourth position where the plunger closes the opening of the introduction path. Item 4. The liquid supply device according to any one of Items 1 to 3, which is movable between positions.

Item 5: the lower end surface of the plunger located in the pump chamber has at least a surface that is inclined with respect to a surface perpendicular to the direction in which the plunger advances and retreats,
Item 5. The liquid supply device according to any one of Items 2 to 4, wherein the oblique surface faces the opening of the introduction path.

Item 6: The liquid supply device according to Item 1, wherein the introduction path is formed inside the plunger, and an opening of the introduction path is formed in the lower end surface of the plunger.

Item 7: The liquid supply device according to any one of Items 1 to 6, comprising a plurality of sets each including the pump chamber, the plunger, the introduction path, and the extraction path.

Item 8: The liquid supply device according to any one of Items 1 to 7, further comprising sealing means for stopping the liquid from being led out from the lead-out path.

Item 9: a syringe connected to the introduction channel and containing a liquid;
pressure adjusting means for adjusting the pressure in the syringe;
Item 9. The liquid supply device according to any one of Items 3 to 8, further comprising: the pressure adjusting means, the operation of the valve, and the control section that controls the operation of the plunger.

Item 10: A liquid ejection device in which a needle is connected to the lead-out path of the liquid supply device according to any one of Items 1 to 9.

Item 11: The liquid ejecting apparatus according to Item 10, further comprising sealing means for stopping liquid from flowing out from the needle.

ADVANTAGE OF THE INVENTION According to this invention, when introducing a liquid into an inside, it can prevent air from entering inside and can reduce the waste of the liquid by a discarding operation|movement.

1 is an explanatory diagram showing the overall schematic configuration of a liquid supply device according to an embodiment of the present invention; FIG. It is explanatory drawing which shows the position of a plunger. It is explanatory drawing which shows the position of a plunger. It is a modified example of the lower end surface of the plunger. Fig. 4 is another embodiment of a liquid supply device; Fig. 4 is another embodiment of a liquid supply device; Fig. 4 is another embodiment of a liquid supply device; It is a figure which shows a prior art.

(overall structure)
An embodiment of the present invention will be described with reference to the drawings. 1 to 3 show the overall configuration of a liquid supply device 10 according to one embodiment of the present invention. The liquid supply device 10 includes a pump body 11 having a pump chamber 12 formed therein, a plunger 13 moving forward and backward with respect to the pump chamber 12, a plunger driving means 14 moving the plunger 13 forward and backward, and one end of the pump chamber 12. A lead-out path 15 provided on the side of the pump chamber 12 for leading out the liquid in the pump chamber 12 and an opening 16 a communicating with the pump chamber 12 on the other end side of the lead-out path 15 for introducing the liquid into the pump chamber 12 . a passage 16, a valve 17 for opening and closing the introduction passage 16, valve driving means (not shown) for driving the valve 17, a syringe 18 connected to the introduction passage 16 and containing liquid, and and a control section 20 for controlling the operation of each section such as the pressure adjusting means 19, the valve driving means, the plunger driving means 14, and the like.

In this specification, the direction in which the pump chamber 12 extends and the direction in which the plunger 13 advances and retreats is defined as the vertical direction shown in FIG. Alternatively, it is the rear side, but the vertical direction is not necessarily limited to the vertical direction. 2 to 7, descriptions of the syringe 18, the pressure adjusting means 19, and the control section 20 are omitted in the following description. 1 to 7 show a cross section of a part of the configuration of the pump main body 11, plunger 13, lead-out path 15, lead-in path main body 24, etc. for explanation.

The pump main body 11 is formed of a rectangular frame and has a pump chamber 12 which is a space extending in the vertical direction. The pump chamber 12 has a circular cross-sectional shape on a plane orthogonal to the axial direction (vertical direction). Note that the cross-sectional shape is not limited to a circle, and may be square, for example. A seal member 11a such as an O-ring is provided annularly on the inner surface of the upper end of the pump chamber 12, and holds the plunger 13 so that the pump chamber 12 is airtight and liquid-tight. The upper end of the pump chamber 12 is covered with a closing member 11b, and the plunger 13 penetrates through a through hole provided in the center of the closing member 11b.

A lead-out path 15 is provided at the lower end of the pump chamber 12 . The lead-out path 15 is a flow path through which the liquid contained in the pump chamber 12 passes, and has a circular cross section perpendicular to the axial direction (vertical direction). The diameter of lead-out path 15 is formed smaller than the cross-sectional diameter of pump chamber 12 . In the present embodiment, the pump chamber 12 refers to a portion that has a constant cross-sectional area along the vertical direction and does not include the lead-out passage 15. The lead-out passage 15 is located at the lower end of the pump chamber 12, It means a portion where the cross-sectional area of the passage is smaller than the cross-sectional area of the pump chamber 12 . However, the cross-sectional areas of the pump chamber 12 and the lead-out path 15 are not limited to this embodiment, and the cross-sectional areas of the pump chamber 12 and the lead-out path 15 are set arbitrarily. The cross-sectional area of lead-out passage 15 may be the same as the area, or the cross-sectional area of lead-out passage 15 may be larger than the cross-sectional area of pump chamber 12 .

An opening 16 a of the introduction path 16 is formed in the inner peripheral surface of the pump chamber 12 , and the opening 16 a of the introduction path 16 is positioned above the outlet path 15 . The vertical distance L2 between the second position P2 when the plunger 13 is at its lowest end and the opening 16a of the introduction passage 16 is the distance L2 between the second position P2 at which the plunger 13 is at its lowest end and the distance L2 of the plunger 13 at its lowest end. The lower end 13a is set to be one-third or less of the vertical distance L1 between the first position P1 at the uppermost end of the pump chamber 12 and the lower end 13a. Preferably, the distance L2 is set to 1/4 or less of the distance L1, and more preferably set to 1/6 or less. More preferably, the opening 16a of the lead-in path 16 is provided in the vicinity of the lead-out path 15, that is, the opening 16a of the lead-in path 16 is provided at a position as close as possible to the upper end 15a of the lead-out path 15, right above it. The first position P1 and the second position P2 will be described later.

In one example, the length of the pump chamber 12 in the vertical direction is set to 60 mm, the diameter of the circular cross section is set to 2 mm, the diameter of the outlet path 15 is set to 1 mm, the diameter of the cross section of the introduction path 16 is set to 1 mm, and the distance L1 is set to 50 mm. Although the distance L2 is set to 7 mm, it is not limited to this.

The plunger 13 has a rod-like shape with a circular cross-section, the upper end portion of which is located outside the pump body 11 , and a plunger driving means 14 for advancing and retreating the plunger 13 with respect to the pump chamber 12 is provided. The plunger driving means 14 is composed of, for example, a reciprocating motion mechanism using a ball screw and a motor. A lower end 13a of the plunger 13 is positioned within the pump chamber 12, and at least the lower end 13a has a circular cross-sectional diameter set substantially equal to the diameter of the pump chamber 12, and is fitted to the inner surface of the pump chamber 12 in an air-tight and liquid-tight manner. The pump chamber 12 is free to advance and retreat. A lower end surface 13b of the plunger 13 is a flat surface parallel to a plane perpendicular to the direction in which the plunger 13 advances and retreats. The diameter of the circular cross-section of the lower end 13a of the plunger 13 does not necessarily have to be set to be substantially the same as the diameter of the pump chamber 12. may be smaller than the diameter of

The plunger 13 is physically movable between a first position P1 and a second position P2 along the vertical direction. A third position P3 and a fourth position P4 are set between the first position P1 and the second position P2. The first position where the plunger 13 is at the uppermost end is, as shown in FIG. , the lower end 13a of the plunger 13 is the uppermost position. The first position P1 is determined by the length of the pump chamber 12 and the length of the plunger 13 .

The second position P2 is the lowest position (one end side) where the plunger 13 can be moved downward in the liquid supply device 10, and the lower end 13a of the plunger 13 is the lowest position. be. In the present embodiment shown in FIGS. 1 to 3, the second position P2 when the plunger 13 is at its lowest end is the same position as the upper end 15a of the lead-out path 15. As shown in FIG. If the diameter of the lead-out path 15 is the same as or larger than the diameter of the plunger 13, the lower end 13a of the plunger 13 can be positioned within the lead-out path 15. In this case, the second position P2 is within the lead-out path 15. Located in

As shown in FIG. 2, the third position P3 is a position where the lower end 13a of the plunger 13 is located above the opening 16a of the introduction passage 16 and does not close the opening 16a. The lower end 13a of the opening 16a of the introduction path 16 is positioned to be substantially the same as the upper end 16b of the opening 16a. The fourth position P4 is a position between the upper end 15a of the lead-out path 15 and the lower end 16c of the opening 16a of the lead-in path 16, as shown in FIG. position. In this embodiment, the fourth position P4 is a position where the lower end 13a of the plunger 13 is at the same position as the lower end 16c of the opening 16a of the introduction passage 16. As shown in FIG.

The plunger 13 can physically move between the first position P1 and the second position P2. The plunger 13 moves between the first position P1 and the fourth position P4, and moves between the first position P1 and the third position P3 during a liquid ejection operation and a liquid introduction operation, which will be described later.

An introduction path body 24 is attached to the outer surface of the pump body 11 , and an introduction path 16 is formed in the introduction path body 24 . The introduction path 16 is a flow path through which liquid passes and communicates with the pump chamber 12 through an opening 16a. The introduction passage 16 is connected to a syringe 18, and the syringe 18 is connected to a pressure source 19b via an electromagnetic valve 19a. The solenoid valve 19a and the pressure source 19b constitute pressure adjusting means 19. As shown in FIG. A liquid is contained in the syringe 18, and when the solenoid valve 19a is opened and a positive pressure is supplied from the pressure source 19b into the syringe 18, the liquid is pressurized and supplied to the introduction path 16, and introduced. It is introduced into the pump chamber 12 through the passage 16 . The introduction path main body 24 is provided with a valve 17 for opening and closing the introduction path 16 . In this embodiment, the valve 17 opens and closes the opening 16a of the introduction path 16, but is not limited to this, and may open and close any part of the introduction path 16, and a known open/close valve 17 is used. The valve 17 is driven by valve driving means (not shown).

The operation of the solenoid valve 19 a for pressurizing the inside of the syringe 18 , the operation of the plunger driving means 14 , the operation of the valve driving means, and the like are controlled by the controller 20 . A general-purpose computer, for example, is used as the control unit 20 . The hardware configuration of a general-purpose computer includes processors such as CPU and GPU, main storage devices such as DRAM and SRAM, and storage units such as HDD and SSD. The storage unit stores various programs, parameters, and the like for operating each unit such as the electromagnetic valve 19a of the pressure adjusting means 19, the plunger driving means 14, and the valve driving means, and these programs are executed by the processor.

(Operation of liquid supply device 10)
(Initial liquid introduction operation)
The operation of the liquid supply device 10 will be described. First, the operation of introducing liquid into the pump chamber 12 (initial liquid introduction operation) when the pump chamber 12 does not contain any liquid, such as when the liquid supply device 10 is initially used or after cleaning, will be described. In the initial state, the valve 17 of the introduction passage 16 is closed. The controller 20 operates the plunger driving means 14 to move the plunger 13 to the fourth position P4 shown in FIG. Next, the control unit 20 opens the electromagnetic valve 19 a to make the inside of the syringe 18 positive pressure, and operates the valve driving means to open the valve 17 of the introduction passage 16 . In particular, when the liquid has a low viscosity (for example, a liquid with a viscosity of about 0.0008 to 0.2 Pa·s), the positive pressure in the syringe 18 is created by opening and closing the solenoid valve 19a in accordance with the timing of introducing the liquid. By turning on and off, it is possible to prevent the liquid from flowing into the pump chamber 12 even if the valve 17 leaks liquid. Depending on the viscosity of the liquid, the solenoid valve 19a may be kept open to keep the pressure inside the syringe 18 always positive. Next, the control unit 20 operates the plunger driving means 14 to move the plunger 13 from the fourth position P4 toward the first position P1. When the plunger 13 is at the fourth position P4, the opening 16a of the introduction passage 16 is closed by the outer peripheral surface of the plunger 13, but the opening 16a and the pump chamber 12 communicate with each other when the plunger 13 moves upward. , the liquid is introduced into the pump chamber 12 through the introduction passage 16 . The liquid moves into the pump chamber 12 due to the suction force generated by the negative pressure in the pump chamber 12 caused by pulling up the plunger 13 and the force generated by pressurization of the liquid in the syringe 18 and the introduction passage 16 by the pressure adjusting means 19 . 12 introduced. When the liquid has a low viscosity (for example, a liquid with a viscosity of about 0.0008 to 0.05 Pa·s), pressurization by the pressure adjusting means 19 is not necessary, and the liquid is forced into the pump chamber 12 only by the suction force. It is also possible to introduce When the plunger 13 reaches the first position P1, the liquid enters at least the space S1 between the second position P2 and the first position P1; The space S1 between the first position P1 is filled. Further, the liquid may also be introduced into the lead-out path 15, and the liquid may be led out from the lead-out path 15 while the plunger 13 is moving upward.

Before the movement of the plunger 13, the space S3 between the second position P2 and the fourth position P4 inside the pump chamber 12, that is, the space S3 between the upper end 15a of the lead-out passage 15 and the fourth position P4, is filled with air. Although there is air in the space S1, the liquid is introduced from the opening 16a of the introduction passage 16 as soon as the plunger 13 starts to be pulled up, and the air in the space S1 is lowered by the gravity of the liquid and the pressure applied to the liquid by the pressure adjustment means 19. It is pushed to the side and exits from the lead-out path 15. - 特許庁By controlling the operation of the pressure adjusting means 19 by the control unit 20, the pressure applied to the liquid inside the syringe 18 and inside the introduction path 16 is increased by the suction force due to the upward movement of the plunger 13, and the air in the space S3 is bubbled. The pressure is adjusted so as to prevent mixing into the liquid. In addition, when a low-viscosity liquid is introduced into the pump chamber 12, pressurization by the pressure adjusting means 19 is not necessary, and the air can be discharged from the lead-out passage 15 only by the weight of the liquid.

According to the above configuration, in the initial liquid introducing operation, the liquid is introduced into the pump chamber 12 while the air in the space S3 is pushed out from the lead-out passage 15 by the liquid. Since the air is pushed downward by at least the dead weight of the liquid and pushed out from the lead-out path 15, the air is less likely to mix with the liquid. In addition, since the distance L2 between the opening 16a of the introduction passage 16 and the discharge passage 15 in the pump chamber 12 is short, and the volume of the space S3 between the opening 16a of the introduction passage 16 and the discharge passage 15 is also small, the space S3 contains a small amount of air. In the initial liquid introduction operation, the air in the space S3 is pushed out from the lead-out passage 15 by the liquid. Air bubbles are less likely to mix into the liquid introduced to 12 . In addition, since air bubbles are less likely to be mixed with the liquid, waste of the liquid can be reduced because there is little or no need to perform the disposal operation of ejecting and discarding the liquid containing air bubbles before the liquid ejection operation. can.

Further, in the present embodiment, the fourth position P4 of the plunger 13 is set such that the lower end 13a of the plunger 13 is substantially at the same position as the lower end 16c of the opening 16a of the introduction passage 16. As soon as the movement in the direction is started, the opening 16a communicates with the pump chamber 12 and the liquid is introduced into the pump chamber 12.例文帳に追加Therefore, the air in the space S<b>3 can be reliably pushed out from the lead-out path 15 .

Further, since the liquid is introduced into the pump chamber 12 at the same time as the plunger 13 is moved upward to the first position P1, the liquid is introduced into the pump chamber 12 after the plunger 13 is pulled up. Less time required for liquid introduction.

(liquid ejection operation)
Next, after the initial liquid introduction operation and in a state where the pump chamber 12 is sufficiently filled with liquid, an operation (liquid ejection operation) of leading out a desired amount of liquid from the lead-out path 15 toward the work or the ejection target is performed. ) will be explained. The plunger 13 is in the first position P1. The controller 20 closes the valve 17 of the introduction path 16 . In this state, the controller 20 moves the plunger 13 downward by a predetermined distance. The pressure exerted on the liquid by the plunger 13 causes the liquid to be expelled through the lead-out channel 15 . The downward movement speed and vertical movement distance of the plunger 13 are adjusted according to the type of liquid and the object to which the liquid is to be discharged. The liquid is ejected until the plunger 13 reaches the third position P3. The plunger 13 may move from the first position P1 to the third position P3 in one discharge, or may move to the third position P3 after repeated discharges.

Since the valve 17 of the introduction path 16 is closed, the liquid does not enter the introduction path 16 when the plunger 13 pressurizes the liquid, and the liquid is reliably discharged from the lead-out path 15 .

(liquid introduction operation)
Next, an operation (liquid introduction operation) for introducing liquid into the pump chamber 12 in a state in which the amount of liquid filled in the pump chamber 12 has decreased after the liquid discharge operation will be described. The plunger 13 is at the third position P3, and the space S2 between the third position P3 and the second position P2, that is, between the third position P3 and the upper end 15a of the lead-out passage 15 in this embodiment. The space S2 is in a state of being filled with liquid. The controller 20 opens the valve 17 of the introduction passage 16 and moves the plunger 13 upward from the third position P3 to the first position P1. Since the third position P3 is above the opening 16a of the introduction passage 16, the opening 16a is not blocked, and liquid is introduced into the pump chamber 12 from the opening 16a of the introduction passage 16 by pulling up the plunger 13. The liquid is drawn into the pump chamber 12 by a suction force caused by the negative pressure in the pump chamber 12 caused by pulling up the plunger 13 and a force generated by pressurization of the liquid in the flange and the introduction passage 16 by the pressure adjusting means 19. 12 introduced.

When the plunger 13 reaches the first position P1, the liquid fills the space S1 between the upper end 15a of the lead-out passage 15 of the pump chamber 12 and the first position P1. Note that the control unit 20 controls the operation of the pressure adjusting means 19, and the pressure applied to the liquid in the syringe 18 and the introduction path 16 is adjusted by the suction force caused by the upward movement of the plunger 13. The pressure may be adjusted to prevent contamination with the Also in the liquid introducing operation, when a low-viscosity liquid is introduced into the pump chamber 12, pressurization by the pressure adjusting means 19 is not necessarily required.

In the liquid introduction operation, since the space S2 between the third position P3 and the upper end 15a of the lead-out path 15 and the lead-out path 15 are already filled with the liquid, the liquid is introduced into the pump chamber 12 and the space At least part of the liquid in S2 and the outlet passage 15 is drawn out from the outlet passage 15 . This prevents air from entering the pump chamber 12 from the lead-out passage 15 .

Further, in the prior art, air is sucked from the nozzle portion in order to pull up the plunger when liquid is introduced, and foreign substances and thickened liquid with increased viscosity may be sucked in together with the air. These foreign substances and thickened substances cause clogging of the lead-out passage 15 and the pump chamber 12 . In the present embodiment, in the initial liquid introduction operation and the liquid introduction operation, it is possible to prevent foreign substances and thickened substances from being sucked from the lead-out path 15 together with air, and clogging due to foreign substances and thickened substances is less likely to occur.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present invention.

(Another embodiment of the lower end surface 13b of the plunger 13)
4A and 4B show another embodiment of the lower end surface 13b of the plunger 13. FIG. In the embodiment of FIGS. 1 to 3, the lower end surface 13b of the plunger 13 is a flat surface parallel to the plane perpendicular to the direction in which the plunger 13 advances and retreats. It may be formed from a surface inclined at an angle. As shown in FIG. 4A, in a cross section along a plane including the axis of the introduction path 16 and the axis of the plunger 13, the obliquely inclined lower end surface 13b faces the opening 16a of the introduction path 16. The angle α between 13b and the direction orthogonal to the axial direction of the plunger 13 (horizontal direction in FIG. 4A) is set to 10 degrees or more and 70 degrees or less. Since other configurations are the same as those of the embodiment of FIG. 1, descriptions thereof will be omitted by assigning the same reference numerals to corresponding portions.

According to the above configuration, when the plunger 13 is pulled up and the liquid is introduced into the pump chamber 12 from the opening 16a of the introduction passage 16 in the initial liquid introduction operation, the air at the lower end 13a of the plunger 13 is displaced by the liquid. The plunger 13 is pressed obliquely downward along the lower end surface 13b of the plunger 13 and exits the lead-out path 15 downward. Therefore, the air in the space S3, particularly near the lower end 13a of the plunger 13, can be reliably pushed out from the pump chamber 12. As shown in FIG.

Further, as shown in FIG. 4B, the lower end surface 13b of the plunger 13 has a flat surface 13c on the opening 16a side (right side in FIG. 4B) with the axis of the plunger 13 as the center, and is opposite to the opening 16a side. The side may be a surface 13 d that is inclined with respect to the surface perpendicular to the axial direction of the plunger 13 . The oblique surface 13d faces the opening 16a of the introduction path 16, and the angle α between the surface 13d and the direction orthogonal to the axial direction of the plunger 13 is set to 10 degrees or more and 80 degrees or less. Since other configurations are the same as those of the embodiment of FIG. 1, descriptions thereof will be omitted by assigning the same reference numerals to corresponding portions.

Even with the above configuration, the air in the vicinity of the lower end 13a of the plunger 13 in the space S3 is pushed obliquely downward along the oblique surface 13d and exits from the lead-out passage 15. can be extruded from

In this embodiment, the oblique surface 13 is a flat surface, but the surface 13 may be a curved surface and may include a curved surface and a flat surface.

(Other embodiments)
In another embodiment of the present invention, as shown in FIG. 5, a needle 22 ("nozzle , ``dispenser'' and collectively referred to as ``needle'' in this specification) is connected to the liquid ejection device 40. The liquid ejecting apparatus 40 may include sealing means 23 for stopping the liquid from being led out from the lead-out path 15 .

In the embodiment of FIG. 5, the sealing means 23 is detachably attached to the lower end of the needle 22 of the liquid ejecting device 40 . In the present embodiment, the sealing means 23 is a cap that seals the lower end of the needle 22 , but the sealing means 23 is not limited to a cap, and any cap can be used as long as it is possible to stop the liquid from being discharged from the discharge path 15 . For example, it may be a valve that opens and closes the lead-out path 15 . Since the liquid does not flow out from the pump chamber 12 through the lead-out path 15 during the liquid introduction operation, it is possible to prevent the liquid from being wasted. Since other configurations are the same as those of the embodiment of FIG. 1, descriptions thereof will be omitted by assigning the same reference numerals to corresponding portions.

Further, the needle 22 of the liquid ejecting device 40 has a small diameter of the internal liquid flow path. As in the prior art, if foreign substances or thickened substances are sucked in together with the air when the liquid is introduced, the needle 22 is especially likely to be clogged. In the present embodiment, in the initial liquid introduction operation and the liquid introduction operation, it is possible to prevent foreign objects and thickened substances from being sucked in together with air, so clogging of the needle 22 by foreign substances and thickened substances is less likely to occur.

Instead of connecting the joint part 21 and the needle 22 to the lead-out path 15, the sealing means 23 may be directly attached to the lower end of the lead-out path 15 of the liquid supply device 10, and the joint part 21 is connected to the lead-out path 15. The liquid supply device 10 may be configured as a single liquid supply device 10 and the sealing means 23 may be attached to the lower end of the joint portion 21 .

(Other embodiments)
A liquid ejection device 40 of the embodiment shown in FIG. 6 is obtained by attaching first joint portions 21A and 21B, a mixing portion 25, a second joint portion 21C, and a needle 22 to a liquid supply device 10 . The liquid supply device 10 includes a set 30A including a pump chamber 12, a plunger 13, a lead-out passage 15, an introduction passage 16, a valve 17, a valve drive means, a syringe 18, and a pressure adjustment means 19. , 30B. In FIG. 6, the symbols A and B are added to the end of the symbols indicating the respective parts to indicate the sets 30A and 30B to which the respective parts belong. In the following description, the symbols A and B are not attached unless it is particularly necessary to distinguish between the sets 30A and 30B. In the embodiment of FIG. 6, one plunger driving means 14 controls the plungers 13A, 13B of each set 30A, 30B, and one control unit 20 controls pressure adjusting means 19A, 19B, valves 17A, 17B, plungers 13A, 13B. , etc., the plunger driving means 14 and the control section 20 may be provided for each of the sets 30A and 30B. In FIG. 6, illustration of the syringes 18 and the pressure adjusting means 19 of each of the sets 30A and 30B is omitted.

Furthermore, the lead-out paths 15A of the respective sets 30A and 30B are connected to the mixing section 25 via the first joint sections 21A and 21B, respectively. The mixing section 25 is a member for mixing the liquids drawn out from the lead-out passages 15 of the sets 30A and 30B, and includes mixing elements therein, for example. A needle 22 is connected to the lower end of the mixing section 25 via a second joint section 21C.

In the embodiment of FIG. 6, the liquid ejection device 40 mixes and ejects two types of liquid, for example, ejects a two-liquid adhesive that is cured by mixing a main agent and a curing agent. In this case, liquids with different properties (for example, a main agent and a curing agent) are introduced into the pump chambers 12 of each set 30A, 30B. In the initial liquid introduction operation, in each of the sets 30A and 30B, the plunger 13 moves from the fourth position P4 toward the first position P1, and the pump chamber 12 Each liquid is introduced into each pump chamber 12 while pushing out the air inside. The air in the pump chamber 12 passes through the lead-out paths 15A, 15B, the first joint portions 21A, 21B, the second joint portion 21C, the mixing portion 25, and the needle 22 and goes out of the liquid ejection device 40.

Next, in the liquid ejection operation, the plunger 13 moves from the first position P1 toward the third position P3, and a desired amount of each liquid is led out from the lead-out path 15. FIG. Each liquid is mixed in the mixing section 25 and discharged from the needle 22 as a liquid mixed at a desired mixing ratio.

In the liquid introducing operation after the liquid discharging operation, the plunger 13 moves from the third position P3 toward the first position P1 to introduce the liquid into the pump chamber 12 . At this time, the space S2 between the third position P3 and the upper end 15a of the lead-out path 15, the liquid existing in the lead-out path 15, and part of the liquid introduced from the lead-in path 16 are led out from the lead-out path 15. , the mixing portion 25 , the second joint portion 21 C, and the needle 22 . However, unlike the liquid discharge operation, the amount of the liquid drawn out in the liquid introduction operation is not adjusted, so even if these liquids are mixed, the liquid will not be mixed at a desired mixing ratio. Therefore, before starting the next liquid ejection operation, the plunger 13 is moved downward, and the liquid in the mixing section 25, the second joint section 21C, and the needle 22 is ejected from the needle 22 and discarded.

According to the above-described embodiment, in the liquid ejection device 40 that mixes and ejects a plurality of liquids of different types, air bubbles are less likely to mix with the liquid when the liquid is introduced into the liquid pump chamber 12 .

(Other embodiments)
In the embodiment of FIG. 6, the sealing means 23 may be attached to the lower end of the needle 22 to stop the liquid from flowing out from the needle 22 during the initial liquid introduction operation and the liquid introduction operation after the liquid ejection operation. The configuration of the sealing means 23 is the same as that of the embodiment shown in FIG. 5, and detailed description is omitted by assigning the same reference numerals to the corresponding configurations.

In the initial liquid introduction operation, the space S3 between the fourth position P4 of each pair 30A, 30B and the upper end 15a of the lead-out path 15, the lead-out path 15, the first joints 21A, 21B, the mixing part 25, Air is contained in the second joint portion 21C and the needle 22, but liquid is not present. When the sealing means 23 is attached to the lower end of the needle 22 and the plunger 13 is moved upward from the fourth position P4, the liquid is introduced into the pump chamber 12 through the introduction passage 16. As shown in FIG. At this time, the liquid pushes out the air in the pump chamber 12, and the air accumulates inside the first joint portions 21A and 21B, the mixing portion 25, the second joint portion 21C, the needle 22, etc. in a compressed state. After the initial liquid introducing operation is completed and before the liquid discharging operation, the sealing means 23 is removed and the plunger 13 is moved downward until the liquid is discharged from the needle 22 . As a result, the air inside the first joint portions 21A and 21B, the mixing portion 25, the second joint portion 21C, the needle 22 and the like is completely pushed out. After that, the liquid ejection operation is started.

When the plunger 13 reaches the third position P3, the liquid ejection operation is stopped and the liquid introduction operation is performed. A sealing means 23 is attached to the needle 22 . At the start of the liquid introduction operation, the space S2 between the third position P3 of each pair 30A, 30B and the upper end 15a of the lead-out path 15, the lead-out path 15, and the first joint portions 21A, 21B contain liquids of different types, respectively. , and the mixing portion 25, the second joint portion 21C, and the needle 22 are filled with a liquid mixed at a desired mixing ratio. The liquid below the space S3 is not led out by the sealing means 23, and each liquid is introduced from the syringe 18 through the introduction path 16 into the pump chambers 12 of each of the sets 30A and 30B.

According to this configuration, liquid is not discharged from the needle 22 during the initial liquid introduction operation and during the liquid introduction operation, so that the mixing portion 25, the second joint portion 21C, and the liquid inside the needle 22 are filled at a desired mixing ratio. It stays in place and no liquid is wasted. Since other configurations are the same as those of the embodiment of FIG. 1, descriptions thereof will be omitted by assigning the same reference numerals to corresponding portions.

(Other embodiments)
The liquid supply device 10 may have a configuration in which the first joint portions 21A and 21B, the mixing portion 25, the second joint portion 21C, and the needle 22 are removed from the embodiment of FIG. That is, a plurality of sets 30A, 30B of pump chambers 12, plungers 13, lead-out passages 15, lead-in passages 16, valves 17, and valve driving means are incorporated in a pump main body 11. As shown in FIG. In this case, syringes 18 and pressure adjusting means 19 are connected to the introduction paths 15 of the sets 30A and 30B, respectively, and one plunger driving means 14 operates the plungers 13 of the sets 30A and 30B at the same time. A control unit 20 controls the operation of each unit such as pressure adjusting means 19A and 19B, valves 17A and 17B, plungers 13A and 13B.

Since the plungers 13 of each set 30A and 30B are operated simultaneously by one plunger driving means 14, the liquid supply device 10 can simultaneously supply a plurality of liquids of different types. Further, when the diameters of the pump chambers 12 and the plungers 13 of the sets 30A and 30B are set to be different, the plunger 13 is moved downward by the same distance by one plunger driving means 14 in the liquid ejection operation. , the amounts of liquid discharged from the lead-out passages 16 of the sets 30A and 30B can be made different.

(Other embodiments)
FIG. 7 shows another embodiment of the invention. In the liquid supply device 10 of the embodiment shown in FIG. 7, the introduction path 16 is formed inside the plunger 13, and the opening 16a of the introduction path 16 is formed in the lower end surface 13b of the plunger 13. As shown in FIG. The plunger 13 has a cylindrical shape, and the upper end of the plunger 13 is connected to the introduction path main body 24 . ing. A valve 17 for opening and closing the introduction path 16 is provided in the introduction path main body 24 . The introduction path main body 24 is freely movable in the advancing and retreating directions together with the plunger 13 . At least at the beginning of the initial liquid introduction operation, the plunger 13 is in the fifth position P5. The fifth position P5 means that the distance L2 between the opening 16a of the introduction path 16 formed in the lower end surface 13b of the plunger 13 and the second position P2 is the distance between the first position P1 and the second position P2. It is a position that is one-third or less of the distance L1 between . The first position P1 is a position where the lower end 13a of the plunger 13 is the highest, as shown in FIG. The plunger 13 is free to move between a first position P1 and a second position P2. Since other configurations are the same as those of the embodiment of FIG. 1, descriptions thereof will be omitted by assigning the same reference numerals to corresponding portions.

Immediately before starting the initial liquid introduction operation, the valve 17 of the introduction path 16 is closed and the plunger 13 is at the fifth position P5. At the start of the initial liquid introduction operation, the valve 17 of the introduction passage 16 is opened, and the liquid is pushed through the lower end surface 13b of the plunger 13 by the force generated by the pressure adjustment means 19 pressurizing the liquid in the flange and the introduction passage 16. It is introduced into the pump chamber 12 through the opening 16a of the introduction path 16 formed in the . At the same time, the plunger 13 is pulled up from the fifth position P5 towards the first position P1. When the plunger 13 reaches the first position P1, the space S1 between the lower end of the lead-out passage 15 of the pump chamber 12 and the first position P1 is filled. Air exists in the space S4 between the fifth position P5 in the pump chamber 12 and the upper end 15a of the lead-out passage 15, but as soon as the plunger 13 starts to be pulled up, the liquid flows out from the opening 16a of the lead-in passage 16. is introduced, and the air in the space S4 is pushed downward by the liquid and leaves the lead-out passage 15. As shown in FIG.

In the liquid ejection operation, the valve 17 of the introduction passage 16 is closed, and the plunger 13 is moved downward by a predetermined distance from the first position P1. The pressure exerted on the liquid by the plunger 13 causes the liquid to be expelled through the lead-out channel 15 . The liquid ejection operation is performed until the plunger 13 reaches the fifth position P5.

Next, in the liquid introduction operation, the valve 17 of the introduction path 16 is opened, and the plunger 13 is moved upward from the fifth position P5 to the first position P1. The liquid is introduced into the pump chamber 12 through the opening 16 a of the introduction passage 16 by the force generated by the pressure adjustment means 19 pressurizing the liquid inside the flange and the introduction passage 16 . At this time, the space S4 between the fifth position P5 and the upper end 15a of the lead-out path 15 and the lead-out path 15 are already filled with the liquid, and the liquid is led out of the lead-out path 15 by at least the weight of the liquid. may occur. Also, part of the liquid introduced from the introduction path 16 may be led out from the lead-out path 15 .

With the above configuration as well, it is possible to prevent air bubbles from entering the liquid during the initial liquid introduction operation and the liquid introduction operation. Incidentally, the liquid ejecting device 40 may be provided with a needle 22 via a joint portion 21 at the lower end of the lead-out path 15 of the embodiment shown in FIG. . Since the sealing means 23 is the same as that of the embodiment of FIG. 5, the description thereof is omitted.

It should be noted that the dimensions, materials, shapes, relative arrangements, etc. of the components described as the embodiment or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Expressions such as "the same", "identical", "equal", and "homogeneous" to express that things are in an equal state not only express a strictly equal state, It shall also represent the state in which a difference exists. Expressions representing square and circular shapes not only represent shapes such as squares and cylinders in a geometrically strict sense, but also include concave and convex portions and chamfered portions to the extent that the same effect can be obtained. The shape shall also be represented. References to "comprise," "comprise," "comprise," "include," or "have" an element are not exclusive expressions that exclude the presence of other elements. "Parallel" and "perpendicular" mean substantially "parallel" and "perpendicular", and not only strictly "parallel" and "perpendicular" but also include an error of several degrees.

10 Liquid supply device 11 Pump main body 13 Plunger 13b Lower end surface 14 Plunger driving means 15 Lead-out path 16 Lead-in path 16a Opening 17 Valve 18 Syringe 19 Pressure adjusting means 20 Control part L1 Distance between the first position of the plunger and the lead-out path L2 Distance between the opening of the introduction path and the outlet path 1 P1 to P4 First to fourth positions 30A, 30B Group 40 Liquid ejection device

Claims (8)

a pump body having a pump chamber formed therein;
a plunger that advances and retreats with respect to the pump chamber;
a driving means for advancing and retracting the plunger;
a lead-out path provided at one end of the pump chamber for leading out the liquid in the pump chamber;
an introduction passage having an opening communicating with the pump chamber on the other end side of the introduction passage for introducing liquid into the pump chamber;
The distance between a second position where the plunger is closest to one end and the opening of the introduction path at the start of the operation of introducing the liquid from the opening of the introduction path into the pump chamber is the second position and the opening of the introduction path. one-third or less of the distance from the first position when the plunger is at the farthest other end of the pump chamber ,
The opening of the introduction path is formed on the inner surface of the pump chamber on the other end side of the introduction path,
a lower end surface of the plunger located in the pump chamber has at least a flat surface that is inclined with respect to a plane orthogonal to a direction in which the plunger advances and retreats;
The liquid supply device , wherein the oblique flat surface faces the opening of the introduction path . further comprising a valve that opens and closes the introduction path,
In the operation of drawing out the liquid from the lead-out path, the valve closes the lead-in path, and the plunger moves between the first position and a third position above the opening of the lead-in path. 2. The liquid supply device of claim 1, wherein the liquid supply device is free to move. In the operation of introducing liquid into the pump chamber from a state in which the pump chamber contains no liquid, the plunger is positioned between the first position and the fourth position where the plunger closes the opening of the introduction path. 2. The liquid supply device of claim 1 , free to move between. 2. The liquid supply device according to claim 1, comprising a plurality of sets including said pump chamber, said plunger, said introduction path, and said outlet path. 2. The liquid supply device according to claim 1, further comprising sealing means for stopping liquid from being led out from said lead-out path. a syringe connected to the introduction channel and containing a liquid;
pressure adjusting means for adjusting the pressure in the syringe;
3. The liquid supply device according to claim 2 , further comprising a control section that controls the pressure adjustment means, the operation of the valve, and the operation of the plunger. 2. A liquid ejection device in which a needle is connected to the lead-out path of the liquid supply device according to claim 1. 8. The liquid ejecting apparatus according to claim 7, further comprising sealing means for stopping liquid from flowing out from said needle.

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