JP5601662B2 - Liquid ejection device - Google Patents

Description

  The present invention relates to a liquid ejecting apparatus for ejecting a certain amount of chemical liquid, for example, with respect to cleaning water flowing in a toilet.

As conventional liquid ejection devices, for example, those disclosed in Patent Document 1 and Patent Document 2 are known. In patent document 1, the piston connected with a piston rod is provided in the cylinder so that reciprocation is possible. The cylinder is provided with a liquid suction valve for sucking liquid and a liquid discharge valve for discharging liquid in the cylinder. A check valve is used as the liquid suction valve and the liquid discharge valve.
When the pressure in the cylinder becomes negative due to the reciprocating motion of the piston connected to the piston rod, the liquid discharge valve is closed and the liquid suction valve is opened. Therefore, a certain amount of liquid flows into the cylinder through the liquid suction valve. Next, when the inside of the cylinder is pressurized by the piston, the liquid suction valve is closed and the liquid discharge valve is opened. Therefore, the liquid in the cylinder is discharged from the liquid discharge valve.

  Patent Document 2 discloses a metering pump that sucks and discharges a discharge fluid into a pressure chamber by a reciprocating motion of a piston portion connected to a piston rod. In the piston portion, a first piston member and a second piston member are coupled via a retainer member. Further, a discharge diaphragm and a pressure diaphragm are arranged opposite to each other on the retainer member side of the first piston member and the second piston member. A space is located on the outer peripheral portion of the retainer member, and is defined by a discharge diaphragm and a pressure diaphragm. The space is configured as a fluid chamber that is substantially filled with fluid. The fluid chamber is filled with a pressurized fluid that is constantly pressurized.

JP 2008-717 A JP 2001-193653 A

  In a conventional liquid ejecting apparatus, for example, Patent Document 1 uses a check valve composed of a ball valve as a liquid suction valve in order to control the flow of liquid flowing into the cylinder and discharged from the cylinder. When sucking in the liquid, since it is in a sealed state, a large force is required to operate the piston, and the liquid suction valve opens after the piston starts to move, resulting in a large driving loss. As a result, it is not suitable when a small amount of liquid is to be discharged stably with high accuracy. In addition, the structure is complicated because cylinders, pistons, check valves, etc. are used, and when the piston is operated, a large force greater than a predetermined value is required, so the power of the drive source also requires a predetermined power, Overall, it becomes an expensive device.

  Patent Document 2 requires that the effective diameter during the operation process of the discharge diaphragm does not change in order to quantify the discharge amount of the discharge fluid. Therefore, the pressure of the pressurized fluid chamber is devised to set it larger than the pressure of the pressure chamber of the compressor acting on the fluid discharge. Since the structure of the piston portion, the discharge diaphragm, the pressure diaphragm, the fluid chamber, and the like is complicated, the apparatus is expensive. Further, a large force is required when reciprocating the piston portion.

  The present invention has been made in view of the above, and an object of the present invention is to provide an inexpensive liquid ejecting apparatus with a simple structure.

In order to solve the above-described problems, a liquid discharge apparatus according to the present invention includes a liquid storage chamber to which a liquid supply pipe that supplies liquid from a liquid supply source is connected, a liquid discharge channel having a liquid discharge port at the tip. An apparatus main body including: a cylinder having both end openings communicating with the liquid storage chamber and the liquid discharge flow path; and the liquid storage chamber that slides within the cylinder and whose rear end portion is located outside the cylinder. in a pipe piston consisting of cylindrical member at both ends opening to move said fluid storage chamber with a movable, an engaging portion engaged with the rear end portion of the pipe piston, the rear end opening of the pipe piston An end wall portion that closes the rear end opening by abutting on the rear end portion of the pipe piston when the rear end portion of the pipe piston is engaged with the rear end portion of the pipe piston. The end wall from the opening. When the pipe piston is slid in a direction to be separated from the cylinder in a state of being interposed, liquid flows into the pipe piston from the rear end opening in the open state, and the end wall portion moves when moving forward. And an inlet valve that pushes the pipe piston into the cylinder in a state in which the pipe piston abuts the rear end opening of the pipe piston and closes the rear end opening, and is disposed in the liquid discharge passage. In a normal state, the cylinder is biased in a direction to abut against the front end opening of the cylinder, and when the pipe piston slides in a direction away from the cylinder, the front end abuts against the front end opening of the cylinder. When the opening is closed and the pipe piston moves in the direction to be pushed into the cylinder, the front end opening is opened away from the front end opening of the cylinder by hydraulic pressure. And having an outlet valve for.

  The inlet valve is connected to a rod member, and includes a drive mechanism that moves the rod member back and forth. The rod mechanism is moved back and forth by the drive mechanism so that an end wall portion of the inlet valve is connected to the pipe piston. It is preferable that the configuration be separated from the rear end opening.

It is preferable that the outlet valve is urged by an elastic member disposed in the liquid discharge channel in a direction in which the outlet valve comes into contact with the front end opening of the cylinder.
The liquid ejection device of the present invention is preferably used for ejecting a certain amount of chemical liquid with respect to the washing water flowing to the toilet.

  According to the present invention, the piston that slides in the cylinder has a pipe piston made of a cylindrical member that is open at both ends, so to say, a double cylinder structure of a cylinder and a pipe piston. When the pipe piston moves rearward, that is, when it moves in a direction that extends relative to the cylinder, the inlet valve opens the rear end opening of the pipe piston, so that the pipe piston moves rearward. As soon as it starts to operate, liquid flows into the pipe piston and cylinder from the rear end opening. For this reason, the resistance when the pipe piston moves backward is small, and the power of the drive source for operating the pipe piston is smaller and less expensive than the conventional one.

  Also, as the pipe piston begins to move backward, liquid flows into the pipe piston and cylinder from the opening at the rear end, so there is no drive loss as in the case of using a conventional check valve, and the liquid discharge amount is accurate. Can be controlled. For this reason, it is suitable for an application in which a small amount of liquid is ejected accurately and in a certain amount, for example, when it is desired to supply a certain amount of a chemical solution of about 0.03 cc to the wash water flowing to the toilet.

  The liquid discharge amount is determined by the liquid volume in the pipe piston and cylinder at the position when the pipe piston is moved backward (extension position), and the position when the pipe piston is pushed into the cylinder by a predetermined amount (contracted position). Therefore, it can be easily adjusted by controlling the stroke amount of the pipe piston.

  Further, it is not necessary to provide a check valve mechanism having a complicated structure as in the prior art, and it is only necessary to provide a cylinder and a pipe piston, and valves for closing the rear end opening of the pipe piston and the front end opening of the cylinder. In addition, it is possible to provide an inexpensive liquid ejecting apparatus having a simple structure.

FIG. 1 is a partial cross-sectional view of a liquid ejection apparatus according to an embodiment of the present invention. FIG. 2 is a front view showing the entirety of the liquid ejection apparatus according to the embodiment of the present invention. FIG. 3A is an operation explanatory diagram when the pipe piston moves rearward, and FIG. 3B is an operation explanatory diagram when the pipe piston moves forward.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1 and 2, the liquid ejection apparatus 10 according to the present embodiment has a liquid storage chamber 12 for storing a liquid such as a drug in the apparatus main body 11 and a liquid ejection port 61 at the tip. A liquid discharge channel 60 is provided. The liquid storage chamber 12 and the liquid discharge channel 60 are provided with a partition wall 13 therebetween. A piston rod 23, which is a rod member, extends downward in the apparatus main body 11 from the outside of the upper part of the apparatus main body 11 so as to move up and down in the liquid storage chamber 12 in FIG.

  The piston rod 23 is configured to be driven up and down by a solenoid 20 and a rod spring 25 that constitute a drive mechanism. That is, the upper part of the apparatus main body 11 is fixed to the support body 22 via the support bracket 21. The solenoid 20 is attached to a support bracket 21, and the upper part of the piston rod 23 is connected to the solenoid 20.

  Further, a rod flange portion 24 is provided on the outer periphery of the front end portion (lower end portion in FIG. 1) of the piston rod 23, and a rod spring is provided between the rod flange portion 24 and the upper wall surface of the liquid storage chamber 12. 25 is arranged. That is, the piston rod 23 is always urged downward by the urging force of the rod spring 25.

  Therefore, when the solenoid 20 is turned on, the piston rod 23 is raised against the urging force of the rod spring 25 by the electromagnetic force of the solenoid 20. When the solenoid 20 is turned off, the piston rod 23 is lowered by the urging force of the rod spring 25. Note that the ON state and OFF state of the solenoid 20 are automatically controlled and switched by a control device (not shown).

  In this embodiment, the drive mechanism for moving the piston rod 23 back and forth is composed of the solenoid 20 and the rod spring 25, but is not limited to this, and is not limited to this. A drive mechanism of a form may be used.

The liquid supplied from a liquid supply source such as a liquid tank is supplied to the liquid storage chamber 12 via the liquid supply pipe 12a .

  The partition wall 13 that separates the liquid storage chamber 12 and the liquid discharge channel 60 is provided with a through hole 13a that penetrates vertically, and a cylinder 41 that is a cylindrical member that is open at both ends is inserted into the through hole 13a. Has been. Therefore, the liquid storage chamber 12 and the liquid discharge flow path 60 are communicated with each other via the cylinder 41.

  In the cylinder 41, a pipe piston 42 made of a cylindrical member having both end openings is slidably inserted. That is, the cylinder 41 and the pipe piston 42 have a double cylinder structure, and the pipe piston 42 can be displaced in the vertical direction of FIG.

  In the present embodiment, the pipe piston 42 is provided so as to slide in the cylinder 41, but the through hole 13a itself formed in the partition wall 13 can also be used as a cylinder in which the pipe piston 42 slides. In the present invention, the term “cylinder” includes not only a cylindrical member different from the partition wall 13 but also a case where such a through-hole 13a itself is configured.

  The rear end portion (upper end portion in FIG. 1) of the pipe piston 42 is held by the front end portion (lower end portion in FIG. 1) of the piston rod 23. More specifically, a pipe flange portion 43 is provided on the outer periphery of the rear end portion of the pipe piston 42. On the other hand, an inlet valve 30 having an end wall portion 34 that opens and closes a rear end opening 42 a of the pipe piston 42 is integrally provided at the front end portion of the piston rod 23.

  The inlet valve 30 is formed by processing from the front end face side of the piston rod 23 into a substantially U-shaped cross section as shown in FIG. 1, and in a direction perpendicular to the longitudinal direction of the piston rod 23. A holding hole 32 penetrating therethrough is provided. The inner bottom surface of the holding hole 32 is the end wall portion 34, and the front end surface is provided with an engaging portion 31 including projecting pieces 31a and 31a protruding inward. The interval between the projecting pieces 31a and 31a is greater than the outer diameter of the pipe piston 42 and less than the outer diameter of the pipe flange portion 43, so that the holding hole portion 32 can move the pipe flange portion 43 in the vertical direction. It is a size with a margin.

  As a result, when the piston rod 23 is displaced relative to the pipe piston 42, the end wall 34 comes into contact with or separates from the rear end opening 42a (the upper end opening in FIG. 1) of the pipe piston 42. Therefore, the rear end opening 42a of the pipe piston 42 is opened and closed.

  That is, when the piston rod 23 moves rearward (upward in FIG. 1), the engaging portion 31 (projection pieces 31 a, 31 a) of the inlet valve 30 provided integrally with the piston rod 23 is connected to the pipe piston 42. The end wall 34 is separated from the rear end opening 42 a of the pipe piston 42 by engaging with a pipe flange 43 provided at the rear end. Accordingly, when the pipe piston 42 moves rearward in this state, the liquid flows into the pipe piston 42 from the rear end opening 42a. On the other hand, when the piston rod 23 moves forward (downward in FIG. 1), the above-described end wall portion 34 of the inlet valve 30 contacts the rear end opening 42a of the pipe piston 42. The opening 42a is pushed into the cylinder 41 with a closed body.

  The liquid discharge flow path 60 provided in the lower part of the apparatus main body 11 includes a small-diameter liquid discharge port 61 located on the distal end side, and a large-diameter portion 62 formed between the liquid discharge port 61 and the partition wall portion 13. Have. Note that, as shown in FIG. 2, a discharge conduit 63 that guides the liquid to a predetermined supply location can be connected to the liquid discharge port 61 of the liquid discharge flow channel 60.

  As shown in FIGS. 1 and 3A, an outlet valve 50 is disposed in the large-diameter portion 62 of the liquid discharge channel 60. The outlet valve 50 is normally urged by an outlet spring 51, which is an elastic member, in a direction in which it abuts against and closes the front end opening 41 a (lower end in FIG. 1) of the cylinder 41. The urging force of the outlet spring 51 is released by the hydraulic pressure generated when the pipe piston 42 is pushed. As a result, when the pipe piston 42 slides in the direction in which the pipe piston 42 is detached from the cylinder 41 (upward in FIG. 1), the outlet valve 50 comes into contact with the front end opening 41a of the cylinder 41 and the front end opening 41a. Occlude. On the other hand, when the pipe piston 42 moves in the direction in which the pipe piston 42 is pushed into the cylinder 41 (downward in FIG. 1), the front end opening 41a is opened away from the front end opening 41a of the cylinder 41 by hydraulic pressure. Is.

Next, the operation of the liquid ejection device 10 described above will be described.
First, when the solenoid 20 is turned on, the piston rod 23 rises against the urging force of the rod spring 25. When the piston rod 23 is raised, as shown in FIG. 3A, the engaging portion 31 (projection pieces 31a, 31a) of the inlet valve 30 provided at the tip of the piston rod 23 is connected to the pipe flange of the pipe piston 42. The part 43 is caught and raised. Since the pipe flange portion 43 is thinner than the vertical gap of the holding hole 32, the pipe piston 42 has a rear end opening 42 a (upper end surface in FIG. 3A) of the inlet valve 30. Separated from the end wall 34. As a result, the pipe piston 42 rises with the rear end opening 42a open, and during that time, the liquid in the liquid storage chamber 12 flows into the pipe piston 42 through the rear end opening 42a.

  When the piston rod 23 moves upward by a predetermined amount and the solenoid 20 is turned off by control of a control device (not shown), the piston rod 23 is lowered by the urging force of the rod spring 25 as shown in FIG. . When the piston rod 23 is lowered, the end wall portion 34 of the inlet valve 30 comes into contact with the rear end opening 42a of the pipe piston 42, so that the rear end opening 42a is lowered in a closed state.

  In a state where the pipe piston 42 is raised, as shown in FIG. 3A, an amount substantially equivalent to an amount corresponding to the amount corresponding to the length of the cylinder 41 and the amount corresponding to the length of the pipe piston 42 is obtained. Liquid is in both. In this state, when the rear end opening 42a of the pipe piston 42 is closed and moved downward, the combined length of the cylinder 41 and the pipe piston 42 is shortened. The amount gradually decreases. Accordingly, the pressure of the liquid in the pipe piston 42 and the cylinder 41 is increased, so that the liquid presses the outlet valve 50 against the urging force of the outlet spring 51, and the liquid discharge flow from the front end opening 41 a of the cylinder 41. It is guided into the channel 60 and further discharged from the liquid discharge port 61 to the outside.

  From the above, when the pipe piston 42 moves rearward (upward in the drawing), that is, when it operates in a direction extending relative to the cylinder 41, the inlet valve 30 is connected to the rear end of the pipe piston 42. In order to open the opening 42a, the pipe piston 42 starts to move backward, and at the same time, the liquid in the liquid storage chamber 12 flows into the pipe piston 42 and the cylinder 41 from the rear end opening 42a. For this reason, the resistance when the pipe piston 42 moves backward is small, and the power of the drive source for operating the pipe piston 42 is smaller and less expensive than the conventional one.

  Further, since the liquid flows into the pipe piston 42 and the cylinder 41 from the rear end opening 42a at the same time as the pipe piston 42 starts to move backward, there is no drive loss as in the case of using the conventional check valve, and the liquid The discharge amount can be accurately controlled. For this reason, it is suitable for an application in which a small amount of liquid is ejected accurately and in a certain amount, for example, when it is desired to supply a certain amount of a chemical solution of about 0.03 cc to the wash water flowing to the toilet.

For example, when the cylinder 41 has a length of 20 mm, an inner diameter of 2 mm, and a stroke of the pipe piston 42 of 10 mm, the discharge amount per stroke is about 0.03 cc. A rod spring 25 for pushing the pipe piston 42 having a spring constant of 450 g / mm is used, and the pressure in the sealed container into which the liquid is injected is 0 kg / cm ² , 2 kg / cm ² , 4 kg / cm ² , 6. The liquid injection experiment under a constant pressure was performed by changing the pressure to 5 kg / cm ² . As a result, the injection amount per one time was in the range of 0.031 cc to 0.032 cc. Moreover, the injection amount per one time was 0.033 cc under no-load conditions. As a result, it was confirmed that a small amount of liquid of about 0.03 cc per one time can be discharged with almost constant accuracy.

  The amount of liquid discharged is determined by the liquid volume in the pipe piston 42 and the cylinder 41 at the position (extension position) when the pipe piston 42 is moved backward, and when the pipe piston 42 is pushed into the cylinder 41 by a predetermined amount. Since the amount corresponds to the difference between the pipe piston 42 and the liquid volume in the cylinder 41 at the position (contracted position), it can be easily adjusted by controlling the stroke amount of the pipe piston 42.

  Further, there is no need to provide a complicated check valve mechanism as in the prior art, and the cylinder 41, the pipe piston 42, the inlet valve 30 that closes the rear end opening 42a of the pipe piston 42, and the front end opening 41a of the cylinder 41. Since it is only necessary to provide the outlet valve 50 for closing the liquid, the structure is simple and the inexpensive liquid discharge device 10 can be provided.

  Further, in the present embodiment, the inlet valve 30 is integrated with the tip of the piston rod 23 for expanding and contracting the pipe piston 42, so that the structure is simple, contributing to the provision of the inexpensive liquid discharge device 10. To do. Of course, the inlet valve 30 may be formed of a member different from the piston rod 23.

DESCRIPTION OF SYMBOLS 10 Liquid discharge apparatus 11 Apparatus main body 12 Liquid storage chamber
12a Liquid supply pipe 20 Solenoid 21 Support bracket 22 Support body 23 Piston rod 24 Rod flange portion 25 Rod spring 30 Inlet valve 31 Engagement portion 32 Holding hole portion
34 End Wall 41 Cylinder 41a Front End Opening 42 Pipe Piston 42a Rear End Opening 43 Pipe Flange 50 Outlet Valve 51 Outlet Spring 60 Liquid Discharge Channel 61 Liquid Discharge Port

Claims (4)

An apparatus main body including a liquid storage chamber to which a liquid supply pipe for supplying a liquid from a liquid supply source is connected, and a liquid discharge channel whose tip is a liquid discharge port;
A cylinder with open ends communicating with the liquid storage chamber and the liquid discharge channel;
A pipe piston made of a cylindrical member having both end openings that slide in the cylinder and whose rear end portion moves in the liquid storage chamber located outside the cylinder;
End with a movable the liquid storage chamber, closing engaging portion engaged with the rear end portion of the pipe piston, the rear end opening by abutting the rear end opening of the pipe piston And the engagement portion engages with the rear end portion of the pipe piston when moving backward, and the end wall portion is separated from the rear end opening of the pipe piston. The pipe piston is slid away from the cylinder to allow liquid to flow into the pipe piston from the open rear end opening, and the end wall portion moves behind the pipe piston when moving forward. An inlet valve that pushes the pipe piston into the cylinder in a state of contacting the end opening and closing the rear end opening;
While being disposed in the liquid discharge flow path and being normally urged in a direction in contact with the front end opening of the cylinder, when the pipe piston slides in a direction away from the cylinder, When the pipe piston moves in a direction to be pushed into the cylinder by contacting the front end opening of the cylinder and closing the front end opening, the pipe piston moves away from the front end opening of the cylinder by hydraulic pressure. A liquid discharge apparatus having an outlet valve for opening a front end opening.   The inlet valve is connected to a rod member, and includes a drive mechanism that moves the rod member back and forth. The rod mechanism is moved back and forth by the drive mechanism so that an end wall portion of the inlet valve is connected to the pipe piston. The liquid ejection device according to claim 1, wherein the liquid ejection device is configured to be separated from and in contact with the rear end opening.   The liquid discharge apparatus according to claim 1, wherein the outlet valve is urged in a direction in contact with a front end opening of the cylinder by an elastic member disposed in the liquid discharge flow path. The liquid discharge apparatus according to claim 1, which is used to discharge a certain amount of chemical liquid to the wash water flowing to the toilet.

Images