JP7180916B1 - Liquid supply device and liquid ejection device - Google Patents

Abstract

A liquid supply device and a liquid ejection device that do not leak liquid from a syringe are provided. A liquid supply device (2) includes a piston (12) which is airtightly fitted in a syringe (10) and is freely movable, a rod (13) having a second end provided with the piston (12), and a liquid in the syringe (10). A first air pressure supply unit 41 that supplies air pressure to the first space S1 between the piston 12 and the piston 12, and a second space S2 between the piston 12 and the cap 11 in the syringe 10. a second pneumatic pressure supply unit 44 for supplying pneumatic pressure to move the rod 13 toward the liquid surface; a mechanism 30 for limiting the movement of the rod 13 away from the liquid surface; Air pressure is supplied to the second space S2 by the air pressure supply unit 44 of No. 2 to move the piston 12 in the direction of the liquid surface. and a piston return mechanism 20 for moving away from the plane.

Description

The present invention relates to a liquid supply device and a liquid ejection device, and more particularly to a liquid supply device and a liquid ejection device that eject and supply liquid stored in a syringe.

As a liquid supply device for discharging and supplying a liquid stored in a syringe, for example, one described in Patent Document 1 has been proposed. The liquid supply device described in Patent Document 1 includes a syringe having one end open and a nozzle at the other end, a cap closing one end of the syringe, and a first nozzle inserted into the syringe and pushing the liquid contained in the syringe. and a second plunger inserted above the first plunger. A first space is formed between the first and second plungers in the syringe, and a second space is formed between the second plunger and the cap. One end of a rod is connected to the second plunger, and a first air flow path communicating with the first space is formed inside the rod. A first air pressure supply section for supplying air pressure to the first space through the first air flow path is connected to the other end of the rod. A second air pressure supply unit is connected to the second space via an air supply member to supply air pressure into the second space. In addition, in order to prevent the second plunger from moving in the direction of coming out of the syringe due to the air pressure in the first space, a restraining mechanism is provided as a moving direction restricting section for restricting the movement of the rod.

When the liquid is discharged, air pressure is supplied to the first space through the first air flow path by the first air pressure supply section. The first plunger is pushed down by air pressure, the liquid in the syringe is pushed downward, and a predetermined amount of liquid is supplied to the nozzle and discharged. When such liquid ejection is repeated multiple times, the liquid in the syringe decreases and the volume of the first space increases. Since a constant air pressure is supplied from the first air pressure supply unit for a certain period of time, as the volume of the first space increases, the pressure on the liquid surface decreases and the amount of liquid supplied to the nozzle decreases. Sometimes. For this reason, air pressure is supplied from the second air pressure supply unit to the second space to move the second plunger downward to reduce the volume of the first space, thereby changing the supply amount of the liquid. makes it difficult for In addition, even when the liquid in the syringe is low, the volume of the first space can be kept small, so the air pressure supply time is shortened, realizing liquid supply with quick response.

JP 2018-20291 A

In the invention described in Patent Document 1, the second plunger is connected to one end of the rod, and the rod is restrained from moving upward from the syringe by a restraint mechanism. Therefore, the second plunger can only move downward. After the air pressure is supplied to the second space and the second plunger is pushed down by a predetermined distance until it hits the first plunger, the supply of air pressure to the second space is released. Since the position of the second plunger does not change, there is a problem that the second plunger slightly presses the first plunger and the liquid gradually leaks out of the syringe.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid supply device and a liquid ejection device in which liquid hardly leaks from a syringe.

The liquid supply device of the present invention comprises a syringe having an open first end and a liquid supply portion provided at a second end to contain a liquid; a cap closing the first end of the syringe; a piston hermetically fitted within a syringe and free to move relative to said syringe; a first end extending outwardly from said first end of said syringe; and a first space formed between the liquid in the syringe and the piston, through a first air flow path to supply air pressure for ejecting the liquid. 1 air pressure supply, and a second space formed between the piston and the cap in the syringe, through a second air flow path, the piston in a direction toward the liquid surface. and a second air pressure supply unit for supplying air pressure to move the rod to the first space when air pressure is supplied to the first space by the first air pressure supply unit. a movement restriction mechanism for restricting the movement of the syringe in a direction away from the liquid surface by air pressure; and the second air pressure supply unit supplying air pressure to the second space to move the piston a piston return mechanism for moving the piston away from the liquid surface by a predetermined distance when the air pressure applied to the second space is released after the piston has been moved in the liquid surface direction.

Prior to the start of liquid delivery, the syringe contains liquid and the piston is either in contact with the liquid surface or at a slight distance from the liquid surface. During liquid supply, the first air pressure supply unit supplies air pressure of a predetermined value to the first space for a predetermined time through the first air flow path. At this time, since the rod is prevented from moving away from the liquid surface by the movement limiting mechanism, the air pressure from the first air pressure supply unit presses the liquid surface, and the liquid is supplied from the liquid supply unit to the needle. When the supply of liquid to the needle is repeated a predetermined number of times, the volume of the first space increases. Since a predetermined air pressure is supplied from the first air pressure supply unit, the larger the volume of the first space, the smaller the pressure on the liquid surface, and the less liquid is supplied. For this reason, the air pressure is supplied from the second air pressure supply unit to the second space through the second air flow path, and the piston is moved toward the liquid surface with respect to the syringe, thereby reducing the first space. do. When the piston moves to a position in contact with the liquid surface or a predetermined position slightly separated from the liquid surface, and the second pneumatic pressure supply unit releases the pneumatic pressure supply, the piston return mechanism moves the piston a predetermined distance. Move away from the surface.

According to this embodiment, when the air pressure applied to the second space is released after the air pressure is supplied to the second space by the second air pressure supply unit to move the piston in the liquid surface direction, The piston moves slightly away from the liquid surface. Since the volume of the first space is increased and the pressure on the liquid surface is reduced, it is possible to prevent the liquid from leaking from the syringe.

In a preferred embodiment, the piston return mechanism includes first and second fixing members provided on the second end side of the rod at predetermined intervals, and the piston in a direction away from the liquid surface. a biasing member for biasing said piston, said piston being movably mounted between said first and second fixed members of said rod.

The piston return mechanism includes a chuck mechanism that grips the rod and a biasing member that biases the chuck mechanism away from the liquid surface, and the piston is fixed to the second end of the rod. The gripping force with which the rod is gripped by the chuck mechanism is greater than the biasing force of the biasing member, and the piston and the rod provided with the piston are moved by the air pressure of the second air pressure supply unit. may be less than the force exerted on the rod when moving in the direction toward the surface of the liquid.

In a preferred embodiment, said first air flow path is formed inside said rod.

In another embodiment, an air supply pipe inside which the first air flow path is formed is further provided.

In another embodiment, an air supply tube is further provided, and the first air flow path is formed inside the air supply tube and inside the lower end of the rod.

In a preferred embodiment, the syringe further comprises a sheet material configured to float on the liquid surface of the liquid contained in the syringe.

The sheet material may be locked to the piston.

The sheet material may be made of a material having a lower specific gravity than the liquid contained in the syringe.

In a preferred embodiment, said syringe is fixed to syringe fixing means and said rod is movable with respect to said syringe.

The rod may be fixed to rod fixing means and the syringe may be movable with respect to the rod.

A liquid ejection device according to the present invention is one in which either a needle or a dispenser is connected to the liquid supply portion of the liquid supply device described above.

According to the present invention, it is possible to provide a liquid supply device and a liquid ejection device that are less likely to leak from a syringe.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing the overall schematic configuration of a liquid supply device and a liquid ejection device according to an embodiment of the present invention, and is an explanatory diagram showing a cross section of a main part; (A) is an enlarged cross-sectional view of the piston return mechanism when air pressure is supplied to the second space, and (B) is the piston return mechanism when the supply of air pressure to the second space is released. is an enlarged cross-sectional view of. 4 is an enlarged cross-sectional view of a cap portion; FIG. FIG. 10 is an explanatory diagram showing the overall schematic configuration of another example of the liquid supply device and the liquid ejection device, and is a diagram showing the main part in cross section. The piston return mechanism and the movement restriction mechanism of the embodiment of FIG. 4 are shown, (A) is an enlarged cross-sectional view when air pressure is supplied to the second space, and (B) is an air pressure to the second space. 4 is an enlarged cross-sectional view when the supply of pressure is canceled; FIG. FIG. 10 is an explanatory diagram showing the overall schematic configuration of another example of the liquid supply device and the liquid ejection device, and is a diagram showing the main part in cross section. FIG. 10 is an explanatory diagram showing the overall schematic configuration of another example of the liquid supply device and the liquid ejection device, and is a diagram showing the main part in cross section. FIG. 5 is an enlarged cross-sectional view showing another example of arrangement of sheet materials; FIG. 2 is an explanatory diagram showing a schematic configuration of the entire liquid ejection device in which a dispenser is connected to a liquid supply portion of the liquid supply device, and is a cross-sectional view of a main part; Fig. 10 shows another example of a liquid supply device and a liquid ejection device, where (A) is an explanatory diagram showing a state before liquid is supplied, and (B) shows a state when air pressure is supplied to the second space; It is an explanatory diagram. Fig. 10 shows another example of a liquid supply device and a liquid ejection device, where (A) is an explanatory diagram showing a state before liquid is supplied, and (B) shows a state when air pressure is supplied to the second space; It is an explanatory diagram.

An embodiment of the present invention will be described with reference to the drawings. A liquid ejection device 1 according to the present embodiment shown in FIG. Note that the needle 4 is sometimes called a nozzle.

A stage (not shown) is arranged below the needle 4, and an object to be coated is placed on the upper surface of this stage. The liquid ejecting apparatus 1 ejects liquid from an ejection port 4a opened at the lower end of a needle 4 toward an object to be coated. In the following description, the up-down direction in FIG. 1 is the up-down direction of the liquid supply device 2 and the liquid ejection device 1 .

The liquid supply device 2 of the present embodiment supplies a liquid to a needle 4, and includes a syringe 10 containing the liquid, a cap 11 closing a first end of the syringe 10, and an airtight seal inside the syringe 10. A piston 12 fitted and relatively movable with respect to the syringe 10, a rod 13 provided with the piston 12, a first air pressure supply unit 41, a second air pressure supply unit 44, A movement restriction mechanism 30 that restricts movement of the rod 13 relative to the syringe 10 in a direction away from the liquid surface (also referred to as an “upward direction” in this embodiment), and a predetermined movement of the piston 12 in a direction away from the liquid surface. and a piston return mechanism 20 that moves a distance L1. In this embodiment, the liquid supply device 2 is designed to supply a liquid volume of about 50 nanoliters (0.05 cubic millimeters) to the needle 4 at one time, but the supply amount is not limited to this.

As shown in FIG. 1, the syringe 10 is a substantially cylindrical container with an inner diameter of approximately 13 mm, and contains liquid to be supplied to the needle 4 . A first end (also referred to as “upper end”) of the syringe 10 is open and an outwardly extending flange portion 10a is formed on the upper edge. A downwardly tapering liquid supply portion 3 is provided at the second end (also referred to as a “lower end”), and a needle 4 is connected to the lower end of the liquid supply portion 3 .

A piston 12 provided on the second end side (lower end side) of the rod 13 is arranged above the liquid contained in the syringe 10 and above a sheet material 70 which will be described later. The piston 12 is air-tightly and liquid-tightly fitted to the inner surface of the syringe 10 and is freely movable in the vertical direction. A first space S1 is formed between the piston 12 in the syringe 10 and the liquid surface. Each time air pressure is applied to the first space S1, pressure is applied to the liquid surface and a predetermined amount of liquid is supplied to the needle 4. As shown in FIG. Details of the piston 12 will be described later.

The rod 13 is provided with the piston 12 at its lower end, and its upper end extends outward from the upper end of the syringe 10 . A first air flow path 50 is formed inside the rod 13 from the upper end to the lower end. The lower end of the rod 13 is positioned within the first space S1, and the first air flow path 50 communicates with the first space S1. The upper end of the first air flow path 50 of the rod 13 is connected to the first air pressure supply section 41 outside the syringe 10 .

A cap 11 is attached to a flange 10a at the upper end of the syringe 10 to airtightly close the opening at the upper end of the syringe 10. As shown in FIG. As shown in FIGS. 1 and 3, the cap 11 has a flange engaging portion 11a. be worn.

As shown in FIG. 3, a movement limiting mechanism 30 is provided in the fitting hole 11b provided in the central portion of the cap 11 in plan view. The movement restriction mechanism 30 supplies air pressure to the first space S1 from the first air pressure supply part 41, and when the liquid supply device 2 supplies the liquid from the liquid supply part 3 to the needle 4, the rod 13 is This is to prevent the liquid from moving away from the liquid surface due to the air pressure in the first space S1. The movement restriction mechanism 30 includes a push nut 31 and a holding member 32 that holds the push nut 31 . The holding member 32 has a substantially cylindrical shape and is fixed by being fitted into the fitting hole 11b of the cap 11 . A through hole 33 through which the rod 13 passes is formed in the central portion of the holding member 32 . A concave portion 36 is provided on the upper surface of the holding member 32 , and a through hole 33 opens on the bottom surface of the concave portion 36 . A push nut 31 is arranged on the bottom surface of the recess 36 . The rod 13 is inserted through the push nut 31, and the push nut 31 allows the downward movement of the rod 13 (toward the liquid surface), but does not permit the upward movement (away from the liquid surface). Restrict. A groove 34 is formed around the inner surface of the holding member 32 below the through-hole 33 and accommodates an O-ring 35 for airtightly holding the rod 13 in the through-hole of the holding member 32 .

The configuration of the movement restricting mechanism 30 is not limited to this embodiment, and any configuration may be used as long as it can restrict the upward movement of the rod 13 . For example, the movement limiting mechanism 30 includes a plurality of stepped portions vertically provided on the outer peripheral surface of the rod 13 and locking claws provided on the holding member 32 and engaged with the stepped portions of the rod 13 . may The stepped portion has a sliding surface that is oblique to the central axis of the rod 13 at the bottom thereof in a cross-sectional view, and a locking surface that is a horizontal surface perpendicular to the central axis. The locking claw provided on the sliding surface slides on the sliding surface and locks onto the stepped portion of the rod 13, thereby restricting the upward movement of the rod 13. As shown in FIG.

The cap 11 is provided with an air supply hole 11c through which the air supply pipe 61 is inserted. The upper end of the air supply pipe 61 is connected to the second air pressure supply portion 44, and the lower end is located in the second space S2 formed between the piston 12 and the cap 11. As shown in FIG. A second air flow path 60 is provided inside the air supply pipe 61, and the second air flow path 60 communicates with the second space S2.

The first air pressure supply unit 41 supplies a predetermined air pressure for discharging liquid from the liquid supply device 2 to the first space S1 through the first air flow path 50. and an electromagnetic valve 43. The electromagnetic valve 43 is connected to the pneumatic pressure source 47 via the regulator 42 and to the upper end of the rod 13 . The electromagnetic valve 43 is turned on and off by a control unit (not shown) to open and close the first air flow path 50 provided inside the rod 13. Turning on the electromagnetic valve 43 opens and closes the first air flow path. 50 is opened to supply a predetermined air pressure to the first space S1. The regulator 42 adjusts the pressure supplied from the air pressure source 47 to a desired pressure value. In this embodiment, the electromagnetic valve 43 moves integrally with the rod 13 . However, the electromagnetic valve 43 may be fixed at a predetermined position within the liquid supply device 2 . In this case, the electromagnetic valve 43 is connected to the upper end of the rod 13 via a flexible tube having a length longer than the moving distance of the rod 13, and only the rod 13 is configured to be freely movable.

The second air pressure supply unit 44 supplies air pressure for moving the piston 12 in the direction toward the liquid surface through the second air flow path 60. The regulator 45 and the electromagnetic valve 46 and The electromagnetic valve 46 is connected to the air pressure source 47 via the regulator 45 and to the upper end of the air supply pipe 61 . The electromagnetic valve 46 is turned on and off by a control unit (not shown) to open and close the second air flow path 60 formed inside the air supply pipe 61 . The flow path 60 is opened and a predetermined air pressure is supplied to the second space S2. A regulator 45 adjusts the pressure from the air pressure source 47 to a desired pressure value.

The regulator 42 and the electromagnetic valve 43 of the first air pressure supply section 41, the regulator 45 and the electromagnetic valve 46 of the second air pressure supply section 44, and the control section are known ones. For example, the control unit may be a computer having a CPU and a memory, and may have any configuration as long as it can control on/off of the electromagnetic valves 43 and 46 . When the pressure values of the air pressures supplied by the first air pressure supply unit 41 and the second air pressure supply unit 44 are the same, the regulator 45 of the second air pressure supply unit 44 is set to the first It may also be used as the regulator 42 of the air pressure supply section 41 .

In this embodiment, the syringe 10 is fixed at a predetermined position in the liquid supply device 2 by the syringe fixing means 5, and the rod 13 is guided by a rod guide means (not shown) and is free to move downward.

Details of the configuration of the piston 12 and the piston return mechanism 20 will be described. As shown in FIGS. 2A and 2B, the piston 12 includes a substantially cylindrical piston body 14 and an O-ring 16 . A groove 15 is formed around the outer peripheral surface of the piston body 14 , and an O-ring 16 is accommodated in the groove 15 to ensure airtightness and liquidtightness between the inner surface of the syringe 10 and the piston 12 . A recess 17 having a circular planar shape is provided in the center of the lower surface of the piston body 14 in plan view, and the recess 17 accommodates a sponge 21 that constitutes an urging member of the piston return mechanism 20 . . The sponge 21 urges the piston 12 upward, has a cylindrical shape with a size that can be accommodated in the recess 17, and has a through hole 21a in the center through which the rod 13 is inserted. A through hole 18 penetrating from the bottom surface of the recess 17 to the upper surface of the piston 12 is formed in the central portion of the piston body 14. 13 so as to be freely movable.

First and second fixing members 22 and 23 are fixed to the lower end portion of the rod 13 at predetermined intervals. Piston 12 is positioned between first and second fixed members 22 and 23 and is free to move relative to rod 13 between first and second fixed members 22 and 23 . That is, the piston 12 is free to move downward together with the rod 13 with respect to the syringe 10, and is also free to move vertically between the first and second fixing members 22 and 23 with respect to the rod 13. . In this embodiment, the distance between the first and second fixing members 22 and 23 is set substantially equal to the thickness of the piston body 14, but the distance between the first and second fixing members 22 and 23 may be longer than the thickness of the piston body 14 . The upward movement of the piston 12 is restricted with respect to the rod 13 by abutting the top surface of the piston 12 on the first fixing member 22 , and the piston 12 is pressed against the second fixing member 23 via the sponge 21 , thereby allowing the rod 13 to move. downward movement is restricted. The position of the piston 12 when the downward movement is restricted depends on the degree of contraction of the sponge 21 .

The sponge 21 and the first and second fixing members 22 and 23 constitute a piston return mechanism 20. As shown in FIG. When the piston return mechanism 20 releases the air pressure applied to the second space S2 after the air pressure is supplied to the second space S2 by the second air pressure supply unit 44 to move the piston 12 downward. First, the piston 12 is moved upward by a predetermined distance L1. In this embodiment, the distance between the first and second fixing members 22 and 23 is set to approximately 8 mm, and the free movement distance L1 of the piston 12 is set to approximately 1 mm, but this is not limitative. not.

In this embodiment, the sponge 21 as the urging member of the piston return mechanism 20 is an open-cell sponge made of urethane foam. (Polyethylene)-based and vinyl-based materials may be used. Fluorine sponges are also preferably used as those having high solvent resistance, and silicone sponges as those having good low adhesion properties. In this embodiment, the thickness (vertical length) of the sponge 21 is set to approximately 3 mm. The biasing member is not limited to the sponge 21 as long as it biases the piston 12 away from the liquid surface. etc. may be used.

As shown in FIG. 1, a sheet material 70 is arranged between the piston 12 in the syringe 10 and the liquid surface so as to be in contact with the liquid surface. floating on the liquid surface. The sheet material 70 is circular in plan view, and the outer diameter of the sheet material 70 is smaller than the inner diameter of the cylindrical syringe 10, but is set to cover approximately 50% or more of the liquid surface. In this embodiment, the thickness (length in the vertical direction) is set to about 3 mm, but it is not limited to this. The sheet material 70 is configured to be able to float on the liquid surface, that is, the density of the sheet material 70 is configured to be lower than the density of the liquid. The sheet material 70 is a flexible sheet-like member, and may be made of a material having a lower specific gravity than the liquid. In this embodiment, an open cell sponge made of urethane foam is used as the material. However, not only urethane foam but also natural rubber, synthetic rubber, PE (polyethylene), and vinyl materials may be used. Fluorine sponges are also preferably used as those having high solvent resistance, and silicone sponges as those having good low adhesion properties. Further, regardless of the material of the sheet material 70, an air layer may be provided inside the sheet material 70 so that the sheet material 70 can float on the liquid surface.

The sheet material 70 functions as a liquid intrusion prevention member that prevents a large amount of liquid from entering the first air flow path 50 that opens on the lower surface of the piston 12, and also functions as a liquid intrusion prevention member. It functions as a liquid surface collapse prevention member that prevents the liquid surface from sinking due to the air pressure supplied from the lower end of the. Note that the sheet material 70 may not be provided in the present embodiment.

The operation of the liquid supply device 2 will be described. Before the start of liquid supply, the syringe 10 contains the liquid, and the piston 12 is at a position where the lower surface of the piston body 14 or the lower end of the rod 13 abuts against the sheet material 70, or at a position close to the sheet material 70. . At this time, the first air flow path 50 provided inside the rod 13 is prevented from entering the liquid by the sheet material 70 or is allowed to enter a slight amount of liquid. When the sheet member 70 is not provided, the lower surface of the piston body 14 and the lower end of the rod 13 are in contact with the liquid surface or are in close proximity to the liquid surface.

During liquid supply, the first air pressure supply unit 41 supplies air pressure of a predetermined value to the first space S1 for a predetermined time through the first air flow path 50 of the rod 13 . At this time, as shown in FIG. 2B, the upper surface of the piston body 14 abuts against the first fixing member 22 to restrict the upward movement of the piston 12, and the rod 13 is moved upward by the movement limiting mechanism 30. Since the needle 4 does not move in any direction, the air pressure from the first air pressure supply section 41 presses the liquid surface, and the liquid is supplied from the liquid supply section 3 to the needle 4 .

When the supply of the liquid to the needle 4 is repeated a predetermined number of times, the volume of the first space S1 increases. Since a predetermined air pressure is supplied from the first air pressure supply unit 41, the larger the volume of the first space S1, the smaller the pressure on the liquid surface, which may reduce the amount of liquid supplied. When the volume of the first space S1 becomes larger than a predetermined set value, air pressure is supplied from the second air pressure supply section 44 to the second space S2 to reduce the first space S1, thereby causing the piston to move. 12 is moved downward relative to the syringe 10;

The second air pressure supply unit 44 supplies air pressure of a predetermined value to the second space S2 for a predetermined time through the second air flow path 60 of the air supply pipe 61 provided in the cap 11 . At this time, as shown in FIG. 2(A), the piston 12 moves downward with respect to the rod 13, the sponge 21 of the piston return mechanism 20 abuts against the second fixing member 23, and the piston 12 moves to the second position. The downward movement is regulated by the fixing member 23 of . At this time, the sponge 21 is compressed by being pressed against the second fixing member 23 by the piston body 14, and accumulates an upward biasing force. Since the rod 13 is free to move downward, the rod 13 and the piston 12 move further downward together.

When the lower surface of the piston body 14 of the piston 12 and the lower end of the rod 13 descend to a predetermined position where the lower end of the rod 13 contacts the sheet material 70 and the second air pressure supply unit 44 stops supplying the air pressure, the air accumulates in the sponge 21 . The applied urging force is released, and the piston 12 is moved upward by a distance L1 until the upper surface of the piston body 14 comes into contact with the first fixing member 22, as shown in FIG. 2(B). It should be noted that the piston 12 does not necessarily have to move upward until the upper surface of the piston body 14 comes into contact with the first fixing member 22 .

Air pressure is supplied to the second space S2 by the second air pressure supply unit 44, and after the piston 12 is moved to a predetermined position in the direction toward the liquid surface, the air pressure applied to the second space S2 is released. However, if the piston 12 is fixed at a predetermined position, the piston 12 slightly presses the liquid surface through the first space even after the air pressure is released by the second air pressure supply unit 44, and the liquid is leaks slowly from the syringe. On the other hand, in this embodiment, after the piston 12 moves toward the liquid surface to a predetermined position, the piston 12 is moved slightly away from the liquid surface by the piston return mechanism. Therefore, the volume of the first space S1 is slightly increased and the pressure on the liquid surface is reduced, so that the liquid can be prevented from leaking from the syringe 10 little by little.

In addition, since the first air flow path 50 is formed inside the rod 13 in this embodiment, the structure of the liquid supply device 2 is simpler than when the first air flow path 50 is provided separately. . Furthermore, since the sheet material 70 is arranged on the liquid surface, the liquid surface is less likely to come into contact with the opening of the first air flow path 50 at the lower end of the rod 13, and the liquid does not enter the first air flow path 50. can be prevented. Furthermore, when air pressure is supplied from the lower end of the rod 13 toward the liquid surface, the liquid surface may become depressed and the amount of liquid supplied may change. can prevent the formation of dents in the

4 and 5 show another embodiment of the invention. In this embodiment, the configuration of the piston 12 and the configuration of the piston return mechanism 20 are different from the embodiment of FIG. As shown in FIG. 4, the piston 12 has a cylindrical piston body 14 and a groove 15 for accommodating an O-ring 16 on the outer peripheral surface thereof. The piston body 14 is fixed to the lower end side portion of the rod 13, and the lower end of the rod 13 protrudes slightly from the lower surface of the piston body 14 and is located in the first space S1. It communicates with the space S1 of 1.

As shown in FIG. 5, an elastic spring 24 constituting an urging member is supported by support means (not shown) below the fitting hole 11b of the cap 11, and is above the fitting hole 11b and above the elastic spring 24. , the holding member 32 of the movement limiting mechanism 30 is slidably arranged in the fitting hole 11b. The lower surface of the holding member 32 is fixed to the upper end surface of the elastic spring 24, which urges the holding member 32 upward and prevents the holding member 32 from coming out of the fitting hole 11b. A chuck mechanism 25 is provided on the upper surface of the holding member 32 to hold the rod 13 passing through the holding member 32 with a predetermined holding force. The chuck mechanism 25 and the elastic spring 24 that constitutes the biasing member constitute the piston return mechanism 20 .

When the second air pressure supply unit 44 applies air pressure to the second space S2, the piston 12 moves downward together with the rod 13. At this time, the chuck mechanism 25 gripping the rod 13 moves downward. Under the force, the holding member 32 located below the chuck mechanism 25 is pushed downward by the chuck mechanism 25 , and the chuck mechanism 25 and the holding member 32 move downward together with the rod 13 . When the elastic spring 24 is compressed to the limit and the downward movement of the chuck mechanism 25 and the holding member 32 is restricted, the downward pulling force of the rod 13 becomes larger than the gripping force of the chuck mechanism 25, and the rod 13 is pulled downward. 13 moves downward even though it is gripped by the chuck mechanism 25 . When the supply of the air pressure to the second space S2 by the second air pressure supply part 44 is released, the elastic spring 24 urges the holding member 32 and the chuck mechanism 25 upward, and the chuck mechanism 25 grips it. The rod 13 thus moved moves upward together with the chuck mechanism 25 and the holding member 32 .

The gripping force in the vertical direction with which the rod 13 is gripped by the chuck mechanism 25 is greater than the biasing force of the elastic spring 24, but the air pressure of the second air pressure supply unit 44 causes the piston 12 and the rod 13 to move downward. It is set to a magnitude smaller than the downward force applied to the rod 13 when it moves. The elastic spring 24 and chuck mechanism 25 constitute the piston return mechanism 20 . 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.

The operation of the liquid supply device 2 of the embodiment of FIG. 4 will be described. During liquid supply, the first air pressure supply unit 41 supplies air pressure of a predetermined value to the first space S1 for a predetermined time through the first air flow path 50 of the rod 13 . At this time, as shown in FIG. 5B, the holding member 32 and the chuck mechanism 25 are urged upward by the elastic spring 24, and the gripping force of the push nut 31 and the chuck mechanism 25 causes the rod 13 to move. It does not move upward, and the air pressure from the first air pressure supply section 41 presses the liquid surface, and the liquid is supplied from the liquid supply section 3 to the needle 4 .

Next, the second air pressure supply unit 44 supplies a predetermined air pressure to the second space S2 for a predetermined time through the second air flow path 60 of the air supply pipe 61 to move the piston 12 downward with respect to the syringe 10. move in the direction At this time, the piston 12 is pressed downward by air pressure, and as shown in FIG. Moving. The elastic spring 24 is pushed and compressed by the holding member 32, and an upward biasing force is accumulated. Further, when the air pressure continues to be supplied to the second space S2, the rod 13 receives a downward force greater than the gripping force of the chuck mechanism 25, and the rod 13 moves further downward with respect to the chuck mechanism 25. .

When the piston 12 descends to a predetermined position and the second air pressure supply section 44 stops supplying air pressure, the biasing force accumulated in the elastic spring 24 is released as shown in FIG. 5(B). The holding member 32 is moved upward, and the rod 13 gripped by the chuck mechanism 25 and the piston 12 fixed to the rod 13 are also moved upward.

As described above, according to the present embodiment as well, the air pressure is supplied to the second space S2 by the second air pressure supply unit 44, and the air pressure is applied to the second space S2 after the piston 12 is moved in the liquid surface direction. When the pressure is released, the piston 12 moves slightly away from the liquid surface, so the volume of the first space S1 slightly increases and the pressure on the liquid surface decreases, so the liquid leaks from the syringe 10. can be prevented. Moreover, since the cap 11 is provided with the piston return mechanism 20, maintenance of the piston return mechanism 20 is easy.

FIG. 6 shows another embodiment of the invention. In this embodiment, the rod 13 is a columnar rod-shaped member, and the first air flow path is not provided inside. The liquid supply device 2 includes an air supply pipe 51, the upper end of which is located outside the syringe 10, the air supply pipe 51 is connected to the electromagnetic valve 43 of the first air pressure supply part 41, and the lower end of the air supply pipe 51 is located outside the syringe 10. It is located in the first space S1. A first air flow path 50 is formed inside the air supply pipe 51 , and the first air flow path 50 communicates with the first space S<b>1 at its lower end to supply air from the first air pressure supply section 41 . Air pressure is supplied to the first space S1.

The air supply pipe 51 includes a first air supply pipe 52 , a second air supply pipe 53 and a third air supply pipe 54 . The first air supply pipe 52 is inserted through the first through hole 11 d formed in the cap 11 , and the upper end is positioned outside the syringe 10 and connected to the electromagnetic valve 43 of the first air pressure supply section 41 . The lower end is located in the upper part of the second space S2 and is connected to the second air supply pipe 53 by a connecting member. The second air supply pipe 53 is arranged in the second space S2, and has its upper end connected to the lower end of the first air supply pipe 52 and its lower end connected to the upper end of the third air supply pipe 54 . The second air supply pipe 53 is made of, for example, a flexible tube, and the length of the tube is set longer than the moving distance of the piston 12 and the rod 13 with respect to the syringe 10 . The second air supply pipe 53 is deformable as the piston 12 and rod 13 move. The third air supply pipe 54 is inserted and held in the second through hole 19 provided in the piston body 14, and its upper end is located in the second space S2 and is connected to the lower end of the second air supply pipe 53 by a connecting member. and the lower end is located in the first space S1. The first air supply pipe 52, the second air supply pipe 53, and the third air supply pipe 54 are formed with first to third air supply passages 52a, 53a, and 54a communicating with each other. Each air supply path 52 a , 53 a , 54 a constitutes a first air flow path 50 . The position of the electromagnetic valve 43 connected to the first air supply pipe 52 of the air supply pipe 51 is below the lower end of the rod 13 and the position of the upper end of the rod 13 when the piston 12 is in an upper position close to the cap 11. Then, the length of the first air supply pipe 52 is adjusted. 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 this embodiment, the first air flow path 50 is not provided inside the rod 13 as in the embodiment of FIG. 51 is provided. Therefore, it is not necessary to provide the electromagnetic valve 43 of the first air pressure supply section 41 at the upper end of the rod 13 . The rod 13 extends upwardly from the cap 11, and when the lower end of the rod 13 and the piston 12 are in an upper position close to the cap 11, the length of extension of the rod 13 from the cap 11 is increased. The liquid supply device 2 is sized to accommodate the rod 13 in a housing (not shown) even when the rod 13 extends from the cap 11 . When the electromagnetic valve 43 of the first air pressure supply unit 41 is connected to the upper end of the rod 13, the rod 13 and the electromagnetic valve 43 protrude upward from the cap 11, and the liquid supply device 2 The housing of the becomes larger. However, since the electromagnetic valve 43 does not have to be provided at the upper end of the rod 13 in this embodiment, the upward projection length from the cap 11 is shortened by the length of the electromagnetic valve 43 as compared with the embodiment of FIG. , the liquid supply device 2 can be made more compact.

FIG. 7 shows another embodiment of the invention. The embodiment of FIG. 7 differs from the embodiment of FIG. 6 in the configuration of the air supply pipe 51 and the first air flow path. In the embodiment of FIG. 7, a third air supply passage 58 is provided inside the lower end of rod 13 . Further, an air supply pipe 55 consisting of a first air supply pipe 56 and a second air supply pipe 57 is provided, and inside the first air supply pipe 56 and the second air supply pipe 57 are a first air supply pipe 56a and a second air supply pipe 56a. An air supply passage 57a is formed. The upper end of the third air supply path 58 is the outer peripheral surface of the rod 13 and opens into the second space S2 and is connected to the lower end of the second air supply path 57 . The lower end of the third air supply passage 58 is open to the bottom surface of the rod 13 and communicates with the first space S1. The first to third air supply paths 56a, 67a, 58 communicate with each other to form the first air flow path 50. As shown in FIG. Other configurations are the same as those in the embodiment of FIG. 6, so corresponding parts are denoted by the same reference numerals and descriptions thereof are omitted.

According to this embodiment, since the downstream portion of the first air flow path 50 is formed inside the lower end of the rod 13, a new air supply pipe is provided in the piston body 14 as in the embodiment of FIG. do not need to be installed. Therefore, even if the syringe 10 is small, the piston body 14 is small, and there is not enough space to install a new air supply pipe, the first air pressure supply part 41 is provided at the upper end of the rod 13. A configuration for supplying air pressure to the first space S1 can be realized without providing the electromagnetic valve 43. Compared to the embodiment of FIG. 1, the upward projection length from the cap 11 is shortened by the length of the electromagnetic valve 43, and the liquid supply device 2 can be made more compact.

FIG. 8 shows another embodiment of the invention. The embodiment of FIG. 8 differs from the embodiment of FIG. 1 in that the sheet member 70 is locked to the piston 12 by a sheet member supporting member 71. As shown in FIG. The sheet material support member 71 is composed of a plurality of rod-like members 71A provided so as to protrude downward from the lower surface of the piston 12 . In this embodiment, a plurality of (for example, four) rod-shaped members 71A are provided on the same circumference at intervals of a predetermined center angle (for example, 90 degrees) in plan view. A retaining member 71a having a larger diameter than the body portion 71b of the rod-shaped member 71A is provided at the tip of each rod-shaped member 71A. The sheet material 70 is provided with holes 70a at locations corresponding to the rod-shaped members 71A. The diameter of the hole 70a is set to be smaller than the retaining member 71a of the rod-shaped member 71A and slightly larger than the diameter of the body portion 71b. A tensile force is applied to the sheet material 70 to enlarge the hole 70a, and the retaining member 71a and the rod-like member 71A are passed through the hole 70a, and the sheet material 70 is locked to the retaining member 71a. The sheet material 70 is vertically movable with respect to the rod member 71A. Although the length of the rod-like member 71A is set to about 3 mm in this embodiment, it is not limited to this. By moving the piston 12 so that the vertical length of the first space S1, that is, the distance between the liquid surface and the lower surface of the piston body 14, is always smaller than the length of the rod-shaped member 71A, the seat The material 70 is kept floating on the liquid surface. 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 this embodiment, since the sheet material 70 is locked to the piston 12, the sheet material 70 can be taken out together when the piston 12 is removed from the syringe 10, and the work of taking out the sheet material 70 is facilitated. Become.

FIG. 9 shows another embodiment of the invention. The liquid ejection device 1 of this embodiment shown in FIG. 9 differs from the implementation of FIG. different from the form. The dispenser 80 of this embodiment discharges the liquid by pressurizing the liquid. 82 and a nozzle plate 84 provided on the lower surface of the head body portion 81 .

The nozzle plate 84 includes a portion 85 into which one end of the pressure member 82 protruding from the head body portion 81 is inserted, an introduction channel 86 for introducing liquid, and a discharge channel 87 formed at the bottom of the recess 85 . ing. A joint portion 88 is formed on the side surface of the nozzle plate 84 , and the inlet of the joint portion 88 communicates with the introduction channel 86 . The liquid supply portion 3 of the liquid supply device 2 is connected to the inlet of the joint portion 88 through the liquid flow pipe 6 . The liquid supplied from the liquid supply device 2 is guided to the concave portion 85 through the introduction channel 86 of the nozzle plate 84 and is discharged from the tip of the discharge channel (nozzle) 87 by pressing with the pressure member 82 .

In this manner, even when the dispenser 80 is connected to the liquid supply device 2, the liquid can be discharged without causing fluctuations in the discharge amount. In addition, the configuration of the dispenser 80 is not limited to the configuration of the present embodiment, and any dispenser 80 may be used. 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.

FIG. 10 shows another embodiment of the invention. In the embodiment of FIG. 1, the syringe 10 is fixed to the syringe fixing means 5, and the piston 12 and the rod 13 move vertically with respect to the syringe 10. However, in this embodiment, the rod 13 is fixed. The syringe 10 is fixed by the means 7 and is vertically movable with respect to the rod 13 while being guided by a syringe guide means (not shown). A needle 4 is connected to the liquid supply portion 3 of the liquid supply device 2 via a flexible liquid flow tube 8 . The needle 4 is fixed to a needle (not shown) so that the position P1 of the ejection port 4a opening at the lower end surface of the needle 4 is the same as the position of the liquid surface when the syringe 10 is filled with the liquid before the liquid is ejected. fixed by means. 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.

The operation of the liquid supply device 2 will be described. Before the liquid is supplied, as shown in FIG. 10A, the cylinder contains the liquid, and the lower surface of the piston 12 is close to the sheet material 70 and the liquid surface. During liquid supply, the first air pressure supply unit 41 supplies a predetermined air pressure to the first space S1 for a predetermined time through the first air flow path 50 of the rod 13 . The air pressure from the first air pressure supply section 41 presses the liquid surface, and the liquid is supplied from the liquid supply section 3 to the needle 4 . At this time, the rod 13 is not moved by the rod fixing means 7 .

When the supply of the liquid to the needle 4 is repeated a predetermined number of times, the liquid surface is positioned below the discharge port 4a of the needle 4 and the volume of the first space S1 increases. In order to reduce the volume of the first space S1, the second air pressure supply section 44 supplies a predetermined air pressure to the second space S2 for a predetermined time. Since the rod 13 is fixed, the syringe 10 moves upward as shown in FIG. When the second air pressure supply unit 44 stops supplying the air pressure, the urging force accumulated in the sponge 21 is released to move the piston 12 upward and reduce the pressure applied to the liquid surface.

According to the present embodiment, even if the amount of liquid contained in the syringe 10 decreases as the discharge of the liquid progresses, the syringe 10 moves upward relative to the rod 13 and the piston 12. The height position of the liquid surface of the liquid thus obtained does not largely deviate from the height position P1 of the discharge port 4a of the needle 4.例文帳に追加Therefore, it is possible to prevent the supply amount of the liquid from fluctuating depending on the remaining amount of the liquid. Further, since the height position of the liquid surface and the height position of the discharge port 4a do not largely deviate, even if the discharge operation is not performed for a long time, the liquid will not flow out from the needle 4 or air will be sucked in from the needle 4. There is no

FIG. 11 shows another embodiment of the invention. In the embodiment of FIG. 1, the syringe 10 is fixed to the syringe fixing means 5, and the piston 12 and the rod 13 move vertically with respect to the syringe 10. However, in this embodiment, the rod 13 is fixed. The syringe 10 is fixed by the means 7 and is vertically movable with respect to the rod 13 while being guided by a syringe guide means (not shown). A dispenser 80 is connected to the liquid supply section 3 of the liquid supply device 2 via the liquid flow pipe 6 . The liquid flow tube 6 is a tube having flexibility, and its length is set longer than the moving distance of the syringe 10 . The configuration of the dispenser 80 is, for example, the same as the configuration shown in FIG. 9, but is not limited to this. The syringe 10 is arranged so as to be always higher than the discharge channel 87 of the dispenser 80 . 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.

The operation of the liquid supply device 2 will be described. Before the liquid is supplied, as shown in FIG. 11A, the cylinder contains liquid up to position P2, and the piston 12 is at a position close to the sheet material 70 and the liquid surface. During liquid supply, the first air pressure supply unit 41 supplies a predetermined air pressure to the first space S1 for a predetermined time through the first air flow path 50 of the rod 13 . The air pressure from the first air pressure supply section 41 presses the liquid surface, and the liquid is supplied from the liquid supply section 3 to the dispenser 80 . At this time, the rod 13 is not moved by the rod fixing means 7 .

When the supply of the liquid to the needle 4 is repeated a predetermined number of times, the liquid level drops and the volume of the first space S1 increases. In order to reduce the volume of the first space S1, the second air pressure supply section 44 supplies a predetermined air pressure to the second space S2 for a predetermined time. Since the rod 13 is fixed, the syringe 10 moves upward as shown in FIG. When the second air pressure supply unit 44 stops supplying the air pressure, the urging force accumulated in the sponge 21 is released to move the piston 12 upward and reduce the pressure applied to the liquid surface.

According to the present embodiment, even if the amount of liquid stored in the syringe 10 decreases as the liquid discharge progresses, the syringe 10 moves upward relative to the rod 13 and the piston 12. The height position P2 of the liquid surface of the liquid does not deviate greatly. Therefore, it is possible to prevent the supply amount of the liquid from fluctuating depending on the remaining amount of the liquid.

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.

1 liquid ejection device 2 liquid supply device 3 liquid supply part 4 needle 4a ejection port 5 syringe fixing means 6, 8 liquid flow pipe 7 rod fixing means 10 syringe 11 cap 12 piston 13 rod 14 piston body 20 piston return mechanism 21 sponge 22 First fixing member 23 Second fixing member 24 Elastic spring 30 Movement limiting mechanism 31 Push nut 32 Holding member 41 First air pressure supply section 44 Second air pressure supply section 50 First air flow path 51 Air supply pipe 52 to 54 first to third air supply pipes 52a to 54a first to third air supply passages 55 air supply pipes 56 to 58 first to third air supply pipes 60 second air flow passage 61 supply Trachea 70 Sheet material 71 Sheet material support member 80 Dispenser L1 Distances P1 and P2 of piston movement Position of liquid surface S1 First space S2 Second space

Claims (12)

a syringe open at a first end and provided with a liquid supply at a second end and containing a liquid;
a cap closing the first end of the syringe;
a piston hermetically fitted in the syringe and free to move relative to the syringe;
a rod having a first end extending outwardly from the first end of the syringe and having the piston at a second end;
a first air pressure supply unit that supplies air pressure for ejecting liquid through a first air flow path to a first space formed between the liquid in the syringe and the piston; ,
Air pressure for moving the piston toward the surface of the liquid is applied through a second air flow path to a second space formed between the piston and the cap in the syringe. a second pneumatic supply that supplies
When air pressure is supplied to the first space by the first air pressure supply unit, the air pressure in the first space causes the rod to move away from the surface of the liquid with respect to the syringe. a movement restriction mechanism that restricts the
When the air pressure applied to the second space is released after the air pressure is supplied to the second space by the second air pressure supply unit to move the piston in the liquid surface direction, the piston is a piston return mechanism that moves a predetermined distance in a direction away from the liquid surface;
A liquid supply device comprising: The piston return mechanism includes first and second fixing members provided on the second end side of the rod at predetermined intervals, and an urging member that urges the piston away from the liquid surface. and
2. The liquid supply device according to claim 1, wherein said piston is movably mounted between said first and second fixed members of said rod. The piston return mechanism includes a chuck mechanism that grips the rod and a biasing member that biases the chuck mechanism away from the liquid surface,
the piston is fixed to the second end of the rod;
The gripping force with which the rod is gripped by the chuck mechanism is larger than the biasing force of the biasing member, and the air pressure of the second air pressure supply unit causes the piston and the rod on which the piston is provided to be liquid. 2. The liquid supply device according to claim 1, wherein the force applied to said rod when moving in a direction toward the liquid surface of said liquid supply device is smaller than the force applied to said rod. 4. The liquid supply device according to any one of claims 1 to 3, wherein said first air flow path is formed inside said rod. 4. The liquid supply device according to any one of claims 1 to 3, further comprising an air supply pipe in which said first air flow path is formed. further comprising an air supply pipe,
4. The liquid supply device according to any one of claims 1 to 3, wherein said first air flow path is formed inside said air supply pipe and inside a lower end portion of said rod. 7. The liquid supply device according to any one of claims 1 to 6, further comprising a sheet material configured to float on the surface of the liquid contained in said syringe. 8. The liquid supply device according to claim 7, wherein said sheet member is engaged with said piston. 9. The liquid supply device according to claim 7, wherein said sheet material is made of a material having a specific gravity smaller than that of the liquid contained in said syringe. 10. The liquid supply device according to any one of claims 1 to 9, wherein the syringe is fixed to syringe fixing means and the rod is movable with respect to the syringe. 10. The liquid supply device according to any one of claims 1 to 9, wherein the rod is fixed to rod fixing means and the syringe is movable with respect to the rod. 12. A liquid ejection device, wherein either a needle or a dispenser is connected to the liquid supply portion of the liquid supply device according to any one of claims 1 to 11.

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