JP2004009645A - Writing utensil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a writing utensil which can prevent ink leakage in nonuse by pressurization only in use, which dispenses with the use of an expensive material with gas barrier properties such as a gas-filled type material by virtue of the pressurization according to need, which can compensate for a decrease in required applied pressure decreased with the use of ink without the use of a particularly complicated mechanism, which is prevented from being pressurized even if a user repeatedly performs pressure operations, and which can secure a stable ink flow rate. <P>SOLUTION: In a barrel body 18, a pressure mechanism 22 for increasing pressure in an ink storage tube 12 is provided between the rear part of the tube 12 and a knock mechanism 20. When the tip of a writing part, which is protruded from the barrel body 18, is pushed for the retraction of a refill unit 14 after the completion of the push-out operation of the knock mechanism 20, a cylinder part 26 relatively advances with respect to a seal part 24 in the pressure mechanism 22 so as to pressurize the inside of an ink storage tube 28. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention mainly relates to a knock-type writing instrument equipped with a refill such as a ball-point pen that enables correction by concealing a mistake or the like with white ink.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there has been known a liquid writing instrument using a white pigment to correct a mistake or the like. In addition, since the white pigment and the solvent are easy to separate, this kind of liquid writing instrument is sealed with ink and balls in a flexible container, and shakes the inner balls to shake the ink when used. There is a need. In addition, there is the trouble of attaching and detaching the cap when using.
[0003]
In order to solve the above-mentioned drawbacks of the liquid writing implement, there has been proposed one in which sedimentation of the pigment is prevented by including a white pigment such as titanium oxide and hollow polymer particles and a gelling agent in the ink.
[0004]
However, this method has the following disadvantages.
In order to prevent the sedimentation of the pigment, the viscosity of the ink increases, and the initial brushability deteriorates. In addition, it is necessary to pressurize the ink storage tube to support the discharge of the ink.
Further, the conventional method of pressurizing the ink storage tube by enclosing the pressurized gas increases costs and complicates manufacturing equipment. Further, since the tip is constantly pressurized, if the tip has a poor sealing property, ink leakage tends to be induced when writing is not performed. Further, since the internal pressure decreases with consumption of the ink, it is necessary to increase the initial internal pressure in order to use up the ink to the end, and ink leakage is more likely to be induced.
[0005]
In addition to the method of filling gas, there is a type that presses by knocking at the time of writing, but it is commercially available.However, the user repeatedly presses the knocking with play regardless of writing, and the inside of the ink storage tube is continuously pressurized. For this reason, there is a problem that it is difficult for the user to control the flow rate of the ink, such as a possibility that the ink is ejected or an excessive amount of the ink during writing.
[0006]
[Problems to be solved by the invention]
The present invention has been made by focusing on the problems of the above-described conventional technology, and since it is possible to use a predetermined ink without pigment sedimentation, it is troublesome to agitate the ink or remove the cap. There is no need to pressurize only when used, preventing leakage of ink when not in use, and pressurizing when needed, so there is no need to use expensive materials with gas barrier properties such as gas-filled type, and use of ink Can be compensated without using a particularly complicated mechanism, and even if the user repeats the pressing operation, the pressing force is not continuously increased, and a stable ink flow rate can be secured. It aims to provide a writing instrument.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the following configuration is provided.
According to the present invention, a refill unit having a writing portion at an end and an ink storage tube at the rear is loaded into a shaft body in a state where the refill unit is repelled rearward by a first spring, and the writing of the refill unit is performed. In a writing instrument that can be moved in and out in conjunction with the push operation and the push release operation of the knock mechanism provided on the rear end side of the shaft main body, the rear portion of the refill unit in the ink storage tube is opened, and the inside of the shaft main body is A pressurizing mechanism is provided between the rear portion of the ink containing tube and the knocking mechanism to increase the pressure inside the ink containing tube, and the pressurizing mechanism moves in a direction to separate the seal portion from the cylindrical portion having the front end opened, the seal portion and the cylindrical portion. And a second spring for repelling, after the pushing operation of the knock mechanism is completed, the tip of the writing portion projecting from the shaft body is pressed to retreat the refill unit. If allowed, the pressurizing mechanism is a writing instrument, characterized in that pressurizing the ink reservoir tube with relatively tube portion is advanced with respect to the sealing portion.
According to the present invention, when the flow rate of the ink is required when using the writing implement, the tip of the writing portion protruding from the shaft body is pressed against the application surface, so that the refill is further pushed into the pressurizing mechanism, and a larger pressing force is applied. Pressure can be applied to the ink storage chamber. In this way, the pressure can be applied only during use, so that ink leakage during non-use can be prevented. Further, since pressurization is performed when necessary, it is not necessary to use an expensive material having gas barrier properties. Further, even if left knocked, the pressurized air gradually leaks, so there is no fear of ink leakage.
[0008]
In the present invention, in conjunction with the pushing operation of the knocking mechanism, the seal portion of the pressurizing mechanism in the shaft main body comes into close contact with the rear end of the ink storage tube of the refill, and then the cylinder portion advances and the ink passes through the seal portion. It is preferable that the inside of the storage tube be pressurized. With this configuration, the pressing mechanism in the shaft body is brought into close contact with the rear end of the refill and is further advanced in conjunction with the pushing operation by the knocking mechanism during the pushing operation, so that a pressurized state is applied to the ink writing portion. Fluidity is supported, and you can start writing as soon as you push and write. Then, when the pressure is reduced during writing, the tip of the writing portion may be pressed to apply pressure.
Further, in the present invention, it is preferable that the elastic force of the first spring is set smaller than the elastic force of the second spring. At the time of the pushing operation of the knock mechanism, the refill unit advances first, and the writing mechanism of the refill does not pressurize until the writing portion of the refill hits the forward portion in the shaft main body and stops.
Further, in the present invention, the resilience of the first spring and the second spring is such that when the pushing operation of the knocking mechanism is completed, the tip of the writing portion projecting from the shaft body is pressed to retreat the refill unit. It is preferable that the repulsion is set to 3 to 15 N (Newton). With a repulsion force of 3 to 15 N in this manner, a firm writing feeling can be provided without giving the user a feeling that the tip of the writing portion is fluffy due to the writing pressure during writing.
[0009]
Further, in the present invention, the pressurizing mechanism releases the pressurized state by communicating with the atmosphere inside the ink storage tube in a state of being immersed in the shaft main body of the writing portion of the refill unit when the knocking mechanism is pushed out. It is preferred that As a result, even if the user repeatedly knocks without using the writing instrument, continuous pressurization in the ink storage tube is not performed when the knock mechanism is pushed out, so that the pressure in the ink storage tube does not increase and ink is ejected. This eliminates problems such as the occurrence of defects and the occurrence of excessive ink on the paper surface. In addition, at the time of non-writing, since there is no need to worry about ink leakage because the balance with the atmospheric pressure can be maintained. In addition, the members used for knocking and pressurizing when necessary do not need to be so precise in the gas barrier properties and the sealing properties of each part, so that a wide range of inexpensive materials can be appropriately selected. In addition, even if it is left knocked, since there is not so much gas barrier property and sealing property, the pressurized air is gradually leaked and there is no fear of ink leakage.
[0010]
In the present invention, the refill unit includes an ink container filled with ink and a follower that follows the ink at the rear end of the ink, and a ball-point pen tip press-fitted in front of the ink container. It is preferable that the ball loosely and rotatably fitted in the inside is provided with a back pressure by a spring, and closes the opening at the tip of the ballpoint pen tip when not writing.
In the present invention, it is preferable that the viscosity of the ink is 1000 mPa · s or less at a shear rate of 400 / s and 300 mPa · s or more at 5 / s in an atmosphere of 25 ° C. By using such an ink, the trouble of stirring the ink and removing the cap can be eliminated.
[0011]
In the present invention, it is preferable that the ink containing tube is filled with at least a white pigment ink containing a white pigment such as titanium oxide and polymer hollow fine particles and a gelling agent. This makes it possible to obtain a white pigment ink that is blended so that sedimentation of the pigment is prevented and fluidity is not impaired as much as possible. This type of white pigment ink tends to have a high viscosity and poor initial earing, but such a problem is eliminated because the ink is pressed by a pressing mechanism.
Further, in the present invention, it is preferable that the cylindrical portion of the pressurizing mechanism also serves as the rotor of the cahn type knock mechanism. It can be shared with the knock mechanism parts, and the number of parts can be reduced.
Further, in the present invention, it is preferable that the shaft main body is formed so as to be able to be divided into two parts.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 to 4 are explanatory diagrams of the operation of the writing instrument according to the embodiment of the present invention (at the time of non-writing, at the time of writing after knocking, at the time of additional pressure, at the time of non-additional pressure), and FIGS. 5 to 8 are partially detailed operations of the writing instrument. It is explanatory drawing (at the time of non-writing, at the time of writing after knocking, at the time of additional pressure, and at the time of non-additional pressure). Each figure is a semi-vertical view.
[0013]
The writing implement according to the embodiment is configured such that a refill unit 14 having a pen tip (an example of a writing section) 10 at the tip and an ink storage tube 12 at the rear is repelled by a first spring 16 toward the rear. The ball-point pen tip 10 of the refill unit 14 can be inserted into the main body 18 and can be protruded and retracted from the distal end opening 18a in conjunction with the push-out operation and the push-out release operation of the knock mechanism 20 provided on the rear end side of the shaft main body 18. In the writing instrument, the rear portion 12r inside the ink storage tube 12 of the refill unit 14 is opened, and the pressure inside the ink storage tube 12 is increased between the rear portion 12r of the ink storage tube and the knock mechanism 20 in the shaft body 18. A pressurizing mechanism 22 is provided. The pressurizing mechanism 22 separates the seal portion 24 from the cylindrical portion 26 with the front end open, and separates the seal portion 24 and the cylindrical portion 26. When the knockout mechanism 20 is pushed out and the tip of the ballpoint pen tip 10 protruding from the shaft main body 18 is pressed to retreat the refill unit 14, In the pressurizing mechanism 22, the seal portion 24 retreats and the cylindrical portion 26 relatively advances to compress the internal air in the internal pressurizing chamber 40, and the compressed internal air opens the check valve 46 to open the seal portion. The inside of the ink storage tube 12 is pressurized through 24.
[0014]
Further, in conjunction with the pushing operation of the knocking mechanism 20, the sealing portion 24 of the pressurizing mechanism 22 in the shaft main body 18 comes into close contact with the rear end 12r of the ink storage tube of the refill unit 14, and then the cylindrical portion 26 moves forward to apply. The air inside the pressure chamber 40 is compressed, and the inside of the ink storage tube 12 is pressurized by the compressed internal air via the seal portion 24 in the same manner as described above.
[0015]
Further, the elastic force of the first spring 16 is set smaller than the elastic force of the second spring 28.
Further, the resilience of the first spring 16 and the second spring 28 presses the tip of the writing portion of the ballpoint pen tip 10 protruding from the shaft main body 18 after the push-out operation of the knock mechanism 20 to retreat the refill unit. The repulsive force in this case is set to 3 to 15 N (Newton), particularly preferably 5 N.
[0016]
The pressurizing mechanism 22 releases the pressurized state in the ink storage tube 12 in a state where the refill unit 14 is immersed in the pen body 18 of the pen point of the ballpoint pen tip 10 when the knock mechanism 20 is pushed out. is there.
The refill unit 14 has an ink container 12 filled with an ink 30 and a grease-like follower 32 following the ink 30 at the rear end of the ink, and a ballpoint pen tip 10 press-fitted in front of the ink container 14. The ball 10a loosely and rotatably fitted inside the tip of the ballpoint pen tip 10 is urged forward by a spring via a push rod (not shown) to apply back pressure, and the non-written Sometimes, the tip opening 10b of the ballpoint pen tip 10 is closed.
The viscosity of the ink 30 is preferably 1,000 mPa · s or less at a shear rate of 400 / s and 300 mPa · s or more at 5 / s in an atmosphere of 25 ° C.
The rear portion of the ink 30 in the ink storage tube 12 is filled with a grease-like follower 32 for the purpose of preventing the solvent content of the ink 30 from volatilizing. When the inner diameter of the ink container 12 is large, it is desirable to fill the follower 32 with a float made of resin (such as polypropylene PP).
Further, the ink container 14 is filled with a white pigment ink containing at least a white pigment such as titanium oxide and polymer hollow fine particles and a gelling agent.
[0017]
Further, the cylindrical portion 26 of the pressurizing mechanism 22 is also used as a rotor of the Kern-type knock mechanism 20 having an uneven portion formed on the peripheral surface. More specifically, a rear end portion of the shaft main body 18 is opened, and a knockout cover 36 having a substantially shell shape having a clip 36a formed on an outer surface so as to cover the open portion is fitted outside so as to be slidable back and forth. A mushroom-shaped decoration 36b is fitted from the outside to the zenith of the knock cover 36 (the rear end direction portion of the shaft main body 18), and a cylindrical knock rod 38 base end portion 38a is fitted and fixed from the inside. On the other hand, a front end portion 38b of the knock rod 38 is fitted into the rear end opening of the shaft main body 18, and an engagement protrusion 38c is formed on the outer periphery of the front end portion 38b so as to protrude outward in the axial radial direction. The engagement with the engagement step portion 18b inside the rear end portion 18 prevents the knock cover 36 from coming off from the shaft main body 18.
[0018]
A cam portion is formed in the distal end portion 38b of the knock bar 38 in the circumferential direction. The gear-shaped mountain valley portion engages with the cam portion on the outer periphery of the cylindrical portion 26 to move the cover and the knock bar forward and backward. As a result, the cylindrical portion 26 advances, stops, and retreats as a rotating body of the knock mechanism 20. The cylindrical portion 26 has a substantially cylindrical shape with a rear end closed, and a hollow deformed cylindrical seal portion 24 slidably contacts an inner peripheral surface portion of the cylindrical portion 26, and an inner bottom portion 26 a of the cylindrical portion 26 and the seal portion 24. The second spring 28 is interposed in the pressurizing chamber 40 between the inner part of the rear part and the rear part, and urges the seal part 24 toward the front. In addition, the inner peripheral surface of the cylindrical portion 26 has a large diameter on the front side and a small diameter at a part where it enters, and corresponds to this large diameter part when the refill unit 14 is moving forward at the time of knocking. When the refill unit 14 abuts on the front shaft 18A and stops moving forward, the seal portion 24 advances relatively to the cylindrical portion 26 and slides on a small-diameter portion to seal the inside of the pressurizing chamber 40 and pressurize the internal air.
That is, the O-ring 42 is fitted into a portion of the seal portion 24 which is in sliding contact with the inner periphery of the cylindrical portion 26, and the rubber ring 44 is fitted between the O-ring 42 and the rear end of the ink storage tube 12 of the refill unit 14. The departments are kept airtight. A check valve 46 having a substantially mushroom shape is inserted into the opening at the distal end of the seal portion 24, and the check valve 46 allows the space from the pressure chamber 40 at the rear to the space at the rear of the ink storage chamber 12. The flow of pressurized air to the section (refill space section) 48 is allowed, and the reverse flow is prevented. However, at the time of knock release, the pressing of the seal portion 24 against the rear end of the ink storage tube 12 is relaxed, the airtightness of the rubber ring 44 is relaxed, and the refill space portion 48 is opened to the atmosphere through the outside of the cylindrical portion 26. It has become.
[0019]
Further, the shaft main body 18 is formed so as to be able to be divided into two parts, a front shaft and a rear shaft (a front shaft 18A and a rear shaft 18B). The ballpoint pen tip 10 at the tip of the refill unit 14 is held at the tip of the ink container 12 by a joint 50 that holds the chip 10 at the front and the rear penetrates the front of the ink container 12. I have.
[0020]
The knocking operation of the writing implement having the above-described configuration will be described with reference to FIGS.
[When not writing]
At the time of non-writing, as shown in FIGS. 1 and 5, the pressurizing chamber 40 and the refill space 48 in the tubular portion (rotor) 26 are open to the atmosphere and are in a non-pressurized state.
[0021]
[When writing]
Then, when the knock cover 36 is pushed for writing and knocked out, the state shown in FIGS. 1 and 5 is changed to the state shown in FIGS. 2 and 6. First, the first spring 16 is compressed, and the knock cover 36, the knock bar 38, the cylindrical portion 26, the seal portion 24, and the refill unit 14 advance.
At this time, the rear end of the refill unit 14 (ink storage tube 12) and the rubber ring 44 at the front end of the seal portion 24 are in close contact with each other, and the rear end of the refill unit 14 is sealed. At this time, the O-ring 42 on the outer periphery of the seal portion 24 does not contact the inner peripheral surface of the cylindrical portion 26, and the pressurizing chamber 40 communicates with the atmosphere.
[0022]
Further, when the refill unit 14 advances, the rib 50a formed on the outer surface of the joint 50 hits the inside of the distal end opening 18a of the front shaft 18A, and the advance of the refill unit 14 stops.
Then, by the knocking operation of the knock cover 36, as shown in FIG. 6, only the knock rod 38 and the cylindrical portion 26 which is a rotor having the pressurizing chamber 40 advance, and the seal portion 24 inside the cylindrical portion 26 is moved. O-ring 42 comes into contact with the inner peripheral surface of cylindrical portion 26, whereby the inside of cylindrical portion 26 is sealed.
Further, when the cylinder portion 26 moves forward with the knocking operation, the air in the cylinder portion 26 is compressed, and the compressed air enters the refill space through the check valve 46, whereby the compressed air causes the refill space portion. 48 is also pressurized. When knocked to a predetermined position, the cam is locked by the cam of the knock mechanism 20, and the retreat unit 14 is restricted from retreating.
[0023]
[At additional pressure]
When the ink is consumed, the refill space 48 increases, and when the pressurization by the above-described knocking operation alone does not provide a sufficient pressure, and as a result, a sufficient ink flow rate cannot be obtained, FIGS. By pressing the pen tip against the writing surface, the rear end 12r of the ink storage tube of the refill unit 14 further pushes the rubber ring 44 and the seal portion 24 into the cylindrical portion 26 as shown in FIG. The pushing amount is restricted by the seal portion 24 abutting on a step inside the cylindrical portion 26. At this time, the air in the pressurizing chamber 40 in the cylindrical portion 26 is compressed, and the compressed air passes through the gap between the check valve 46 and the seal portion 24 to pressurize the refill space 48 as well. In this case, it is desirable that the repulsive force of the second spring 28 be set sufficiently higher than the writing pressure so that the pen tip portion does not fluff during normal times. Therefore, the repulsive force of the spring is set to 5N when writing.
[0024]
[Additional pressure writing]
When the pen tip is separated from the writing surface after the above-described additional pressure operation, the refill unit 14 is pushed back by the elastic force of the second spring 28, and returns to the writing position as shown in FIGS. At this time, the volume in the pressurizing chamber 40 in the cylindrical portion (rotor) 26 becomes larger than that at the time of the additional pressure, and returns to the state at the time of writing. As a result, the compressed air in the refill space 48 of the refill unit 14 also tries to return to the inside of the cylindrical portion 26. However, since the pressure in the refill space 48 is higher than the pressure in the pressurizing chamber 40 in the cylindrical portion, the compressed air can freely pass through the seal portion 24. The check valve 46 installed so as to move in close contact with the rubber ring 44 of the seal portion 24 by the pressure of the refill space portion 48 is sealed, and the pressure in the refill space portion 48 can be maintained.
[0025]
[At release]
By pressing the knock cover 36 after the writing and performing the knocking operation, the non-writing state of FIGS. 1 and 5 is restored.
[0026]
In the above-described embodiment, a knock-type ballpoint pen without a cap has been described as a position embodiment of the present invention. Although the inconvenience of removing the cap when trying to write has been eliminated, it goes without saying that the writing implement of the present invention can be suitably implemented even with a cap.
Further, in the above-described embodiment, the writing implement has been described as a ballpoint pen as a writing unit in the refill as a preferred example of the present invention. However, the present invention can be implemented in a writing implement having a writing unit other than the ballpoint pen.
[0027]
【The invention's effect】
According to the present invention, the following effects can be obtained because of the configuration described above.
According to the present invention, when the flow rate of the ink is required when using the writing implement, the tip of the writing portion protruding from the shaft body is pressed against the application surface, so that the refill is further pushed into the pressurizing mechanism, and a larger pressing force is applied. Pressure can be applied to the ink storage chamber. In this way, the pressure can be applied only during use, so that ink leakage during non-use can be prevented. Further, since pressurization is performed when necessary, it is not necessary to use an expensive material having gas barrier properties. Further, even if left knocked, the pressurized air gradually leaks, so there is no fear of ink leakage. In addition, since it is possible to use a predetermined ink or the like without sedimentation of the pigment, it is not necessary to stir the ink or remove the cap.
[0028]
Further, since the pressure can be simultaneously applied in conjunction with the operation by the knock, the user can use the device without being conscious of the pressure, and the operation feeling is excellent.
In addition, if the pressure inside the refill is not sufficient due to ink consumption, additional pressure can be applied by the natural act of pressing the tip of the writing section against the paper surface (no need to change), so operability is improved. Good and comfortable to use until the end.
In addition, the refill itself does not require any components for pressurization, so that the cost of the refill can be kept low, and the running cost due to replacement of the refill can be reduced.
In addition, instead of using a multi-stage knock, the knocking mechanism is simplified and the size of the mechanism is shortened in order to separate the push-in operation of the tip and the operation method of increasing the pressure during the first extension knock. And the overall length of the shaft body can be shortened with good usability.
[0029]
Further, by releasing the knock, the pressurizing chamber of the cylindrical portion is ventilated to the atmosphere, so that even if the knocking operation is repeated, there is no continuous pressurization. Also, the pressurization by pressing the pen tip portion is limited to a certain pressure regardless of how many times the pen is pressed because the pressurizing chamber is a closed space. Therefore, the internal pressure of the refill does not increase even if the user repeats knocking even though the user does not use the ink, so that there is no problem such as an ink jetting accident or an excessive ejection of ink on the paper.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of an operation (at the time of non-writing) of a writing instrument according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram of an operation (at the time of writing) of the writing instrument of FIG. 1;
FIG. 3 is an explanatory view of the operation (at the time of additional pressure) of the writing instrument of FIG. 1;
FIG. 4 is an explanatory view of the operation (at the time of non-additional pressure) of the writing instrument of FIG. 1;
FIG. 5 is a partial detailed operation of the writing instrument of FIG. 1 (when not writing).
FIG. 6 is a partially detailed operation (at the time of writing) of the writing instrument in the state of FIG. 2;
FIG. 7 is a partially detailed operation (at the time of pressurization) of the writing instrument in the state of FIG. 3;
FIG. 8 is a partially detailed operation of the writing instrument of FIG. 4 (when not writing).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Ball-point pen tip 12 Ink storage tube 14 Refill unit 16 First spring 18 Shaft main body 18A Front shaft 18B Rear shaft 20 Knock mechanism 22 Pressurizing mechanism 24 Seal part 26 Tube part 28 Second spring 30 Ink 32 Follower 34 Spring 36 Knock Cover 38 Knock rod 40 Pressurizing chamber 42 O-ring 44 Rubber ring 46 Check valve 48 Refill space

Claims (10)

A refill unit having a writing portion at the tip and an ink storage tube at the rear is loaded into the shaft body in a state where the refill unit is repelled rearward by the first spring, and the writing portion of the refill unit is connected to the shaft. In a writing instrument that can be protruded and retracted in conjunction with the pushing operation and the pushing release operation of the knock mechanism provided on the rear end side of the main body,
A rear portion of the ink storage tube of the refill unit is opened, and a pressure mechanism for increasing the pressure in the ink storage tube is provided between the rear portion of the ink storage tube and the knock mechanism in the shaft body,
The pressurizing mechanism has a seal portion, a cylindrical portion having a front end open, and a second spring that resiliently moves in a direction to separate the seal portion and the cylindrical portion.
After the push-out operation of the knock mechanism is completed, when the refill unit is retracted by pressing the tip of the writing portion protruding from the shaft main body, the pressure mechanism causes the tubular portion to move forward relative to the seal portion, and the ink to move. A writing implement characterized by pressurizing the inside of a storage tube. In conjunction with the pushing operation of the knock mechanism, the seal portion of the pressurizing mechanism in the shaft body comes into close contact with the rear end of the ink storage tube of the refill, and then the cylinder portion advances to pressurize the inside of the ink storage tube via the seal portion. A writing implement characterized by the following. The writing instrument according to claim 1, wherein an elastic force of the first spring is set smaller than an elastic force of the second spring. The resilient force of the first spring and the second spring is 3 to 15 N (when the repelling unit is retracted by pressing the tip of the writing portion protruding from the shaft body after the pushing operation of the knock mechanism is completed). The writing implement according to any one of claims 1 to 3, wherein the writing implement is set to (Newton). The pressurizing mechanism releases the pressurized state by communicating with the inside of the ink storage tube to the atmosphere in a state of being immersed in the shaft main body of the writing portion of the refill unit when the knocking mechanism is pushed out. The writing implement according to any one of claims 1 to 4. The refill unit has an ink container filled with ink and a follower that follows the ink at the rear end of the ink, and a ball-point pen tip press-fitted in front of the ink container, and is rotatable inside the tip of the ball-point pen tip. The writing implement according to any one of claims 1 to 5, wherein the ball loosely fitted in the (1) is provided with a back pressure by a spring and closes an opening of a tip of a ballpoint pen tip when not writing. . The viscosity of the ink is 1000 mPa · s or less at a shear rate of 400 / s and 300 mPa · s or more at 5 / s in an atmosphere of 25 ° C. 7. A writing implement according to any one of the preceding claims. 8. The ink container according to claim 1, wherein the ink container is filled with a white pigment ink containing at least a white pigment such as titanium oxide and hollow polymer particles and a gelling agent. Writing implement. The writing instrument according to any one of claims 1 to 8, wherein the cylinder of the pressurizing mechanism is also used as a rotor of a Kern-type knock mechanism. The writing instrument according to any one of claims 1 to 9, wherein the shaft main body is formed so as to be able to be divided into two parts.

Images