JP4236748B2 - Liquid ejector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reciprocating pump type liquid ejector for spraying or ejecting liquid, and more particularly to a means for sucking back liquid remaining in a nozzle.
[0002]
[Prior art]
The pump chamber is pressurized by pushing down the push-down head, the suction valve is closed, the discharge valve is opened, and the liquid in the pump chamber is ejected from the nozzle of the push-down head in the liquid or mist state, and the push-down head is lifted by the urging force. A reciprocating pump type liquid ejector is widely known in which the pump chamber is negatively pressurized and the discharge valve is closed, and the suction valve is opened to suck the liquid in the container into the pump chamber.
[0003]
[Problems to be solved by the invention]
In this type of liquid ejector, it is planned that all of the liquid ejected by pressurizing the pump chamber by depressing the depressing head will be ejected from the nozzle. It was easy to remain inside. Therefore, when the liquid to be injected is a solution other than water, such as detergents, chemicals, and cosmetics, in a liquid injector that injects (sprays) mist, the solution component solidified by drying causes clogging of the nozzle. In the liquid ejector that ejects liquid as it is, there is a problem that the remaining solution drips and stains the surroundings.
[0004]
Therefore, conventionally, a suction chamber having a variable volume is provided in communication with the nozzle, and the volume of the suction chamber is reduced when the head is pushed down, and the volume is restored when the push is released. A proposal has been made to suck back the liquid remaining in the back into the chamber. Then, as a means for changing the volume of the suck back chamber, the cap is slid against the head so that the space between the two becomes the suck back chamber, and this cap is always urged in the upward direction by the spring. There has been known an invention in which the volume of the suction chamber is reduced by pushing down and the volume of the suction chamber is restored when the push is released (JP-A-10-34036, etc.). In addition, the space between the two is made a sucking back chamber by covering the head with a cap that elastically deforms against the head, the volume of the sucking back chamber is reduced by crushing the cap by pushing down, and the cap is restored by elastic return of the cap when releasing the pushing down. An invention for returning the volume of the return chamber has been known (Japanese Utility Model Publication No. 7-17406, Japanese Patent Laid-Open No. 9-34036, etc.).
[0005]
However, in the former invention, the structure including the spring is complicated, and there is a problem that the sealing means between the head and the cap must be fully considered. In the latter invention, the purpose is to inject liquid. Even though the injection pressure is suitable for a liquid dispenser with a relatively low pressure, the liquid dispenser for injecting a mist that requires a high injection pressure has a problem that the cap expands unnecessarily during pressurization. .
[0006]
[Means for Solving the Problems]
The present invention has been invented for the purpose of providing a liquid dispenser that solves the above-described problems inherent to a liquid dispenser that injects a solution other than water. Is pressurized, the suction valve is closed, the discharge valve is opened, and the liquid in the pump chamber is ejected from the nozzle of the depressing head in a liquid or mist state. The following invention is disclosed in a reciprocating pump type liquid ejector that closes the discharge valve and opens the suction valve to suck the liquid in the container into the pump chamber.
[0007]
That is, the present invention relates to a means for sucking back the liquid remaining in the nozzle, and includes a head body having a suck-back chamber communicating with the nozzle, and a relay member communicating the suck-back chamber and the pump chamber through a central communication passage. The head main body is configured as an elastically deformable tapered insertion portion that constitutes a push-down head and has an end portion of the relay member having a tapered inner peripheral surface of the suck-back chamber that can be inserted halfway into the entrance path. The insertion part of the relay member is further pushed into the entry path of the sucking back chamber due to the deformation caused by pushing down, and the insertion part whose shape has been restored by releasing the pushing down is slid back to the initial position of the entry path. It is characterized by.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific examples of the liquid dispenser of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a view showing a non-pressurized state of the liquid dispenser of the present invention. This liquid dispenser is provided with a reciprocating pump 10 that sucks the lower end into a cap 1 that is attached to a liquid container by means such as screwing, and communicates with a pipe (not shown) to push down a piston against an urging force and A conventionally known basic structure in which a push-down head 20 having a side 22 is provided above the reciprocating pump, a suction valve 50 is provided on the liquid container side of the reciprocating pump, and a discharge valve 40 is also provided on the push-down head 20 side. Have.
[0009]
The reciprocating pump 10 includes a lower cylinder 11 suspended in the cap 1, a lower sliding pipe 12 provided with a small-diameter piston portion 13 that slides in the cylinder, and a lower sliding pipe 12. The upper slide tube 14 is provided in the lower cylinder 11, which is movably extrapolated and has a large-diameter piston portion 15 which is slid in a cylinder portion 35 of a relay member 30 of a push-down head described later. By urging the lower sliding tube 12 in the upward direction by the coil spring 17, the upper sliding tube 14 whose lower end engages with the contact step 12A provided in the middle of the outer periphery of the lower sliding tube is also in the upward direction. Be energized by. In this case, the relay member 30 slides in the inner overhanging cylindrical portion 2 in which the cylinder portion 35 projects from above the cap 1, and the flange portion 35 </ b> A provided on the outer periphery of the lower end is in the inner periphery of the inner overhanging cylindrical portion 2. The upper limit is regulated by abutting against the provided abutting step 2A, and the upper limits of the upper sliding tube 14 and the lower sliding tube 12 are also regulated accordingly. A small-diameter pump chamber A is formed between the small-diameter piston portion 13 below the lower sliding tube 12 and the suction valve 50 below the lower cylinder 11, and the large-diameter piston portion 15 and the relay member above the upper sliding tube 14. A large-diameter pump chamber B is formed between the discharge valves 40 above the cylinder portion 35 of the 30, and the pump chamber is configured by communicating both pump chambers through the lower sliding tube and the hollow portion of the upper sliding tube. Is done.
[0010]
The suction valve 50 has a configuration in which a valve hole 56 provided below the lower cylinder 11 is closed by a ball 51 from the inside of the cylinder. On the other hand, the discharge valve 40 is configured such that a valve hole 42 provided above the cylinder chamber 35 of the relay member 30 is closed from the inside of the cylinder by a conical valve body 41 provided at the center above the upper sliding tube 14.
[0011]
In the present invention, the push-down head 20 is composed of a head body 21 having a suck-back chamber 23 that communicates with a nozzle 22 and a relay member 30 that communicates the suck-back chamber and the pump chamber with a central communication passage 34. The relay member 30 has a configuration in which the cylinder portion 35 is suspended downward, and a relay cylinder portion 31 having a communication passage 34 communicating with a valve hole 42 of a discharge valve of the cylinder portion is erected upward. And the front-end | tip of the relay cylinder part 31 is made into the insertion part 32 which should be inserted in the entrance path 24 of the suction return chamber 23 of a head main body. In this case, the head main body 21 slides in the outer projecting cylindrical portion 3 protruding from above the cap 1 when pressed down, and a flange portion 21A provided on the outer periphery of the lower end is provided on the inner periphery of the outer projecting cylindrical portion 3. The upper limit is regulated by coming into contact with the stepped portion 3A. Therefore, the relay member 30 urged in the upward direction by the coil spring 17 through the lower sliding tube 12 and the upper sliding tube 14 has the insertion portion 32 at the tip of the relay cylinder portion 31 sucking the head body. The head body 21 is always brought into contact with the entrance path 24 of the return chamber 23, and the head body 21 is pushed up to the upper limit.
[0012]
In the above configuration, when the head body 21 is pushed down against the biasing force of the coil spring 17, the upper sliding tube 14 having the large diameter piston portion 15 and the lower sliding tube 12 having the small diameter piston portion 13 are lowered, The liquid in the pump chamber composed of the large-diameter pump chamber B and the small-diameter pump chamber A is compressed. In this case, by further pushing down, the lower sliding tube 12 having the small-diameter piston portion 13 is lowered with respect to the upper sliding tube 14 having the large-diameter piston portion 15 due to the inner diameter difference between the two pump chambers. 40 is opened, and the liquid is ejected from the ejection nozzle 22. When the head main body 21 is pushed down to the lower limit, the discharge valve 40 is closed (see FIG. 2). By releasing the lowering, the lower sliding pipe 12 having the small diameter piston portion 13 and the large lower sliding pipe 12 are released. The upper sliding tube 14 having the diameter piston portion 15 rises, the pressure in the pump chamber becomes negative, the suction valve 50 is opened, and the liquid in the container is sucked up into the pump chamber.
[0013]
On the other hand, according to the present invention, the entrance path 24 of the suction return chamber 23 of the head body has a tapered inner peripheral surface, and the insertion section 32 at the tip of the relay cylinder part 31 of the relay member is the entrance path. It is a tapered shape that can be elastically deformed and has a shape that can be inserted halfway. In this embodiment, the conical shape with the head cut off is formed into a tapered shape, and the entire relay member 30 including the insertion portion 32 is integrally formed of relatively soft plastic so as to be elastically deformable.
[0014]
In the above configuration, when the head main body 21 is pushed down against the urging force for liquid extraction, the insertion portion 32 of the relay cylinder portion 31 of the relay member becomes the head main body due to the compression of the coil spring 17 and the increase in the internal pressure of the pump chamber. The suction passage 23 of the suction return chamber 23 comes into contact with a strong force to enter the entrance passage. In this case, when the insertion portion 32 is made of a hard material, the entry is blocked. However, as described above, the insertion portion has a tapered shape that can be elastically deformed, so that it is contracted by being pressed against the tapered entry passage 24. As a result, the volume of the suck-back chamber 23 is reduced corresponding to the amount pushed (see FIG. 3). Then, after the liquid is extracted, the pressing force of the head body is released to restore the shape of the insertion portion 32 pressed against the entry path 24. In this case, since the entry path and the insertion portion are both tapered, the relay is performed. When the head body 21 is slid back to the original position with respect to the member 30, the volume of the suction chamber 23 increases corresponding to the distance L that is slid back (see FIG. 4). As a result, the suction chamber 23 whose volume has increased has a negative pressure, and the liquid remaining in the nozzle 22 is sucked back into the suction chamber.
[0015]
In the above case, the insertion part 32 of the relay cylinder part 31 of the relay member is communicated with the inlet path 24 of the suction return chamber 23 of the head body only in the central communication path 34, and the space between the outer periphery of the insertion part and the inner periphery of the inlet path It goes without saying that it must be kept in On the other hand, the user does not necessarily push down the head main body 21 vertically but may tilt it down. In this case, the insertion portion 32 of the relay cylinder portion 31 is located in the entrance path 24 of the suction chamber 23. There is a risk of non-contact. Therefore, in this embodiment, a cylindrical portion 24 that covers the relay cylindrical portion 31 is provided below the opening of the inlet passage 24 of the head main body 21 sucking back chamber 23, and an inner periphery of the cylindrical portion is provided in the middle of the relay cylindrical portion. A support skirt portion 33 that is in sliding contact with the peripheral wall surface is provided. As a result, the relay cylinder portion 31 always follows the push-down angle of the head main body 21, so that the insertion portion 32 correctly contacts the expected position of the entrance path 24 of the suction chamber 23. Further, even if liquid leaks from the outer periphery of the insertion portion 32 and the inner periphery of the entry path 24, it is received by the support skirt portion 33 of the relay cylinder portion, and further entry to the outside is prevented.
[0016]
【The invention's effect】
The liquid ejector of the present invention having the above configuration has the following specific effects.
(1) Since the liquid remaining in the nozzle is sucked back by the sucking-back chamber having a variable volume, the situation in which the liquid remains and the nozzle is clogged due to solidification by drying is eliminated.
[0017]
(2) Do not use a means for changing the volume of the suck back chamber by covering the cap that slides against the push-down head, and enter the entrance path with the tapered inner peripheral surface of the suck back chamber up to this point. Since it is a means to change the volume of the suction chamber by inserting an elastically deformable tapered insertion portion having an insertable shape, the structure is simplified by eliminating the need for a spring, and the head and There is no need to consider sealing means with the cap.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a push-down head of a liquid ejector according to the present invention when it is raised most.
FIG. 2 is a cross-sectional view of the push-down head when lowered, as in the above.
FIG. 3 is a cross-sectional view showing the main part of the first invention when the volume of the suction chamber is reduced.
FIG. 4 is a cross-sectional view of the suction chamber in the normal state.
[Explanation of symbols]
20 Depressing head 21 Head body 22 Nozzle 23 Suction return chamber 24 Inlet path 30 Relay member 32 Insertion section 40 Discharge valve 50 Suction valve

Claims (1)

The pump chamber is pressurized by depressing the depressing head (20), the suction valve (50) is closed, the discharge valve (40) is opened, and the liquid in the pump chamber is discharged from the nozzle (22) of the depressing head (20). The liquid is ejected in a liquid or mist state, and the pump head is reduced to a negative pressure by raising the push-down head (20) by the urging force, the discharge valve (40) is closed, and the suction valve (50) is opened to open the liquid in the container. In the reciprocating pump type liquid ejector for sucking the liquid into the pump chamber, the head body (21) having the suction chamber (23) communicating with the nozzle (22), and the suction chamber (23) and the pump chamber are arranged in the center. The push-down head (21) is constituted by the relay member (30) communicating with the communication path (34), and the end of the relay member (30) is tapered in the suction chamber (23). An elastically deformable tapered insertion portion (32) having a shape that can be inserted halfway into the entry path (24) having an inner peripheral surface, and insertion of the relay member (30) by deformation due to depression of the head body (21). The insertion portion (32) whose shape has been restored by releasing the push-down slides to the initial position of the entry passage (24) while the portion (32) is further pushed into the entry passage (24) of the suction chamber (23). A liquid ejector characterized by being returned.

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