KR20010023863A - Writing Utensil - Google Patents

Abstract

Insert a pressure equalizing tube with a pressure equalizing path inside the ink storage chamber, and connect the tip to the vicinity of the pen body, and communicate the tail end to the outside.In the case of non-writing, the pressure equalizing path acts as a feeder. Compensation for expansion and contraction of air, etc. maintains the inside at the same pressure as atmospheric pressure, and at the time of writing, the pressure of ink is prevented from acting on the pen body by making the vicinity of the pen body at the same pressure as the atmospheric pressure by this equalization passage. do. This compensates for the head pressure of the ink at the time of writing, applies a constant pressure almost equal to atmospheric pressure to the pen body, and compensates for expansion and contraction of air and the like in the ink reservoir.

Maintain the inside at the same pressure as atmospheric pressure.

Description

Writing Instruments {Writing Utensil}

In general, writing instruments are classified into a form of ink storage, so-called mid-sized shapes which fill a porous body such as cotton in the ink chamber and hold the ink by capillary force in the porous body, and liquid ink in the ink storage chamber. There is a so-called ink storage type writing instrument that directly stores the ink.

The above-mentioned medium surface type has a simple structure but a small amount of ink retention and a supply of ink to the pen body by capillary force, which limits the flow rate of ink to the pen body. There is a shortage such that the ink supply amount is insufficient and only handwriting remains.

In addition, the above ink storage type can store a large amount of ink, and since the supply flow rate of ink to the pen body is not limited in principle, only handwriting remains even in the case of early writing. There is an advantage to not. However, the ink storage type is a mechanism or a pen body that compensates for changes in head pressure caused by air or ink in the ink storage chamber due to a temperature change, shrinkage, or a change in posture of a writing instrument. It is necessary to provide a mechanism for controlling the supply flow rate of the ink, and the structure is complicated. Moreover, even if such a compensation mechanism is provided, there are disadvantages such as unstable pressure or flow rate of ink supplied to the pen body, depending on the temperature, air pressure, change of posture of the writing instrument, and the like.

There are various kinds of structures of the ink storage writing instruments. As a representative example, for example, a feeder in the form of bellows used in a conventional so-called fountain pen is provided. This holds ink by capillary forces in a feeder having a corrugated flow path having a small cross-sectional area. When the air or the like in the ink storage chamber expands, excess ink is retained by being extruded into the feeder, and when the shrinkage occurs in the ink storage chamber, the ink retained in the feeder is sucked into the ink storage chamber. In this way, expansion and contraction in the ink storage chamber are compensated for and pressure is kept constant.

Moreover, there exist some which used the slide plug as another structure. This makes the ink reservoir chamber cylindrical and communicates with the open end side to the atmosphere, and installs a slide plug freely sliding in the axial direction while maintaining airtightness and liquid tightness therein. It is a compartment of ink and air in the room. This slide plug slides in response to ink expansion, contraction, and consumption of ink by writing, thereby maintaining the pressure of the ink at a constant pressure almost equal to atmospheric pressure. In addition, in order to control the supply of ink to the pen body, a means such as providing a valve mechanism for opening a valve at a micro differential pressure is employed between the ink storage chamber and the pen body.

By the way, all of these can compensate for the expansion of the air, ink, shrinkage, etc. in the ink storage chamber, but cannot sufficiently compensate for the change in head pressure due to the posture of the writing instrument. That is, when writing, the writing instrument is almost vertically used. Therefore, if the axial depth between the free surface of the ink inside the ink reservoir and the pen body is 80 mm, for example, the head pressure corresponding to 80 mm is generated. Such head pressure is a slight pressure, but depending on the type of pen body, such head pressure causes a change in handwriting and drops of so-called droplets from which ink is extruded from the pen body.

Although there are various forms of the pen body described above, in general, the pen body has a so-called ball tip, a fiber, etc., in which a ball is freely rotated at the tip of a ball holder. There is a so-called felt tip made of porous material. These various pen bodies have their respective characteristics, but the elements of common important characteristics are ink seal pressure and ink drawing pressure.

That is, these pen bodies hold ink and seal the ink by a capillary force between the gap between the ball and the ball holder at the ball tip, and the gap between the fibers at the felt tip. The differential pressure within and outside the range in which the action can be maintained is the ink seal pressure. When the pressure inside and outside the pen body exceeds this ink seal pressure, for example, when the internal pressure is higher than the ink seal pressure, the ink inside is extruded through these gaps, so-called drop drops occur, and the internal pressure is higher than this ink seal pressure. When lowered, the ink in these gaps is sucked in, and air is sucked into the ink storage chamber through this gap.

In addition, when these pen bodies consume the ink in the above-described gaps by writing, new ink is drawn out from the inside, and the pressure for sucking out the new ink is the ink extraction pressure. Therefore, when the internal pressure becomes lower than this ink extraction pressure, writing becomes impossible. The ink seal pressure and the ink extraction pressure differ depending on the type of pen body, but in the same type of pen body, the ink seal pressure and the ink extraction pressure are almost the same.

By the way, the ball tip has about 100mm of ink seal pressure and ink withdrawal pressure in the case of oily ink having high viscosity, but about 20mm in the case of quick-drying ink using a low viscosity aqueous ink or a volatile solvent. There is nothing else. Felt tips also generally have high ink seal pressures and ink withdrawal pressures of 100 mm to several 100 mm.

Since the felt tip has high ink seal pressure, that is, ink holding power due to its capillary force, only a small amount of ink can be transferred to a writing surface that is not absorbent, such as a resin film, and generally these writing surfaces. Only "blurred" can be written. On the other hand, the ball tip using water-based ink and quick-drying ink has a weak ink holding power, so that it can be written on the surface which does not have absorbency such as a resin film. In particular, when quick-drying inks are used, the ink transferred to the resin film dries in an instant, so that writing on the surface of a water-repellent material such as polyethylene film, which has not been possible in the past, is possible. In addition, the ball tip transfers the ink adhering to the surface to the writing surface by rotating the ball, so that the outline of the writing line is clear and the writing of the thin line is possible.

However, since the ball tip using the aqueous or quick-drying ink has only the ink seal pressure and the ink extraction pressure of about 20 mm as described above, in the writing instrument using the same, the pressure of the ink supplied to the ball tip is almost equal to that of the outside, that is, atmospheric pressure. It is necessary to control stably by pressure.

In addition, the felt tip has a large ink seal pressure and an ink withdrawal pressure as described above, but when a differential pressure inside and outside occurs, dropping drops and inhalation of air do not occur, but the amount of ink held in the felt tip is easily Change. Therefore, if the internal pressure is slightly increased, the amount of ink contained in this felt tip increases, so that it becomes a so-called ink rich state, and the handwriting becomes dark undesirably. On the other hand, if the internal pressure is slightly lowered, the amount of ink retained in the felt tip decreases, resulting in a so-called ink poor condition, and the handwriting is blurred undesirably. Therefore, even if it is a writing instrument provided with this felt tip, it is of course desirable to stably control the pressure of the ink to be supplied.

However, in the feeder mechanism as described above, only the function of compensating expansion contraction of air and the like in the ink storage chamber to maintain the pressure in the ink storage chamber at a pressure almost equal to atmospheric pressure, and the head pressure of the ink as described above. Could not compensate. In addition, since the feeder has a complicated passage in the form of a corrugated container, it is easy to cause a closed end such as clogging due to ink drying therein, and such a closed end becomes remarkable especially when a quick-drying ink is used.

In the above-described slide plug writing instrument, the pressure difference between the head pressure of the ink in the ink storage chamber and the pressure corresponding to the sliding resistance of the slide plug acts on the pen body when writing, but also the change in the head pressure of the ink. Correspondingly, the pressure of the ink changes. Therefore, it is difficult to accurately control the pressure of the ink acting on the aqueous ball tip or the like within the range of the ink seal pressure even if the slide plug type is provided with a valve mechanism for opening the valve at such a low differential pressure.

As described above, in the ink storage type writing implement, the pressure in the ink storage chamber is always kept constant, and the ink pressure supply is supplied to the pen body without the fluctuation of the ink pressure due to the head pressure or the like of the ink inside during writing. Although it is preferable to always control the pressure of the ink to be equal to the external atmospheric pressure and to a constant pressure, such a conventional ink pressure compensation mechanism is not necessarily satisfactory.

The present invention relates to an ink reservoir-type writing instrument which directly stores liquid ink. More specifically, the present invention relates to an ink reservoir-type writing instrument in which the pressure of ink supplied to the pen body is kept constant.

1 is a longitudinal sectional view of the writing instrument of the first embodiment;

2 is a cross-sectional view taken along line 2-2 of FIG. 1;

3 is a longitudinal sectional view of a state of the horizontal posture of the first embodiment;

4 is a longitudinal sectional view of a state of the posture of the reverse standing position of the first embodiment;

5 is a longitudinal cross-sectional view of a state of the standing position of the first embodiment;

6 is a longitudinal sectional view of the drying prevention mechanism of the first embodiment;

7 is a longitudinal sectional view of the drying prevention mechanism of the first embodiment;

8 is a longitudinal sectional view of the writing instrument of the second embodiment;

9 is a longitudinal sectional view of a state of the horizontal posture of the second embodiment;

10 is a longitudinal sectional view of a state of the inverted posture of the second embodiment;

11 is a longitudinal cross-sectional view of a state of the upright position of the second embodiment;

12 is a longitudinal sectional view of the drying prevention mechanism of the third embodiment;

13 is a longitudinal cross-sectional view of the drying prevention mechanism of the fourth embodiment;

14 is a longitudinal sectional view of the drying prevention mechanism of the fifth embodiment;

FIG. 15 is a longitudinal sectional view of the drying prevention mechanism of the fifth embodiment; FIG.

16 is a longitudinal cross-sectional view of the drying prevention mechanism of the sixth embodiment;

17 is a longitudinal sectional view of a drying prevention mechanism of a sixth embodiment;

18 is a longitudinal cross-sectional view of the writing instrument of the seventh embodiment;

19 is a longitudinal sectional view of a cap-mounted state of the drying prevention mechanism of the seventh embodiment;

20 is a longitudinal cross-sectional view of a cap removed state of the drying prevention mechanism of the seventh embodiment;

21 is a longitudinal sectional view of the ink blocking mechanism of the eighth embodiment;

Fig. 22 is a longitudinal sectional view of the ink blocking mechanism of the eighth embodiment.

23 is a longitudinal sectional view of the ink blocking mechanism of the ninth embodiment;

24 is a longitudinal sectional view of the ink blocking mechanism of the ninth embodiment;

25 is a longitudinal cross-sectional view of the writing instrument of the tenth embodiment;

26 is a longitudinal cross-sectional view of the writing instrument of the eleventh embodiment;

27 is an enlarged longitudinal sectional view of a part of the writing instrument of the eleventh embodiment;

28 is an exploded perspective view of a part of the writing instrument of the eleventh embodiment;

29 is a longitudinal cross-sectional view of the writing instrument of the twelfth embodiment;

30 is a cross-sectional view taken along line 13-13 of FIG. 12;

31 is a longitudinal sectional view of a state of the horizontal posture of the twelfth embodiment;

32 is a longitudinal sectional view of a state of the inverted posture of the twelfth embodiment;

33 is a longitudinal sectional view of a standing posture of the twelfth embodiment;

34 is a longitudinal sectional view of a drying prevention mechanism of a twelfth embodiment;

35 is a longitudinal sectional view of a drying prevention mechanism of a twelfth embodiment;

36 is a longitudinal cross-sectional view of the writing instrument of the thirteenth embodiment; And

It is a longitudinal cross-sectional view of the writing implement of 14th Embodiment.

The present invention has been made in view of the above circumstances, and it is possible to control the pressure of the ink acting on the pen body to an accurate pressure close to atmospheric pressure. For example, the pen body has a narrow ink pressure range such as a ball tip of an aqueous or quick-drying ink. It is also to provide a writing instrument that enables stable writing and is simple in structure and highly reliable in operation.

In order to achieve the above object, the writing instrument of the present invention is substantially parallel to the axial direction of the ink storage chamber and the ink storage chamber formed in the main body, the pen body provided at the front end of the main body, and communicating with the pen body. The tip portion is provided with a equalizing passage in which the tip portion communicates with a position near the pen body in the tip portion of the ink storage chamber described above, while the tail end portion communicates with the outside from the tail end side of the body.

Therefore, since the equalization passage always communicates with the outside in the ink storage chamber, when the air or ink in the ink storage chamber expands or contracts due to temperature change, the ink is extruded in the equalization passage or Ink or air is sucked through the pressure passage, and the pressure in the ink storage chamber is always maintained at a pressure equivalent to atmospheric pressure. When the writing instrument is set at the time of writing, the head pressure of the ink in the ink storage chamber is generated, but the equalization passage is in communication with the position near the pen body in the tip portion of the ink storage chamber. In the communicating position, the ink pressure is equal to atmospheric pressure. Therefore, the air in the ink storage chamber above the ink has only a pressure corresponding to the head pressure of the ink to become negative pressure, and is balanced and stabilized in this state.

Therefore, the communicating portion of the equalization passage near the pen body in the ink reservoir is always at atmospheric pressure even at the time of writing, and the head pressure acting on the pen body corresponds to the distance between the communicating portion of the equalizing passage and the pen body. It is chickenpox pressure, and only a small amount of chicken pox pressure is applied to the pen body. Therefore, even with a small pen body in the range of ink sealing pressure, such as a ball tip for aqueous or quick-drying ink, drops of ink do not occur, and stable writing is possible. In addition, the pressure control mechanism of the ink of the writing instrument basically does not include any moving part, a fine orifice, a part using capillary force, etc., and its operation is very stable, reliable, and easy to manufacture.

In the preferred embodiment, the pressure equalizing passage is formed in the tubular pressure equalizing tube in which the tip end portion is inserted in the ink storage chamber in the axial direction, and the tip end portion is opened near the pen body in the tip end portion of the ink reservoir chamber, and the tail end portion communicates with the outside. It is. Therefore, the structure is very simple and the reliability is high. In addition, it is possible to extend the distal end of the pressure equalizing tube so that it is very close to the pen body, so that the head pressure of the ink acting on the pen body at the time of writing can be set to about several mm.

In a preferred embodiment, an ink reservoir having an ink reservoir formed therein is provided in the main body, and the gap formed between the inner circumferential surface of the main body and the outer circumferential surface of the ink reservoir is used as the pressure equalizing passage described above. The pressure equalizing passage is formed so as to communicate with the inside of the ink reservoir at a position near the pen body of the distal end, while the distal end communicates with the outside at the distal end side of the main body. Therefore, the structure is simple, and the gap between the ink reservoir and the writing instrument body is formed, and the heat of the writer's hand is prevented from being transferred to the ink and air in the ink reservoir, and the heat of the writer's hand is prevented. It is effective in preventing expansion of ink or air.

In the preferred embodiment, the cross-sectional shape and the cross-sectional dimension of the pressure equalizing passage described above are maintained in the liquid column in the pressure equalizing passage by the ink which penetrates therein by the surface tension of its free surface. The position with air is set to the cross-sectional shape and the cross-sectional dimension which do not produce the gas-liquid exchange action to exchange. Therefore, even if the writing instrument is in any posture, ink does not flow out through this equalization passage, and a special structure for preventing the ink from leaking is unnecessary, and the structure is simple.

In the preferred embodiment, the ink reservoir is almost normal, and the cross-sectional area of the equalization passage is set in the range of 1/30 to 1/4 of the cross-sectional area of the ink reservoir. Therefore, in writing instruments having normal dimensions, by setting this equalization passage in this range, gas-liquid exchange action does not occur, and when ink in the ink storage chamber expands due to a normal temperature change, It can be accommodated into the tender path to achieve sufficient compensation.

In a preferred embodiment, the main body has a drying prevention mechanism for preventing the ink from drying by blocking the communication between the end of the pressure equalizing passage and the outside of the pressure equalizing passage and the tip of the pressure equalizing passage and the ink storage chamber during non-writing. Is installed. The writing instrument of the present invention is only the free surface of the liquid column of the ink in the pressure equalizing passage as the evaporation surface of the ink, and there is no exchange action between the solvent vapor of the ink in the pressure equalizing passage and the gas and gas with the air. Although the drying is small, by providing such a drying prevention mechanism, the drying of the ink can be almost completely prevented, and even when the drying ink is used, the drying of the ink can be prevented over a long period of time.

In a preferred embodiment, the pen body is a ball tip, and the distance between the tip of the equalization passage and the tip of the ball tip is 20 mm or less. Therefore, even with such a pen body having a narrow range of ink seal pressure, ink does not become excessively supplied by the head pressure at the time of writing.

In a preferred embodiment, the pen body is a felt tip, and the main body is provided with an ink blocking mechanism for blocking the communication of ink between the ink storage chamber and the felt tip during non-writing. In the writing instrument of the present invention, the pressure of the ink acting on the felt tip at the time of writing is almost equal to the atmospheric pressure, and the amount of the ink contained in the felt tip is not excessive. The amount of ink contained in the felt tip is excessive or excessive due to the micro-differential pressure generated during the expansion and contraction of air, and the supply of the ink to the felt tip is blocked during this non-writing. The same closure can be prevented.

Moreover, in a preferable embodiment, the scattering prevention mechanism of the mist of ink which has a curved or labyrinth-shaped path | pass is provided in the tail end part of the said equalization path | pass. Therefore, even when a strong impact acts on the writing instrument and the ink in the equalization passage is scattered due to the mist, the mist of the ink does not scatter to the reservoir or the outside, and contaminates the surroundings. none. In addition, the curved or labyrinth shaped passages have the effect of preventing evaporation of the solvent of the ink.

In a preferred embodiment, the above-described drying prevention mechanism is a slide chamber which is formed at the end of the ink storage chamber and communicates with the inside of the ink storage chamber and communicates with the outside of the writing instrument, and the slide inside the slide chamber. An airtight slide plug having a predetermined gap between the inner circumferential surface of the seal and freely sliding in the axial direction and blocking communication between the ink storage chamber side and the outer side; an inner circumferential surface of the slide chamber and the airtight slide plug; It is provided with the viscous fluid which has predetermined viscosity maintained by the capillary force between the poles between.

Therefore, the gap between the outer circumference of the hermetic slide plug and the inner circumference of the slide chamber is hermetically sealed by the above-mentioned viscous fluid, so that the slide chamber is partitioned, and the communication between the ink storage chamber and the outside is always blocked. Therefore, the vapor of the solvent of the ink is prevented from being scattered by diffusion, and the evaporation of the ink in the ink storage chamber is surely prevented.

In addition, when air or vapor in the ink storage chamber expands or contracts due to temperature changes, or when the external air pressure changes, the airtight slide plug moves in the slide chamber and expands and contracts in the ink storage chamber. Compensate for the difference between outside air pressure. In this case, a viscous fluid is filled between the gap between the airtight slide and the slide chamber, and the viscous fluid does not directly contact the airtight slide plug and the slide chamber. Therefore, this hermetic slide plug moves smoothly and without resistance, and the above pressure difference is completely compensated, and there is no substantial pressure difference between the ink storage chamber and the outside.

In addition, when a significant temperature change or a large airtight change occurs, and the airtight slide plug is moved to one side of the slide chamber to the maximum and further movement is impossible, the pressure difference between the airtight slide plug and the slide chamber is increased. The viscous fluid is eliminated from the gap, and the gap is in communication with the ink reservoir and the outside, and the pressure difference between the ink reservoir and the outside is eliminated.

In addition, the viscous fluid flow occurs due to the movement of the hermetic slide plug. However, since the rate of temperature change or air pressure change is slow, the moving speed of the hermetic slide plug is also very slow at this time. Resistance rarely occurs. On the other hand, when the writing instrument is dropped on the floor, a large load acts on the airtight slide plug due to the impact, but a large flow resistance is generated when the flow velocity of the viscous fluid is large. Therefore, when such a shock load is applied, this hermetic slide plug hardly moves, and this hermetic slide plug functions as a fixed partition wall for partitioning the slide chamber, and completely blocks communication between the ink storage chamber and the outside. Therefore, it is possible to prevent the ink in the ink storage chamber from leaking into the slide chamber by this impact.

In addition, such a structure is simple in structure, easy to manufacture, and can be manufactured at a low price, and in the case of a significant temperature change or air pressure change, the pressure is balanced by eliminating the viscous fluid from the above-described gaps. Since the slide chamber has a small volume necessary to compensate for the temperature change and the air pressure change in the normal range, the writing instrument can be made compact.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to drawings. 1 to 7 show writing instruments according to the first embodiment of the present invention, which are discarded after use using a quick-drying ink using a solvent such as an alcohol system and using a ball tip as a pen body.

This writing instrument has a substantially cylindrical main body 1, the tip of the main body 1 is provided with the above-described ball tip 2, and the tail end of the main body 1 has a tail plug. (3) is attached. In addition, these main bodies 1 and the micro 3 are formed by injection molding a synthetic resin material. In addition, although the cap of this writing instrument is abbreviate | omitted in this figure. Arbitrary caps can be employed.

In the main body 1, an almost cylindrical ink storage chamber 4 is formed, and the ink 5 is filled in the ink storage chamber 4 above. The tip end portion of the ink storage chamber 4 is formed in a tapered shape and directly communicates with the ball tip 2 described above. Moreover, the tail end side of this main body 1 is partitioned by the partition member 6, and the drying prevention mechanism 20 mentioned later is provided in the tail end side of this partition member 6. As shown in FIG.

In the center of the ink storage chamber 4, a pressure equalizing tube 7 is provided along the axial direction of the ink storage chamber 4, and the pressure equalizing tube 7 is formed as a pressure equalizing passage 8. have. The tail end of the pressure equalizing pipe 7 is attached to the partition member 6 through this, and is communicated to the outside through the holes formed in the drying prevention mechanism 20 and the field 3. In addition, the tip end portion of the pressure equalizing tube 7 extends to the position near the ball tip 2 of the tip end portion in the ink storage chamber 4, and communicates with the ink storage chamber 4 at this position.

In this embodiment, the distance between the tip of the pressure equalizing tube 7, that is, the tip of the pressure equalizing passage 8 and the ball tip 2 is set to about 10 mm, and this distance is determined by the ink chamber pressure of the ball tip 2. It is set shorter than the equivalent depth of head pressure. In this embodiment, the inner diameter of the ink storage chamber 4 is set to about 8 mm, the inner diameter of the pressure equalizing tube 7, that is, the diameter of the pressure equalizing passage 8 is set to about 2 mm, and the pressure equalizing passage ( The cross-sectional area of 8) is about 1/16 of the cross-sectional area of the ink storage chamber 4.

Moreover, the cylindrical reservoir part 9 is formed in the tail end side of the said partition member 6, and the tail end side of this reservoir bar part 9 is partitioned by the partition wall member 11. As shown in FIG. The inside is formed of a reservoir bar 10. The reservoir bar 10 discharges the leaked ink when ink flows out from the pressure equalizing passage 8 in the pressure equalizing pipe 7 described above. In addition, the partition wall member 11 protrudes from the center portion toward the tip side of the partition wall member 11 to prevent the outflow to the outside. The bar 10 is in communication with the outside, so that when the ink leaked into the reservoir bar 10 is solid, even when the writing instrument is horizontally or inverted, the tip end portion of the spill prevention tube 12 is drawn into the ink. Unless it is submerged, this ink does not spill out.

Next, the structure of the above-mentioned drying prevention mechanism 20 is demonstrated. The drying prevention mechanism 20 prevents the ink from being dried almost completely by blocking the flow of the vapor of air or ink solvent, but basically the communication between the pressure equalizing passage 8 and the outside is secured. The pressure equalizing passage 8 is always maintained at a pressure equivalent to atmospheric pressure. The space between the partition wall member 11 and the tailings 3 is formed as an oil chamber 22, and a partition member 21 is provided at a central portion in the substantially axial direction of the oil chamber 22. The oil chamber 22 is divided into two chambers. On the outer circumferential surface of the partition member 21, slits 24 of a plurality of minute cross sections continuous in the axial direction are formed, and the front end side and the tail end side of the oil chamber 22 communicate with each other via these slits 24. .

The oil chamber 22 is filled with a predetermined amount of nonvolatile oil, such as silicon oil 23 having a predetermined viscosity. In addition, the above-described spill prevention pipe portions 25 and 26 are protruded from the tail end side of the tailings 3 and the partition wall member 11 and communicate with the outside through these writing instruments. Even if it is in a posture, this silicone oil 23 is comprised so that it may not flow out from the oil chamber 22. FIG. The silicon oil 23 is normally held in the slit 24 of the partition member 21 by surface tension and occludes it, thereby preventing the solvent vapor of the quick-drying ink from diffusing to the outside. have.

Next, with reference to Figs. 3 to 5, the compensating effect of the pressure of the ink of the writing instrument of the first embodiment will be described. 3 shows a case in which the writing instrument is in a horizontal posture in a non-writing state. In this case, when the amount of the ink 5 is large, the tip portion of the pressure equalizing pipe 7 described above is immersed in the ink as shown in FIG. However, since the pressure equalizing passage 8 in the pressure equalizing tube 7 is relatively small in diameter, the ink is retained as the liquid column 5a by the surface tension, and the ink and the pressure equalizing passage 8 in the pressure equalizing passage 8 are retained. The so-called gas-liquid exchange action that the position of air exchanges does not occur.

Therefore, in this state, when the air in the ink storage chamber 4 expands due to, for example, a temperature rise, the ink is extruded in the equal pressure passage 8 by the amount of expansion thereof, and the ink storage chamber 4 is It is maintained at a pressure nearly equal to atmospheric pressure. When the air in the ink storage chamber 4 contracts, the liquid column 5a of the ink extruded into the pressure equalizing passage 8 is pushed back into the ink storage chamber 4, and the ink storage chamber 4 The pressure inside is maintained at a pressure equivalent to atmospheric pressure. In the above case, the ink in the pressure equalizing passage 8 does not undergo a gas-liquid exchange action, but only moves in the pressure equalizing passage 8 in the axial direction while remaining in the state of the liquid column 5a. It does not flow out from the pressurization path 8.

4 shows a case in which the writing instrument is inverted in a non-writing state. Also in this case, as described above, the liquid column 5a of the ink in the equalization passage 8 moves in response to the expansion and contraction of the air in the ink storage chamber 4 to compensate for the expansion and contraction. The inside of the storage chamber 4 is maintained at a pressure equivalent to atmospheric pressure.

5 shows a case in which this writing instrument is standing. In this case as well, the liquid column 5a of the ink in the pressure equalizing passage 8 moves up and down in response to the expansion and contraction of the air in the ink storage chamber 4 in the same manner as described above. It compensates and maintains the inside of this ink storage chamber 4 at the pressure equivalent to atmospheric pressure.

In addition, in the above case, after the air in the ink storage chamber 4 greatly contracts and the liquid column 5a in the pressure equalizing passage 8 moves to the tip of the pressure equalizing passage 8, the pressure equalizing tube Outside air from the furnace 8 enters the ink storage chamber 4 to compensate for shrinkage. In addition, after the air in the ink storage chamber 4 expands significantly and the liquid column 5a of the ink in the pressure equalizing passage 8 reaches the end of the pressure equalizing passage 8, the ink is the reservoir bar described above. Although the outflow prevention tube 12 is protruded in the reservoir bar 10, the ink does not spill out to the outside and is retained in the reservoir bar 10.

In addition, when the writing instrument falls to the floor, the ink in the pressure equalizing passage 8 may mist and scatter from the tail end of the pressure equalizing passage 8 due to the impact. Ink is accommodated in this reservoir bar 10 and does not flow out.

As described above, this pressure equalizing path 8 acts as a kind of feeder that compensates for expansion or contraction of air or ink in the ink storage chamber 4 when not written. In this case, the relationship between the cross-sectional area between the equalization passage 8 and the ink storage chamber 4 and the diameter of the equalization passage 8 are appropriately set, whereby the ink is filled with the reservoir bar as described above. 10) Extruded into or through the equalization passage 8, it is possible to set so that outside air rarely enters the ink storage chamber 4 only.

That is, the expansion or contraction rate of air when the temperature is changed from T1 ° C to T2 ° C is (T2-T1) / (273 + T1). Therefore, within the normal temperature range, the change in temperature is 1 ° C. The rate of expansion or contraction of the air is about 0.3%. Therefore, for example, assuming that the range of temperature change is ± 30 ° C, the expansion or contraction of the air in this ink storage chamber 4 is about 9%. In this embodiment, since the ink storage chamber 4 has a normal cross-sectional area substantially constant in the axial direction, the air in the ink storage chamber 4 expands or contracts about 9% in the axial direction.

In the case where the entirety of the ink storage chamber 4 is almost filled with air, that is, the ink is near zero, the length of the pressure equalizing passage 8 described above is the length of the ink storage chamber 4. Since the cross-sectional area of the equalization passage 8 is set to 9% of the cross-sectional area of the ink storage chamber, for example, when the air in the ink storage chamber 4 expands in the axial direction by 9%, The liquid column 5a of the ink in the pressure passage 8 becomes (9/100) × (100/9) = 1, and the liquid column 4a of this ink moves to the end of the equalization passage 8 to the maximum. However, the reservoir bar 22 does not leak. When the air in the ink storage chamber 4 contracts, air can flow from the equalization passage 8 into the ink storage chamber 4 to compensate for the shrinkage of the air.

In the state of use or storage of such writing utensils, the temperature change rarely exceeds ± 30 ° C, and in general, the ink storage chamber 4 is filled with ink to some extent, and the volume of air Is less than the above assumptions. Therefore, in general, when the cross-sectional area of the equalization passage 8 is set to about 1/10 of the cross-sectional area of the ink storage chamber 4, ink flows from the equalization passage 8 to the reservoir bar 10. The possibilities can certainly be ruled out.

In addition, in order to hold the ink as the liquid column 5a in the equalization passage 8 as described above, the diameter of the equalization passage 8 may be reduced. The diameter of the equalization passage 8 for this purpose also varies depending on the properties such as viscosity of the ink, but if the diameter is about 6 mm or less, the normal ink can be maintained in the liquid column. However, as described above, in order to reduce the possibility that the liquid column 5a in the pressure equalizing passage 8 becomes mist and scatters when the writing instrument is dropped on the floor or the like, the pressure of the pressure equalizing passage 8 The inner diameter is preferably about 3 mm or less.

In addition, although the above-mentioned explanation demonstrated the case where this equalization path | route 8 acted as a feeder at the time of non-writing, in the writing, this equalization path | route 8 is almost zero, and its length is short at the front-end | tip. It is a state where the liquid column 5a of the ink is present. That is, in such a writing instrument, ink is filled at the temperature at the time of writing, that is, at room temperature, and in this manufacturing state, only a liquid column 5a of ink of some length exists in the pressure equalizing path 8. . And the change of temperature as mentioned above is periodic, and after temperature rises or falls, it returns to the state of the original room temperature. Moreover, the ink of such writing instruments is sufficiently degassed at the time of manufacture, and does not discharge gas in the ink storage chamber 4 after filling, and the volume of ink decreases with writing. Therefore, in the normal case, at the time of writing, the inside of the equalization passage 8 is almost zero, and the liquid column 5a of the short ink exists only at the tip end thereof.

In addition, the above-mentioned equalizing passage 8 has the effect of preventing the drying of the ink 5, particularly in the case of quick-drying ink. That is, since the cross-sectional area of the equalization passage 8 is small, and the area of the free surface of the liquid column 5a of the ink therein is also small, the amount of solvent evaporation of the ink from this surface is small. The equalization passage 8 is small in diameter and long in the axial direction, and the velocity of the gas flow in the interior thereof is very slow, and the Reynolds of the gas flow in the equalization passage 8 is also very slow. The Reynolds number is a very small value and the behavior of the gas in this passage is a complete laminar flow region.

Therefore, in this passage, not only the gas-liquid exchange action as described above occurs, but also the gas exchange action does not occur. Therefore, the exchange action between the gas and the gas such that the position of the solvent evaporated from the free surface of the liquid column 5a of the ink on the front end side of the pressure equalizing path 8 and the air on the tail end side are hardly generated. Do not. Therefore, in the pressure equalizing path 8, the solvent vapor diffuses to the tail end side by its molecular motion, and in the vicinity of the free surface of the liquid column 5a on the tip end side, the solvent vapor is saturated steam pressure at the temperature, but As a result, the vapor pressure of the solvent vapor decreases continuously, resulting in a continuous vapor pressure distribution. Therefore, the vapor pressure of the solvent vapor in the opening of the trailing end of the equalization passage 8 is lowered, and the amount of the solvent vapor evaporating from the opening of the trailing end is also reduced.

In view of the above, when the cross-sectional area of the equalization passage 8 is made small and the length is long, the free surface of the liquid column 5a of the ink therein becomes small, and the evaporation due to the diffusion becomes small. However, if the cross-sectional area of the pressure equalizing passage 8 is made small, the free surface of the liquid column 5a of the ink in the pressure equalizing passage 8 becomes the opening portion of the end portion when the air in the ink storage chamber 4 expands. It reaches near and evaporation by the said diffusion increases more. In order to effectively prevent evaporation of the solvent vapor due to the diffusion, at least 25 mm between the free surface of the liquid column 5a of the ink in the pressure equalizing passage 8 and the opening at the end of the pressure equalizing passage 8. An antidiffusion length of length is required.

Therefore, when the temperature rises within the range of the expected temperature change, and the liquid column 5a of the ink moves in the pressure equalizing passage 8 to the end, the free surface of the liquid column 5a and the equalizing passage. What is necessary is just to set the cross-sectional area, the internal volume, and the length of this equalization path | path 8 so that said diffusion prevention length may remain 25 mm or more between the tail end part of (8).

In addition, the temperature range of ± 30 ℃ of the above-mentioned temperature range is extreme, such as when writing instruments are brought into the warm room from the outside of a cold door, or when the writing instruments are left on a dashboard of a car parked in cold sunlight. In the case where such an unusual temperature change occurs, when the ink is allowed to flow from the equalization passage 8 to the reservoir bar 10, the range of this temperature change is assumed to be about ± 10 ° C. Is enough.

In consideration of the above conditions, the equalization passage 8 has an inner diameter of 6 mm or less, preferably 3 mm or less, and an internal content of 3% or more of the internal volume of the ink storage chamber 4, and this content integral. It is preferable to have the length which added the diffusion prevention length of 25 mm or more to the remainder which was subtracted.

In the case of general writing instruments, if the cross-sectional area of the equalization passage 8 as described above is set within the range of 1/30 to 1/4 of the cross-sectional area of the ink storage chamber 4, the equalization passage 8 It is possible to suppress the temperature change and the like sufficiently, and to suppress the diffusion of the solvent vapor of the ink in the pressure equalizing passage 8 to a low enough practically.

Moreover, in this embodiment, the reservoir bar 10 is formed in the distal end side of this equalization passage 8, and the leak prevention pipe | tube with a narrow diameter between this reservoir bar 10 and the drying prevention mechanism 20 ( 12, 26) are provided, so that the gas-gas exchange action as described above can be prevented from inside the outflow pipes, and since only the vaporization of the solvent vapor due to diffusion occurs, further evaporation is prevented. It works.

Next, the operation of the writing instrument at the time of writing will be described. When writing, as shown in FIG. 1 and FIG. 5, this writing implement is written with the ball tip 2 facing down. In this state, the ink 5 accumulates below the ink storage chamber 4 and the air moves to the upper portion of the ink storage chamber 4. In this state, the head pressure usually corresponds to H1 + H2 acts on the ball tip 2. However, the tip of the pressure equalizing tube 7, that is, the pressure equalizing passage 8 reaches the depth of H1, and the tail end of the pressure equalizing passage 8 communicates with the outside. Normally, at the time of writing, only the liquid column 5a of very short ink is present in the equalization passage 8 as described above. Therefore, the tip end of the equalization passage 8, that is, the depth portion of H1 of the ink 5 is at the same pressure as the atmospheric pressure.

For this reason, the liquid level of the ink 5 in this ink storage chamber 4 will go down a little, and the air of the upper part of this ink storage chamber 4 will expand | swell, and only the head pressure equivalent to H1 of the ink 5 will be low pressure. In this state, it is balanced and stable. In this case, the ink penetrates into the equalization passage 8 by the amount corresponding to the drop of the liquid level of the ink 5, and the depth of the liquid column 5a of the ink in the equalization passage 8 is H3. do.

In this case, for example, when H1 is set to 50 mm and the axial length of the portion of the air in the ink storage chamber 4 is 50 mm, the air in the ink storage chamber 4 has the head pressure for this 50 mm. The pressure decreases as much as corresponding to, and the expansion is about 50 × 50/10000 = 0.25mm in the axial direction, assuming that one pressure is about 10000 mm of head pressure. Therefore, the amount of fall of the liquid level of this ink 5 is also 0.25 mm like this.

On the other hand, in this embodiment, since the cross-sectional area of the equalization passage 8 is 1/16 of the cross-sectional area of the ink storage chamber 4, the liquid level of the ink 5 in the ink storage chamber 4 decreases the surface area. The rise of the liquid column 5a of the ink in the equalization passage 8 is 0.25 x 16 = 4 mm. Therefore, in practice, the pressure at the tip of the equalization passage 8, i.e., the position of the depth of H1, is increased by the head pressure of 4 mm of H3 described above with respect to atmospheric pressure, and this is a very fine front force, which is actually negligible. .

Therefore, the head pressure acting on this ball tip 2 is H2 + 4mm. In this embodiment, since H2 is set to about 10 mm as described above, only the head pressure corresponding to this 14 mm acts on the ball tip 2, so that the ink chamber pressure of the ball tip 2 is low, for example, about 20 mm. Even in this case, the ink is not extruded.

In addition, the thing of this embodiment can make the front-end | tip part of the equalizing pipe 7 very close to the ball tip 2, and there is no restriction | limiting in the length of H2 of FIG. 5 in principle. For example, if the tip end of the pressure equalizing tube 7 is made thin, and the inner diameter of the ball holder of the ball tip 2 is enlarged, and the tip end of the pressure equalizing tube 7 is inserted into the ball holder, the pressure equalizing tube 7 The tip, that is, the tip of the equalization passage 8, can be brought close to, for example, 1 mm of the ball of the ball tip 2.

As described above, since the pressure acting on the ball tip 2 is minute and almost constant pressure almost always corresponds to H2, stable writing can be performed. In addition, when ink is consumed by writing, the liquid level of the ink in the ink storage chamber 4 and the equalization passage 8 decreases, but the amount of ink used in one writing is very small, and the change of the ink liquid level during writing Can also be ignored.

In addition, the air in the ink storage chamber 4 may expand during writing due to heat of the hand of the writer. However, in this case, the temperature rise is about several degrees Celsius. For example, even if the temperature rises by 3 degrees Celsius, the expansion of this air is 0.3% x 3 = 0.9%, even if the length of the air portion in the axial direction is 50 mm. Direction, only 50 × 0.9 / 100 = 0.45 mm is expanded, so that the lowering of the liquid level of the ink in the ink storage chamber 4 is 0.45 mm, and the increase in the height H3 of the liquid column 5a in the pressure equalizing passage 8 0.45 x 16 = 7.2 mm, and hardly affects writing. In order to reduce the influence of the temperature rise during writing, the cross-sectional area of the pressure equalizing path 8 may be set large in a range that satisfies other conditions.

As described above, the pressure compensating action at the time of nonwriting of the writing instrument of this embodiment and the pressure adjusting action at the time of writing are stabilized and controlled only by the balance of the pressure of each part. Therefore, there is no part that affects the dimensional accuracy, such as the movable part or the fine orifice, and no fluctuating element such as capillary force is used, so that high reliability is obtained, the structure is simple, and the manufacturing is easy.

Next, the operation of the above-described drying prevention mechanism 20 will be described with reference to FIGS. 6 and 7. 6 shows a case where the writing instrument is in a horizontal position. In the usual case, the silicone oil 23 contained in the oil chamber 22 is held by capillary force into the slit 24 of the partition member 21 to close these slits 24. Doing. Therefore, in such a case, the oil chamber 22 is completely blocked by the partition member 21 and the oil 23, the solvent vapor of the ink inside is completely prevented from evaporating, and drying of the ink is prevented. Is prevented.

When the air or the like in the ink storage chamber 4 expands or contracts due to temperature change or the like, differential pressure is generated on both sides of the partition member 21. Therefore, the oil 23 is moved from one side of the partition member 21 to the other side through these slits 24 by the differential pressure, thereby compensating for the pressure change, and thus the above-described pressure equalizing passage 8 and The inside of the ink storage chamber 4 is maintained at a pressure such as atmospheric pressure.

When the amount of expansion or contraction of air in the ink storage chamber 4 is large, the oil in the slit 24 is removed after the oil 23 has completely moved from one side to the other side of the partition member 21. As shown in FIG. 7, air or solvent vapor becomes bubbles to move from one side to the other side of the partition member 21 to compensate for the pressure. In this case, although there is some evaporation of the solvent vapor, such a state rarely occurs, and the amount of the solvent vapor to evaporate is also small. Therefore, by such a drying prevention mechanism 20, even if it is a quick-drying ink, the drying can be prevented almost completely.

In addition, the oil 23 is viscous and thus has flow resistance. However, the expansion and contraction of the air in the ink storage chamber 4 due to the temperature change as described above is very gentle, so that the oil 23 Since the flow velocity is also very small, the flow resistance is small, and the pressure difference inside and outside caused by the drying prevention mechanism 20 is negligibly small.

As described above, the equalization passage 8 and the leakage preventing pipes 12 and 26 of the reservoir bar 10 have an effect of preventing evaporation of solvent vapor of ink, and thus, the above-described drying prevention mechanism ( By adding 20), evaporation of the solvent vapor of the ink can be almost completely prevented, and even in the case of fast-drying ink having a very high evaporation rate, it can be prevented from drying for a long time.

In addition, this invention is not limited to said 1st Embodiment. For example, Figs. 8 to 11 show writing instruments in the second embodiment of the present invention. The ink reservoir 30 is provided in the main body 1 of this writing implement, and the inside is formed with the ink reservoir 4 in which the ink 5 is stored. And the nozzle part 32 is formed in the front-end | tip part of this ink reservoir 30, and the tip opening of this nozzle part 32 is opened in the pen body and the felt tip 2a in this embodiment. . An annular gap 31, 35 is formed between the inner circumferential surface of the main body 1 and the outer circumferential surface of the ink reservoir 30 and the nozzle portion 32, and the annular gap 31, 35) is formed as a pressure equalizing passage.

The tip portions of the equalization passages 31 and 35 communicate with the tip openings of the nozzle portion 32 of the ink reservoir 30 as described above, and the trailing ends of the equalization passages 31 and 35 come to the front. Through the reservoir bar 10 and the drying prevention mechanism 20 as described in the communication with the outside. In the case of this embodiment, the width of the equalization passage 35 is relatively large, and the width of the equalization passage 31 is relatively small, and the first implementation described above is carried out in the equalization passage 31. It is comprised so that ink may become liquid column 5a and hold | maintains similarly to the form. In addition, in order to maintain the ink in the liquid columnar state in the annular pressure equalizing path 31, the width of the ink is preferably about 2 mm or less.

In addition, although the annular protrusion part is formed in the outer peripheral part of the said ink reservoir 30 in the inner peripheral part of the main body 1, the slits 33 and 34 are formed in these protrusion parts, respectively, The equalization passages 31 and 35 communicate with each other and the outside by the slit. In addition, the thing of this 2nd Embodiment is the same structure as the thing of 1st Embodiment mentioned above except the above-mentioned point, and the same code | symbol is attached | subjected to the same part as the said 1st Embodiment in FIGS. Is omitted. The thing of this second embodiment operates in the same manner as the above-described first embodiment. That is, Fig. 9 is a case where the writing instrument is in a substantially horizontal posture in the non-writing state. In this case, the liquid level of the ink 5 is formed in the ink reservoir 30 and the nozzle part 32, and air exists in the upper part, and this part of air passes through the equalization passages 35 and 31. FIG. Communicates to the outside and compensates for the expansion and contraction of the air due to temperature changes to maintain the inside at atmospheric pressure.

10 shows a case where the writing instrument is inverted at the time of nonwriting. In this case, a part of the ink accumulates on the tail end side in the equalization passage 35. 11 shows a case in which the writing instrument is in a position in which the felt tip 2a is set downward, and in this case, a part of the ink sticks to the tip end side of the equalization passage 35. In any of the above cases, part of the ink is present in the slit 33 or the equalization passage 31 in the form of a liquid column, and the inside and the outside are sealed by this ink, and the free surface of the liquid column is a small area. Therefore, since the evaporation of the ink solvent is small, and the equal pressure passage 31, which is an annular narrow gap, prevents the exchange of the solvent vapor and air of the ink, the evaporation of the ink solvent is prevented. It is the same as the case of embodiment of.

And when writing with the writing implement of this 2nd Embodiment, as shown in FIG.8 and FIG.11, the felt tip 2a is set to the downward direction. In this case, the air inside the ink expands due to the head pressure H1 of the ink in the ink reservoir 30, and the liquid level of the ink in the ink reservoir 30 is lowered slightly. The height H3 of the liquid column 5a of the ink in the equalization passage 35 increases. Since the tip of the nozzle portion 32 of the ink reservoir 30, that is, the tip of the pressure equalizing passage 35, is almost equal to the atmospheric pressure, the felt tip 2a has a head pressure of H2, strictly H2 + H3. Only the action, and a constant pressure close to atmospheric pressure acts on the felt tip 2a, and stable writing is possible as in the case of the first embodiment described above.

In the second embodiment, an annular gap, that is, a pressure equalizing passage 31, is formed between the main body 1 and the ink reservoir 30 which is the ink reservoir, and the pressure equalizing passage 31 is formed. Insulate. Therefore, heat from the outside, for example, heat of the writer's hand is less likely to be transferred to the ink reservoir 30, and there is an advantage that the expansion of air in the ink reservoir 30 during writing can be reduced. In addition, as described above, the nozzle portion 32 is formed at the tip end of the ink reservoir 30, and the width, that is, the cross-sectional area, of the equalization passages 31 and 35 can be changed. Therefore, the cross-sectional area and the width of the equalization passage 31 are set to a dimension that can hold the ink in the liquid column state, and the cross-sectional area of the equalization passage 35 is made larger than this, and the ink reservoir in the writing state of FIG. Due to the rise of H3 of the liquid column 5a of the ink in the equal pressure passage 35 accompanying the lowering of the liquid level of the ink 5 in the 30, and the expansion of the air in the ink reservoir 30 during writing. There is also an advantage that the rise of H3 can be suppressed low.

In addition, the above-mentioned drying prevention mechanism can employ | adopt various things other than the above-mentioned. For example, in FIG. 12, the drying prevention mechanism 20a in 3rd Embodiment is shown. The partition member 21 is made into a simple disc, and a plurality of slits 24 are provided around it, and one chamber of the oil chamber 22 of this drying prevention mechanism is also used as the reservoir bar described above.

The action of this embodiment is the same as that of the embodiment described above, but the structure is simple and the production is easy. In addition, since the silicon oil 23 does not dissolve with the ink, even if they are mixed in the oil chamber 22 or in the pressure equalizing passage 8, writing does not interfere.

13, the drying prevention mechanism 20b in 4th Embodiment is shown. This is a porous block member 40 made of a porous material such as a foam of a continuous bubble or a fiber bundle, for example, as the partition member. This is because the silicon oil 23 is held in capillary force into the gap between the porous block member 40. It acts and prevents vaporization of the ink solvent vapor. In the case where the differential pressure is generated due to expansion and contraction of the internal air, the silicon oil 23 flows from one side of the oil chamber 22 to the other side through the porous compartment member 40 to compensate for the differential pressure. When expansion shrinkage equal to or greater than the amount of the flowing silicon oil 23 occurs, the oil between the poles in the porous block member 40 is eliminated and air flows to compensate for the expansion shrinkage, thereby to compensate for the expansion shrinkage. Maintain the pressure at the same pressure as atmospheric pressure.

14 and 15 show a drying prevention mechanism 20c according to the fifth embodiment. This forms a central chamber 41 in communication with the pressure equalizing path 8 at the distal end of the main body 1 of the writing instrument, and partitions the central chamber 41 to provide elasticity such as rubber material. The valve sheet member 42 made of a material is provided. And the valve hole 43 is formed in the center part of this valve seat member 42. As shown in FIG. Moreover, in this center chamber 41, the substantially cylindrical center 45 is accommodated freely in the radial direction and the axial direction. The conical valve body portion 46 and the shaft portion 44 protruding from the tip end thereof are formed at the tail end side of the pivot 45, and the shaft portion 44 flows in the valve hole 43 described above. The invasion is freely inserted. In addition, a conical tapered surface 47 is formed on the tip end side of the central chamber 41, and the tip end of the weight 45 is configured to contact the tapered surface 47. As shown in FIG. In addition, the tapered surface 47 is formed with a radial slit 47a for ensuring ventilation.

In the drying prevention mechanism 20c of this embodiment, when the writing instrument is in a horizontal position as shown in FIG. 14 at the time of non-writing, the tip portion of the above-described weight 45 is along the tapered surface 47 described above. It slides in radial direction and this center weight 45 moves to the tail end side. As a result, the valve body portion 46 on the side of the remaining portion of the weight 45 is pressed into the valve hole 43 described above, thereby closing the valve hole 43. Therefore, at the time of nonwriting, communication between the equalization passage 8 of the writing instrument and the outside is blocked, and evaporation of the ink solvent is prevented. In the case of the posture in which the writing instrument is inverted at the time of nonwriting, the weight 45 moves to the tail end side by its weight, and closes the valve hole 43 in the same manner as described above.

When writing, the writing instrument is in a posture with the pen body facing downward as shown in FIG. 15. In this case, the front end of the weight 45 slides and advances the taper surface 47 in the radial direction. As a result, the valve body portion 46 of the central body 45 is separated from the valve hole 43, and the valve hole 43 opens the valve so that the pressure equalizing passage 8 communicates with the outside. When the writing instrument is not in use, the equalization passage 8 and the outside are shut off. When the writing instrument is moved even during the non-use, the center 45 moves and the valve hole 43 momentarily opens the valve. Open. Therefore, in practice, the expansion and contraction of the expansion contraction is also performed by these actions. In addition, even when the writing instrument is moved and stood up prior to writing, as described above, the central 45 moves, the valve hole 43 opens the valve, and the inside of the writing instrument is at a pressure equal to atmospheric pressure prior to writing.

16 and 17 show a drying prevention mechanism 20d in the sixth embodiment. In the same manner as in the fifth embodiment, the central chamber 51 communicating with the pressure equalizing passage 8 is formed on the end of the main body 1, and the central weight 52 is radially formed therein. And the movement in the axial direction is freely accommodated.The skirt-shaped valve body part 53 formed in the taper surface of the front end side is protruded in the substantially center part of this center weight 52. Moreover, this center chamber 51 is provided. The rear end surface of the partition wall member 11 to be configured is formed of a conical tapered surface, and a slit 55 is formed on a part of the tapered surface 54, and the valve body portion 53 described above is formed. The front end surface of the trailing edge 3 of this writing instrument is formed as a valve seat surface which abuts against the tail end side surface of the valve body part 53 mentioned above.

In this embodiment, as shown in Fig. 16, when the writing instrument is in a horizontal posture at the time of writing, the tapered surface of the valve body portion 53 of the above-described weight 52 is tapered of the partition wall member 11. It slides in the radial direction along the surface 54 and moves axially to the tail end side, and this valve body part 53 comes in close contact with the valve seat surface of the front end surface of the tail 3, and the equalization passage 8 Block communication with the outside. In the case where the writing instrument is in an inverted state, the weight 52 moves to the tail end side by the weight thereof, and is in close contact with the valve seat surface of the tip of the tail end 3 so that the pressure equalizing passage 8 and the outside are similar. Block it. When the writing instrument is in an upright position as shown in Fig. 17 at the time of writing, the valve body portion 53 of the weight 52 slides toward the center portion of the tapered surface 54 and axially at the tip side. The valve body portion 53 is separated from the valve seat surface at the tip of the tail 3, and the pressure equalizing path 8 communicates with the outside.

18-20, the drying prevention mechanism 20e in 7th Embodiment is shown. This prevents drying by blocking and communicating the ink storage chamber 4 and the pressure equalizing tube 8 in response to the detachable operation of the cap 60.

The holder member 61 of the pen body slides freely at the distal end of the main body 1 of the writing instrument, and the pen body, for example, the ball tip 2 is attached to the distal end of the holder member 61. In addition, a seal skirt portion 62 is provided on the end of the holder member 61, and the seal skirt portion 62 slides freely in close contact with the inner circumferential surface of the main body 1 to maintain liquid tightness. have. Further, a conical valve seat surface 63 is formed on the tip end side of the inner surface of the holder member 61. And when this holder member 61 is retracted as shown in FIG. 19, the front end surface of the pressure equalizing pipe 7 will be in close_contact with this valve seat surface 63, and the inside of the ink storage chamber 4 and this bacteria The communication between the tip of the pressure pipe 7, that is, the tip of the pressure equalizing passage 8, and the communication between the outside of the pressure equalizing path 8 and the ink storage chamber 4 are blocked. Prevent evaporation.

In addition, an annular concave groove 64 is formed in the outer circumferential surface of the distal end of the tip of the holder member 61, and an annular recess elastically fits into the concave groove 64 in the inner circumferential surface of the cap 60. The projection 65 is formed. In addition, an annular seal portion 66 is formed on the inner surface of the tip portion of the cap 60, and is fitted to the tip portion of the ball tip 2 to prevent drying. In addition, a vent hole 67 is formed in the cap 60, and when the cap 60 is fitted, the air inside is compressed and prevented from being pushed into the writing instrument through the ball tip 2.

As shown in FIG. 19, when the above-mentioned drying prevention mechanism 20e fits the cap 60 at the time of non-writing, the projection 65 of this cap 60 becomes the recessed groove 64 of the holder member 61. As shown in FIG. ), The holder 60 is retracted when the cap 60 is fitted to the end side, and the tip end portion of the pressure equalizing tube 7 is in close contact with the valve seat surface 63 of the inner surface thereof. Then, the communication between the ink storage chamber 4 and the pressure equalizing tube 7, that is, the pressure equalizing passage 8, is blocked. Therefore, in this non-writing state, the ink in the ink storage chamber 4 is completely sealed, and evaporation of the solvent is prevented.

As shown in Fig. 20, when the cap 60 is removed at the time of writing, the holder member 61 moves forward together with the cap 60, and the tip of the pressure equalizing tube 7 is held by the holder member 61. And the pressure equalizing path 8 and the inside of the ink storage chamber 4 communicate with each other, and the pressure adjusting action and the head pressure adjustment function as described above are made possible, and stable writing is possible. . In this case, the holder member 61 is slightly eccentric with respect to the main body 1, and the shoulder 66 formed on the outer periphery of the tip end of the holder member 61 hangs on the leading edge of the main body 1. The holder member 61 is prevented from retreating due to the pen pressure when writing and writing.

In addition, the drying prevention mechanism in this writing implement can employ | adopt the thing of the other structure which achieves the same objective besides the various mechanisms mentioned above.

As described above, when the pen body is, for example, a felt tip, the ink seal pressure is high, but the amount of ink contained in the felt tip increases or decreases due to a change in the pressure in the ink reservoir. In some cases, the handwriting may be darkened or blurred. Therefore, when the temperature changes during non-writing and the air in the ink storage chamber expands, there is a compensating effect of the pressure caused by the pressure equalization passage as described above. The amount of ink contained is excessive, so that a so-called ink rich state is caused and the handwriting is easily darkened, which is undesirable. In the writing implements of the eighth embodiment shown in Figs. 21 and 22, an ink interruption mechanism 70a for preventing such closure is provided.

The mechanism is provided with a partition member 71 for partitioning the inner surface of the tip end portion of the ink storage chamber 4 described above, and a blocking chamber 73 between the partition member 71 and the felt tip 2a. It is formed. In addition, an orifice hole 72 having a small cross-sectional area is formed in the central portion of the partition member 71, and the ink reservoir chamber 4 and the blocking chamber 73 communicate with each other through the orifice hole 72. Air is filled in the cut-off chamber 73.

In the ink blocking mechanism of the eighth embodiment, when the writing instrument is placed in a horizontal position at the time of non-writing, for example, a small amount of ink 5b penetrating into the blocking chamber 73 is blocked. The lower end side of the felt tip 2a is stuck to the circumferential wall portion below 73, and the air 5 is in contact with the ink 5b. Therefore, in this blocking chamber 73, the ink in the ink storage chamber 4 is not connected to the felt tip 2a in a liquid state, but is cut off by air once. Further, even when a minute differential pressure is generated during pressure compensation such as expansion or contraction of air in the ink storage chamber 4, the ink is held in the orifice hole 72 of the partition member 71 by capillary force. Therefore, the ink is not extruded into the blocking chamber 73 or the air or ink is drawn into the ink storage chamber 4 from the blocking chamber 73 according to such a small differential pressure. Therefore, such a differential pressure is interrupted by this blocking chamber 73, and the amount of the ink contained in the felt tip 2a is prevented from becoming undesirably excessive or too low by this differential pressure, and this felt tip 2a is prevented. The amount of ink contained in the) is kept constant.

In addition, as shown in Fig. 22, when the writing instrument is erected with the felt tip 2a facing down at the time of writing, a small amount of ink 5b in the blocking chamber 73 is placed on the end of the felt tip 2a. It contacts and supplies the ink consumed by writing to this felt tip 2a. When the ink 5b in the blocking chamber 73 is consumed, the inside of the blocking chamber 73 becomes low pressure, and ink is supplied into the blocking chamber 73 through the orifice hole 72 by the differential pressure. In this case, the amount of the ink 5b in the blocking chamber 73 is kept constant and stable ink can be supplied.

23 and 24 show the ink blocking mechanism 70b in the ninth embodiment. The disc-shaped diaphragm member 81 made of a flexible material such as synthetic rubber is provided in the distal end of the main body 1, and the ink storage chamber 4 and the felt tip 2a are provided by the diaphragm member 81. Communication with) is blocked. In the central portion of the diaphragm member 81, a valve hole 82 is formed through the diaphragm member 81. Moreover, in the tip part of this main body 1, the holder member 83 hold | maintains sliding freely in the axial direction, and the felt tip 2a is hold | maintained at the tip part. The valve shaft portion 85 protrudes from the distal end side of the holder member 83, and the valve shaft portion 85 is elastically and densely fitted in the valve hole 82 of the diaphragm 81 described above. The ink passage 84 communicates with the felt tip 2a, and the ink passage 84 communicates with the opening 86 opened on the main surface of the valve shaft 85.

In the ink blocking mechanism 70b of this embodiment, as shown in FIG. 23 at the time of non-writing, the valve hole 82 of the diaphragm member 81 is elastically in close contact with the outer peripheral surface of the valve shaft portion 85 described above. The opening 86 is closed, and communication between the ink storage chamber 4 and the felt tip 2a is blocked. Therefore, in this state, even when a small differential pressure is generated in the ink reservoir during the pressure compensation action, the differential pressure does not act on the felt tip 2a, so that the amount of ink contained in the felt tip 2a is not desired. It does not increase or decrease.

At the time of writing, as shown in FIG. 24, when the felt tip 2a is pressed against the writing surface W, the holder member 83 retreats in the axial direction by the pen pressure, and the diaphragm member 81 is incomplete. Deform to the side. As a result, the valve hole 82 of the diaphragm member 81 deforms and expands, a gap is formed between the main surface of the valve shaft portion 85, and the opening 86 is opened. Therefore, the ink storage chamber 4 and the felt tip 4a communicate with each other through this opening 86 to supply ink.

In addition, in each of the above-described embodiments, the writing instrument in the form of discarding after use has been described, but the writing instrument of the present invention is not limited thereto. For example, in the tenth embodiment shown in Fig. 25, the ink storage chamber and the pen body which are free of protrusion by the ink storage chamber and the pen body which can be exchanged with respect to the writing instrument body, or the knock mechanism can be knocked out with respect to the writing instrument body. It is a so-called refill writing instrument which is an assembly of.

This refill 90 has a structure substantially the same as that of the first embodiment described above, and includes a main body 1, a ball tip 2, a pressure equalizing pipe 7, and a reservoir bar 10. In Fig. 25, portions corresponding to those in the first embodiment are denoted by the same reference numerals and description thereof will be omitted. In this refill-type writing instrument, the above-mentioned drying prevention mechanism is omitted because it is required to be compactly formed, but it has a sufficient drying prevention function to use a quick-drying ink.

That is, such a refillable writing instrument is generally formed small in diameter in order to be accommodated in the main body of the writing instrument. Therefore, the cross-sectional area of the ink storage chamber 4 is also small, and accordingly, the cross-sectional area of the pressure equalizing passage 8 in the pressure equalizing pipe 7 is also small. Therefore, the equalization passage 8 is long in length with respect to the cross-sectional area. Therefore, as described above, the action of preventing solvent evaporation of the ink in the pressure equalizing passage 8 is large and exhibits a sufficient drying prevention function. Also, as described above, also in the leak-proof tube 25 of the micro-projection 3 protruding into the reservoir bar 10, there is also an effect of preventing evaporation of the solvent of the ink, and only with these effects, fast-drying ink is used. It is possible.

26 to 28 show an eleventh salicy form of the present invention. This prevents the liquid column of the ink in the pressure equalizing passage from misting and scattering by impact or the like, and has the effect of preventing the evaporation of the solvent of the ink, and it is possible to omit the evaporation preventing mechanism of the various solvents as described above. .

In the eleventh salicy form, the basic structure is the same as that of the tenth embodiment described above, and the reservoir bar 10 partitioned by the partition member 6 is provided on the distal end side of the body 1, The pressure equalizing path 8 in the pressure equalizing tube 7 communicates with this reservoir bar 10. And the scattering prevention mechanism is provided in the tail end side of this equalizing pipe 7, ie, the end part which communicates with the reservoir bar 10. As shown in FIG.

In the drawing, reference numeral 101 denotes a scattering preventing member of the scattering preventing mechanism, and the scattering preventing member 101 includes a head 102 and a neck 103. And this neck part 103 is densely fitted in the tail end part of the equalizing pipe 7 mentioned above. The outer diameter of the head 102 is slightly smaller than the inner diameter of the reservoir bar 10, and is annular between the outer circumferential surface of the head 102 and the inner circumferential surface of the reservoir bar 10. The gap is formed.

Moreover, the radial communication groove 104 is formed in the front end side surface of this head 102, ie, the surface which opposes the partition member 6, for example. Moreover, the communication groove 105 is formed also in the main surface of the neck part 103 along the axial direction, and these communication grooves 104 and 105 communicate with each other. In addition, in the case of this embodiment, the communication groove 105 of the neck part 103 mentioned above forms the shape which cut out the main part of the neck part 103 flatly, and this neck part 103 is a pressure equalizing tube 7. In the case of fitting inwardly, an interval between the inner circumferential surface of the equalization tube 7 and the bow-shaped gap, i.e., a passage, is formed.

Moreover, in the surface which opposes the partition member 6 of the head 102 mentioned above, the some processus | protrusion 106 is protruded, These protrusions 106 abut the partition member 6, and this partition member ( The gap 107 is formed between 6) and the head 102.

In the eleventh embodiment described above, the pressure equalizing path 8 in the pressure equalizing tube 7 communicates with the reservoir bar 10 through the communication grooves 104 and 105 of the scattering preventing member 102. In the same manner, when the writing instrument is set at the time of writing while maintaining the inside of the ink storage chamber 4 at normal atmospheric pressure by compensating for expansion and contraction of air or the like in the ink storage chamber 4 of the writing instrument, Relieves hydrocephalus.

The communication grooves 104 are formed along the radial direction, and the communication paths formed of the communication grooves 104 and 105 have a maze shape that is bent in the middle. Therefore, even if this writing instrument falls from a high place, a strong impact acts, and even if the liquid column 5a of the ink in the pressure equalizing passage 8 scatters in the mist form due to the impact, the mist of the ink remains in the reservoir. There is no scattering until the bar 10. Therefore, the mist from the reservoir bar 10 to the outside through the outflow prevention pipe 25 is surely prevented.

In addition, since the end end side of the equalization passage 8 communicates with the reservoir bar 10 in the communication grooves 104 and 105 which are the narrow passages described above, in the communication grooves 104 and 105, air and ink are solvents. There is no exchange action between the gas and the vapor, and since it is a narrow passage, there is little diffusion and the evaporation of the solvent vapor is sufficiently prevented. Moreover, in this embodiment, the length in the axial direction of the said reservoir bar 10 is formed comparatively long, and the length of the outflow prevention tube 25 formed in the field 3 is formed relatively long. Therefore, there is an effect of preventing evaporation of sufficient solvent vapor even in the long outflow prevention tube 25. Therefore, the thing of this embodiment can fully prevent the evaporation of quick-drying ink, even if the above-mentioned evaporation prevention mechanism is not provided.

In addition, in this embodiment, even when the air in the ink storage chamber 4 excessively expands and the ink flows into the reservoir bar 10 as described above, the air in the ink storage chamber 4 shrinks again. In this case, the ink flowing out into the reservoir bar 10 can be efficiently returned to the ink storage chamber 4.

That is, the gap 107 is formed between the head 102 and the partition member 6 of the scattering prevention member 101, and the spilled ink is in the gap 107 by capillary force, and It is held in one communication groove 104,105. Therefore, when the writing instrument is in a horizontal or pen-down position, when the air in the ink storage chamber 4 expands and contracts again, all of the ink in the reservoir bar 10 is the gap 107 and the communication grooves 104 and 105 described above. The suction is sucked into the pressure equalizing path 8 through the inside and returns to the ink storage chamber 4 without leaving. When the air is inflated and contracted with the writing instrument inverting the pen body upward, the tip of the pressure equalizing tube 7 protrudes on the liquid level of the ink. Since there is no outflow into the reservoir bar 10, no ink remains in this reservoir bar 10.

In addition, in the case of this eleventh embodiment, the passage formed in the above-mentioned scattering preventing member 101 is not limited to the above-described one, and any passage is a curved or labyrinth-shaped passage that prevents scattering of mist of ink. It may be a shape.

29 to 35 show a twelfth embodiment provided with 20f of drying preventing mechanisms of different inks.

As described above, the end portion side of the ink storage chamber 4 is provided with a partition member 6, and the inside of the main body 1 between the partition member 6 and the above described edge 3 is cylindrical. The slide chamber 110 is formed. The tip end side of the slide chamber 110 communicates with the pressure equalizing passage 8 in the pressure equalizing tube 7 through the communication hole 111 formed in the center of the partition member 6.

Moreover, the outflow prevention pipe 12 protrudes along the axial direction toward the inner side, i.e., the inside of the slide chamber 110, in the center part of the above-mentioned tail 3. The tail end side of the slide chamber 110 communicates with the outside through this flow prevention tube 112. In addition, since the distal end of the leakage preventing tube 112 is located at the center of the slide chamber 110 away from the inner circumferential surface, the liquid in the slide chamber 110 leaks to the outside even when the writing instrument is in an arbitrary posture. It is configured not to.

In the slide chamber 110, the hermetic slide plug 113 is free to slide in the axial direction. This hermetic slide plug 113 and its tip end form a closed cylindrical user, and a predetermined gap is formed between the outer circumferential surface and the inner circumferential surface of the slide chamber 110. In the case of this embodiment, the width between the poles also corresponds to the inner diameter of the slide chamber 110 and the characteristics of the viscous fluid, but is set in the range of 0.05 to 0.1 mm in a normal writing instrument.

The slide chamber 110 is filled with a small amount of viscous fluid. As the viscous fluid, silicone oil having a predetermined viscosity is suitable. The silicon oil 115 is held by capillary force between the outer circumferential surface of the hermetic slide plug 113 and the inner circumferential surface of the slide chamber 110. Therefore, the silicon oil 115 is interposed between the outer circumferential surface of the hermetic slide plug 113 and the inner circumferential surface of the slide chamber 110 as an oil film, and these are not in direct contact.

30, the groove part 114 is formed in the outer peripheral surface of this hermetic slide plug 113 along an axial direction. Therefore, in the part of this groove part 114, the cross-sectional area of the gap part between the outer peripheral surface of this airtight slide plug 113 and the inner peripheral surface of the slide chamber 110 becomes large. Therefore, the silicone oil 115 held by the capillary force between the outer circumferential surface of the hermetic slide plug 113 and the inner circumferential surface of the slide chamber 110 has a holding force by the capillary force in the portion of the groove 114. It is smaller than this other part.

In addition, when the airtight slide plug 113 has a plurality of protrusions 116 formed on the distal end face of the user-cylindrical hermetic slide plug 113, the partition member 113 is moved to the distal end side. These protrusions 116 abut against 16, and a gap is formed between the front end face of the hermetic slide plug 113 and the partition member 6, and the communication hole 111 formed in the partition member 6 is formed. ) Is not blocked. In addition, the tip of the leak-proof pipe 112 is formed to be obliquely cut shape, even when the airtight slide plug 113 is moved to the uneven end to the limit and abuts the tip of the leak-proof pipe 112. It is designed so as not to block the tip opening of the).

The pressure compensation action of the ink of the writing instrument of the twelfth embodiment is the same as that described above. That is, FIG. 31 shows the case where the writing instrument is in a horizontal posture in the non-writing state, FIG. 32 shows the case where the writing instrument is inverted in the non-writing state, and FIG. To compensate for the head pressure.

Next, the operation of the drying prevention mechanism of the ink described above with reference to FIGS. 34 and 35 will be described. As described above, the ink supply mechanism of this embodiment assumes that the pressure equalizing passage 8 in the pressure equalizing tube 7 is always maintained at the same pressure as the external atmospheric pressure. However, when the tail end side of the equalization passage 8 is released to the outside as it is, the vapor of the solvent of the ink in the ink storage chamber 4 evaporates to the outside through the equalization passage 8, and the ink dries. In particular, when quick-drying ink is used, this evaporation is severe, and there is a problem such that the ink in the ink storage chamber 4 dries and becomes impossible to write before the ink of the writing instrument is consumed.

In this embodiment, the above-mentioned equalizing passage 8 communicates with the outside through the slide chamber 110, but the slide chamber 110 is closed by the airtight slide plug 113, and the outer peripheral surface and the slide chamber The gap between the inner peripheral surface of the 110 and the silicon oil 115 is filled and sealed. Therefore, the vapor of the solvent of the ink diffused to the slide chamber 110 through the pressure equalizing passage 8 is blocked from the outside by the hermetic slide plug 113 and does not diffuse to the outside. Therefore, the ink in the ink storage chamber 4 does not dry out.

Next, when a temperature change, air pressure change, or the like occurs, air or vapor inside the ink storage chamber expands and contracts, and a differential pressure is generated between the ink storage chamber 4 and the external atmospheric pressure. In such a case, the hermetic slide plug 113 moves in the slide chamber 110, compensates for the expansion contraction and the differential pressure, and in the pressure equalizing passage 8 and the ink storage chamber 4 Is maintained at the same pressure as normal atmospheric pressure. Therefore, a differential pressure does not generate | occur | produce between the pressure in this ink storage chamber 4 and an external pressure, and the above-mentioned supply control effect | action of an ink does not occur, and stable ink supply is attained.

In addition, in the usual case, the hermetic slide plug 113 is located at an intermediate position of the slide chamber 110, as shown in FIG. 34, and slides in the axial direction to compensate for the above pressure. As described above, the outer circumferential surface of the hermetic slide plug 113 and the inner circumferential surface of the slide chamber 110 are not in direct contact with each other, and the silicon oil 115 is interposed between the gaps in the form of an oil film. Therefore, when this hermetic slide plug 113 is moved, this silicone oil 115 flows and lubricates, and the movement of this hermetic slide plug 113 is performed smoothly and with a very small resistance. Therefore, the pressure difference between the inside and outside of the ink storage chamber 4 due to the movement resistance of the hermetic slide plug 113 hardly occurs, and the ink storage chamber 4 is maintained at the same pressure as the external atmospheric pressure.

In addition, the silicon oil 115 has a relatively high viscosity, and flow resistance is generated when the silicon oil 115 flows. However, this temperature change and external air pressure change occur at long periods, such as a one-day cycle, and the speed of the change is gentle. Therefore, the moving speed of the hermetic slide plug 113 corresponding thereto is also very slow. Since the resistance when the viscous fluid such as the silicone oil 115 flows is proportional to the flow velocity, when the hermetic slide plug 113 moves smoothly, the silicone oil 115 The flow resistance becomes very small and almost no resistance occurs as described above.

On the other hand, when this writing instrument is accidentally dropped on the floor or the like, for example, a large impact acts on the writing instrument, and a large load also acts on the airtight slide plug 113. However, as described above, the viscous fluid such as the silicon oil 115 has a very large resistance when the flow velocity is large. Therefore, for the momentary impact load as described above, the silicon oil 115 generates a large resistance, and the airtight slide plug 113 hardly moves. Therefore, when such an impact is applied, the airtight slide plug 113 acts as a fixed partition wall, and no flow or pressure change of air in the slide chamber 110 or the pressure equalizing passage 8 occurs, and ink Outflow and mist scattering are prevented.

In addition, the expansion and contraction rate of the air is, for example, about 10% of the volume change with respect to the temperature change of 30 ° C. Therefore, if the volume in the slide chamber 10 is 10% or more of the inside volume of the ink storage chamber 4, the expansion and contraction of air in the ink storage chamber 4 can be compensated for the temperature change of 30 ° C or more. Can be. In addition, since a temperature change of 30 ° C. or more rarely occurs in a normal environment in which writing instruments are used, it is generally sufficient to set the content of the slide chamber 110 to about 10% of the content of the ink storage chamber 4.

However, the writing instruments may be exposed to a temperature difference of 30 ° C. or more, for example, when the writing instruments are left in a temperature difference between the interior and the outside of a cold climate or a dashboard of a car parked in cold sunlight. In such a case, the hermetic slide plug 113 moves to one side of the slide chamber 10, that is, to the front end side of the slide chamber 110 as shown in FIG. 35, and further movement is impossible. .

In this case, a certain pressure difference occurs on both sides of the hermetic slide plug 113. This pressure difference removes the silicon oil 115 from the gap between the outer circumference of the hermetic slide plug 113 and the inner circumferential surface of the slide chamber 110. Therefore, air flows through the gap in which the silicon oil 115 is removed, and the differential pressure inside and outside the ink storage chamber 4 is eliminated. In this case, since the protrusion 116 is formed on the front end surface of the hermetic slide plug 113, the protrusion 116 abuts against the partition member 6, and thus the front end face of the slide plug 113. Since the gap is formed between the partition member 6 and the partition member 6, the communication hole 111 of the partition member 6 is not blocked.

In addition, when the air in the ink storage chamber 4 greatly expands, the hermetic slide plug 113 is moved to the end of the slide chamber 110 to the maximum and the leakage preventing pipe 12 of the tail 3 Although contact with the tip of the tip ends, further movement is impossible, but the communication is performed by removing the silicon oil 115 in the gap as described above. In addition, since the tip end portion of the outflow prevention tube 112 is formed to be obliquely cut, the tip opening of the outflow prevention tube 12 is not blocked by the abutment of the hermetic slide plug 113.

In the above state, since the vapor of the solvent of the ink in the ink storage chamber 4 flows out to the outside, or air flows into the ink storage chamber 4 from the outside, the ink flows with the circulation of such gas. The vapor of the solvent evaporates. However, such a large temperature change rarely occurs, and the amount of vapor evaporated in such a process is very small, and there is no drying of ink, which is a problem.

Moreover, in this embodiment, the groove part 114 is formed in the outer peripheral surface of the airtight slide plug 113, and the capillary force which hold | maintains the silicone oil 115 is formed in the part of this groove part 114. As shown in FIG. It is small. Therefore, when the above-mentioned differential pressure is generated, the silicon oil 115 of the part of the groove 114 is excluded and air is distributed, so that the communication with the silicon oil can be carried out with a smaller differential pressure.

In the actual product, the capillary force of the silicon oil 115 held in the annular gap between the outer circumferential surface of the hermetic slide plug 113 and the inner circumferential surface of the slide chamber 110 is influenced by gravity and other influences. , Non-uniform in each part. Therefore, even if the groove 114 is not formed as described above, the silicon oil is first removed from the small portion of the capillary force and communication is performed before the entire silicon oil is excluded. Therefore, the groove 114 as described above does not necessarily need to be formed.

Next, a thirteenth embodiment of the present invention will be described with reference to FIG. The thing of this embodiment is itself provided with the ink supply mechanism which provided the partition slide plug 120 in the ink storage chamber 4, and is equipped with the other ink drying prevention mechanism 20g.

The partition slide plug 120 holds liquid tightly between the inner circumferential surface of the ink storage chamber 4 to accommodate sliding freely. The tip end side is filled with ink 5 from the partition slide plug 120. The tail end side is formed as an air portion 121 in which air is present. When the ink 5 is consumed by writing, the partition slide plug 120 moves to the tip end side.

Moreover, in this embodiment, the inflow prevention pipe 127 which protrudes toward this slide chamber 110 side in the center part of the partition member 126 between the said ink storage chamber 4 and the slide chamber 110 mentioned above. This protrudes and prevents the silicon oil and the like in the slide chamber 110 from flowing into the ink storage chamber 4.

In addition, at the center of the partition member 126, an outflow prevention tube 128 protruding toward the ink storage chamber 4 protrudes, so that the ink slides even if the ink leaks into the air portion 121. Outflow to the chamber 110 is prevented.

In addition, the tip ends of the inflow prevention pipe 127 and the outflow prevention pipe 128 have a shape in which the oblique cut is formed, and the tip openings of the inflow prevention pipe 127 and the outflow prevention pipe 128 are not obstructed when the airtight slide plug 113 abuts. have. In addition, in this embodiment, the said inflow prevention pipe 127 and the outflow prevention pipe 128 are formed in the same shape, and it is comprised so that it is not necessary to distinguish the front and back of this partition member 126 when assembling.

In addition, the thing of this embodiment is the same as that of 11th embodiment mentioned above except the above-mentioned point, The same code | symbol is attached | subjected to the part corresponding to this 12th embodiment in FIG. 36, and the description is abbreviate | omitted.

In this embodiment, since the ink and the air in the ink storage chamber 4 are partitioned by the partition slide plugs 120, the outflow of the ink into the slide chamber 110 is effectively prevented. This compartment slide plug ink supply mechanism has an advantage that the structure is simple and can hold a large amount of ink. However, in this type, there is a closed end that when the ink dries and adheres to the sliding surface between the partition slide plug 120 and the ink storage chamber 4, smooth sliding of the partition slide plug 120 is inhibited. As described above, however, the ink drying prevention mechanism can almost certainly prevent the drying of the ink, and can reliably solve the drawbacks of the above-mentioned partition slide plug type ink supply mechanism.

37 shows the drying prevention mechanism 20h of the fourteenth embodiment of the present invention. This is provided with the so-called middle surface ink supply mechanism which filled the porous body 130, such as cotton fiber and felt, in the ink storage chamber 4. As shown in FIG.

The porous body 130 as described above is accommodated in the ink storage chamber 4, and ink is held in the porous body 130 by capillary force. In this embodiment, in this porous body 130, a larger amount of ink than usual, that is, a large amount of ink leaking out of the porous body 130, is maintained. In addition, the front end of the porous body 130 is provided with a relay core 131 such as felt having a capillary force larger than that of the porous body 130, and ink is supplied to the pen body 2 through the relay core 131. .

The end end side of the porous body 130 is formed as an air chamber 132 in an empty space. In addition, in the partition member 136 which divides the ink storage chamber 4 and the slide chamber 110, the inflow prevention tube 137 and the outflow prevention tube 138 protrude as mentioned above. In addition, in this embodiment, the outflow prevention tube 138 which protrudes into the ink storage chamber 4 is formed long in length.

In addition, the thing of this embodiment is the same as that of 13th embodiment mentioned above except the above-mentioned point, The same code | symbol is attached | subjected to the part corresponding to this 13th embodiment in FIG. 37, and the description is abbreviate | omitted.

In this embodiment, the ink is held by the capillary force in the porous body 130 in the ink storage chamber 4, and the ink is supplied to the pen body 2 in predetermined amounts. Therefore, the structure is simple and the operation is stable. However, the ink supply mechanism of this type has a closed end in that the amount of ink held in the porous body 130 is small. If the amount of ink retained in the porous body 130 is too large, a portion of the ink leaks out of the porous body 130 and leaks through a communication path with the outside, resulting in excessively small amount of ink. If this happens, the amount of ink to be retained becomes small, and at the same time, there is a disadvantage that only the handwriting remains. For this reason, it is necessary to precisely control the amount of ink held in the porous body 130 at the time of manufacture of this type of thing.

In the above embodiment, the air chamber 132 is formed in the ink storage chamber 4, and the outflow prevention tube 138 protrudes from the partition member 136. Therefore, even if ink leaks out from the porous body 130, this ink accumulates in the air chamber 132 and does not flow out to the slide chamber 110. FIG. Therefore, it is possible to hold a large amount of ink in the porous body 130, and it is not necessary to precisely control the amount of the ink held in the porous body 130 during manufacture, and this double-sided ink is easy to manufacture. The shortcomings of the supply mechanism can be compensated for.

As described above, this ink drying prevention mechanism can almost certainly prevent the drying of the ink. In the case where a large amount of ink is held in the porous body 130, for example, when the writing instrument falls to the floor and an impact is applied, mist of ink easily scatters from the porous body 130. However, in this embodiment, since the airtight slide plug 113 is interposed between the inflow prevention tube 37 and the tail end leakage prevention tube 112 which mutually oppose each other, the mist of this ink prevents these inflow prevention tubes ( 137 and the spill prevention pipe 112 can be surely prevented from flying to the outside.

In addition, this invention is not limited to said embodiment, The kind of pen body and other structure are not necessarily limited to the thing of above-mentioned embodiment. When the fast drying ink is not used, it is not necessary to provide the drying prevention mechanism, the reservoir bar, or the like as described above, and the equalization passage may be communicated with the outside as it is.

As described above, according to the present invention, at the time of writing, the inside of the tip portion of the ink storage chamber is adjusted to a pressure substantially equal to the atmospheric pressure by the equalization passage, and the head pressure acting on the pen body can be arbitrarily low and constant. Stable ink supply and writing is possible. In addition, this unevenness passage compensates for the expansion and contraction of air in the ink storage chamber and maintains the ink storage chamber at about the same pressure as the atmospheric pressure. In addition, the writing instrument of the present invention has no moving parts such as subtle valve mechanisms, no parts using capillary forces such as fine orifices, and acts only by balancing the pressure of each part, so that the operation reliability is very high. In addition, the pressure of the ink can be controlled stably. Therefore, the structure is simple, easy to manufacture and can reduce the price, it is possible to provide a cheap writing instruments with good writing characteristics.

Claims (10)

A main body of the writing instrument, a pen body provided at the tip end of the main body, an ink storage chamber formed in the main body and in communication with the pen body, and disposed substantially in parallel with the axial direction of the ink storage chamber, and the tip end portion is disposed in the ink storage chamber. A writing instrument, comprising: a pressure equalizing passage communicating with a position near the pen body in the distal end of the yarn and simultaneously communicating with the distal end from the distal end side of the body. 2. The pressure equalizing passage as set forth in claim 1, wherein said equalizing passage is inserted into said ink storage chamber axially and is formed in a tubular pressure equalizing tube in which the leading end is opened near the pen body in the leading end of said ink storage chamber, and the tail end is connected to the outside. Writing instruments characterized in that. An ink reservoir having an ink reservoir formed therein is provided in the main body, and a gap formed between the inner circumferential surface of the main body and the outer circumferential surface of the ink reservoir is formed as the equalization passage. And the equalization passage communicates with the inside of the ink reservoir at a position near the pen body of the distal end, while the distal end communicates with the outside at the distal end side of the main body. The cross-sectional shape and cross-sectional dimension of the pressure equalizing passage as claimed in claim 1, wherein the ink penetrating the inside is maintained in the liquid column in the pressure equalizing passage by the surface tension of the free surface. A writing instrument characterized in that the position with air is set to a cross-sectional shape and a cross-sectional dimension which do not cause the gas-liquid exchange action to be exchanged. The ink storage chamber according to claim 1, wherein the ink storage chamber has a substantially cylindrical shape, and the cross-sectional area of the equalization passage is set in a range of 1/30 to 1/4 of the cross-sectional area of the ink storage chamber. Writing instrument made with. 2. The drying according to claim 1, wherein the main body prevents drying of ink by preventing communication between the end of the pressure equalizing passage and the outside of the pressure equalizing passage and the tip of the pressure equalizing passage and the ink storage chamber when not written. Writing instruments characterized in that the prevention mechanism is provided. The writing instrument according to claim 1, wherein the pen body is a ball tip, and a distance between the tip of the equalization passage and the tip of the ball tip is 20 mm. 2. The ink pen according to claim 1, wherein the pen body is a felt tip, and the main body is provided with an ink blocking mechanism for blocking communication of ink between the ink storage chamber and the felt tip during non-writing. Writing instruments. The writing instrument as set forth in claim 1, wherein at the tail end of the pressure equalizing passage, an ink mist scattering prevention mechanism having a curved or labyrinth shaped passage is provided. The slide chamber as set forth in claim 1, wherein said drying prevention mechanism is formed on the end of said ink storage chamber in said body and communicates with said ink storage chamber and communicates with the outside of said writing instrument. An airtight slide plug having a predetermined clearance between the inner circumferential surface of the slide chamber and a sliding slide in the axial direction to block communication between the ink storage chamber side and the outer side, and the inner circumferential surface of the slide chamber. And a viscous fluid having a predetermined viscosity held by capillary force between the gaps between the airtight slide plugs.