JP7365228B2 - liquid dispensing tool - Google Patents

Description

The present invention relates to a liquid discharging tool.

Conventionally, writing instruments such as ballpoint pens and markers, pen-shaped correction fluid, liquid glue, and other applicators that allow liquid to flow out from a tip provided at the front of the shaft body are known, and furthermore, by applying pressure, Structures that can increase the amount of liquid flowing out are also known.
For example, in writing instruments, as in Patent Document 1 (Japanese Unexamined Patent Publication No. 2000-335173), a pressurizing mechanism is provided at the rear of the ink storage tube, and the ink in the ink tank is pressurized in conjunction with the pressing operation of the knock body. There is a structure that can be used. With a writing instrument equipped with such a pressure mechanism, it is possible to increase the amount of ink flowing out from the pen tip, thereby making handwriting thicker or darker.

Japanese Patent Application Publication No. 2000-335173

However, the writing instrument of Patent Document 1 requires a pressurizing mechanism to apply pressure, and the structure becomes complicated, which increases the risk of failure and increases costs. In addition, the ballpoint pen of Patent Document 1 has a structure in which the ink is pressurized in conjunction with the extrusion operation of the knock mechanism, so the amount of pressure cannot be adjusted. Even when this is not necessary, the ink is constantly pressurized.
In addition, because the structure allows the pressure mechanism to compress only the air in the space behind the refill (liquid storage tube) that stores ink, the ink (liquid) inside the refill can be used without being used. Compared to the compression force when the amount of air in the space behind the refill is small, the compression force when the amount of ink decreases and the amount of air in the space behind the refill increases, so as a result, the amount of air in the space behind the refill is small. When you start using a ballpoint pen where air is easily compressed, a lot of ink is ejected, the ink is consumed and the air in the space behind the refill increases, and when the air becomes difficult to compress, the amount of ink ejected decreases and the ink is The structure is such that the ejection amount of the ink is easily influenced by the remaining amount of the ink.

An object of the present invention is to obtain a liquid discharging device that has a simple structure, can adjust the pressure applied to the liquid, and has a structure in which the pressure is not easily affected by changes in the remaining amount of liquid in the liquid storage tube. purpose.

The present invention
"1. A cylindrical dispensing tool body, and a cap that is removably attached to the front and rear of the dispensing tool main body and has one end open and the other end closed,
A liquid dispensing tool for discharging a liquid stored inside the dispensing tool main body from a tip provided in front of the dispensing tool main body,
A liquid storage tube for storing the liquid is provided inside the discharge tool main body,
A first space portion located behind the liquid contained in the liquid storage tube is provided at a rear portion of the liquid storage tube,
having a second space communicating with the first space between the discharge tool main body and the liquid storage tube,
The cap has an annular convex portion on the inner circumferential surface on the open end side thereof that slides on the outer circumferential surface of the dispensing tool main body,
A key protrusion is provided on the outer circumferential surface of the dispensing device main body or the inner circumferential surface of the cap,
A circumference of the inner circumferential surface of the cap or the outer circumferential surface of the dispensing tool body at different lengths along the axial direction that engages with the key protrusion. It has a plurality of keyways formed at intervals on the top,
The second space is located in the dispensing tool main body at a position forward of the rear end of the liquid storage tube and at a position behind the annular convex portion of the cap when the cap is attached to the rear of the dispensing tool main body. has a hole communicating with the part,
When the cap is attached to the rear of the dispensing device main body by aligning the key protrusion with any of the plurality of key grooves, the key protrusion slides on the key groove and the step in the axial direction of the key groove. The annular convex portion of the cap moves forward while slidingly contacting the outer peripheral surface of the dispensing device main body, so that the liquid flows between the first space and the second space. A liquid dispensing tool that is pressurized via compressed air in a closed space.
2. The liquid discharging tool according to item 1 above,
When the cap is attached to the rear of the dispensing tool main body, a gas storage part is formed between the cap and the dispensing tool main body, and the gas containing part communicates with the second space part through the hole,
The liquid discharging tool has a structure in which the sealed space is constituted by the first space, the second space, and the gas storage part.
3. The liquid discharging tool according to item 1 or 2 above,
The liquid discharging tool has a structure in which engagement between the key protrusion and the plurality of key grooves starts before compression of the sealed space.
4. The liquid discharging tool according to any one of items 1 to 3 above,
The liquid dispensing tool has a structure in which at least an outer circumferential surface of the dispensing tool main body is displaced in an axial radial direction when the cap is attached to the rear of the dispensing tool main body.
5. The liquid discharging tool according to any one of items 1 to 4 above,
The dispensing device main body has a tapered rear portion,
The hole is formed in the rear part,
The liquid dispensing device has a structure in which, when the cap is attached to the rear of the dispensing device main body, the annular convex portion of the cap presses against the outer peripheral surface of the dispensing device main body and moves forward while deforming it inwardly.
6. The liquid discharging tool according to any one of items 1 to 5 above,
A liquid discharging tool having a structure in which the other end of the cap has a flat surface shape or an arcuate surface shape. ”.

The liquid dispensing tool of the present invention applies the liquid through the compressed air in the sealed space composed of the first space and the second space by attaching the cap to the rear of the main body of the dispensing tool. It is a structure that makes it easier to discharge liquid by pressurizing compressed air to a pressure higher than atmospheric pressure. More specifically, the annular convex portion on the open end side of the cap slides on the outer circumferential surface of the dispensing device main body, so that the inside of the cap, the first rear space, and the second rear space become sealed spaces; By moving the cap forward in this state, the air in the closed space is compressed, and the liquid is pressurized via the compressed air.
Therefore, by attaching the cap to the rear of the liquid applicator and adjusting the amount by which the cap is advanced while sliding the annular protrusion on the open end side of the cap against the outer peripheral surface of the dispensing tool body, air can be removed. The compression force changes; for example, if you move the cap forward a little to apply weak pressure to the liquid, the amount of ink flowing out from the nib will increase slightly, making the handwriting a little thicker or darker. When the cap is moved forward and strongly pressurized, the amount of ink flowing out from the pen tip increases, making it possible to make handwriting thicker or darker.

Furthermore, when the cap is attached to the rear of the dispensing tool body by aligning the key protrusion with one of the plurality of key grooves, the key protrusion slides in the key groove and comes into contact with the step in the axial direction of the key groove. By moving the compressor forward to a certain point, it is possible to easily keep the amount of air compressed in the closed space constant.
In addition, when attaching the cap to the rear of the dispensing tool body, if the annular convex part on the open end side of the cap is in contact with the outer circumferential surface of the dispensing tool body, and the cap is not advanced any further. It becomes possible to write at atmospheric pressure without pressurizing the liquid.
In other words, the liquid dispensing device of the present invention has a structure in which the liquid can be pressurized by attaching the cap to the rear of the dispensing device main body, and the width can be adjusted by adjusting the pressure applied to the liquid according to the user's purpose. It can be used for a wide range of purposes, and by aligning the key protrusion with one of the multiple key grooves and attaching the cap to the rear of the dispensing tool body, it is possible to easily keep the amount of air compressed in the closed space constant. .
Furthermore, since the structure is simple, it is possible to provide a low-cost liquid discharging tool with less risk of failure.
In addition, since the hole connecting the second space and the outside is provided at a position forward of the rear end of the liquid storage tube in the dispensing tool body, even if liquid leaks from the rear end of the liquid storage tube , the The liquid tends to flow toward the rear inner side of the dispensing device main body, and the liquid is difficult to leak out of the dispensing device main body.

Furthermore, since the liquid discharging device having the structure of the present invention compresses the air in the sealed space composed of the first space and the second space, it is possible to pressurize a large volume of air, and the liquid discharging device can pressurize a large volume of air inside the liquid storage pipe. Even if the amount of liquid decreases and the air inside the liquid storage tube increases, the pressurizing force is unlikely to change, and as a result, the amount of liquid discharged can be stabilized.
Furthermore, when the cap is attached to the rear of the dispensing tool main body, a gas storage section is formed between the cap and the dispensing tool main body and communicates with the second space section through the hole, and the gas storage section communicates with the second space section through the hole. By adopting a structure in which the sealed space consists of two spaces and a gas storage part, a larger volume of air can be pressurized, the liquid in the liquid storage tube decreases, and the air in the liquid storage tube increases. Even when the pressure is applied, changes in the pressurizing force are less likely to occur, and the amount of liquid discharged can be stabilized.

Furthermore, by adopting a structure in which the engagement between the key protrusion and the plurality of key grooves is started before the compression of the sealed space, the key protrusion can be attached to the circumference of the inner circumferential surface of the cap or the outer circumferential surface of the dispensing tool body. Since the air in the closed space is not compressed until it is aligned (engaged) with one of the multiple keyways formed at intervals above, alignment is easy and the position After finishing the alignment, the air in the closed space can be compressed, making it easy to operate.

Furthermore, when the cap is attached to the rear of the dispensing tool main body, at least the outer peripheral surface of the dispensing tool main body is displaced in the radial direction, so that the annular convex part of the cap is aligned with the outer peripheral surface of the dispensing tool main body. It can be moved forward while being in close contact with each other, making it possible to efficiently compress the air in the closed space.
In this case, the material of the dispensing device body may be such that the entire dispensing device body or only its surface is molded with soft resin such as polypropylene resin, polyethylene resin, ABS resin, olefin thermoplastic elastomer, styrene thermoplastic elastomer, or polyester. It can be molded from thermoplastic elastomer, polyurethane thermoplastic elastomer, etc. Furthermore, by forming the dispensing tool main body with a thin wall thickness, at least the outer circumferential surface of the dispensing tool main body can be pressed and deformed by the annular convex portion of the cap.
Further, the material of the cap is preferably molded from a hard resin such as polycarbonate resin, acrylic resin, or AS resin in order to displace the dispensing tool main body in the axial radial direction with the annular convex portion of the cap.

Further, the dispensing device main body has a tapered rear portion, and the hole is formed in the rear portion, and when the cap is attached to the rear of the dispensing device main body, the annular convex portion of the cap discharges. By applying pressure to the outer peripheral surface of the device body and moving it forward while deforming it inward, the annular shape of the cap can be adjusted to the position where air compression starts, that is, when the cap is attached to the rear of the dispensing device body. The cap can be easily attached to the position where the convex portion first contacts the outer circumferential surface of the dispensing tool body. In addition, by gradually advancing the cap from that position, even if it receives the repulsive force of the compressed air, the fit between the cap and the dispensing tool body gradually becomes tighter, so the repulsive force of the air will cause the cap to close. The structure is such that it is difficult for the body to be pushed back.
In addition, when the rear part of the dispensing tool main body is formed into a tapered shape, the side surface thereof may be formed with a gently sloped surface with no irregularities on the surface, or may be formed with a gently arcuate surface. In addition, the amount of change in the outer diameter of the tapered end should be such that the difference in outer diameter from the point where air compression starts to the point where compression ends is 0.05 mm to 1 mm. Even when the cap is attached to the device, it is difficult for the cap to slip off from the main body of the dispensing tool.

Furthermore, by having a structure in which the surface of the other end of the cap is flat or arcuate, the burden on the fingers is reduced when pressing the end surface of the cap with the pad of your finger and attaching it to the rear of the dispensing tool body. be done. Its surface area is preferably 90 mm ² or more.

Although the shape of the dispensing tool main body is not particularly limited, a rod-like shape like a writing instrument is preferable so that the discharging tool main body can be easily held.
Further, the annular convex portion provided on the open end side of the cap may be formed integrally with the cap, or may be provided by fixing an O-ring or the like on the inner surface of the cap.

In the case of a writing instrument, the tip may be a ballpoint pen tip, a felt tip, or the body of a fountain pen equipped with a brush tip or a pen core, and in the case of an applicator, a fiber bundle, a sponge, etc. may be mentioned. Since the distal tip is the final path for discharging the liquid in the storage tube to the outside, the size of the liquid flow path and the presence or absence of a valve mechanism will make contact with the rear end of the liquid stored in the liquid storage tube. It is related to the pressurized state of air. For example, if the liquid channel is large, the liquid can be easily discharged even if the pressure is slightly higher than atmospheric pressure. By providing a valve mechanism on the tip, even if the air in the sealed space consisting of the gas storage section, first space, and second space is greatly compressed, liquid will be discharged unintentionally. This can be prevented.

Note that when the atmospheric pressure is 1000 hPa, for example, in the case of writing ink with a low viscosity (as an example, the ink for writing instruments with a viscosity of 1 mPa・s to 2000 mPa・s in an environment of 20° C.), the air in the closed space is By increasing the atmospheric pressure to a range of 1,500 hPa exceeding the atmospheric pressure of 1,000 hPa, it is now possible to make it easier to discharge writing instrument ink. For writing ink with a viscosity of 3000 mPa·s to 50000 mPa·s), the writing ink can be easily discharged by pressurizing the air pressure in the sealed space to a range of 1100 hPa to 5000 hPa. You will be able to do this. However, the numerical value to be pressurized is not particularly limited, and may be appropriately set depending on the characteristics such as the viscosity of the liquid and the structure of the tip as described above.

The liquid is not particularly limited as long as it can be stored in the liquid storage tube, and may be appropriately selected depending on the use of the liquid discharging tool, such as writing ink, correction fluid, liquid glue, cosmetic liquid, etc. The writing ink is not particularly limited, such as oil-based ink or water-based ink, and ink having shear thinning properties can also be used.
In addition, thermochromic inks that use microcapsule pigments containing thermochromic materials as coloring agents generally tend to have difficulty in increasing handwriting density because the capsules contain coloring materials, but the present invention By using a structured liquid ejecting tool, it is possible to increase the density of handwriting by increasing the amount of ink flowing out due to pressurization.
In addition, methods for increasing the density of handwriting of thermochromic ink containing microcapsule pigment include increasing the amount of microcapsule pigment serving as a coloring agent, and increasing the particle size of microcapsule pigment. When the amount of the microcapsule pigment is increased, the viscosity of the ink becomes high and it becomes difficult to flow out, and when the particle size of the microcapsule pigment is increased, the pigment becomes difficult to pass through the ink flow path, and the ink becomes difficult to flow out. There is a risk that it will be difficult for the water to leak out. However, even with such ink, the liquid ejecting tool having the structure of the present invention can be used because the ink can be forcibly ejected by pressurizing the ink.
In addition, even if the ink contains solids with a relatively high specific gravity such as titanium oxide or bright pigments and has a high viscosity when standing to prevent the solids from settling in the liquid, the liquid with the structure of the present invention can be used. Similar to the thermochromic ink containing the microcapsule pigment, the ejection tool can forcibly eject the ink by pressurizing the ink.
Furthermore, even in cases where dry liquid, such as correction fluid or liquid glue, adheres to the distal tip, the liquid can be pressurized to make it easier to discharge.
As described above, the liquid discharging device of the present invention has a structure suitable as a discharging device for various liquids.

According to the present invention, it is possible to obtain a liquid discharging tool that has a simple structure, can adjust the pressure applied to the liquid, and has a structure in which the pressure is not easily affected by changes in the remaining amount of liquid in the liquid storage tube.

FIG. 2 is a longitudinal cross-sectional view of the ballpoint pen of the present embodiment, with a portion shown as a side view. FIG. 2 is a diagram showing a state in which the cap is attached to the rear of the shaft in the ballpoint pen of FIG. 1; 3 is a diagram showing a state in which the cap is advanced from the state in FIG. 2. FIG. 4 is a diagram showing a state in which the cap is further advanced from the state in FIG. 3. FIG. FIG. 3 is a diagram showing a state in which the cap of FIG. 2 is rotated 180 degrees and then advanced. 6 is a diagram showing a state in which the cap is further advanced from the state in FIG. 5. FIG.

Next, the present invention will be explained with reference to the drawings, but the present invention is not limited to the following embodiments. In this embodiment, a cap-type ballpoint pen will be explained as a liquid discharging tool, but the liquid discharging tool of the present invention can also be used for writing instruments such as markers and fountain pens, applicators such as correction pens and liquid glue, or makeup tools. It is possible to use it in tools.
In this embodiment, the side where the pen tip is located is expressed as the front, and the opposite side is expressed as the rear. In order to make the explanation easier to understand, similar members and similar parts in the drawings are designated by the same reference numerals.

FIG. 1 is a longitudinal cross-sectional view of the ballpoint pen of this embodiment, with a portion shown as a side view.
As shown in FIG. 1, the ballpoint pen 1 (liquid dispensing tool) of the present embodiment has a shaft body 2 (discharging tool main body) composed of a front shaft 3 and a rear shaft 4 screwed onto the front shaft 3. be. A ballpoint pen refill 5 is disposed inside the shaft body 3, and the ballpoint pen refill 5 stores ink 6 (liquid). Behind the ink 6, a grease-like ink follower 7 is disposed. It has been accommodated. The ink follower 7 prevents the ink 6 from flowing backward and moves forward as the ink 6 decreases.
The ballpoint pen refill 5 has a ballpoint pen tip 5b (tip tip) disposed in front of the ink tank 5a ( liquid storage tube ) protruding from the front end opening 3a of the front shaft 3, and a ballpoint pen tip 5b (tip tip) disposed in front of the ink tank 5a (liquid storage tube) protrudes from the front end opening 3a of the front shaft 3. It is held between the reduced diameter portion 3b and a rib 4a formed on the rear inner surface of the rear shaft 4, and is fixed to the shaft body 2.

The gap between the front end opening 3a of the front shaft 3 and the ballpoint pen tip 5b of the ballpoint pen refill 5 is sealed with silicone rubber (not shown). Further, the front shaft 3 and the rear shaft 4 have a press-fitting portion 3d provided in front of the fitting portion 3c of the front shaft 3, and a press-fitting receiving portion 4c provided in front of the fitting receiving portion 4b of the rear shaft 4. It is sealed by being press-fitted.
The shaft body 2 is provided with a round hole 4d having a diameter of 1 mm and centered 10 mm ahead of the rear end 5c of the ink tank 5a on the rear shaft 4.
The rear part of the ink tank 5a has a first space K1 located behind the ink 6 and the ink follower 7 stored in the ink tank 5a, and a first space K1 is provided between the shaft body 2 and the ink tank 5a. It has a second space K2 that communicates with the first space K1. The hole 4d communicates the second space K2 with the outside, but even if the ink 6 leaks from the rear end 5c of the ink tank 5a, the hole 4d is located forward of the rear end 5c of the ink tank 5a. Since the ink 6 is located in the rear shaft 4 , the ink 6 easily flows toward the inner side of the rear part of the rear shaft 4 and has a structure that prevents it from leaking to the outside of the cylinder body 2 .

A cap 8 is attached to the front shaft 3 to protect the ballpoint pen tip 5b. The cap 8 is provided with an annular convex portion 8b on the inner circumferential surface on the open end 8a side, and the convex portion 8b rides over the protrusion 3e formed on the outer circumferential surface of the front shaft 3, so that the cap 8 is attached to the shaft body. At the same time, the ballpoint pen tip 5b comes into contact with an elastomer inner cap 8c provided on the cap 8, thereby preventing the ballpoint pen tip 5b from drying out.
In this embodiment, the rear shaft 4 is molded from polypropylene, which is a soft resin, and the cap 8 is molded from polycarbonate, which is a hard resin. Further, both the rear shaft 4 and the cap 8 are molded from transparent resin, so that the inside can be visually checked.

Ink 6 was prepared by first collecting 20.0 parts by mass of a titanium oxide dispersion, 1.0 parts by mass of a solvent (ethylene glycol), 40.0 parts by mass of water, and 1.0 parts by mass of a dispersant (surfactant). After sufficient dispersion using a disperser, centrifugation is performed to remove coarse components to obtain a titanium oxide dispersion. Thereafter, 62.0 parts by mass of the prepared titanium oxide dispersion, 24.4 parts by mass of water, and 10 parts of the resin emulsion (acrylic emulsion) were added. 0 parts by mass, 1.0 parts by mass of phosphate ester surfactant, 1.0 parts by mass of pH adjuster (triethanolamine), 1.0 parts by mass of rust inhibitor (benzotriazole), 0.2 parts by mass of antifungal agent. A base ink was prepared by heating and stirring the mass part with a magnetic hot stirrer. Thereafter, while heating the base ink prepared above, 0.4 parts by mass of a shear thinning agent (succinoglycan) was added and thoroughly mixed and stirred using a homogenizer stirrer until a uniform state was obtained. Filtration was performed using filter paper to obtain white ink.

Next, a state in which the cap 8 is attached to the rear of the shaft body 2 and the ink 6 is pressurized will be described using FIGS. 2 to 4. FIG. 2 is a diagram showing the ballpoint pen of this embodiment in a state where the cap is attached to the rear of the ballpoint pen body. FIG. 3 is a diagram showing a state in which the cap is advanced from the state in FIG. 2. FIG. 4 is a diagram showing a state in which the cap is further advanced from the state in FIG. 3.
As shown in FIG. 2, in the ballpoint pen 1 of this embodiment, when the cap 8 is attached to the rear of the shaft body 2, the annular convex portion 8b of the cap 8 comes into contact with the outer peripheral surface of the rear shaft 4. , the cap 8 is prevented from falling off the rear shaft 4.

When the cap 8 is further advanced relative to the shaft body 2 from the state shown in FIG. 2, the annular convex portion 8b of the cap 8 advances to the position shown in FIG. 3 beyond the front end of the hole 4d of the rear shaft 4. , a gas storage part K3 is formed between the cap 8 and the shaft body 2 and communicates with the second space part K2 via the hole 4d, and the first space part K1, the second space part K2, and the gas storage part K3 are formed. A closed space MK is constituted by this.

In this embodiment, one key projection 8k is provided on the inner peripheral surface of the cap 8, and one key projection 8k is provided on the outer peripheral surface of the shaft body 2 at different lengths along the axial direction that engages with the key projection 8k. Two key grooves 41 m and 42 m are provided on the circumference of the outer peripheral surface of the shaft body 2 at an interval of 180 degrees. The front step part 41md of the keyway 41m in the axial direction is formed 2 mm ahead of the front step part 42md of the keyway 42m in the axial direction, and when the key protrusion 8k is engaged with the keyway 42m, When the key protrusion 8k is engaged with the keyway 41m, the cap 8 can be mounted 2 mm forward with respect to the shaft body 2.
In FIG. 2, the key protrusion 8k of the cap 8 is aligned with the keyway 41m of the shaft 2, and the rear part of the shaft 2 is inserted through the open end 8a of the cap 8.
When the cap 8 is advanced from the state shown in FIG. 2 to the state shown in FIG. The cap 8 is positioned relative to the cap 2.

By advancing the cap 8 from the state shown in FIG. 3 to the state shown in FIG. The air inside the closed space MK constituted by the two-space part K2 and the gas storage part K3 is compressed, and the ink 6 is pressurized. The rear shaft 4 of this embodiment is formed into a tapered shape having a gently arcuate surface whose diameter decreases toward the rear end. When attaching the cap 8 to the rear of the shaft body 2, this makes it easy to reach the position where the annular convex portion 8b of the cap 8 first contacts the outer peripheral surface of the shaft body 2, that is, the position shown in FIG. A cap 8 can be attached.
Further, as mentioned above, since the rear shaft 4 is made of soft resin, when the cap 8 is attached to the rear of the shaft body 4, the annular convex portion 8b of the cap 8 is formed on the outer periphery of the rear shaft 4. Since the cap 8 moves forward so as to be fitted while pressing the surfaces and deforming it inward, the airtightness of the closed space MK becomes high, and the cap 8 moves forward to absorb the repulsive force of the compressed air in the closed space MK. Even when subjected to strong force, the fitting force between the cap 8 and the shaft body 2 is increased, so that the cap 8 does not fall off from the shaft body 2, and air can be reliably compressed.

In this embodiment, the inner diameter of the annular convex portion 8b of the cap 8 is 10 mm, and the annular convex portion 8b where compression of the air in the closed space MK is started is the outer diameter of the rear shaft 4 at the position shown in FIG. is 10.2 mm, and the outer diameter of the rear shaft 4 is 10.4 mm at the position of the annular convex portion 8b where compression of the air in the closed space MK ends as shown in FIG. 4, and from the position of FIG. 3 to the position of FIG. , the difference in outer diameter of the tapered rear shaft 4 when the annular convex portion 8b moves forward is 0.2 mm.

In addition, in the cap 8 of this embodiment, the end surface 8d opposite to the open end 8a is formed into a gentle arc shape, and the surface area is 133 ^mm2 . The burden on the fingers when attaching the cap 8 to the rear of the shaft body 2 by pressing with the belly is reduced.

Note that the pressure applied to the ink 6 changes depending on the amount of ink 6 stored in the ink tank 5a, and when there is a large amount of ink 6 and the first space K1 in the ink tank 5a is small, the pressure applied is large. When the amount of ink 6 is small and the first space K1 in the ink tank 5a is large, the pressing force tends to be small.
However, as described above, in this embodiment, the air compressed when attaching the cap 8 to the shaft body 2 is in a closed space composed of a first space K1, a second space K2, and a gas storage part K3. Since it is the entire air inside the MK, it is not easily influenced by the first space K1 whose volume changes depending on the remaining amount of ink 6.
Specifically, in the state shown in FIG. 3 where the ink 6 in the ink tank 5a is unused, the volume of the first space K1 is 100 mm ³ , and although not shown, when the ink 6 is small, the volume of the first space K1 is 100 mm 3 . The volume of one space K1 is 1400 mm ³ , and the ratio of volume change is large. On the other hand, in the state shown in FIG. 3 where the ink 6 is unused, the volume of the closed space MK is 2100 mm ³ , and when there is only a small amount of ink 6 (not shown), the volume of the closed space MK is 3400 mm ³ . , the rate of volume change is small.
In fact, when the atmospheric pressure is 1000 hPa, the ballpoint pen 1 of this embodiment shown in FIG. 3 moves the cap 8 to the position shown in FIG. When installed at the rear, the air pressure in the closed space MK can be pressurized to 1300 hPa, and the cap 8 can be moved to the position shown in FIG. When attached to the rear, the air pressure in the closed space MK can be pressurized to 1200 hPa, and there is little change in the amount of pressurization.

In FIG. 4, the key protrusion 8k is advanced from the state shown in FIG. 3, that is, the state in which the annular convex portion 8b has exceeded the front end of the hole 4d of the rear shaft 4, until it comes into contact with the front step portion 41md of the keyway 41m. , the forward movement is restricted by the key protrusion 8k coming into contact with the front step portion 41md. In this state, the cap 8 moves forward by 4 mm, which is L1, and the air in the closed space MK is compressed, and the air pressure is increased to 1300 hPa.

FIG. 5 is a diagram showing a state in which the cap of FIG. 2 is rotated 180 degrees and then advanced. FIG. 6 is a diagram showing a state in which the cap is further advanced from the state shown in FIG.
In FIG. 5, the key protrusion 8k of the cap 8 is engaged with the keyway 42m of the shaft body 2, and the cap 8 is positioned with respect to the shaft body 2. In addition, in FIG. 6, from the state shown in FIG. 5, that is, the state in which the annular convex portion 8b exceeds the front end of the hole 4d of the rear shaft 4, until the key protrusion 8k abuts the front step portion 42md of the keyway 42m. When the key protrusion 8k comes into contact with the front step portion 42md, the forward movement is restricted. In this state, the cap 8 moves forward by 2 mm, which is L2, and the air in the closed space MK is compressed, and the air pressure is increased to 1100 hPa.

Therefore, in the ballpoint pen 1 of this embodiment, when the key protrusion 8k of the cap 8 is engaged with the key groove 41m of the shaft body 2 when the ink 6 in the ink tank 5a is unused, When the key protrusion 8k of the cap 8 is engaged with the key groove 42m of the shaft body 2, the air pressure inside the closed space MK becomes 1100 hPa. In this way, the air pressure in the sealed space MK for pressurizing the liquid 6 can be adjusted, and the cap 8 is attached to the shaft body 2 until the key protrusion 8k comes into contact with both the front step portions 41md and 42md. On the other hand, by being moved forward, it becomes easier to keep the amount of air compressed in the closed space constant.
In addition, when the cap 8 is removed from the shaft body 2 as shown in FIG. 1, or when the cap 8 is loosely attached to the rear of the shaft body 2 as shown in FIG. It is possible to write at atmospheric pressure of 1000 hPa.

In this way, the ballpoint pen 1 of this embodiment has a structure in which the pressure applied to the ink 6 can be adjusted, and the pressure applied is not easily affected by changes in the amount of ink 6 remaining in the ink tank 5a.

1...Ballpoint pen (liquid discharge tool),
2...Shaft body (discharge tool body),
3...front axis,
3a...front end opening, 3b...diameter reduction part, 3c...fitting part, 3d...press-fitting part, 3e...protrusion part,
4... Rear shaft, 4a... Rib, 4b... Fitting receiving part, 4c... Press-fitting receiving part, 4d... Hole part,
41m...Keyway, 41md...Front step,
42m...Keyway, 42md...Front step,
5... Ballpoint pen refill, 5a... Ink tank ( liquid storage tube ), 5b... Ballpoint pen tip (tip tip), 5c... Rear end part,
6...Ink (liquid),
7... Ink follower,
8... Cap, 8a... Open end, 8b... Annular convex portion, 8c... Inner cap, 8d... End surface,
8k...Key protrusion,
K1...first space part, K2...second space part, K3...gas storage part, MK...closed space.

Claims (6)

It comprises a cylindrical dispensing device main body, and a cap that is detachable from the front and rear of the dispensing device main body and has one end open and the other end closed,
A liquid dispensing tool for discharging a liquid stored inside the dispensing tool main body from a tip provided in front of the dispensing tool main body,
A liquid storage tube for storing the liquid is provided inside the discharge tool main body,
A first space portion located behind the liquid contained in the liquid storage tube is provided at a rear portion of the liquid storage tube,
having a second space communicating with the first space between the discharge tool main body and the liquid storage tube,
The cap has an annular convex portion on the inner circumferential surface on the open end side thereof that slides on the outer circumferential surface of the dispensing tool main body,
A key protrusion is provided on the outer circumferential surface of the dispensing device main body or the inner circumferential surface of the cap,
A circumference of the inner circumferential surface of the cap or the outer circumferential surface of the dispensing tool body at different lengths along the axial direction that engages with the key protrusion. It has a plurality of keyways formed at intervals on the top,
The second space is located in the dispensing tool main body at a position forward of the rear end of the liquid storage tube and at a position behind the annular convex portion of the cap when the cap is attached to the rear of the dispensing tool main body. has a hole communicating with the part,
When the cap is attached to the rear of the dispensing device main body by aligning the key protrusion with any of the plurality of key grooves, the key protrusion slides on the key groove and the step in the axial direction of the key groove. The annular convex portion of the cap moves forward while slidingly contacting the outer peripheral surface of the dispensing device main body, so that the liquid flows between the first space and the second space. A liquid dispensing tool that is pressurized via compressed air in a closed space.
The liquid discharging tool according to claim 1,
When the cap is attached to the rear of the dispensing tool main body, a gas storage part is formed between the cap and the dispensing tool main body, and the gas containing part communicates with the second space part through the hole,
The liquid discharging tool has a structure in which the sealed space is constituted by the first space, the second space, and the gas storage part. The liquid ejection tool according to claim 1 or 2,
The liquid discharging tool has a structure in which engagement between the key protrusion and the plurality of key grooves starts before compression of the sealed space. The liquid ejection device according to any one of claims 1 to 3,
The liquid dispensing tool has a structure in which at least an outer circumferential surface of the dispensing tool main body is displaced in an axial radial direction when the cap is attached to the rear of the dispensing tool main body. The liquid ejection tool according to any one of claims 1 to 4,
The dispensing device main body has a tapered rear portion,
the hole is formed in the rear part,
The liquid dispensing device has a structure in which, when the cap is attached to the rear of the dispensing device main body, the annular convex portion of the cap presses against the outer peripheral surface of the dispensing device main body and moves forward while deforming it inwardly. The liquid ejection tool according to any one of claims 1 to 5,
A liquid discharging tool having a structure in which the other end of the cap has a flat surface shape or an arcuate surface shape.

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