JP2006297800A - Pressurizing-type writing utensil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressurizing-type writing utensil which can prevent an ink from dripping from a pen point due to an excess inner pressure applied to the ink, under an almost equilibrium state of an inner and an outer pressure of a blocked part which ensues the leakage of a pressurized air from a blocked surface at a specified lapse of time. <P>SOLUTION: This pressurizing-type writing utensil comprises a valvular mechanism part located behind a follower and a knocking mechanism part with a piston function behind the valvular mechanism part. The knocking mechanism part is installed as a knocking bar remains always urged backward to a barrel through a spring. The valvular mechanism part has a wall part partitioned across a space part, ahead of the forward end of the knocking bar, and further, a hole opened penetrating through the wall part, a receiving seat formed at the forward end of the hole and a spring-urged valve body installed so as to allow the valve body to come into contact with the receiving seat and block the hole. In addition, the space part is compressed by advancing the knocking bar, resulting in the pressurizing of the rear end of the follower, and the contact surface between the valve body and the receiving seat, is set in an appropriate contact state. After pressurizing, the pressurized air leaks after the specified lapse of time to almost equilibrate the inner/outer pressures of the blocked part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a writing instrument using ink that is easy to run out of ink in the initial writing, a writing instrument in which various fillers are mixed in the ink, a writing instrument filled with ink that can be easily erased by rubbing the handwriting written on the paper with an eraser, The present invention relates to a pressure-type writing instrument that can correct mistakes by concealing it with white ink.

JP-A-8-52407 7-506862 JP 2001-150865 A Reality 6-32220 JP 2004-291576 A

(Patent Document 1)
Conventionally, a liquid applicator using a white pigment for correcting an error or the like is known. In addition, since the white pigment and the solvent can be easily separated, this type of liquid applicator has a flexible container filled with ink, balls, and the like, and needs to be shaken and stirred in use. Further, the ink is ejected by pressing the side surface of the container. However, when the remaining amount of ink decreases, there is annoyance that the ink is not ejected even if the side wall of the container is strongly pressed.
(Patent Document 2)
In addition, there is a known ink that does not need to be agitated by using ink having shear thinning viscosity, but there is a problem that the ink tends to run out when it is applied upward.
(Patent Document 3)
In addition, a pumping-type pressurizing mechanism is provided at the rear end of the shaft cylinder, and is positioned at the rear end of the follower that is disposed in front of the shaft cylinder so as to contact the rear end of the ink and follow the ink as it is consumed. The valve mechanism is disposed, and air is pushed into the rear end hole of the shaft cylinder by the forward operation of the pressurizing mechanism portion. At that time, the valve opens at a predetermined pressure and the rear end of the follower is pressurized. There has been proposed one configured to support fluidity of the ink toward the tip side.
(Patent Document 4)
It is composed of a pen core made of a porous material, a fiber assembly or a coating liquid storage material made of a continuous porous material, and ink is derived by capillary force. This has a problem that ink drops from the pen tip when the viscosity of the ink is too low. On the other hand, when the viscosity of the ink is higher than a predetermined value or the colored fine particles are larger than a predetermined value, there is a problem that the pen tip is clogged and writing becomes impossible.
(Patent Document 5)
It has a pen core such as a sign pen or marker at the tip, a follower that follows the ink and a trailing end of the ink is disposed in the rear ink container, and a pumping type pressurizing mechanism is further provided behind it. This is a pressure-type writing instrument. In this pressurizing mechanism, the outer peripheral portion is in close contact with the inner peripheral portion of the rear barrel, and a knock mechanism portion that is locked to the rear barrel so as to be able to move backward is communicated with the pressurized air in front of the knock mechanism portion. A valve mechanism is provided so that when the knock mechanism is advanced, the space is compressed and the rear end of the follower is pressurized.

  In general, a ballpoint pen using a low-viscosity ink or an ink having shear thinning viscosity has a large amount of ink flowing out, and the diameter of the ink containing tube is increased to increase the amount of ink loaded. Further, since the viscosity of the ink is smaller than that of the oil-based ballpoint pen, the flow resistance with respect to the ink containing tube is small. Therefore, ink leakage (ink flows backward at the rear end of the ink containing tube) is likely to occur due to the weight of the ink, dropping or knocking impact. For this reason, it usually moves following the ink consumption at the time of writing at the trailing edge of the ink. However, a grease-like follower that suppresses the back flow of the ink against the ink's own weight and impact is also available. A rod is provided immersed in the follower. However, even if the follower is provided, when writing upwards, if the ink on the back of the ball of the chip runs out, the ink head is added directly, so that a significant back flow occurs and there is a risk of soiling hands and clothes. In addition, since the viscosity of the ink is low and the amount of outflow is large, there is a problem that the ink oozes out (direct current) when a gap is formed between the tip ball and the tip holding portion when the tip side is faced downward. In particular, in the case of liquid applicators that use white pigments to correct errors, etc., the size that the tip ball retracts due to pen pressure due to reasons such as increasing the ink flow rate and eliminating clogging due to drying. The clearance between the peripheral surface of the tip ball and the inner surface of the ball holding portion of the chip is large.

  In a writing instrument such as a marker pen, a marker, etc., which has a pen core composed of a porous body having continuous pores at the tip, a so-called plastic core formed by a complicated capillary tube in the axial direction, a fiber assembly, etc. Ink that can be easily erased by scrubbing the eraser with the eraser, so-called correction ink that conceals misprints in white, metallic color ink, ink with glitter, pearl ink, ink that dries the writing line very quickly Ink contains pigment particles, polymer particles, metal powder, metal foil, mica, etc., and the viscosity of the ink exceeds a predetermined value, such as ink with high viscosity at high solids concentration and shear thinning viscosity. If it is high or the colored fine particles are larger than a predetermined size, there is a problem that the pen tip is clogged and writing becomes impossible.

The present invention is a ballpoint pen that uses ink that is easy to break ink in the initial writing, a ballpoint pen in which various fillers are mixed in the ink, a ballpoint pen that is filled with ink that can be easily erased by rubbing the handwriting written on the paper with an eraser, A ballpoint pen that can be corrected by concealing misprints etc. with white ink is supported by a pressurizing action and can be written.
In addition, in a writing instrument such as a sign pen or a marker having a pen tip made of a porous core having continuous pores at the tip, a so-called plastic core formed by a complicated capillary tube in the axial direction, a fiber assembly, etc. The ink written on the paper can be easily erased by rubbing with an eraser, so-called correction ink that conceals misprints etc. in white, metallic color ink, ink with lame, pearl ink, extremely dry writing lines Like fast ink, pigment ink, polymer particles, metal powder, metal foil, mica, etc. are included in the ink, and ink such as ink with high solid content concentration, high viscosity and shear thinning can be used. In this case, even if the viscosity of the ink is higher than a predetermined value or the colored fine particles are larger than a predetermined value, the problem that the pen tip is clogged and writing becomes impossible is solved.
Further, when the writing instrument is left in a strong pressure state when not used, for example, there is a possibility that ink may fall off from the pen tip when left for a long time under the influence of a rapid temperature rise or the like. At the same time, the task is to solve the problem.

The present invention has the following configuration in order to achieve the above-described problems.
In the pressure type writing instrument according to the first aspect of the present invention, the shaft cylinder is provided with a follower which is disposed at the rear end of the ink and prevents ink from evaporating and follows the ink consumption. In the pressurization type writing instrument in which the mechanism portion is further provided with a knock mechanism portion having a piston function for pressurization behind the valve mechanism portion, the knock mechanism portion is configured so that the knock bar is interposed via a spring. The valve mechanism is provided in a state where it is always urged rearward with respect to the shaft cylinder, and the valve mechanism part has a wall part partitioned by a space part in front of the front end of the knock bar, and a hole penetrates the front and rear ends of the wall part. A tapered or spherical receiving seat is formed at the front end of the hole, and a valve body biased by a spring so as to close the hole in contact with the receiving seat is provided. If the space is compressed when the rod is advanced, When the pressure is higher than the predetermined pressure, the closed state of the hole by the valve body is released, the pressurized air passes through the hole and the rear end of the follower is pressurized, and the contact surface between the valve body and the receiving seat is in an appropriate contact state. The pressurized air leaks from the closed surface in a predetermined elapsed time after pressurization, and the inside and outside of the closed portion are substantially in equilibrium.

  A pressure-type writing instrument according to a second aspect of the present invention is the pressure-type writing instrument according to the first aspect, wherein a circumferential recess is formed in the outer shaft portion in front of the knock bar, and A ventilation groove communicating from the bottom surface to the front end surface is formed, and the seal ring is closely inserted into the recess so as to slide back and forth, and when the knock bar is advanced, the seal ring approaches the rear end side in the recess and seals. When the front and rear parts of the ring cannot be vented, the outer periphery of the seal ring slides in close contact with the inner periphery of the ink containing tube by further advancement, the rear end of the follower is pressurized, and the knock bar is retracted The seal ring approaches the front end side of the recess, and the front and rear portions of the seal ring are in communication with each other through the ventilation groove, and the pusher can be retracted with the rear end of the follower in communication with the outside air.

In the pressure-type writing instrument of the present invention, a ballpoint pen using ink that is likely to run out of ink in the initial writing can be written with the aid of the pressing action. Also, a white pigment ink containing at least a white pigment such as titanium oxide, polymer hollow fine particles, etc. and a gelling agent, blended so that the precipitation of the pigment is prevented and fluidity is not impaired, and a pressurizing mechanism by pumping There is no problem that the white pigment and the solvent are separated from each other as in the prior art, so there is no need to stir the ink, and there is no trouble of pressing the side of the container during writing. It can be provided. Further, when the convex portion provided at the front end of the knock bar is brought into contact with the rear end of the valve body, an appropriate pressure can be set according to the characteristics of the ink.
Further, even if the strength of the spring that presses the convex portion varies in a direction stronger than the predetermined strength, the set pressure can be maintained. In addition, only the front shaft cylinder is consumed by detachably connecting the ballpoint pen tip, the front cylinder filled with ink, and the rear cylinder, which is provided with a pressurizing mechanism so as to send compressed air by pumping. The product can be manufactured at a low cost.

The pressure-type writing instrument of the present invention has a pen nib composed of a porous body having continuous pores at the tip, a so-called plastic core having a complex capillary formed in the axial direction, a fiber assembly, and the like. In writing instruments such as sign pens and markers,
Ink with low viscosity prevents ink from dropping, ink that can be easily erased by scrubbing with eraser, so-called correction ink that conceals misprints in white, metallic color ink, ink with glitter, pearl tone Ink, pigment particles, polymer particles, metal powder, metal foil, mica, etc. are contained in the ink, such as ink that dries very fast in writing lines, and has high viscosity at high solids concentration and shear thinning. Ink such as ink can be used, and even when the viscosity of the ink is higher than a predetermined value or the colored fine particles are larger than a predetermined value, the problem that the pen tip is clogged and cannot be written can be avoided.

  In addition, there is a possibility that ink may fall off from the pen tip when it is left under strong pressure when the writing instrument is not used and left for a long time under the influence of a rapid temperature rise or the like. For example, pressurized air leaks from the clogging surface within a specified elapsed time, and the pressure inside and outside the clogged part is almost in equilibrium, eliminating the problem of ink dropping from the pen tip without applying excessive internal pressure to the ink. It becomes possible.

1 to 3 show a pressure-type writing instrument according to a first embodiment of the present invention, which is shown as a pressure-type ballpoint pen 1.
First, the ballpoint pen 1 includes a front shaft cylinder 2, a tip 7, a valve body 6, a receiving member 4, an ink 10, a follower 11, a follower bar 12, a rear shaft cylinder 13, and a pumping-type additive provided at the rear end of the rear cylinder. As a final form of the writing instrument, a cap (not shown) that is fitted to the front shaft portion 3 is provided.

  The front shaft cylinder 2 is a resin molded product (usually a transparent resin), and has a tapered front shaft portion 3 integrally formed at the tip, and a joint portion (female screw portion) behind the ink containing portion filled with ink and follower. 2b) is provided. Further, an inner hole 3a is formed from the tip, and there is an expanded hole (becomes the valve chamber 5) at the rear end of the inner hole, and ribs 3c are provided radially at a plurality of locations at the front end of the hole. . In addition, PP resin, a nylon resin molded product, etc. are used for the front shaft cylinder 2 as an example.

On the other hand, the receiving seat member 4 has a tapered or spherical valve body receiving seat 4a on the front surface, and is provided with a guide hole 4d penetrating from the center of the valve body receiving seat 4a to the rear end.
Further, a convex portion 4b is formed in a circumferential shape in front of the outer peripheral portion, and a circumferential or protruding locking portion 4c is formed in the rear.
The receiving member 4 is inserted from the rear end of the front barrel 2 and is positioned in contact with the step portion 2a at the front end of the inner bore of the front barrel, and the convex portion 4b is in close contact with the front bore surface thereof. Further, the locking portion 4c is bitten and locked to the rear inner hole surface.
In addition, it is also possible to provide a groove part and a protrusion between the inner hole surface of the front shaft cylinder 2 and the outer peripheral part of the receiving member 4 and to lock them using elastic deformation.

  As described above, the valve chamber 5 is formed between the front receiving seat 3d serving as the rear end of the rib 3c and the valve body receiving seat 4a serving as the front end of the receiving seat member 4. A spherical valve body 6 is inserted before the receiving seat member 4 is locked, and the valve body 6 is loosely fitted in the valve chamber 5. The valve body 6 is not limited to a spherical shape but may be a rod-shaped piece. In that case, it is not necessary to provide the rib 3c at the front end of the valve chamber by forming a groove through which ink can flow in the front outer periphery of the valve body.

The tip 7 is crimped so that the tip ball 8 is rotatably held in a state where the tip ball 8 is substantially in contact with a seat having a channel through which ink can flow.
Further, a spring 9 is inserted into the tip inner hole 7a, the rear end of the shaft portion 7b behind the tip is properly crimped, and the rear end of the spring 9 is provided so as not to be extracted. Further, an upright rod shaft portion 9 a is formed at the tip of the spring 9, and the tip of the rod shaft portion 9 a abuts against the back surface of the tip ball 8 in a pressing manner. The tip ball 8 is brought into close contact with the inner edge of the ball holding portion of the chip 7 by the pressing.

  It is extremely important for the tip ball 8 to be in close contact with the inner surface of the ball holding portion for drying the writing tip and preventing direct current of the ink even if the ink has a high viscosity. That is, in particular, the ball-point pen for correcting typographical correction is set to have a larger dimension for the tip ball to retract than the ball-point pen for writing in order to increase the amount of ink discharged. In addition, the surface roughness of the inner surface of the chip holding the tip ball 8 as necessary, the inner surface is ground to improve the crimping accuracy, and the secondary plastic processing is performed to increase the crimping accuracy. The In addition, surface treatment or the like is considered on the contact surface with the tip ball if necessary.

The tip 7 is pressure-bonded to the inner hole 3 a at the tip of the front shaft portion 3.
The tip 7 is crimped so that the tip ball 8 is rotatably held in a state where the tip ball 8 is substantially in contact with a seat having a channel through which ink can flow.
Further, a spring 9 is inserted into the inner hole portion of the tip 7, and the rear end of the tip shaft portion 7b is appropriately crimped (caulking portion 7c) so that the rear end of the spring 9 cannot be pulled out. It is possible to provide a pressing member for pressing the back surface of the tip ball 8 on the front surface of the spring, and it is also possible to form the rod shaft portion in a coil shape with a very thin winding. Furthermore, the tip can be made of a resin molded product with excellent wear resistance and ink sealing performance, and the spring seat that presses the back of the tip ball can be configured as an integral or separate spring seat. is there.
As described above, when the tip side is facing downward, the valve body 6 abuts against the front receiving seat 3d, and the tip ball from the tip inner hole 7a passes through the groove formed between the guide hole 4d, the valve chamber 5, and the rib. Conducts to the back of 8.

The front cylinder 2 has an ink containing portion behind the guide hole 4d. In the ink containing portion, a low-viscosity ink or an ink having a shear thinning viscosity, for example, a white pigment ink 10 is used for correction correction application. Filled, and the trailing end of the ink is filled with a grease-like follower 11 that follows the ink as the ink is consumed. Further, the follower 11 is incompatible with ink and has a performance of preventing ink evaporation. Moreover, the resin-made follower stick | rod 12 which has specific gravity substantially equivalent to a follower is immersed in a follower as needed. The follower may be a follower such as silicon rubber.
The white pigment ink 10 contains at least a white pigment such as titanium oxide or polymer hollow fine particles and a gelling agent, and is formulated so that the precipitation of the pigment is prevented and the fluidity is not impaired as much as possible. It is. In addition, since the ink has shear thinning viscosity, it can be applied with high concealability in combination with a decrease in viscosity due to rotation of the tip ball.

The rear barrel 13 has a knock bar 17 at the rear end, and is provided with a joint portion (male screw portion 13g) in front of a cylinder portion where a pressurizing mechanism is disposed so as to send compressed air by pumping. A seal portion 13h formed as a circumferential convex portion is formed on the front outer peripheral portion. When the rear barrel 13 is coupled to the front barrel 2 by screwing or the like, the seal portion 13h can be in sliding contact with the inner surface of the front barrel to increase the airtight effect.
The pumping type pressurizing mechanism includes a valve mechanism portion and a knock mechanism portion provided so as to compress a space portion formed behind the valve mechanism portion.

The valve mechanism is configured as follows.
First, the bush 14 is provided with a hole serving as a valve chamber from the front end in the axial center portion, and a tapered or spherical receiving seat 14b is formed at the rear end of the hole, and a vent hole 14c having a slightly small diameter is formed. Is provided penetrating to the rear end, and a spring is provided between the valve body and the inner step portion 13f provided in front of the inner hole of the rear barrel 13 so that the spherical valve body 15 is in close contact with the receiving seat 14b. 16 is laid, and the bush 14 is tightly fitted into the inner hole of the rear shaft cylinder 13 with the front end in contact with an inner step portion 13e separately provided in front of the inner hole of the shaft cylinder 13, so that the valve mechanism portion is Composed.
As described above, normally, the valve body 15 is in close contact with the receiving seat 14b, the vent hole 14c is closed, and the inner hole of the rear barrel is divided in an airtight manner.

By the way, the contact surface between the valve body 15 and the receiving seat 14b is provided in an appropriate contact state. After pressurization, the pressurized air leaks from the obstruction surface after a predetermined time, and the pressure inside and outside the obstruction portion is almost equal. It is designed to be in an equilibrium state.
As one means, the valve body 15 is formed of a suitable porous sintered body or elastic body. In addition, uneven portions and grooves are formed on the surface of the valve body 15, and fine uneven portions such as satin or mesh are formed. In this case, it can also be achieved by forming an uneven portion on the receiving seat 14b.
In other words, the valve mechanism section exerts the necessary pressure when the writing instrument is used, but when the writing instrument is not in use, the pressurized air leaks from the blocking surface after a predetermined elapsed time, and the inside and outside of the blocking section Therefore, the problem of ink dropping off from the pen tip can be solved without applying excessive internal pressure to the ink.

A knock mechanism is disposed behind the valve mechanism.
The knock mechanism is configured as follows.
A tapered slit portion 13c that is tapered from the rear end side toward the front side is formed on the side surface of the rear end portion of the rear barrel 13 and has a step portion 13d at the front end of the slit portion having a predetermined length in the axial direction. 13b is formed.
Further, the knock bar 17 has a flange portion at the rear end and a shaft portion formed in front thereof, a step portion 17b is provided at the front end of the flange portion, and a projection 17a and a substantially front end of the shaft portion outer periphery substantially in the middle of the outer periphery of the shaft portion. A circumferential recess 17c is formed, and a ventilation groove 17g communicating from the front side of the bottom surface of the recess 17c to the front end surface is formed. A seal ring 18 made of an elastic material such as rubber is tightly sealed in the recess 17c. Further, the seal ring 18 is slidable in the front-rear direction in the recess while being in close contact with the bottom surface of the recess 17c.
As will be described later, when the knock rod 17 is moved forward, the seal ring 18 approaches the rear end side in the recess 17c so that the front and rear portions of the seal ring 18 cannot be vented. When the inner periphery 13a of the cylinder is slid closely, the valve mechanism is opened, the rear end of the follower 11 is pressurized, and when the knock bar 17 is retracted, the seal ring 18 is moved to the front end side of the recess 17c. The front and rear portions of the seal ring 18 are in communication with each other through the ventilation groove 17g (the valve mechanism is closed at that time), and the knock rod 17 is configured to retreat in communication with the outside air.
The seal ring 18 is selected to have good airtightness and slipperiness. In addition, other lubricants are taken into consideration.

Further, an inner hole 17e having an appropriate depth is formed from the front end to the rear end at the front end of the knock bar 17, an inner shaft portion 17d is formed at the axial center of the inner hole 17e, and further forward of the shaft portion 17d. A convex portion 17f that protrudes further from the front end surface of the knock bar is formed. The knock bar 17 is inserted from the rear end of the rear barrel 13, a knock spring 19 is laid between the rear end of the inner hole 17e and the rear end of the bush 14, and the protrusion 17a is tapered. The projecting portion 17a is locked to the front surface of the stepped portion 13d, and the knock bar 17 is always urged backward with respect to the rear barrel 13 by the knock spring 19.
Further, the shaft part front of the knock bar is fitted into the rear end hole of the rear barrel 13, and the outer peripheral part of the seal ring 18 is in sliding contact with the inner peripheral part of the rear end hole. At that time, since the seal ring 18 is close to the front end side of the recess 17c and the front and rear portions of the seal ring 18 communicate with each other through the ventilation groove 17g, the space portion 20 formed at the front end of the knock bar 17 communicates with the outside air. is doing.

  That is, immediately before the knock bar 17 is moved forward, the space 20 of the rear barrel 13 is communicated with the outside air, the knock bar 17 is appropriately advanced, and the seal ring 18 is moved toward the rear end side in the recess 17c. The front and rear portions of 18 are blocked from outside air in a state in which ventilation is impossible, and are configured to be pressurized as the space portion 20 is reduced. Further, in a state where the knock bar 17 is advanced and the space portion 20 is appropriately compressed, a convex portion 17f provided at the front end of the knock bar 17 is provided with a valve so that the close contact with the receiving seat 14b of the valve body 15 is released. It contacts the rear end of the body 15.

As described above, the rear end space of the follower 11 is blocked from the outside air by screwing the male screw portion 13g of the rear shaft portion 13 into the female screw portion 2b of the front shaft cylinder 2.
In addition, the joint part which couple | bonds a front axis cylinder and a rear axis cylinder is not restricted to a screw part, but can be achieved also by the elastic engagement of an uneven part.

  4 and 5 show a second embodiment of the present invention, which is shown as a pressure-type ballpoint pen 21. FIG. The second embodiment is a simplified structure of the first embodiment and is basically the same. That is, there is no ink backflow prevention valve mechanism facing the rear end of the tip 7 in the inner hole portion in front of the front barrel 22, and the follower 24 provided at the rear end of the ink 10 has a follower rod. Not soaked. This indicates that the embodiment 1 is perfect for preventing ink backflow while the embodiment 2 is substantially free of problems.

FIG. 6 is a pressure-type ballpoint pen shown as Embodiment 3 of the present invention, and shows only another form of the rear barrel portion.
In this embodiment, a rear shaft portion 26a is provided at the rear of the central flange portion 26c, and a joint 26 in which a female screw portion 26b and a seal portion 26f are integrally formed at the front portion of the flange portion. The rear shaft portion 26a is fitted into the inner hole of the rear shaft cylinder. Further, a receiving seat 26d is formed at the substantially rear end of the inner hole portion formed in the axial center of the joint 26, and a vent hole 26e is provided through the rear end. The valve body 27 is spring-loaded so as to be in close contact with the receiving seat 26d. 28, is pressed against the front end of the spring 28, and the press-fit cylinder 29 is fixed to the inner hole on the front end side of the joint 26, so that a valve chamber is formed between the rear end portion 30 of the press-fit cylinder 29 and the receiving seat 26d. In addition, a through-hole communicating with the valve chamber is provided in the axial center of the press-fitting cylinder 29 to constitute a valve mechanism portion. The knock mechanism is configured in the same manner as in the first embodiment. In addition, the basic configuration of the pumping type pressurizing mechanism constituted by the valve mechanism portion and the knock mechanism portion has been described above, but various forms can be adopted for the valve mechanism portion and the knock mechanism portion depending on the design convenience.

Although the embodiment of the present invention has been described above, the front cylinder shown in the first and second embodiments in which the tip is filled with the tip and the ink is filled in the rear is the pumping type pressurizing mechanism shown in the third embodiment. It can comprise in combination with the rear axis | shaft cylinder which comprised this.
Also, in order to prevent the evaporation and drying of ink and follower at the rear end of the front cylinder filled with ink, a seal portion (for example, a film subjected to vapor deposition of aluminum or the like is welded to the rear end surface of the front cylinder or When the rear barrel with the pressurizing mechanism is joined, the seal portion is removed or if it is in the form of a film, it is broken and joined at the front end of the joint portion of the rear barrel Only the front shaft cylinder can be used as a consumable item.

(Function)
Next, the operation of the pumping type pressurizing mechanism will be described below.
When the rear end of the knock bar 17 is pressed from the state shown in FIG. 2 to move forward, the outer periphery of the seal ring 18 comes into close contact with the entire inner periphery of the rear barrel 13 as shown in FIG. Is close to the rear end side in the recess 17c, and the front and rear portions of the seal ring 18 are blocked from outside air, and the knock rod 17 further advances, so that the outer peripheral portion of the seal ring 18 moves to the rear shaft. The cylinder 13 slides in close contact with the inner peripheral portion 13a, and the internal pressure increases as the space portion 20 is reduced.
Further, in a state where the knock bar 17 is advanced and the space portion 20 is appropriately compressed, a convex portion 17f provided at the front end of the knock bar 17 is provided with a valve so that the close contact with the receiving seat 14b of the valve body 15 is released. By abutting against the rear end of the body 15 and the pressurized air being pushed forward of the valve body, the rear end of the follower 11 is pressurized and the fluidity of the ink toward the tip side is supported.

That is, it prevents the ink from separating from the peripheral surface of the tip ball due to a drop impact or poor ink fluidity and prevents the continuous outflow of ink and recovers when interrupted. Become.
Also, an appropriate pressure is set depending on the characteristics of the ink. In this case, the volume of the space portion 20 when the outer peripheral portion of the seal ring 18 is in close contact with the entire inner peripheral portion of the rear barrel 13 and the convex portion 17 f provided at the front end of the knock rod 17 are the rear end of the valve body 15. It is possible to set how much the volume of the space portion is when it comes into contact with the valve, taking into account the leak value of the seal portion. In addition, by contacting the rear end of the valve body 15 with the convex portion 17f, a predetermined pressure can be set even if the strength of the spring 16 that presses the valve body against the seat 14b varies more than the predetermined strength. It becomes.
Note that if the strength of the spring 16 is set with high accuracy, the convex portion 17f may not be used.
Further, when retreating, the valve body 15 is closed when the seal ring 18 is close to the front end side of the recess 17c and the front and rear portions of the seal ring 18 communicate with the outside air through the ventilation groove 17g, and the knock rod 17 is smoothly retreated. To do.

Next, functions of the ballpoint pen 1 will be described.
First, in a state where writing is not performed, the tip ball 8 is brought into close contact with the inner edge of the chip holding portion by the pressing of the spring 9, so that direct current and backflow of the ink 10 are prevented. Further, since the tip ball 8 is slightly retracted by the writing pressure, a gap is formed and the ink can flow out, and the ink is written by the rotation of the tip ball 8 by writing.
Even if the spring 9 is not pressed, if the ink viscosity is not too low, the ink filling amount is not too large, or the ink containing portion is not too large, the rear end of the follower is pressurized. Ink direct current and backflow can be prevented.
However, in consideration of writing with the tip 7 facing upward or repeated knock impacts, it is desirable to press with the spring 9 to prevent direct current and backflow of ink.

  The follower bar is used when the ink containing portion has a large diameter. That is, the grease-like follower has a problem that when the ink containing portion has a large diameter, the grease-like follower is easily deformed and damaged due to an impact or the like. It is possible to increase the rigidity by immersing a resin-made follower rod having a specific gravity substantially equal to that of the follower in the follower.

  In addition, the direct current and the backflow of the ink are effected by pressing the tip ball with a spring. Provided so that the valve body faces upward and the valve body closes the guide hole, the incomplete contact state with the tip ball due to processing variations of the ball holding portion, and the clearance between the ball holding portion and the tip ball Even if a solid incomplete state occurs when solid matter adheres to the ink, backflow of the ink can be reliably prevented.

  The ink backflow prevention structure with the follower bar and valve body described above demonstrates the performance when the ink container has a large diameter and is easy to backflow, when repeated upward writing, or when an impact is applied. It is not essential as a component, and in particular, a ballpoint pen for correcting errors is rarely used because it is rarely used upward.

(Other embodiments)
The pressure-type writing instrument can be provided as a pressure-type sign pen or marker by providing a pen core such as a sign pen or marker at the tip of the shaft tube. Basically, it is the same as the case of the ballpoint pen described above.
As an example of the nib structure, a pen nib is fitted to the front end of the nib structure so that the pen nib can be moved back and forth within an appropriate range, and an ink communicating valve element is provided behind the nib. It can be arranged. This communication valve body is made of an elastic material such as silicone rubber, and is a cylindrical body having a wall portion at the rear end, and an ink communication valve portion having an appropriate slit portion is provided at the center of the wall portion. Yes. The rear end of the pen core is in contact with the ink communication valve section, and when the pen core is retracted by pressing during writing, the slit section of the ink communication valve section opens and the ink core section side to the pen core side Ink is provided so that ink can be communicated. Further, as the valve body structure in which the valve portion is opened to allow ink to communicate when the pen core is retracted, various mechanisms shown in the related art can be used.

  In addition, the pen core consists of a porous body having continuous pores, a so-called plastic core formed by a complicated capillary tube in the axial direction, a fiber assembly, etc. Ink that can be easily erased by scrubbing with an eraser, so-called correction ink that conceals misprints in white, metallic color ink, ink with glitter, pearl ink, pigment particles, polymer particles, metal powder, Ink containing metal foil, mica, etc., high viscosity at high solids concentration, ink with shear thinning can be used, ink viscosity is higher than predetermined, or colored fine particles are predetermined Even when it is larger than the above, the problem that the pen tip is clogged and cannot be written can be normally written using the pressurizing action.

It is a longitudinal cross-sectional view which shows the principal part of the front cylinder of the pressurization type writing instrument which is Embodiment 1 of this invention. It is a longitudinal cross-sectional view which shows the rear part and rear-axis part of the front cylinder of the pressurization type writing instrument which is Embodiment 1. FIG. FIG. 3 is an enlarged cross-sectional view showing an operating state of a pressurizing mechanism of the pressurizing writing instrument according to the first embodiment. It is a longitudinal cross-sectional view which shows the principal part of the front cylinder of the pressurization type writing instrument which is Embodiment 2 of this invention. It is a longitudinal cross-sectional view which shows the rear part and rear axis | shaft part of the front cylinder of the pressurization type writing instrument which is Embodiment 2. FIG. It is a longitudinal cross-sectional view which shows the rear part and rear axis | shaft part of the front cylinder of the pressurization type writing instrument which is Embodiment 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ball-point pen 2 Front shaft cylinder 2a Step part 2b Female screw part 3 Front shaft part 3a Inner hole 3b Hole part 3c Rib 3d Front receiving seat 4 Receiving member 4a Valve body receiving seat 4b Protruding part 4c Locking part 4d Guide hole 5 Valve chamber 6 Valve body 7 Tip 7a Tip inner hole 7b Shaft portion 7c Caulking portion 8 Tip ball 9 Spring 9a Rod shaft portion 10 Ink 11 Follower 12 Follower rod 13 Rear shaft cylinder 13a Inner peripheral portion 13b Slit portion 13c Tapered slit portion 13d Step Part 13e Inner step part 13f Inner step part 13g Male screw part 13h Seal part 14 Bush 14a Rear end part 14b Seat 14c Vent 15 Valve body 16 Spring 17 Knock rod 17a Projection part 17b Step part 17c Recess part 17d Inner shaft part 17e Inner shaft part 17e Hole 17f Protrusion 17g Ventilation groove 18 Seal ring 19 Knock spring 20 Space 21 Bo Pen 22 before the barrel 23 front barrel section 24 follower 25 after the shaft tube 26 joint 26a after the axial portion 26b female screw portion 26c flange portion 26d receiving seat 26e vent 26f seal 27 the valve element 28 the spring 29 press-fit tube 30 the rear end

Claims (2)

The shaft cylinder is provided with ink and a follower that prevents ink from evaporating and follows the ink as it is consumed. The valve mechanism is located behind the follower, and the valve mechanism is pressurized behind the valve mechanism. In a pressure-type writing instrument provided with a knock mechanism having a piston function of
The knock mechanism portion is provided in a state in which the knock rod is always urged rearward with respect to the shaft cylinder via a spring, and the valve mechanism portion is partitioned with a space portion in front of the front end of the knock rod. A hole is provided through the wall and the front and rear ends of the wall, and a tapered or spherical receiving seat is formed at the front end of the hole. A spring is used to close the hole by contacting the receiving seat. An energized valve body is provided, and when the knock bar is advanced, the space is compressed and the closed state of the hole by the valve body is released above a predetermined pressure, and the pressurized air passes through the hole. Then, the rear end of the follower is pressurized, and the contact surface of the valve body and the receiving seat is provided in an appropriate contact state, and after the pressurization, the pressurized air leaks from the closed surface after a predetermined time. Thus, the pressure-type writing instrument is characterized in that the inside and outside of the closed portion are substantially in equilibrium. A circumferential recess is formed in the outer shaft portion in front of the knock bar, and further, a ventilation groove communicating from the bottom surface of the recess to the front end surface is formed, and the seal ring is inserted into the recess so as to slide back and forth. When the knock bar is moved forward, the seal ring approaches the rear end of the recess and the front and rear portions of the seal ring cannot be vented. With further advancement, the outer periphery of the seal ring closely contacts the inner periphery of the ink containing tube. The rear end of the follower is pressurized, and when the knock bar is retracted, the seal ring approaches the front end side of the recess, and the front and rear portions of the seal ring communicate with each other through the ventilation groove. The pressurization type writing instrument according to claim 1, wherein the push body can be retracted in a state where the pressure body communicates with outside air.

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