JP6807524B2 - Liquid supply device - Google Patents

Description

The present invention relates to a liquid supply device that discharges and supplies a liquid stored in a syringe.

A substantially cylindrical syringe is used as a container for storing a liquid such as an adhesive paste. When supplying the liquid from the syringe, air pressure is supplied to the inside of the syringe, and the liquid is pressurized through the plunger inserted inside the syringe to discharge the liquid from the lower end of the syringe. In the discharge of the liquid by pressurization through the plunger, the discharge amount of the liquid fluctuates as the amount of the liquid stored in the syringe changes. That is, when the remaining amount of liquid in the syringe decreases, the empty volume in which no liquid exists in the syringe increases, and even if air pressure is supplied under the same conditions, the pressing force exerted on the liquid due to the compressibility of air is not constant. There is a drawback that stable liquid discharge cannot be performed due to fluctuations in the discharge amount and discharge response time. For the purpose of improving such a defect of liquid discharge by a syringe, a liquid supply device devised so that the volume of an empty portion in the syringe is substantially constant has been conventionally proposed (for example, a patent). Documents 1 and 2).

In the prior art shown in Patent Document 1, in a dispenser configured to pressurize the inside of the syringe 3 by the air pressure supplied from the pipe 12 and move the plunger to discharge the liquid, the inside of the syringe 3 having an integral structure with the pipe 12 The piston 13 is moved by the pipe drive unit 12A so that the volume of the empty portion in the syringe 3 becomes substantially constant. Further, in the prior art shown in Patent Document 2, the piston is based on the result of detecting the air pressure of the pressure adjusting chamber 115, which is an empty space formed between the piston 113 and the liquid level in the syringe 112, by the pressure sensor 121. The position of the 113 in the syringe 112 is controlled.

Japanese Unexamined Patent Publication No. 4-247261 Japanese Unexamined Patent Publication No. 2013-193001

Since a liquid supply device that uses a syringe as a storage container is widely and widely used, its configuration is simple in addition to the function of discharging and supplying a certain amount of liquid with stable responsiveness as described above. Moreover, it is desired that the workability at the time of maintenance such as replacement of a syringe is excellent. However, the prior art shown in the above-mentioned examples of patent documents cannot always satisfy such a demand, and a new measure has been required.

Therefore, an object of the present invention is to provide a liquid supply device capable of supplying a fixed amount of liquid with stable responsiveness in a configuration using a syringe as a storage container with a simple configuration.

The liquid supply device of the present invention has a substantially cylindrical syringe in which one end is opened and a discharge pipe is connected to the other end, and the liquid is inserted into the syringe and pushes the liquid in the syringe toward the other end. a first plunger, sandwiched between the second plunger than said first plunger is inserted into the one end side, from outside the space before Symbol syringe and said first plunger and said second plunger From the first air flow path leading to the first space, the first air pressure supply unit that supplies air pressure to the first space through the first air flow path, and the space outside the syringe. Air pressure is supplied to the second space through a second air flow path leading to a second space located between the one end portion of the syringe and the second plunger and the second air flow path. It is provided with a second pneumatic supply unit .

According to the present invention, in a configuration using a syringe as a storage container, a constant amount of liquid can be supplied with stable responsiveness with a simple configuration.

Configuration explanatory view of the dispenser which incorporated the liquid supply device of one Embodiment of this invention Configuration explanatory view of the liquid supply device of one embodiment of the present invention Exploded view of the liquid supply device according to the embodiment of the present invention Explanatory drawing of movement direction limiting part in liquid supply apparatus of one Embodiment of this invention An operation explanatory view of the liquid supply device according to the embodiment of the present invention.

Next, an embodiment of the present invention will be described with reference to the drawings. First, the configuration of the dispenser 1 in which the liquid supply device 2 of the present embodiment is incorporated will be described with reference to FIG. In FIG. 1, the dispenser 1 is a droplet of liquid 11 from a nozzle 10 provided at the lower end of a liquid storage portion 9 provided with a discharge head 8 with respect to a coating object 13 placed on the upper surface of a stage 12. Has a function of flying and discharging (arrow a).

The liquid supply device 2 described below is incorporated in the dispenser 1. The liquid supply device 2 supplies the liquid 11 stored in the syringe 3 to the liquid storage unit 9 provided in the discharge head 8 via the supply pipe 5. The discharge head 8 includes an actuator that drives a liquid discharge mechanism built in the liquid storage unit 9, and the discharge head 8 is driven by a driver 7 that receives a command from the dispenser control unit 6, whereby the liquid 11 from the nozzle 10 Droplets are ejected. That is, in the example shown here, the connecting member 4 which is a discharge pipe provided in the syringe 3 is connected to the liquid storage portion 9 of the dispenser 1 which discharges the liquid 11 via the supply pipe 5.

Next, the configuration and function of the liquid supply device 2 will be described with reference to FIGS. 2 to 5. Note that, unlike the example shown in FIG. 1, an example in which the liquid supply device 2 is used alone is shown. Therefore, as a discharge pipe attached to the syringe 3, a nozzle 4a for discharging the liquid 11 is connected instead of the connecting member 4 for connecting the supply pipe 5.

In FIG. 2, the syringe 3 for storing the liquid 11 is a substantially cylindrical container. As shown in FIG. 3, a flange portion 3c extending outward is formed on the outer periphery of one end portion 3a, which is the upper end portion of the syringe 3, and the entire inner circumference is open. A nozzle 4a, which is a discharge pipe for discharging the liquid 11, is connected to the other end 3b (the lower end of the syringe 3) on the opposite side of the one end 3a.

A first plunger 21 that pushes the liquid 11 in the syringe 3 toward the other end 3b side is inserted in the syringe 3. By pushing down the first plunger 21, the liquid 11 in the syringe 3 is pressed toward the other end 3b side and discharged from the nozzle 4a. A second plunger 22 is inserted at one end 3a side of the first plunger 21 at a predetermined interval. The space sandwiched between the first plunger 21 and the second plunger 22 inside the syringe 3 is the first space S1. In the present embodiment, the first plunger 21 is pushed down by applying an air pressure in the first space S1.

The first plunger 21 has a bowl shape in which the central portion thereof is recessed toward the other end 3b side of the syringe 3. The second plunger 22 has a shape in which the central portion of the surface facing the first plunger 21 projects toward the first plunger 21. By forming the first plunger 21 and the second plunger 22 in such a shape, the volume of the first space S1 sandwiched between the first plunger 21 and the second plunger 22 can be reduced as much as possible. it can. Therefore, in a configuration in which the first plunger 21 is pushed down by applying air pressure in the first space S1, it is possible to improve the responsiveness of the pushing down operation of the first plunger 21.

A cap 23 for covering the upper end portion is attached to one end portion 3a of the syringe 3. As shown in FIG. 3, a flange engaging portion 23b is formed on the cap 23. By setting the cap 23 on one end portion 3a and engaging the flange portion 3c with the flange engaging portion 23b, the cap 23 is formed. Is attached to the syringe 3. The cap 23 is provided with a seal portion 26 for airtightly inserting the rod 24, which is a rod-shaped member described below. Above the seal portion 26, a restraint mechanism 25 (see FIG. 4) as a movement direction control unit having a function of limiting the movement direction of the rod 24 is arranged.

Further, the cap 23 is provided with an air supply member 29 having an air supply hole 23a and an internal flow path 29a communicating with the air supply hole 23a. The air supply hole 23a and the internal flow path 29a are formed in the cap 23 and are connected to a second air flow path that leads from a space outside the syringe 3 to a second space S2 sandwiched between the cap 23 and the second plunger 22. It has become.

Here, an air pressure applying mechanism for applying air pressure in the first space S1 and the second space S2 will be described. One end (lower end) of the rod 24 is connected to the second plunger 22, and the other end (upper end) of the rod 24 extends outward and upward from one end 3a of the syringe 3. The rod 24 is a hollow member in which a first air flow path 24b is formed inside the rod body 24a, and the upper end portion of the first air flow path 24b is a first air pressure supply unit having an air pressure generating portion. It is connected to 31.

At the lower end of the rod 24 coupled to the second plunger 22, the first air flow path 24b opens into the bottom of the second plunger 22 and leads to the first space S1. That is, the first air flow path 24b of the rod 24 is configured to lead from the space outside the syringe 3 to the first space S1 sandwiched between the first plunger 21 and the second plunger 22. In this way, by using the internal hole of the rod 24 as the first air flow path 24b, the structure of the liquid supply device 2 can be simplified.

The first air pressure supply unit 31 is controlled by the control unit 30 and has a function of supplying air pressure to the first space S1 through the first air flow path 24b. A first valve 27 for opening and closing the first air flow path 24b is provided in a portion of the rod 24 located in the second space S2 above the second plunger 22. That is, in the present embodiment, the first air pressure supply unit 31 has a first valve 27 that controls the supply of air pressure generated in the air pressure generation unit, and the first valve 27 is a rod 24. It is configured to be attached to the portion located in the space S2 of 2.

As a position for arranging the first valve 27, a portion located in the second space S2 is desirable as shown here, but the first valve 27 is located on another portion, for example, the upper part of the rod 24 protruding to the outside of the syringe 3. The valve 27 of 1 may be arranged. During operation of the liquid supply device 2, the first valve 27 is opened in a state where air pressure is applied to the first air flow path 24b by the first air pressure supply unit 31, so that the second valve 27 is opened. Pneumatic pressure is supplied into the first space S1 from the lower end of the first air flow path 24b opened in the bottom surface of the plunger 22 (arrow b). Then, due to this pneumatic pressure, the first plunger 21 presses the liquid 11 in the syringe 3 toward the other end 3b side.

The air supply hole 23a provided in the cap 23 communicates with the internal flow path 29a of the air supply member 29, and further communicates with the second air pressure supply unit 32 via the second valve 28 communicating with the air supply member 29. It is connected. The second pneumatic supply unit 32 has a pneumatic generation unit like the first pneumatic supply unit 31. By controlling the second air pressure supply unit 32 by the control unit 30, air pressure is supplied to the second space S2 through the internal flow path 29a and the air supply hole 23a, which are the second air flow paths (arrow c). ..

As a result, a downward pressing force acts on the second plunger 22, and the second plunger 22 moves following the first plunger 21 side. That is, the second air pressure supply unit 32 that supplies air pressure to the second space S2 through the above-mentioned second air flow path moves the second plunger 22 toward the first plunger 21 side. It is a drive unit. By adopting such a configuration, the second plunger 22 can be moved with a simple configuration, and the mechanism portion for moving the second plunger 22 is not in contact with the second plunger 22 or the rod 24. This makes it possible to easily replace the syringe 3.

In the movement of the second plunger 22 toward the first plunger 21, the first space S1 between the first plunger 21 and the second plunger 22 has a substantially constant volume. The second plunger 22 is made to follow the first plunger 21. When the first plunger 21 and the second plunger 22 move to a predetermined position near the lower end portion in the syringe 3, it is determined that the liquid 11 in the syringe 3 is consumed and the syringe 3 needs to be replaced. Plunger.

Therefore, the liquid supply device 2 is provided with a function as a notification unit that notifies the timing of replacement of the syringe 3. As shown in FIG. 2, a remaining amount detection mark 24c is formed at a predetermined position near the upper end portion of the rod body 24a of the rod 24. A mark detection sensor 33 capable of detecting the remaining amount detection mark 24c is arranged at the mark detection position set above the restraint mechanism 25, and the detection result by the mark detection sensor 33 is transmitted to the control unit 30. To.

When the second plunger 22 gradually moved downward and the remaining amount detection mark 24c reached the detection position by the mark detection sensor 33 (see FIG. 5), the second plunger 22 moved to a predetermined position on the syringe 3. That is, it is detected that the liquid 11 in the syringe 3 is consumed and the syringe 3 should be replaced, and the control unit 30 notifies that fact. Therefore, the mark detection sensor 33 and the control unit 30 function as a notification unit that notifies the replacement of the syringe 3 by detecting the position of the rod 24.

Next, the configuration and function of the restraint mechanism 25 as the movement direction limiting portion provided in combination with the cap 23 will be described. In the present embodiment, air pressure is applied to the first space S1 in order to push and move the first plunger 21, and when this air pressure is applied, the air pressure in the first space S1 is used. It is necessary to restrict the movement of the second plunger 22 so that it does not move upward. That is, in order to prevent the second plunger 22 from moving in the direction of exiting the syringe 3 (upper end side) due to the pneumatic pressure of the first space S1, it is required to limit the moving direction of the rod 24.

In the liquid supply device 2 shown in the present embodiment, a restraint mechanism 25 as a movement direction limiting unit having such a function is provided in combination with the cap 23. As a result, the syringe 3 can be easily replaced, the length of the rod 24 can be set as short as possible, and the size of the liquid supply device 2 can be made compact.

Here, a specific configuration example of the restraint mechanism 25 will be described with reference to FIG. In the example shown in FIG. 4A, a rod 24 having a plurality of peripheral convex portions 24d provided with a locking surface 24e and a sliding surface 24f for selective locking is formed on the outer peripheral surface, and the locking claw 25c is used. The configuration example in which the rod 24 is sandwiched from both sides by the selective locking member 25a provided with the above is shown.

That is, in FIGS. 4 (a) and 4 (1), the rod 24 is prohibited from moving in the direction of the arrow e by engaging the locking claw 25c with the locking surface 24e provided on the peripheral convex portion 24d. On the other hand, in FIGS. 4A and 4A, the locking claw 25c comes into contact with the sliding surface 24f provided on the rod body 24a, and the selective locking member 25a rotates around the shaft support portion 25b (arrow). d) By doing so, the anchoring action of the locking claw 25c does not work, and the rod 24 is allowed to move in the direction of the arrow f.

Further, in the example shown in FIG. 4B, a cylindrical rod 24 having a smooth outer peripheral surface is used, and a wedge-shaped elastic member 35 made of an elastic body such as rubber is mounted in the holding gap 34a. Indicates a configuration example in which the rod 24 is sandwiched from both sides. That is, in FIGS. 4 (b) and 4 (1), the elastic member 35 is displaced in the wedge fastening direction in the holding gap 34a, so that the rod 24 is sandwiched by the elastic member 35, and the rod 24 is prohibited from moving in the arrow g direction. Will be done.

On the other hand, in FIGS. 4 (b) and 4 (2), since the elastic member 35 is displaced in the wedge releasing direction in the holding gap 34a, the pinching force by the elastic member 35 does not act on the rod 24, and the arrow of the rod 24 Movement in the h direction is allowed. In addition to the above configuration example, various mechanisms such as a configuration in which a feed screw and a one-way clutch are combined to allow movement in only one direction are provided as a configuration of a movement direction limiting unit that limits the movement direction of the rod 24. Can be used.

In FIG. 5, as a result of sequentially ejecting the liquid 11 stored in the syringe 3 in the liquid supply device 2 from the nozzle 4a, the liquid 11 is consumed and both the first plunger 21 and the second plunger 22 are of the syringe 3. It shows the state of having moved to a predetermined position where replacement is required. That is, in this state, the remaining amount detection mark 24c formed on the rod 24 moves to the position where it is detected by the mark detection sensor 33, thereby notifying that the syringe 3 should be replaced as described above.

As described above, in the liquid supply device 2 shown in the present embodiment, the first plunger 21 is inserted into the syringe 3 whose one end is open and pushes the liquid 11 in the syringe 3 toward the other end. A second plunger 22 inserted closer to one end than the first plunger 21, and a rod-shaped member having one end coupled to the second plunger 22 and the other end extending outward from one end of the syringe 3. Through a rod 24, a first air flow path leading from a space outside the syringe 3 to a first space S1 sandwiched between the first plunger 21 and the second plunger 22, and a first air flow path. The first pneumatic supply unit 31 that supplies air pressure to the first space S1, the second plunger drive unit that moves the second plunger 22 toward the first plunger 21, and the second plunger 22 are second. In order to prevent the rod 24 from moving in the direction of exiting from the syringe 3 due to the air pressure in the space S1, a restraining mechanism 25 as a movement direction limiting portion for limiting the movement of the rod 24 is adopted.

With such a configuration, in the process of sequentially discharging the liquid 11 in the syringe 3, even if the remaining amount of the liquid 11 in the syringe 3 becomes low, the air pressure for pushing down the first plunger 21 acts. Since the volume of the space S1 is kept as small as possible, it is possible to reduce the variation in the discharge amount of the liquid 11. Even when the remaining amount of the liquid 11 in the syringe 3 is reduced, the responsiveness of the first air pressure supply unit 31 to the change in air pressure does not deteriorate, and the liquid 11 is discharged from the syringe 3 to the end. It is possible to control the amount with a high system.

Further, in the configuration shown in the present embodiment, since the amount of air supplied into the syringe 3 can be reduced as much as possible, it is possible to suppress the temperature rise of the syringe 3, and the liquid 11 caused by the temperature rise of the syringe 3 It is possible to suppress changes in the physical properties of. Since the amount of air supplied into the syringe 3 is small, the time required for one discharge can be shortened, and the discharge cycle indicating the number of discharges per unit time can be improved. ing. Due to such an effect, in a configuration in which the syringe 3 is used as a storage container, a fixed amount of liquid can be supplied with stable responsiveness with a simple configuration.

The liquid supply device of the present invention has the effect of being able to supply a fixed amount of liquid with a stable response in a simple configuration in a configuration using a syringe as a storage container, and a constant amount of liquid such as paste. It is useful in the field of discharging and supplying.

1 Dispenser 2 Liquid supply device 3 Syringe 4 Connecting member 4a Nozzle 9 Liquid storage part 11 Liquid 21 First plunger 22 Second plunger 23 Cap 24 Rod 24b First air flow path 24c Remaining amount detection mark 25 Restraint mechanism 27 1st valve 28 2nd valve 30 Control unit 31 1st pneumatic supply unit 32 2nd pneumatic supply unit 33 Mark detection sensor S1 1st space S2 2nd space

Claims (11)

A substantially cylindrical syringe with one end open and a discharge tube connected to the other end.
A first plunger that is inserted into the syringe and pushes the liquid in the syringe toward the other end.
A second plunger inserted closer to one end of the first plunger ,
The first air flow path communicating the first space sandwiched by the space outside the front Symbol syringe and said first plunger and said second plunger,
A first air pressure supply unit that supplies air pressure to the first space through the first air flow path,
A second air flow path leading from a space outside the syringe to a second space located between the one end of the syringe and the second plunger.
A liquid supply device including a second air pressure supply unit that supplies air pressure to the second space through the second air flow path . One end is further coupled to the second plunger and the other end further comprises a rod-like member extending outward from the one end of the syringe.
The liquid supply device according to claim 1, wherein the first air flow path is formed inside the rod-shaped member. Further comprising a cap attached to said one end of said syringe,
It said second air passage, Ru is formed on the cap, a liquid supply apparatus according to claim 1. The claim further comprises a movement direction limiting portion that limits the movement of the second plunger in order to prevent the second plunger from moving in the direction of exiting the syringe due to the air pressure in the first space. The liquid supply device according to 1. Further provided with a cap attached to the one end of the syringe
The liquid supply device according to claim 4 , wherein the movement direction limiting portion is coupled to the cap. The liquid supply device according to claim 2 , wherein the first air pressure supply unit has a valve for controlling the supply of air pressure generated in the air pressure generation unit, and the valve is mounted on the rod-shaped member. The liquid supply device according to claim 6 , wherein the valve is mounted on a portion of the rod-shaped member located in the second space. The central portion of the first plunger is recessed toward the other end of the syringe, and the central portion of the surface of the second plunger facing the first plunger is on the first plunger side. The liquid supply device according to claim 1, which has a protruding shape. The liquid supply device according to claim 1, further comprising a notification unit that notifies that the syringe is to be replaced by detecting the position of the second plunger . The liquid supply device according to claim 1, wherein the discharge pipe is a nozzle. The liquid supply device according to claim 1, wherein the discharge pipe is connected to a liquid storage portion of a dispenser that discharges a liquid.

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