JP4017381B2 - Fluid dispenser - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluid discharge device comprising a valve plunger that separates from a valve seat provided in a cylinder and sucks fluid into the cylinder, and an elastically deformable overhanging portion that slidably holds the outer periphery of the valve plunger. It is about a vessel.
[0002]
[Prior art]
The fluid ejector includes, for example, a trigger type pump that causes a pump action by a user's trigger (trigger) operation, a nozzle head type that causes a pump action by a user's nozzle head operation, and the like. The valve plunger that is separated from the valve seat provided in the cylinder and sucks the fluid into the cylinder and the piston or guide shaft having an internal flow path for introducing the valve plunger can slide the outer periphery of the valve plunger. Japanese Patent Application No. 2001-319579 has already proposed a fluid ejector provided with an elastically deformable overhanging portion.
[0003]
FIG. 4 is a cross-sectional view showing the nozzle head type pump 200 exemplified as the fluid ejector and the mouth portion 10a of the container 10 to which the pump 200 is attached.
[0004]
The nozzle head type pump 200 is provided in the cylinder 220 with a cap 210 attached to the mouth portion 10 a of the container 10, a cylinder 220 having a pipe Co attached to the inside of the cap 210 and sucking up the contents of the container 10. A hollow having a valve plunger 230 for sucking fluid into the cylinder 220 apart from the seat 220a, and an internal passage 240r for introducing the valve plunger 230 with a return spring S1 disposed between the valve plunger 230 and the valve plunger 230 Guide shaft 240, a piston 250 attached to the outer periphery of the guide shaft 240 and slidable in the cylinder 220, and protruding from the inner passage 240r of the guide shaft 240 so that the outer periphery 230f of the valve plunger 230 can slide. Hold the valve plastic A sealed space R 1 composed of the jar 230, the guide shaft 240, the piston 250, and the cylinder 220 is defined, and the valve plunger 230 is separated from the seat portion 220 a provided in the cylinder 220 by pulling the guide shaft 240 back in the cylinder 220. On the other hand, the piston 250 is pushed into the cylinder 220 together with the guide shaft 240 to pressurize the sealed space R1, thereby separating from the outer peripheral portion 230f of the valve plunger 230 and discharging the fluid in the sealed space R1. A nozzle head 270 attached to the discharge side of the guide shaft 240, a holding member 280 provided between the cap 210 and the upper surface of the flange of the cylinder 220, the opening 10 a of the container 10, and the cylinder 220. Bottom of flange And a packing Po interposed therebetween.
[0005]
The overhanging portion 260 provided in the internal flow path 240r of the guide shaft 240 maintains hermeticity (hereinafter referred to as sealing property) with the outer peripheral portion 230f of the valve plunger 230 and operates as follows.
[0006]
Specifically, the overhang portion 260 is made of an elastic body such as rubber or elastomer, and in the process of pushing the piston 250 into the cylinder 220 together with the guide shaft 240 by the push-down operation of the nozzle head 270, the valve plunger 230 is connected to the cylinder. The valve plunger 230 is integrally held until it is seated on the valve seat 220a provided in 220. After the valve plunger 230 is seated on the valve seat 220a, the outer periphery of the valve plunger 230 is opposed to the urging force of the return spring S1. Slide along 230f. At this time, the overhanging portion 260 pushes the piston 250 together with the guide shaft 240 into the cylinder 220 along the valve plunger 230 to pressurize the sealed space R1, thereby resisting the elastic force of the outer peripheral portion 230f of the valve plunger 230. The sealed space R1 is opened to the internal flow path 240r formed in the guide shaft 240, and the fluid in the sealed space R1 is discharged from the internal flow path 240r through the opening 270a of the nozzle head 270.
[0007]
Thereafter, in the process of pulling back the guide shaft 240 in the cylinder 220, the overhanging portion 260 holds the outer peripheral portion 230f of the valve plunger 230 again by the urging force of the return spring S1, and pulls up the valve plunger 230 integrally. The plunger 230 is separated from the valve seat 220a of the cylinder 220 until it abuts against the end of the spring, and then only the guide shaft 240 is returned to the original position.
[0008]
[Problems to be solved by the invention]
By the way, such a fluid ejector slides along the outer peripheral portion 230f of the valve plunger 230 via the overhang portion 260 when the guide shaft 240 is pulled back in the cylinder 220. 5 is formed on the outer peripheral portion 230f of the valve plunger 230 with a protruding portion 231 with which the tip of the protruding portion 260 abuts, and the protruding portion 231 has a protruding portion. When the guide shaft 240 is pulled back, the guide shaft 240 finishes the relative movement with respect to the valve plunger 230 when the guide shaft 240 is pulled back, that is, the position at which the suction of the contents into the sealed space R1 is completed. I came up with the idea of securing (airtightness).
[0009]
However, in the pump container having the above-described configuration, as will be described later (embodiment), the pressure seal between the piston 250 and the holding member 280 in the vertical direction (see region Y in FIG. 4). The fluid is prevented from being discharged through the air hole 220h provided in the cylinder 220, and the convex portion 231 (see FIG. 5) of the valve plunger 230 and the overhanging portion 260 are pressure-contact sealed in the vertical direction. In this configuration, the upper and lower seal portions are provided at two different locations, and in order to maintain both seals, accuracy is required for component dimensions, assembly, and the like.
[0010]
For this reason, the overhanging portion 260 is configured to seal against the valve plunger 230 in the radial direction, but the fluid pressurized in the sealed space R1 is elastically deformed against the elastic force of the overhanging portion 260. Even at the position where the suction of the contents into the sealed space R1 is completed, the tip of the overhanging portion 260 comes into contact with the position when the fluid in the sealed space R1 is extremely pressurized. Depending on the shape of the convex portion 231, as shown by a two-dot chain line in FIG. 4, the tip of the overhang portion 260 gets over the convex portion 231 and falls from the outer peripheral portion 230 f of the valve plunger 230, thereby causing the fluid in the sealed space R 1 to flow. It may be discharged.
[0011]
The present invention has been made in view of the above-described problems, and the elastically deformable overhanging portion provided in the internal flow path of the piston or the guide shaft pulls back the guide shaft or the piston in the cylinder. An object of the present invention is to provide a fluid ejector that can reliably prevent the discharge of fluid from the sealed space without being separated from the outer periphery of the valve plunger at a position where the guide shaft or the piston finishes moving relative to the valve plunger. To do.
[0012]
[Means for Solving the Problems]
In order to solve this problem, the fluid discharge device according to the first aspect of the present invention has a valve plunger that is separated from a valve seat provided in the cylinder and sucks the fluid into the cylinder, and an internal passage that introduces the valve plunger. A hollow piston that is slidable in the cylinder, and an outer space of the valve plunger that protrudes from the internal passage of the piston is slidably held to define a sealed space composed of the valve plunger, the piston, and the cylinder. Pulling the piston back in the cylinder separates the valve plunger from the valve seat provided in the cylinder, while pushing the piston into the cylinder to pressurize the sealed space to separate the valve plunger from the outer periphery of the valve plunger. In the fluid ejector including the elastically deformable overhanging portion that discharges the fluid in the valve plunger, It is characterized in that a return portion is provided on the outer peripheral portion of the outer peripheral portion at a position where the piston finishes moving with respect to the valve plunger when the stone is pulled back to cover the tip of the overhang portion and prevent the tip from being bent. To do.
[0013]
The overhanging portion according to the first invention may be formed integrally with the piston or may be provided as a separate body.
[0014]
A fluid discharge device according to a second aspect of the present invention is a valve plunger that is spaced from a valve seat provided in the cylinder and sucks fluid into the cylinder, and a hollow guide shaft having an internal passage for introducing the valve plunger, A piston attached to the outer periphery of the guide shaft and slidable in the cylinder, and extends from the inner passage of the guide shaft and slidably holds the outer periphery of the valve plunger so that the valve plunger, the guide shaft, the piston, and the cylinder The valve plunger is separated from the valve seat provided in the cylinder by pulling back the guide shaft in the cylinder, while the piston is pushed into the cylinder together with the guide shaft to pressurize the sealed space. As a result, the fluid in the sealed space is drained away from the outer periphery of the valve plunger. In the fluid ejector comprising the elastically deformable overhanging portion, the valve plunger covers the tip of the overhanging portion at the outer peripheral portion where the guide shaft finishes moving relative to the valve plunger when the guide shaft is pulled back. It is characterized in that it is provided with a return portion for preventing the tip from curling.
[0015]
In addition, the overhang | projection part based on 2nd invention may be integrally molded with the guide shaft, or may be provided as a separate body.
[0016]
In the fluid ejector according to the third aspect of the present invention, in the first or second aspect, the valve plunger is preferably composed of a plurality of parts divided with respect to the axial direction.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0018]
FIG. 1 is a cross-sectional view showing a nozzle head type pump 100 which is an embodiment of a fluid ejector according to the present invention and a mouth portion 10a of a container 10 to which the pump 100 is attached, and FIG. 2 is a region of FIG. It is principal part sectional drawing which shows X. FIG.
[0019]
The nozzle head type pump 100 discharges a liquid such as an emulsion, for example, and includes a cap 110 attached to the mouth portion 10a of the container 10 and a pipe attached to the inside of the cap 110 to suck up the contents of the container 10. A return spring S1 is disposed between the valve plunger 130 and a cylinder 120 having C1, a valve plunger 130 that is separated from a seat 120a provided in the cylinder 120 and sucks fluid into the cylinder 120, and A hollow piston 140 having an internal flow path 140r for introducing the valve plunger 130 and slidable in the cylinder 120, and an outer peripheral portion 130f of the valve plunger 130 extending over the entire circumference extending from the internal flow path 140r of the piston 140. The valve plunger 130 and the piston are slidably held. An elastically deformable overhanging portion 150 that defines a sealed space R1 composed of 140 and the cylinder 120, and an internal flow path 160r that is attached to the back surface of the piston 140 and that introduces the valve plunger 130 together with the internal flow path 140r of the piston 140. A guide shaft 160, a nozzle head 170 attached to the discharge side of the guide shaft 160, a holding member 180 provided between the cap 110 and the flange upper surface of the cylinder 120, and the mouth of the container 10. 10a and a packing P1 interposed between the lower surface of the flange of the cylinder 120.
[0020]
As shown in FIG. 1, the valve plunger 130 includes two parts, a suction side part 131 and a discharge side part 132 that are divided in the axial direction. The suction side part 131 is seated on a seat part 120a provided in the cylinder 120 and serves as a suction valve, and the discharge side part 132 is slidable by an overhanging part 150 having an outer peripheral part 130f provided on the piston 140. Hold and act as a discharge valve.
[0021]
As shown in FIG. 2, the discharge-side part 132 is located at a position where the piston 140 finishes moving with respect to the valve plunger 130 when the piston 140 is pulled back (in this embodiment, the front end of the valve plunger 130 on the nozzle head 170 side). A return portion 133 that covers the tip 150e of the overhang 150 provided on the piston 140 and prevents the tip 150e from curling is provided on the outer periphery. The return portion 133 extends, for example, toward the suction side part 131 along the outer peripheral portion 130f of the valve plunger 130, and is continuously formed over the entire circumference of the valve plunger 130 or the entire circumference of the valve plunger 130. An annular groove 133a is formed at a portion where the tip 150e of the projecting portion 150 is in pressure contact. In the present embodiment, the return portion 133 is formed over the entire circumference. However, the shape is not limited to this and may be intermittently formed as long as the protruding portion 150 is prevented from being bent.
[0022]
As shown in FIG. 2, the projecting portion 150 of the piston 140 has a substantially claw-like cross-sectional shape having a tip 150 e that contacts the outer peripheral portion 130 f of the valve plunger 130, and is an elastic body such as rubber or elastomer integrally with the piston 140. Molded. As a result, the protruding portion 150 has its tip 150e in radial contact with the outer peripheral portion 130f of the valve plunger 130 to maintain a sealing property (hereinafter referred to as a sealing property) with the outer peripheral portion 130f of the valve plunger 130. Behaves like
[0023]
In the process of pushing the piston 140 into the cylinder 120, the overhanging portion 150 holds the outer end portion 130 f of the valve plunger 130 integrally until the valve plunger 130 is seated on the valve seat 120 a provided in the cylinder 120. However, after the valve plunger 130 is seated on the valve seat 120a, the piston 140 slides along the outer peripheral portion 130f of the valve plunger 130 against the urging force of the return spring S1. At this time, the piston 140 is pushed into the cylinder 120 along the valve plunger 130 to pressurize the sealed space R1, so that when the pressure in the sealed space R1 increases, the tip 150e of the overhanging portion 150 causes the elasticity of the overhanging portion 150. The valve plunger 130 is separated from the outer peripheral portion 130f against the force.
[0024]
Thereafter, the tip 150e of the overhanging portion 150 is brought into pressure contact with the outer peripheral portion 130f of the valve plunger 130 again due to the pressure drop in the sealed space R1, so that in the step of pulling back the piston 140 from the cylinder 120, the biasing force of the return spring S1 The outer peripheral portion 130f of the valve plunger 130 is held again, the valve plunger 130 is pulled up integrally, the valve plunger 130 is separated from the valve seat 120a of the cylinder 120 until it hits the spring end, and then only the piston 140 is moved back to the original position. The position is returned to the position (the return portion 133 with which the overhang portion 150 is in pressure contact).
[0025]
The cylinder 120 of this embodiment has an air hole 120h on its side surface for preventing negative pressure generated on the back surface of the piston 140. The piston 140 is provided with a return spring S1 as shown in a region Y in FIG. By receiving all of the force, the holding member 180 is pressed against the holding member 180, so that when the nozzle head type pump 100 falls down, the contents flowing in from the air hole 120h provided on the side surface of the cylinder 120 are For example, the guide shaft 160 and the holding member 180 are sealed so as not to be discharged.
[0026]
Here, the pumping action of the nozzle head type pump 100 will be described.
[0027]
When the user first presses the nozzle head 170 in FIG. 1 in the direction of arrow d, the guide shaft 160 pushes the valve plunger 130 together with the piston 140 into the cylinder 120 against the urging force of the return spring S1, and the piston 140 The valve plunger 130 held at the tip 150 e of the overhang portion 150 is seated on the valve seat 120 a of the cylinder 120.
[0028]
When the nozzle head 170 is further pressed thereafter, the piston 140 slides along the outer peripheral portion 130f of the valve plunger 130 via the tip 150e of the overhanging portion 150, so that the piston 150 resists the urging force of the return spring S1. The sealed space R1 is pressurized by being pushed into 120.
[0029]
Then, the pressure rises in the sealed space R1, and the tip 150e of the overhanging portion 150 is pushed away from the outer peripheral portion 130f of the valve plunger 130 against the elastic force to be separated from the outer peripheral portion 130f of the valve plunger. The internal air is discharged to the discharge port 170a of the nozzle head 170 through the internal flow paths 140r and 160r. Thereafter, when the user removes his / her finger from the nozzle head 170, the tip 150e of the overhang portion 150 is elastic. The seat is again seated on the outer peripheral portion 130f of the valve plunger by force. At this time, as the nozzle head 170 is raised, the tip 150e of the overhang 150 pulls the valve plunger 130 away from the seat 120a of the cylinder 120 and creates a negative pressure in the sealed space R1. The contents inside are sucked up from the pipe C1 and introduced into the sealed space R1.
[0030]
Thereafter, when the user presses the nozzle head 170, the overhanging portion 150 provided on the piston 140 causes the valve plunger 130 to be seated on the seat portion 120a of the cylinder 120, and then the piston 150 pressurizes the contents in the sealed space R1. The pressurized contents push the tip 150e of the overhanging portion 150 away from the outer peripheral portion 130f of the valve plunger 130 against the elastic force of the overhanging portion 150 to separate it from the outer peripheral portion 130f of the valve plunger 130, The liquid is discharged from the discharge port 170a of the nozzle head 170 through the internal flow paths 140r and 160r.
[0031]
FIGS. 3A and 3B are cross-sectional views of the main part showing the relationship between the tip 150e of the overhanging portion 150 and the return portion 133 of the valve plunger 130 in the sealed space R1, and FIG. The content in the sealed space R1 shows an appropriate pressure state, and FIG. 3B shows the state in which the content in the sealed space R1 is extremely pressurized. FIG. 3C shows a modification of the projecting portion 150. The relationship between the tip 150e and the return portion 133 of the valve plunger 130 when the contents in the sealed space R1 are in an appropriate pressure state is shown in the sealed space R1. It is principal part sectional drawing shown in the state.
[0032]
In this embodiment, when the nozzle head 170 returns to the original position, the return portion 133 of the valve plunger 130 covers the tip 150e of the overhang portion 150, as shown in FIG. For this reason, even if the contents in the sealed space R1 are extremely pressurized, the return portion 133 of the valve plunger 130 causes the tip 150e of the overhang portion 150 to extend in the radial direction (see FIG. 3B). Since the tip 150e is held against the arrow F), the tip 150e of the overhanging portion 150 does not fall from the outer peripheral portion 130f of the valve plunger 130 to discharge the contents in the sealed space R1. In addition, although the overhang | projection part 150 of this embodiment is a thing of the shape where the front-end | tip 150e extends along the outer peripheral part 130f of the valve plunger 130, the shape of the front-end | tip 150e is not restricted to this, For example, It may consist of a straight tip as shown in FIG.
[0033]
That is, according to the present embodiment, the valve plunger 130 covers the distal end 150e of the overhanging portion 150 at the outer peripheral portion where the piston 140 finishes moving with respect to the valve plunger 130 when the piston 140 is pulled back. 150e is provided with a return portion 133 that prevents dripping, so that even if the contents in the sealed space R1 are extremely pressurized at the position where the contents have been sucked into the sealed space R1, the valve Since the return portion 133 of the plunger 130 holds the tip 150e of the overhanging portion 150 in the radial direction, the content sucked into the sealed space R1 is discharged to the internal flow path 140r of the piston 140 and the internal flow path 160r of the guide shaft 160. There is no end.
[0034]
Therefore, according to the present embodiment, even if the contents in the sealed space R1 are extremely pressurized at the position where the suction of the contents into the sealed space R1 is completed, the liquid is discharged from the sealed space R1. An appropriate amount of contents according to the pump operation can be discharged without leaking.
[0035]
As a second embodiment of the present invention, the valve plunger 230 of the nozzle head type pump 200 disclosed in FIG. 4 can be replaced with the valve plunger 130 of the first embodiment.
[0036]
According to this embodiment, the valve plunger 130 has a tip 260e (see FIG. 5) of the projecting portion 260 on the outer peripheral portion where the guide shaft 240 finishes moving with respect to the valve plunger 130 when the guide shaft 240 is pulled back. Is provided with a return portion 133 that covers the top and prevents the tip 260e from curling, so that the content in the sealed space R1 is extremely pressurized at the position where the suction of the content into the sealed space R1 has been completed. Even in such a state, since the return portion 133 of the valve plunger 130 holds the tip 260e of the overhang portion 260, the content sucked into the sealed space R1 is discharged to the internal flow path 240r of the guide shaft 240. There is no.
[0037]
Therefore, according to the second embodiment, as in the first embodiment, the contents in the sealed space R1 are extremely pressurized at the position where the suction of the contents into the sealed space R1 is completed. In addition, an appropriate amount of contents corresponding to the pump operation can be discharged without liquid leakage from the sealed space R1.
[0038]
Further, the valve plunger 130 of the present embodiment is composed of two parts, an intake valve part 131 and a discharge valve part 132 that are divided with respect to the axial direction thereof. In the first embodiment, the assembly operation with the piston 140, the second In the embodiment, the assembling work with the guide shaft 240 is facilitated, so that the assembling workability for the nozzle head type pump is improved. In addition, the valve plunger 130 of this embodiment consists of two parts divided | segmented with respect to the axial direction, However, Even if it consists of two or more parts, it is further with respect to the axial direction. It may consist of a single part that is not divided.
[0039]
The above description only shows a preferred embodiment of the present invention, and those skilled in the art can make various modifications within the scope of the claims. For example, the projecting portion 150 of the first embodiment is The piston 140 is not limited to the one integrally formed with the piston 140, and may be provided separately from the piston 140. The position of the return portion 133 provided in the valve plunger 130 may be a position where the piston 140 or the guide shaft 240 ends the movement with respect to the valve plunger 130 when the piston 140 or the guide shaft 240 is pulled back. It is not limited to the nozzle head side tip.
[0040]
In addition, the nozzle head type pump may be of a type in which the user presses a tray-like nozzle head provided on the piston via cotton or puff to take out contents such as cleansing liquid. The fluid discharger is not limited to the nozzle head type pump, but may be a trigger pump that causes a pump action by pulling a finger hooked on the trigger by the user, and the discharge liquid is discharged in a mist form. It may be a spray type.
[0041]
【The invention's effect】
The fluid discharge device according to the first aspect of the present invention prevents the tip of the tip from curling by covering the tip of the overhang at the outer periphery of the position where the piston ends the movement with respect to the valve plunger when the valve plunger pulls back the piston. Since it has a return part, the return part of the valve plunger overhangs even when the contents in the sealed space are extremely pressurized at the position where the content has been sucked into the sealed space. Since the tip of the part is held in the radial direction, the content sucked into the sealed space is not discharged from the internal flow path of the piston.
[0042]
Therefore, according to the first invention, even if the contents in the sealed space are extremely pressurized at the position where the suction of the contents into the sealed space is completed, the liquid leaks from the sealed space. In addition, an appropriate amount of contents according to the pump operation can be discharged.
[0043]
The fluid ejector according to the second aspect of the present invention covers the tip of the overhanging portion on the outer periphery of the position where the guide shaft finishes moving with respect to the valve plunger when the valve plunger pulls back the guide shaft. Since it has a return part to prevent the valve plunger return part even if the contents in the sealed space are extremely pressurized at the position where the content has been sucked into the sealed space Since the tip of the overhanging portion is held, the content sucked into the sealed space is not discharged from the internal flow path of the guide shaft.
[0044]
Therefore, according to the second invention, as in the first invention, even if the contents in the sealed space are extremely pressurized at the position where the suction of the contents into the sealed space is completed, the sealed space An appropriate amount of contents corresponding to the pump operation can be discharged without leaking from the inside.
[0045]
The third invention is the above first or second invention, wherein the valve plunger is composed of a plurality of parts divided with respect to the axial direction thereof, so that the assembly work with the piston or the guide shaft is facilitated. Assembling workability for the fluid ejector according to the first or second aspect of the present invention is improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a nozzle head pump that is a first embodiment of a fluid ejector according to the present invention and a mouth portion of a container to which the pump is attached.
2 is a cross-sectional view of a main part showing a region X in FIG. 1;
FIGS. 3A and 3B are main part sectional views showing the relationship between the valve plunger and the overhanging part in the sealed space according to the first embodiment, respectively, and FIG. 3C shows the present invention. It is a modification of the overhang | projection part which concerns on this, Comprising: It is principal part sectional drawing which shows the relationship between this overhang | projection part and a valve plunger in the state in sealed space.
FIG. 4 is a cross-sectional view showing a nozzle head type pump exemplified as a conventional fluid ejector and a mouth portion of a container to which the pump is attached.
FIG. 5 is a cross-sectional view of a main part showing a relationship between a valve plunger and a projecting portion provided in an internal flow path of the guide shaft.
[Explanation of symbols]
100 Nozzle head type pump
110 cap
120 cylinders
120a seat
130 Valve plunger
130f Valve plunger outer periphery
131 Suction side parts
132 Discharge side parts
133 Return part
140 piston
140r internal flow path
150 Overhang part
150e Tip of overhang
160 Guide shaft
160r internal flow path
170 Nozzle head
180 Holding member
200 Nozzle head type pump
210 cap
220 cylinders
220a seat
230 Valve plunger
240 Guide shaft
240r internal flow path
250 piston
260 Overhang
270 nozzle head
280 Holding member
Po, P1 packing
Co, C1 pipe
S1 return spring
R1 sealed space

Claims (3)

A valve plunger that is spaced apart from a valve seat provided in the cylinder and sucks fluid into the cylinder; a hollow piston that has an internal passage for introducing the valve plunger and is slidable in the cylinder; and The valve plunger protrudes from the internal passage so as to slidably hold the outer periphery of the valve plunger so as to define a sealed space composed of the valve plunger, the piston and the cylinder, and the piston is pulled back in the cylinder. While the plunger is separated from the valve seat provided in the cylinder, the piston is pushed into the cylinder to pressurize the sealed space, so that the fluid in the sealed space is separated from the outer peripheral portion of the valve plunger. In the fluid ejector comprising the elastically deformable overhanging portion for discharging,
The valve plunger is provided with a return portion that covers the tip of the protruding portion and prevents the tip of the tip from being bent at the outer peripheral portion of the position where the piston finishes moving with respect to the valve plunger when the piston is pulled back. A fluid ejector characterized by being. A valve plunger that separates from a valve seat provided in the cylinder and sucks fluid into the cylinder, a hollow guide shaft having an internal passage for introducing the valve plunger, and the cylinder attached to the outer periphery of the guide shaft A sealed space comprising a piston that is slidable inside and a valve plunger, the guide shaft, the piston, and the cylinder that slidably holds the outer periphery of the valve plunger so as to protrude from the internal passage of the guide shaft. The valve plunger is separated from the valve seat provided in the cylinder by pulling the guide shaft back in the cylinder, and the piston is pushed into the cylinder together with the guide shaft in the sealed space. From the outer periphery of the valve plunger by pressurizing In the fluid ejection device comprising an elastically deformable projecting unit for discharging the fluid in the enclosed space in between,
The valve plunger includes a return portion that covers the distal end of the overhanging portion and prevents the distal end from curling at an outer peripheral portion where the guide shaft finishes moving relative to the valve plunger when the guide shaft is pulled back. Fluid ejector characterized by being a thing. The fluid ejector according to claim 1 or 2, wherein the valve plunger is composed of a plurality of parts divided in the axial direction.

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