JP2011218578A - Writing utensil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a writing utensil capable of surely preventing ink from leaking from a pen point by avoiding involving of air, easily interchanging an ink tank without generating dust of the pen point, and easily confirming the remaining amount by making the ink tank flexible.SOLUTION: The writing utensil feeds the ink in the ink tank 12 to a pen core 10 by pressing the pen core 10 onto a writing object. An ink feeding mechanism 14 includes: a front piston body 20 in which a communicating path 20a moved back and forth with the pen core 10 and communicating the pen core 10 with a storing space part 22 is formed; a back piston body 24 in which the inside is the storing space part 22 and the storing space part 22 is communicated with the ink tank 12 side; a check valve 26 arranged in the communicating path 20a of the front piston body 20 and for preventing the ink from flowing reversely from the pen core 10 side to the storing space part 22 side; and a valve body 28 arranged in the storing space part 22 of the back piston body 24 and for preventing the ink from flowing reversely from the storing space part 22 to the ink tank 12 side.

Description

  The present invention can be used for various purposes including board markers, industrial markers, etc., and also has industrial benefits such as the use of highly environmentally conscious users because there is little waste after writing. It relates to a certain writing instrument.

  Recently, there has been proposed a technique for replacing an ink tank in a writing instrument for marking an object for reasons such as a reduction in environmental load.

  For example, Japanese Patent Laid-Open No. 2001-287494 (Patent Document 1) is an ink tank exchangeable writing instrument. However, in this writing instrument, the pressure inside the ink tank rises due to a change in temperature, a change in atmospheric pressure, etc., and an unexpected ink outflow from the pen tip when the valve is opened during writing or the like can be considered.

  Therefore, as disclosed in Japanese Patent Application Laid-Open No. 2000-177290 (Patent Document 2), an applicator using a flexible container as an ink tank has been proposed.

  However, in the ink tank of this type of flexible container, it is necessary to replace the pen tip with the ink tank at the time of replacement, and thus the tip tip dust is generated after the replacement. Further, the applicator has a structure in which the valve body simply opens and closes and the tank is an elastic bag-like body. When ink is reduced during writing, air is passed from the nib tip through the valve body into the tank. In order to perform air replacement to introduce air, it is necessary to bend the flexible container by its own weight in the case of ink having viscosity, so that stable application is difficult.

  In addition, the conventional valve mechanism may cause air to be caught in the ink tank.

  JP-A-2005-218961 (Patent Document 3) is an applicator using a flexible container as an ink tank. In this applicator, the ink tank can be separated from the coating member, but when the ink tank and the coating member are mounted, there is a possibility of air replacement, and stable coating is difficult.

  Japanese Utility Model Laid-Open No. 07-04364 (Patent Document 4) is a pump having a soft bag body. When this is used as a writing instrument and the writing instrument with a pen core attached to the piston body is used in the opposite direction, the pump does not operate and the liquid does not flow out.

JP 2001-287494 A JP 2000-177290 A Japanese Patent Laid-Open No. 2005-218961 Japanese Utility Model Publication No. 07-04364

  In view of such circumstances, the present invention eliminates air entrainment and can reliably prevent ink leakage from the pen tip, can easily replace the ink tank without generating dust at the pen tip, and can be used as an ink tank. The present invention intends to provide a writing instrument that is bent to easily check the remaining amount.

The present invention relates to a writing instrument, which is a writing instrument having an ink supply mechanism in which a pen core is attached to the front end side, and an ink tank that is flexible as ink is consumed is attached to the rear end side.
The ink supply mechanism has a function of temporarily storing the ink flowing in from the ink tank in the storage space portion, restricting the ink in the storage space portion to return to the ink tank, and sending it only to the pen core side,
The ink supply mechanism includes a front piston body that is moved back and forth together with the pen core and formed with a communication passage that communicates the pen core with the housing space portion, and the inside is a housing space portion, and the housing space portion faces the ink tank side. A communicating rear piston body, a check valve disposed in the communicating path of the front piston body for preventing ink from flowing back from the pen core side to the housing space side, and a housing space for the rear piston body And a valve body for preventing the ink from flowing backward from the storage space to the ink tank side,
The front piston body and the rear piston body are slidably contacted with each other so that the front piston body and the rear piston body can be moved relative to each other in a state where the communication path of the front piston body communicates with the housing space, and the front piston body moves backward and forward relative to the rear piston body To reduce / increase the volume in the accommodating space,
By reducing the volume in the storage space, the check valve is opened and the valve body is closed so that the ink in the storage space flows to the pen core side, while the volume in the storage space is reduced. As a result of the increase, the check valve is closed and the valve element is opened, so that the ink in the ink tank flows into the storage space.

  In the present invention, it is preferable that the sliding portion between the front piston body and the rear piston body is sealed with an elastic body.

  In the present invention, it is preferable that the check valve and the valve body are held in the piston body by fitting a step formed inside each piston body with other parts.

  In the present invention, it is preferable that a spring member for biasing the front piston body forward with respect to the rear piston body is interposed between the front piston body and the rear piston body.

  In the present invention, it is preferable that the flexible ink tank is removable from the ink supply mechanism and can be replaced.

  In the present invention, the ink in the ink tank preferably contains a volatile solvent having a high vapor pressure.

  According to the writing instrument of the present invention, since the writing instrument has an ink supply mechanism in which a pen core is attached to the front end side and an ink tank that is flexible with ink consumption is attached to the rear end side, Since the tank is deformed, there is no need for air replacement.

  Then, the front piston body and the rear piston body are slidably contacted with each other in a state where the communication path of the front piston body communicates with the housing space, and the front piston body moves backward and forward relative to the rear piston body. As a result, the volume in the storage space is decreased / increased, and the check valve is opened and the valve body is closed due to the decrease in the volume in the storage space. On the other hand, the check valve is closed and the valve element is opened due to the increase in the volume in the storage space, so that the ink in the ink tank flows into the storage space. Therefore, even if the ink in the ink tank is reduced by writing, the ink in the ink tank can be sent to the pen core and used for writing by operating the ink supply mechanism.

  Further, since the ink supply device can be configured with a small number of simple configurations of the front piston body, the rear piston body, the check valve, and the valve body, the manufacturing cost and assembly are easy.

  In addition, a mechanism for moving the front piston body backward or forward relative to the rear piston body is preferable from the viewpoint of ease of handling, as the front piston body moves by pressing the pen core.

  In the present invention, if the sliding portion between the front piston body and the rear piston body is sealed with an elastic body, the ink can be sent to the pen core without loss by the ink supply mechanism.

  In addition, if the check valve and the valve body are held in the piston body by fitting the step formed inside each piston body with other parts, the step and the check valve or valve body are in close contact with each other. Thus, the liquid tightness can be improved, and the ink can be surely fed.

  In addition, a spring member that urges the front piston body forward relative to the rear piston body is interposed between the front piston body and the rear piston body. The pen core can be urged forward to return.

  In addition, the flexible ink tank can be removed from the ink supply mechanism and exchanged, so that the waste to be discarded does not include the ink supply mechanism, and the disposal process can be performed conveniently.

  Also, if the ink in the ink tank contains a volatile solvent having a high vapor pressure, the ink tank is a flexible ink tank, so the internal volume of the ink tank decreases as the ink decreases, and the ink tank Since no space is generated, the ink does not volatilize or does not occur. Therefore, even during long-term storage, the ink tank can be easily stored without being swollen by the volatile gas of the solvent.

It is a general view of the writing instrument which concerns on embodiment of this invention, Comprising: (a) is at the time of cap mounting, (b) is at the time of cap non-mounting. In the writing instrument of FIG. 1, it is explanatory drawing of the ink supply mechanism which provided the pen core, Comprising: (a) is a front perspective view, (b) is a front view, (c) is a longitudinal cross-sectional view, (d) is a side view (E) is a rear perspective view, and (f) is a rear view. FIGS. 3A and 3B are explanatory views of a check valve and a valve body in the ink supply mechanism of FIG. 2, wherein FIG. 3A is a front perspective view, FIG. 2B is a front view, FIG. (E) is a side view at a position rotated by 90 ° from (d), (f) is a longitudinal sectional view in the state of (e), (g) is a rear perspective view, and (h) is a front view. is there. FIG. 3 is an explanatory diagram of a front piston body in the ink supply mechanism of FIG. 2, wherein (a) is a front perspective view, (b) is a front view, (c) is a longitudinal sectional view, and (d) is a side view. e) is a rear perspective view, and (f) is a rear view. FIG. 3 is an explanatory diagram of a rear piston body in the ink supply mechanism of FIG. 2, wherein (a) is a front perspective view, (b) is a front view, (c) is a longitudinal sectional view, and (d) is a side view. e) is a rear perspective view, and (f) is a rear view. It is explanatory drawing of the holder in the writing instrument of FIG. 1, Comprising: (a) is a front perspective view, (b) is a front view, (c) is a longitudinal cross-sectional view, (d) is a side view, (e) is back A perspective view and (f) are back views. FIG. 1 is an explanatory view of a joint in the writing instrument, where (a) is a front perspective view, (b) is a front view, (c) is a longitudinal sectional view, (d) is a side view, and (e) is a rear view. A perspective view and (f) are back views. It is explanatory drawing of the ink tank in the writing instrument of FIG. 1, Comprising: (a) is a side view, (b) is a longitudinal cross-sectional view. (A) to (d) in the operation of the ink supply mechanism of FIG. 2, the front piston body moves backward by pressing the pen core, and then the front piston body moves / returns forward. It is an operation explanatory view.

  Hereinafter, a writing instrument according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is an overall view of a writing instrument according to an embodiment, in which (a) is when the cap is mounted, and (b) is when the cap is not mounted. 2 is an explanatory view of an ink supply mechanism provided with a pen core in the writing instrument of FIG. 1, wherein (a) is a front perspective view, (b) is a front view, and (c) is a longitudinal sectional view. (D) is a side view, (e) is a rear perspective view, and (f) is a rear view.

  As shown in FIGS. 1 and 2, the writing instrument according to the embodiment includes an ink supply mechanism 14 in which a pen core 10 is attached to the front end side and an ink tank 12 that is flexible as ink is consumed is attached to the rear end side. The ink supply mechanism 14 temporarily stores the ink flowing from the ink tank 12 in the storage space 22 and restricts the ink in the storage space 22 from returning to the ink tank 12. This has a function of sending only to the pen core 10 side.

  When the writing instrument is not used, as shown in FIG. 1A, the cap 8 covers the pen core 10 and the joint 16 and is fitted in front of the outer shaft 18, and when used, as shown in FIG. 1B. Then, the cap 8 is removed to expose the pen core 10. In this writing instrument, the ink in the ink tank 12 is supplied to the pen core 10 by pressing the pen core 10 against the object to be written.

  The ink supply mechanism 14 includes a front piston body 20 having a communication passage 20a that moves back and forth together with the pen core 10 and communicates the pen core 10 with the storage space 22, and an internal space that is the storage space 22. Ink is prevented from flowing back from the pen core 10 side to the containing space portion 22 side disposed in the rear piston body 24 where the space portion 22 communicates with the ink tank 12 side and the communication path 20a of the front piston body 20. And a valve body 28 disposed in the housing space 22 of the rear piston body 24 for preventing the ink from flowing back from the housing space 22 to the ink tank 12 side. ing.

  Then, the front piston body 20 and the rear piston body 24 are slidably contacted with each other in a state where the communication passage 20a of the front piston body 20 communicates with the housing space portion 22, and the front piston body 20 is moved to the rear piston body. By moving backward and forward with respect to 24, the volume in the accommodating space 22 is reduced or increased.

  Further, as shown in FIG. 1, the outer shaft 18 has a tip portion 18 a that has a stepped diameter smaller than that of the center portion, and the cap 8 is externally fitted to the tip portion that has the smaller diameter. In the hollow of the front end portion 18a of the outer shaft 18, the front end of the cylindrical joint 16 protrudes and is fixedly disposed so as to cover the pen core 10 from the hollow opening. A holder 30 that can move back and forth with the pen core 10 is mounted inside the joint 16, and a porous material that functions as a temporary ink reservoir is provided between the front portion 30 a of the holder 30 and the pen core 10. A body (such as a sponge) 32 is arranged in a cylindrical shape. A front piston body 20 is fitted on the rear end portion of the holder 30, and a check valve 26 mounted in the front piston body 20, the holder 30, and the communication path 20a is fixed.

  A rear piston body 24 is fitted and fixed to the rear end portion 18 b of the outer shaft 18, and then a front portion of a substantially trumpet-shaped connection port body 34 is fitted into the rear opening of the piston body 24. In the connection port body 34, a flange 34 a at the center in the axial direction projects radially outward, and the flange 34 a prevents the connection port body 34 from entering the rear piston body 24. In addition, an insertion pipe portion 34b that extends into the ink tank 12 at the rear portion and serves as an ink introduction path projects from the connection port body 34 so as to protrude rearward.

  A spring member 36 is interposed between the front piston body 20 and the rear piston body 24 and is disposed on the inner peripheral portion of the outer shaft 18. The core 10 is repelled toward the front. The spring member 36 is preferably made of a material that does not easily corrode, such as SUS or a highly elastic resin material.

  Each part of the writing instrument will be described.

  3A and 3B are explanatory views of the check valve 26 and the valve body 28 in the ink supply mechanism 14 of FIG. 2, wherein FIG. 3A is a front view, FIG. 3B is a front perspective view, and FIG. (D) is a side view, (e) is a side view at a position rotated by 90 ° from (d), (f) is a longitudinal sectional view in the state of (e), (g) is a rear view, h) is a rear perspective view.

  In the embodiment, as shown in FIG. 3, the check valve 26 and the valve body 28 have the same shape, and it is not necessary to manufacture the mold individually, so that the manufacturing cost and management can be simplified and made efficient.

  As shown in FIG. 3, the check valve 26 and the valve body 28 are provided with cup-shaped main bodies 26a and 28a, and front portions 26b and 28b project in a thin film shape or a valve shape at the front ends of the main bodies 26a and 28a. The rear portions 26c and 28c protrude radially outward at the rear end portions of the main bodies 26a and 28a and are expanded in a flange shape. The front portions 26b and 28b are formed in a hollow structure having a rectangular cross section with the front end closed by a wall portion, and slits 26d and 28d are cut into the wall portion closing the front end. The check valve 26 and the valve body 28 are formed of an elastic material such as rubber so that they can be elastically deformed flexibly. Accordingly, the slits 26d and 28d are closed (closed) when the internal pressure (ink pressure or air pressure) of the main bodies 26a and 28a is negative or 0, and when the internal pressure increases, the ink pushes the slits 26d and 28d open. Open (open state). Further, the check valve 26 and the valve body 28 are held in the piston body by fitting the step formed inside the front piston body 20 and the rear piston body 24 with other parts.

  Specifically, in the check valve 26, the flange-shaped rear portion 26c of the check valve 26 is mounted in the stepped portion 20d (step) in a state where the check valve 26 is disposed in the front portion 20b of the front piston body 20. The flange-like rear portion 26c is pressed and fixed on the periphery of the rear portion 30b of the holder 30 from the front. Accordingly, the rear portion 26 c of the check valve 26 is sandwiched and fixed between the front piston body 20 and the holder 30.

  Further, the valve body 28 is attached from behind to the stepped portion of the rear end 24a in the accommodating space 22 of the rear piston body 24, and the flange-shaped rear portion 28c of the valve body 28 is aligned with the stepped portion. The flange-shaped rear portion 28c is pressed from behind and fixed at the front edge of the connection port body 34. Accordingly, the rear portion 28c of the valve body 28 is sandwiched and fixed by the rear piston body 24 and the connection port body 34.

  The check valve 26 and the valve body 28 can be made of various elastic materials such as natural rubber, silicone rubber, and elastomer.

  4 is an explanatory view of the front piston body 20 in the ink supply mechanism 14 of FIG. 2, wherein (a) is a front perspective view, (b) is a front view, (c) is a longitudinal sectional view, and (d). Is a side view, (e) is a rear perspective view, and (f) is a rear view.

  As shown in FIG. 4, the front piston body 20 has a hollow structure in which a small-diameter cylindrical rear portion 20 c is reduced in a step shape from a large-diameter cylindrical front portion 20 b and has a rear portion in the front portion 20 b. A stepped portion 20d having a small diameter in a stepped shape in an undercut shape is formed in a portion subsequent to. A groove 20e is formed at the rear end of the rear portion 20c, and an elastic body 38 such as an O-ring (O-ring) is fitted into the groove 20e and sealed. The elastic body 38 ensures the liquid-tightness of the sliding contact portion between the front piston body 20 and the rear piston body 24.

  5A and 5B are explanatory views of the rear piston body 24 in the ink supply mechanism 14 of FIG. 2, wherein FIG. 5A is a front perspective view, FIG. 5B is a front view, and FIG. 5C is a longitudinal sectional view. ) Is a side view, (e) is a rear perspective view, and (f) is a rear view.

  As shown in FIG. 5, the rear piston body 24 is formed in a flange shape whose outer peripheral surface is enlarged in two stages at the rear end portion 24 a, and the rear end portion 24 a of the flange shape connects the rear piston body 24 to the outer shaft 18. It has a function of positioning means that prevents it from entering the outer shaft 18 when it is fitted into the rear end portion 18b. The rear piston bodies 24 are substantially cylindrical and formed in concentric circles whose diameter is increased in two stages from the axial center to the rear end of the inner peripheral surface of the rear piston body 24, and the inner peripheral space is formed in the accommodating space 22. It will be. The rear portion 20c of the front piston body 20 is inserted and assembled to the inner periphery of the front end portion 24b of the rear piston body 24, and ink leakage is prevented by a seal by the elastic body 38. The front end of the connection port body 34 is attached to the rear end 24 a of the rear piston body 24.

  6 is an explanatory view of the holder 30 in the writing instrument of FIG. 1, wherein (a) is a front perspective view, (b) is a front view, (c) is a longitudinal sectional view, and (d) is a side view, (E) is a rear perspective view, and (f) is a rear view.

  As shown in FIG. 6, the holder 30 has a substantially cylindrical shape in which a large and small cylinder in which the front portion 30 a is formed to have a larger diameter than the rear portion 30 b is continuous in a step shape. A wall portion 30c having a hole in the center is formed at the boundary between the front portion 30a and the rear portion 30b. As shown in FIG. 2, when the pen core 10 is mounted from the front, an undercut formed in a small diameter so as to fit and fix the rear end portion of the pen core 10 is formed adjacent to the wall portion 30c. Ink flows from the rear portion 30b to the rear end portion of the pen core 10 through the hole. Further, the porous body 32 is loaded so as to surround the pen core 10. Further, the front portion 30a is mounted in the joint 16 so as to be relatively movable (slidable).

  FIG. 7 is an explanatory view of the joint 16 in the writing instrument in FIG. 1, (a) is a front perspective view, (b) is a front view, (c) is a longitudinal sectional view, and (d) is a side view, (E) is a rear perspective view, and (f) is a rear view.

  As shown in FIG. 7, the joint 16 has a substantially cylindrical shape in which large and small cylinders in which the front part 16 a is formed to have a smaller diameter than the rear part 16 b are stepwise. A rib 16c for guiding the side surface of the pen core 10 along the axial direction is formed in the front portion 16a so as to protrude inward. A gap having a protruding height of the rib 16 c leads from the side surface of the pen core 10 to the porous body 32 so that the outside air can flow through the porous body 32.

  8A and 8B are explanatory diagrams of the ink tank 12 in the writing instrument of FIG. 1, in which FIG. 8A is a side view and FIG. 8B is a longitudinal sectional view.

  As shown in FIG. 8, the ink tank 12 is flexible and can be removed from the ink supply mechanism 14 and a new ink tank 12 can be mounted.

  Specifically, as shown in FIG. 8, a flexible ink tank main body 12b is accommodated in a rigid exterior shaft 12a that has no problem when writing on the exterior. The ink tank main body 12b is a material that is not affected by deterioration due to the properties of the ink contained therein, and various materials can be used as long as they are flexible. For example, a bag body in which linear low density polyethylene (LLDPE) is used as a base material and the periphery is bonded with polyethylene terephthalate (PET) is used. Furthermore, it is preferable to form an aluminum vapor deposition layer between the LLDPE layer and the PET layer, since the suppression of volatilization of the ink content liquid and gas outflow can be improved.

  The supply port (spout) 12c attached to the ink tank main body 12b may be configured so that the ink of the content liquid does not flow out when the insertion tube portion 34b of the connection port body 34 of the ink supply mechanism 14 is inserted and attached. Therefore, the material and configuration are not particularly limited, and various configurations can be taken. In the embodiment, as shown in FIG. 8, an elastic rubber or elastomer insertion wall is provided in the frame of the supply port 12c, and an insertion tube portion 34b is inserted into the insertion wall so that the inside of the ink tank main body 12b. Ink is sent to the ink supply mechanism 14.

  The ink stored in the ink tank 12 contains a volatile solvent having a high vapor pressure. The composition of the ink stored in the ink tank 12 is, for example, ethanol, methanol, acetone, methyl ethyl ketone, ethyl acetate, methyl acetate, propyl acetate, butyl acetate, hexane, isohexane, methylcyclohexane, toluene, xylene, dichloromethane, trichloroethylene, diethyl ether. Ink containing one or more volatile solvents can be accommodated.

  The operation of the writing instrument according to the embodiment will be described.

  9A to 9D show the operation of the ink supply mechanism 14 shown in FIG. 2, when the pen core 10 is pressed to move the front piston body 20 to the rear side, and then the front piston body 20 moves to the front side. It is an operation explanatory view when moving to and returning to.

  As shown in FIG. 9A, when the pen core 10 is not pressed against the paper surface or writing target surface when not in use, the pen core 10 is in its original position, and the front piston body 20 is moved forward by the spring member 36. This is a state where the check valve 26 and the valve body 28 are not opened (the slits 26d and 28d are closed).

  Then, when the user presses the pen core 10, the pen core 10, the holder 30, and the front piston body 20 are subjected to the elastic force of the spring member 36, as shown in FIGS. Move backwards against it. As a result, the rear portion 20c of the front piston body 20 enters the housing space portion 22 from the front portion 20b of the rear piston body 24, the volume in the housing space portion 22 decreases, and the ink pressure in the housing space portion 22 increases. (If the ink is not filled, the air pressure becomes higher). As a result, the check valve 26 is in the open state (slit 26d is in the open state), and the valve body 28 is in the closed state (slit 28d is in the closed state). It flows through the pen core 10 side. In addition, when there is no ink in the accommodation space part 22, it will exhaust.

  Thereafter, when the pressing to the pen core 10 is stopped, as shown in FIG. 9D, the front piston body 20 is moved forward by the elastic force of the spring member 36, and the volume in the accommodation space 22 is increased. As a result, the ink pressure in the storage space 22 is reduced, the check valve 26 is closed (slit 26d is closed), and the valve body 28 is opened (slit 28d is open). Due to the pressure reduction in the storage space 22, the ink in the ink tank 12 flows from the insertion tube portion 34 b of the connection port 34 through the valve body 28 into the storage space 22. Even when there is no ink in the storage space 22, since the pressure is negative, the ink flows into the storage space 22.

  Then, as shown in FIG. 9A, the pen core 10 is then waited until it is pressed at the original position.

  According to the writing instrument of this embodiment, since the writing instrument has the ink supply mechanism 14 to which the pen core 10 is attached at the front end side and the ink tank 12 that is flexible with ink consumption is attached to the rear end side, the ink consumption Accordingly, since the ink tank 12 (ink tank main body 12b) is deformed, there is no need for air replacement.

  Further, the front piston body 20 and the rear piston body 24 are slidably contacted with each other in a state where the communication passage 20a of the front piston body 20 communicates with the housing space portion 22, and the front piston body 20 is slidably contacted. By moving backward and forward with respect to 24, the volume in the accommodating space 22 is reduced or increased.

  The check valve 26 is opened and the valve body 28 is closed due to a decrease in the volume in the storage space 22 so that the ink in the storage space 22 flows to the pen core 10 side. Since the check valve 26 is closed and the valve body 28 is opened due to the increase in the volume in the storage space 22, the ink in the ink tank 12 flows into the storage space 22. Even if the ink in the ink tank 12 is reduced, by operating the ink supply mechanism 14 via the pen core 10, the ink in the ink tank 12 can be sent to the pen core 10 for writing. In addition, since the ink supply device can be configured with a small number and simple configuration of the front piston body 20, the rear piston body 24, the check valve 26, and the valve body 28, manufacturing cost and assembly are easy.

  If the sliding portion between the front piston body 20 and the rear piston body 24 is sealed by the elastic body 38, the ink can be sent to the pen core 10 without loss by the ink supply mechanism 14.

  Further, if the check valve 26 and the valve body 28 are held in the piston body by fitting the step formed inside each piston body (the front piston body 20 and the rear piston body 24) and other parts, The step, the check valve 26 and the valve body 28 are in close contact with each other to improve the liquid tightness, and it is possible to ensure the reliable feeding of ink.

  Further, a spring member 36 that urges the front piston body 20 forward with respect to the rear piston body 24 is interposed between the front piston body 20 and the rear piston body 24, thereby pressing the pen core 10. By releasing, the pen core 10 can be reliably urged forward and returned.

  In addition, the flexible ink tank 12 can be removed from the ink supply mechanism 14 so that the ink tank 12 can be exchanged, so that the ink supply mechanism 14 is not included in the waste to be discarded, and the disposal process can be performed conveniently.

  If the ink in the ink tank 12 contains a volatile solvent having a high vapor pressure, the ink tank 12 is a flexible ink tank 12. Since no space is generated in the tank 12, the ink does not volatilize or does not occur. Therefore, the ink tank 12 is not easily swollen with the volatile gas of the solvent even when stored for a long period of time. Can be played.

  The writing instrument of the present invention can be used for various purposes such as board markers, industrial markers, etc., and the use of highly environmentally conscious users because there is little waste after writing. It can be used as a writing instrument that can improve the above benefits.

8 Cap 10 Pen Core 12 Ink Tank 12a Exterior Shaft 12b Ink Tank Body 12c Supply Port 14 Ink Supply Mechanism 16 Joint 16a Joint Front Part 16b Joint Rear Part 16c Joint Rib 18 Outer Shaft 18a Outer Shaft End 18b Rear end portion 20 Front piston body 20a Communication path 20b Front piston body front portion 20c Front piston body rear portion 20d Front piston body stepped portion 20e Front piston body groove 22 Storage space portion 24 Rear piston body 24a Rear end portion 24b Front end portion 26 Check valve 26a Check valve body 26b Check valve front portion 26c Check valve rear portion 26d Check valve slit 28 Valve body 28a Valve body main body 28b Valve body front portion 28c Valve body rear portion 28d Valve body slit 30 Holder 30a Holder front 30b Holder rear 30c Holder wall 32 Porous body 34 Connection port The insertion tube portion 36 the spring member 38 the elastic body of the flange 34b coupler body of 4a coupler body

Claims (6)

A writing instrument having an ink supply mechanism in which a pen core is attached to the front end side, and an ink tank that is flexible with ink consumption is attached to the rear end side,
The ink supply mechanism has a function of temporarily storing the ink flowing in from the ink tank in the storage space portion, restricting the ink in the storage space portion to return to the ink tank, and sending it only to the pen core side,
The ink supply mechanism includes a front piston body that is moved back and forth together with the pen core and formed with a communication passage that communicates the pen core with the housing space portion, and the inside is a housing space portion, and the housing space portion faces the ink tank side. A communicating rear piston body, a check valve disposed in the communicating path of the front piston body for preventing ink from flowing back from the pen core side to the housing space side, and a housing space for the rear piston body And a valve body for preventing the ink from flowing backward from the storage space to the ink tank side,
The front piston body and the rear piston body are slidably contacted with each other so that the front piston body and the rear piston body can be moved relative to each other in a state where the communication path of the front piston body communicates with the housing space, and the front piston body moves backward and forward with respect to the rear piston body. To reduce / increase the volume in the accommodating space,
The check valve is opened and the valve body is closed due to the decrease in the volume in the storage space, so that the ink in the storage space flows to the pen core side, while the volume in the storage space is increased. Thus, the check valve is closed and the valve body is opened, so that the ink in the ink tank flows into the storage space.   The writing instrument according to claim 1, wherein a sliding portion between the front piston body and the rear piston body is sealed with an elastic body.   3. The writing instrument according to claim 1, wherein the check valve and the valve body are held in the piston body by fitting a step formed inside each piston body and other parts.   4. The writing instrument according to claim 1, wherein a spring member for biasing the front piston body forward with respect to the rear piston body is interposed between the front piston body and the rear piston body.   5. The writing instrument according to claim 1, wherein the flexible ink tank is removable from the ink supply mechanism and can be replaced.   The writing instrument according to claim 1, wherein the ink in the ink tank contains a volatile solvent having a high vapor pressure.

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