JP2019107900A - Knock-type ballpoint pen - Google Patents

Abstract

To provide a ballpoint pen capable of obtaining a sufficient writing distance even with a large particle size ink.SOLUTION: A knock-type ballpoint pen 1 comprises a cylindrical barrel 20 internally containing a refill 3 consisting of an ink containing tube 30 containing ink and a ballpoint pen tip 32 inserted into the tip of the ink containing tube 30 through a joint 31, a shaft body 2 consisting of a substantially conical tip member 21 screwed to the tip end portion of the barrel 20, and a knock mechanism 4 for drawing out the tip end portion of the refill 3 from the tip end portion of the shaft main body 2 or pulling it into the inside. By sufficiently securing the ink flow path inside the ballpoint pen tip 32, the writing distance is 200 m or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a knock type ballpoint pen which can obtain a sufficient writing distance even when using an ink having a large particle diameter.

In recent years, various pigments have been used as components of ink for ballpoint pens. Among them, pigments of metal particles for giving metallic luster to drawn lines, or reversible thermochromic microcapsule pigments capable of making drawn lines colorless by frictional heat have a relatively large particle size. If the particle diameter of the pigment used in the ink is large, the ink may be clogged in the gap between the caulking portion at the tip of the ballpoint pen tip and the writing ball or in the gap between the ball house containing the writing ball and the writing ball . Therefore, there is a problem that the ink is faded and a sufficient writing distance can not be secured.
In order to solve this problem, it has been practiced to increase the moving distance (hereinafter referred to as the clearance) of the writing ball in the ball house.

However, when the clearance is increased, the writing ball may drop out of the ball house due to an impact. In the case of a knock-type ballpoint pen in particular, such dropout is likely to occur due to an impact at the time of knocking accompanying storage of a refill.
Then, the ball-point pen which a writing ball can not fall off easily from a ball house is indicated by patent documents 1.

Patent No. 5484186 gazette

However, although the ballpoint pen described in Patent Document 1 is difficult to drop the writing ball from the ball house, the ink is consumed more than necessary, and a sufficient writing distance can not be obtained. Further, not only the crimped portion contacts the crimped portion and the paper surface at the time of writing and the crimped portion wears, but also the fibers of the paper are rubbed, and the scraped away paper fibers intrude into the ball house as the writing ball rotates. May block the aisle.
Therefore, in the present invention, it is an object of the present invention to provide a ballpoint pen capable of obtaining a sufficient writing distance even with an ink having a large particle diameter.

The present invention provides a refill 3 having a ballpoint pen tip 32 which is a writing unit at its tip,
A shaft main body 2 accommodating the refill 3;
A coil spring 40 for urging the refill 3 rearward;
And a knock portion 41 provided at the rear of the shaft body 2 and disposed behind the refill 3 and interlocking with the refill 3;
A knock-type ballpoint pen 1 in which the writing position is achieved by pressing the knocking portion 41 forward and causing the refill 3 to protrude from the tip of the shaft main body 2,
The ballpoint pen tip 32 comprises a writing ball 33, and a holder 34 for holding the writing ball 33 at its tip,
A caulking portion 34b for holding the writing ball 33 is provided at the tip of the holder 34, and a ball house provided at the tip of the holder 34 and inserted in the inner space of the holder 34 35, there are formed a back hole 37 provided from the rear end of the holder 34 to the front end direction to the vicinity of the ball house 35, and an ink guiding hole 36 connecting the back hole 37 and the ball house 35;
The ball house 35 has a cylindrical surface 35a substantially parallel to the axis, a bottom surface 35b which is a conical surface which is continuously reduced in diameter rearwardly from the cylindrical surface 35a, and a curved surface of the writing ball 33 on the bottom surface 35b. And a ball receiving seat 35c which has been transferred,
At a plurality of locations equally spaced around the ink guiding hole 36, ink grooves 36a which are radial grooves bored from the ball house 35 side toward the rear are formed.
A resilient member 38 for biasing the writing ball 33 in the distal direction is inserted in the back hole 37, and the tip portion of the resilient member 38 linearly extends in the distal direction, and the ink guiding hole And 36 is formed as a biasing portion 38a that abuts on the rear end of the writing ball 33 and biases the rear end of the writing ball 33,
The maximum volume of ink stored in the refill 3 is 0.5 ml or more, and the sphericity of the writing ball 33 is 0.5 μm or less, and the writing ball 33 is the ballpoint pen tip in the holder 34 The clearance which is movable in the axial direction of 32 is less than 30 μm, and the average particle diameter of the pigment used in the ink is 0.3 μm or more and less than the clearance, and the writing ball 33 of the crimped portion 34 b is The holding force is equal to or less than the knock load at the time of pressing the knock portion 41, and
The pressing load of the resilient member 38 is less than the weight of the shaft body 2,
The diameter of the writing ball 33 is A, the writing ball extension B is a distance at which the writing ball 33 protrudes from the tip of the holder 34, the clearance is C, and the inner diameter of the cylindrical surface 35a of the ball house 35 is D When the inner diameter of the ink guide hole 36 is E, the outermost diameter of the ball seat 35c is F, and the wire diameter of the urging portion 38a is G,
The writing ball 33 is held in the crimped portion 34b so that (B + C) <0.4A,
The ball house 35 is formed such that D ≧ (A + 0.03 mm) and F <0.65 A,
The ink guiding hole 3 is formed so that E ≦ 0.6 A,
The biasing portion 38a is formed to satisfy 0.4E ≦ G ≦ 0.6E,
The knock load is 5 N or more
Therefore, the writing distance is 200 m or more.

Here, "a force for holding the writing ball 33 of the caulking portion 34b" is a ball holding force, and is a static load required to drop the writing ball 33 axially forward from the rear of the ballpoint pen tip 32. Say
The “knock load” refers to a load required when the user presses the knock portion 41 in order to extend or retract the tip of the refill 3 from the shaft body 2.
Further, by setting the sphericity of the writing ball 33 to 0.5 μm or less, the rotation of the writing ball 33 is not inhibited, and the discharge of the ink can be made smooth.

Further, by making the pressing load of the resilient member 38 less than the weight of the shaft body 2, it is possible to provide a smooth writing taste of the writing ball 33.
In addition, by forming the tip of the ballpoint pen tip 32 so that (B + C) <0.4A, the distance that the writing ball 33 protrudes from the writing tip is less than 40% of the ball diameter at the maximum. It becomes difficult to fall off.
Further, since the cylindrical surface 35a of the ball house 35 is formed such that D ≧ (A + 0.03 mm), the diameter D of the cylindrical surface 35a is wider than the diameter A of the writing ball 33 by at least 0.03 mm. The flow path is sufficiently secured. Further, since the ball receiving seat 35c is formed to have an F <0.65 A, the writing ball 33 can smoothly rotate at the time of writing, and the opening of the groove can be secured. The road is also secured.

Further, by forming the ink guiding hole 36 so as to satisfy E ≦ 0.6 A and forming the urging portion 38 a so as to satisfy 0.4 E ≦ G ≦ 0.6 E, the ink passage can be secured. . When a shear thinning ink is used, at the time of writing, the urging portion 38a moves up, down, left, and right within the ink guide hole 36, agitation of the ink is performed, and the discharge of the ink is improved.
Further, when the knock load is 5 N or more, it is possible to prevent the tip of the refill 3 from being drawn out of the shaft body 2 by mistake, and to prevent unnecessary ink contamination.
Further, by forming the ink circulation hole having a smaller diameter than the press-fit portion with the ballpoint pen tip 32 in the joint 31, it is possible to prevent the ball jumping due to the knocking impact.

Note that by providing the erasing member 41a made of a soft member at the rear end of the knock portion 41, the impact applied to the ballpoint pen 1 when falling when the knock portion is directed downward may be absorbed.
The ink suitable for the present invention contains at least colored resin particles having an average particle diameter of 1 μm or more and being non-thermoplastic and non-colored particles having a glass transition point of less than 0 ° C. It is characterized in that it contains 5 to 30% by weight of particles with respect to the total amount of the ink composition, and has a shear thinning that can be erased by the rubbing operation of the erasing member 41a. In addition, the thermochromic composition containing at least the essential three components of the electron donating color forming organic compound, the electron accepting compound, and the reaction medium for determining the occurrence temperature of the color forming reaction of the both is encapsulated in a microcapsule An ink which contains 5 to 30% by weight of a thermochromic microcapsule pigment having an average particle diameter of 1 μm or more with respect to the total amount of the ink composition, and which can be discolored or decolored by the friction operation of the erasing member 41a It is. Here, the "average particle diameter" is a value of D50 measured by a particle size analyzer [Microtrac HRA 9320-X100 (manufactured by Nikkiso Co., Ltd.)].

The outer diameter 34c of the crimped portion 34b provided at the tip of the holder 34 may be chamfered. As a result, it is possible to reduce the frictional resistance generated between the crimped portion 34b at the time of writing and the paper surface, and to suppress abrasion of the crimped portion 34b and scraping of fibers of the paper surface. Therefore, it is possible to suppress the falling off of the writing ball 33 and the blur at the time of writing.
In the ballpoint pen tip 32 of the ballpoint pen 1 according to the present invention, an inwardly projecting portion 37a projecting inward is provided at the tip of the back hole 37 and in contact with the rear end of each ink groove 36a. It is also good. By providing the inward convex portion 37a, even if the biasing portion 38a of the elastic member 38 is inclined toward the ink groove 36a at the time of writing, the inward convex portion 37a is abutted before being fitted into the ink groove 36a. Therefore, when the urging portion 38a of the resilient member 38 fits into the ink groove 36a, it is possible to prevent the passage of the ink from being blocked. Furthermore, since the flow path of the ink that stitches between the inward convex portions 37a is formed, the ink outflow resistance is lowered, and therefore, it is difficult to cause the blur at the time of writing.

  The rear end portion of the refill 3 may be provided with a pressure mechanism 5 capable of applying pressure to the refill 3 from the rear end of the refill 3. Here, the “pressure mechanism 5” is a mechanism that applies pressure to the ink in the refill 3. Specifically, a method of sealing pressurized gas in a space in the refill 3 or a sealed space (pressure chamber 42c) is provided in the rear portion of the ink in the refill 3 in the interior of the shaft main body 2, and knocking There is a method of designing pressure to be applied to the closed space when applying the pressure, and the pressure is applied to the ink in the refill 3 or the like. When the pressure mechanism 5 is provided, even if the ink viscosity is increased to prevent direct current, the ink is sufficiently discharged, and a smooth writing feeling is obtained.

  In the case where the pressure mechanism 5 is provided on the ballpoint pen 1 by a method of providing a closed space, an O-ring 52 is provided at the back of the refill 3 to prevent the inflow of air when forming the closed space inside the shaft 2. Etc. may be provided. The O-ring 52 serves as a buffer member to absorb an impact applied to the ballpoint pen 1 at the time of knocking. The buffer member may not be the O-ring 52, but may be in contact with the rear end of the refill 3 as long as it has an elastic action.

  Since the ballpoint pen in the present invention is configured as described above, even when ink having a large average particle diameter is used for the ballpoint pen, falling of the writing ball due to impact or the like at the time of knocking does not easily occur. It is possible to provide a knock-type ballpoint pen which is less likely to cause writing defects and which can obtain a sufficient writing distance of 200 m or more.

It is front sectional drawing of the ball-point pen in 1st Embodiment. It is front sectional drawing of the front-end | tip of the ball-point pen tip which concerns on this invention. It is an enlarged front view of the tip of a ballpoint pen tip concerning the present invention. It is II sectional drawing of FIG. However, the outer circumference of the holder and the writing ball are omitted. It is a fragmentary sectional view showing the state of the holder and ballistics member of a ball-point pen tip concerning the present invention. However, the writing ball is omitted. It is front sectional drawing of the ball-point pen in 2nd Embodiment. It is a front fragmentary sectional view of the ball-point pen in 3rd Embodiment. It is an expanded view which shows the rotor and cam of the knock mechanism in 3rd Embodiment.

First Embodiment
The ballpoint pen 1 in the first embodiment is, as shown in FIG. 1, a knock-type ballpoint pen, which is internally incorporated with the shaft body 2 and the refill 3 accommodated in the shaft body 2 so as to be movable back and forth in the axial direction. And a knock mechanism 4 for causing the pen tip of the refill 3 to protrude and retract from the tip of the shaft main body 2.
(Axis body 2)
The shaft main body 2 is composed of a cylindrical shaft cylinder 20 accommodating the refill 3 therein, and a substantially conical tip member 21 screwed to the tip end portion of the shaft cylinder 20.

The rear end portion of the barrel 20 is provided with a clip member 22 for holding the cloth of the pocket when it is inserted into the pocket provided on the user's clothes.
The bottom end of the proboscis 21 is open, and a thread groove is formed on the inner peripheral surface thereof. Thus, the spout 21 is attached to the barrel 20.
(Refill 3)
The refill 3 includes an ink storage tube 30 storing ink, and a ballpoint pen tip 32 attached to the tip of the ink storage tube 30 via a joint 31. Further, an ink flow hole having a smaller diameter than that of the press-in portion with the ballpoint pen tip 32 is formed in the joint 31.

Here, the maximum volume of the ink stored in the ink storage tube 30 is 0.5 ml or more. The ink contained therein is an eraser erasable ink erasable by an erasing member 41a described later, and the average particle diameter of the ink is 0.3 μm or more and less than the clearance described later (see FIG. 3). Further, a pressure mechanism (not shown) is provided at the rear end of the refill 3. Specifically, the pressurized gas is sealed in the space in the refill 3, whereby pressure is applied to the ink in the refill 3 from the rear end of the refill 3.
As shown in FIG. 2, the ballpoint pen tip 32 comprises a writing ball 33 and a holder 34 for holding the writing ball 33 at its tip.

  The diameter of the writing ball 33 is 0.4 mm or less, and the sphericity of the writing ball 33 is 0.5 μm or less. The sphericity value is a value measured with an sphericity measuring machine (manufactured by Mitutoyo Corp. ROUNDTEST RA-2000). In addition, as shown in FIG. 3, the diameter of the writing ball 33 is shown in FIG. 3, the writing ball dimension which is the distance the writing ball 33 protrudes from the tip of the holder 34 is B, and the writing ball 33 is a ballpoint pen tip 32 in the holder 34. Assuming that the clearance which is an axially movable amount is C, the writing ball 33 is held by the holder 34 so that the clearance is less than 30 μm and the relationship of (B + C) <0.4A is established.

At the tip of the outer periphery of the holder 34, as shown in FIG. 2, a tapered portion 34a having a tapered shape and a crimped portion 34b formed by plastically deforming the tip of the tapered portion 34a inward are formed. ing. Here, the writing ball 33 is held in the crimped portion 34b, and the crimped portion 34b is formed such that the force for holding the writing ball 33 by the crimped portion 34b is equal to or less than the knock load described later. The outer diameter 34c of the crimped portion 34b shown in FIG. 3 is chamfered.
In the internal space of the holder 34, as shown in FIG. 5, the ball house 35 into which the writing ball 33 is inserted inside the tapered portion 34a, and from the rear end of the holder 34 to the vicinity of the ball house 35 A back hole 37 and an ink guiding hole 36 connecting the back hole 37 and the ball house 35 are formed.

The ball house 35 has a cylindrical surface 35a substantially parallel to the axial center, a bottom surface 35b which is a conical surface which continues to decrease in diameter continuously to the cylindrical surface 35a, and the curved surface of the writing ball 33 is transferred to the bottom surface 35b. And the ball receiving seat 35c. Here, as shown in FIG. 4, assuming that the inner diameter of the cylindrical surface 35a of the ball house 35 is D, the inner diameter of the ink guide hole 36 is E, and the outermost diameter F of the ball seat 35c, the ball house 35 has D ≧. It is formed to be (A + 0.03 mm) and F <0.65A.
In addition, the ink guiding holes 36 are formed so that E ≦ 0.6 A, and in the three equally spaced portions around the ink guiding holes 36, as shown in FIGS. An ink groove 36 a, which is a groove penetrating radially from the house 35 side to the tip portion of the back hole 37, is formed.

  In the back hole 37, as shown in FIG. 2, a resilient member 38, which is a wound spring that biases the writing ball 33 in the distal direction, is inserted. The tip end portion of the resilient member 38 is formed as a biasing portion 38a extending in the tip end direction through the ink guiding hole 36 to abut against the rear end of the writing ball 33 and bias the same as shown in FIGS. It is done. Here, assuming that the wire diameter of the biasing portion 38a is G, the biasing portion 38a is formed so as to satisfy 0.4E ≦ G ≦ 0.6E. Further, the pressing load of the resilient member 38 is equal to or less than the weight of the shaft body 2. Further, as shown in FIG. 5, an inward projecting portion 37a is formed at the tip of the back hole 37 at a position in contact with the rear end of each ink groove 36a.

(Knock mechanism 4)
The knock mechanism 4 is a mechanism related to the extension of the tip end of the refill 3 from the shaft main body 2 and the pulling-in to the inside of the shaft main body 2.
As shown in FIG. 1, the knock mechanism 4 includes a coil spring 40 for urging the refill 3 to the rear end side, a knock portion 41 provided at the rear end of the shaft cylinder 20, and the knock portion 41 and the refill 3. And a rotor 42 located between them. Here, the knock load in the present embodiment is 5N or more. Further, at the rear end of the knock portion 41, an erasing member 41a is provided. The erasing member 41a is an eraser and is made of a soft member capable of erasing the eraser erasable ink described above. Since the erasing member 41a is a soft member, the impact applied to the ballpoint pen 1 when dropped can be absorbed by the erasing member 41a.

Second Embodiment
The ballpoint pen 1 according to the second embodiment, as shown in FIG. 6, includes a shaft body 2 which can be divided into two, a refill 3 accommodated in the shaft body 2 so as to be movable back and forth in the axial direction, and a built-in refill 3. It consists of a knock mechanism 4 which makes the pen tip project from the tip of the shaft main body 2 and a pressure mechanism 5 supported by a rotor 42 which is a part of the knock mechanism 4 and in contact with the refill 3.
Here, although the refill 3 is different from the first embodiment in that the refill 3 includes the ink storage tube 30 and the ballpoint pen tip 32 directly attached to the tip of the ink storage tube 30, the refill 3 is different from the first embodiment Similarly, the ink storage tube 30 may be fitted with the ballpoint pen tip 32 via a joint. The structure of the ballpoint pen tip 32 is the same as that of the first embodiment.

(Axis body 2)
As shown in FIG. 6, the shaft main body 2 is cylindrical, and has a tip end shaft 23 whose tip is tapered, and a back end shaft 24 which is cylindrically engaged with the rear end of the tip end shaft 23. It consists of
The front shaft 23 has an open front portion formed into a tapered cylindrical shape, and an open rear portion formed thin, and a screw groove (not shown) for fastening is circumferentially screwed on the outer peripheral surface thereof.
The rear shaft 24 is formed in a cylindrical shape, and a screw groove (not shown) which is detachably screwed with the rear portion of the front shaft 23 is screwed in the circumferential direction on the front inner peripheral surface. A substantially oval drop-off preventing rib (not shown) is protruded radially inward, and a plurality of drop-off preventing ribs are arranged in parallel in the circumferential direction at predetermined intervals. Further, a clip member 22 which is a stopper is integrally formed on the rear outer peripheral surface of the rear shaft 24 in the axial direction.

(Knock mechanism 4)
As shown in FIG. 6, the knock mechanism 4 includes a coil spring 40 interposed between the shaft body 2 and the ink storage tube 30, a knock portion 41 provided at the rear end of the rear shaft 24, and an ink storage tube A rotor 42 is slidably inserted into a distal end portion of the shaft 30 with a gap, a plurality of cams 43 protruding from the outer peripheral surface of the rotor 42, and a rear end of the inner peripheral surface of the shaft main body 2 It comprises a plurality of striated bodies 44.
The coil spring 40 is inserted into the tip end portion of the ink containing tube 30 and contacts the open front peripheral edge of the shaft main body 2 to elastically bias the ink containing tube 30 in the rear direction of the shaft main body 2.

The knocking portion 41 is a knocking operation portion for feeding out or rotating the tip end of the refill 3 from the shaft main body 2, and is provided at the rear end of the rear shaft 24. At the front of the knock portion 41, a rotor 42 described later is detachably and relatively rotatably fitted. A knock portion cam (not shown) corresponding to the rotor 42 is provided at the tip of the knock portion 41, and an erasing member 41a capable of erasing ink is provided at the rear end.
The rotor 42 is formed into a substantially bottomed cylindrical shape, and a knock portion 41 is fitted to the closed bottom. Then, each time the erasing member 41 a of the knocking portion 41 is knocked, the rotor 42 rotates at a predetermined angle (15 ° to 60 °, preferably 18 ° to 30 °).

The rotor 42 is formed in a hollow, substantially convex shape continuously provided with an enlarged diameter portion 42a and a reduced diameter portion 42b, and the inside is formed as a pressure chamber (volume reduction space) 42c for external air (air). And the inner circumferential surface is formed from the opening direction to the bottom direction in which it is closed from the opening direction, the largest diameter surface 42d, the large diameter surface 42e, the reduced diameter surface 42f, and the smallest diameter surface 42g. It is effectively regulated by the fall prevention rib (not shown) of the rear shaft 24.
A plurality of continuous saw teeth (not shown) are circumferentially provided on the step surface of the enlarged diameter portion 42 a and the reduced diameter portion 42 b of the rotor 42. In addition, between the diameter expansion surface 42d and the diameter expansion surface 42e, between the diameter expansion surface 42e and the diameter reduction surface 42f, and between the diameter reduction surface 42f and the diameter reduction surface 42g, a tapered step surface is formed. Are formed respectively.

When writing, the rotor 42 having such a configuration slides in the front direction of the shaft main body 2 to be closely fitted to the end of the ink containing tube 30 and press-fits the end of the ink containing tube 30 Demonstrate. On the other hand, when writing is not performed, the end of the ink storage tube 30 is shallowly fitted, and a large gap is formed between the end of the ink storage tube 30 and the pressure chamber 42c.
A plurality of cams 43 are juxtaposed in a row on the outer peripheral surface of the rotor 42 and are provided at intervals of 60 ° or less, preferably 30 ° or less. Each cam 43 is slidably fitted between a plurality of strips 44 provided at the rear of the inner peripheral surface of the shaft body 2.

A plurality of strips 44 are juxtaposed in a row at the rear of the inner peripheral surface of the shaft main body 2 and project at intervals of 60 ° or less, preferably 30 ° or less. Each strip 44 is formed in a substantially linear shape in the axial direction of the shaft main body 2 and plays a guiding function of the cam 43. Further, the tip end surface of each strip 44 is notched in the circumferential direction, and this notch and the cam 43 mesh with each other.
That is, when the knocking portion 41 is knocked when not writing, the rotor 42 is rotated, the cam 43 provided on the outer peripheral surface of the rotor 42 and the wire 44 are engaged, and the refill 3 protrudes from the front of the shaft main body 2 Do. At this time, the cam 43 and the web 44 mesh with each other, and the refill 3 does not move backward even if it is written. At the time of writing, when knocking on the knocking portion 41 again, the rotor 42 is rotated, the meshing between the linear members 44 and the cams 43 is released, and the cams 43 are slidably fitted between the plural linear members 44. Slide in the direction of the ink containing tube 30. As a result, the cams 43 are positioned between the plurality of strips 44, and the ballpoint pen tip 32 protruding from the front of the shaft main body 2 retracts, and writing can not be performed.

(Pressure mechanism 5)
The pressure mechanism 5 is a mechanism that applies pressure to the ink in the refill 3.
As shown in FIG. 6, the pressing mechanism 5 is slidably fitted in the rotor 42, and is provided with a sealing rubber holder 50 provided at a position opposite to the end face of the ink storage tube 30; The pressure spring 51 is interposed between the rubber holder 50 and the rotor 42, and the O-ring 52 for ensuring airtightness fitted on the outer peripheral surface of the rubber holder 50.
The rubber holder 50 is formed in a substantially cylindrical shape using a synthetic resin made of polyacetal, polyoxymethylene, polyformaldehyde or the like, and a fitting groove 50a cut in the circumferential direction is formed on the outer peripheral surface.

  The pressure spring 51 is a coil spring whose elastic force is larger than that of the coil spring 40 and functions to elastically bias the rubber holder 50 toward the end of the ink containing tube 30. One end of the pressure spring 51 is inserted into the rubber holder 50 via an attachment rib (not shown), and the other end is inserted into the reduced diameter portion 42b of the rotor 42 via an attachment rib (not shown). ing. The pressure spring 51 is fully compressed before the rubber holder 50 retracts and comes into contact with the step surface between the enlarged diameter surface 42 e and the reduced diameter surface 42 f of the rotor 42. Further, the resilient force of the pressure spring 51 and the coil spring 40 is formed such that the knock load of the entire ballpoint pen 1 is 5 N or more.

The O-ring 52 is molded into an endless ring using silicone rubber or NBR, which is an elastic material excellent in heat resistance, cold resistance, ozone resistance, electrical characteristics, oil resistance, etc., and is formed in the fitting groove 50 a of the rubber holder 50. It is fitted.
When writing, the O-ring 52 deforms in close contact with the diameter-expanded surface 42e of the rotor 42 so that the outside air in the shaft main body 2 can not flow into the pressure chamber 42c of the rotor 42, and the ink storage tube from the pressure chamber 42c Inject compressed external air to the end of the 30. Therefore, pressure can be applied to the ink storage tube 30, and ink discharge can be promoted. When the O-ring 52 has not been written yet, the O-ring 52 faces the enlarged diameter surface 42 e of the rotor 42 via a gap, and the outside air can flow into the pressure chamber 42 c of the rotor 42. Therefore, the enlarged diameter surface 42e of the rotor 42 and the O-ring 52 of the rubber holder 50 are separated from each other to define the flow path of the outside air, so the inside of the shaft main body 2 and the pressure chamber 42c of the rotor 42 Communicate with each other. By this communication action, the pressure chamber 42c of the rotor 42 and the ink storage tube 30 are not pressurized. In addition, the O-ring 52 also plays a role as a buffer member that absorbs an impact when the ink storage tube 30 collides backward when knocking.

Third Embodiment
As shown in FIG. 7, the ballpoint pen 1 according to the third embodiment has a shaft body 2, a refill 3 axially accommodated in the shaft body 2 so as to be movable back and forth, and a pen tip of the built-in refill 3. And a knocking mechanism 4 for projecting from the tip of the main body 2.
Here, the shaft body 2 and the refill 3 are configured in the same manner as in the first embodiment. The pressure mechanism is also provided to the ballpoint pen 1 as in the first embodiment.
(Knock mechanism 4)
As shown in FIG. 7, the knock mechanism 4 includes a coil spring 40 interposed between the shaft body 2 and the ink storage tube 30, a knock portion 41 provided at the rear end of the shaft cylinder 20, and a knock portion 41. 42, and a plurality of cams 43 projecting from the outer peripheral surface of the rotor 42, and a clip member 22, which are integrally formed with the inner peripheral surface And a rear cylinder 45 having a plurality of strips 44.

The knocking portion 41 and the rotor 42 respectively have a knocking portion cam (not shown) and a knocking cam (not shown) which are cam slopes respectively corresponding to each other, and the rotor 42 is rotated by an axial forward knocking operation. It is configured to rotate in a predetermined direction only at predetermined angles.
Furthermore, when the pressing after the knocking operation is stopped, the refill 3 is always urged rearward by the coil spring 40, and the aforementioned knocked portion 41 is produced by the cam 43 of the rotor 42 and the corresponding linear member 44 of the rear cylinder 45. And the rotor 42 in the same direction as the rotation by the rotor 42. That is, the rotor 42 rotates at a predetermined angle, and at a certain point (one with the above configuration, makes one round), and this operation is repeated. Further, the tip end portion of the rotor 42 is always in contact with the refill 3, and the front-rear position of the cam 43 determines the pen tip position of the tip of the refill 3.

As in the first embodiment of the present invention, an erasing member is attached to the rear end of the knock portion 41 as in the first embodiment. Moreover, the knock load at the time of pressing the knock part 41 is also 5N or more similarly.
Here, the configuration of the strip 44 in the third embodiment and the rotational movement and vertical shift in contact with the strip 44 when transitioning from the writing time to the unwriting time by pressing the knock portion 41 are performed. The operation of the cam 43 of the child 42 will be described with reference to FIG. FIG. 8 is a schematic view showing the positional relationship between the cams 43 of the rotor 43 and the strip 44, and the cam 43 of the rotor 42 with respect to a developed version of the strip 44 formed on the inner surface of the rear cylinder 45. Indicates the position of The upper part of the figure shows the direction of the pen point, and the cam 43 of the rotor 42 is given rotational force by the cam mechanism of the knock portion 41 and the rotor 42 described above, so from left to right Moving.

FIG. 8A shows a state in which the tip of the refill 3 protrudes from the tip of the shaft main body 2 in the writing state, and the cam 43 has the first slope 44a of the strip 44 and the repelling force of the coil spring 40. It is pressed and fixed to the first vertical wall 44b.
In this state, when the knocking portion 41 is pushed, the cam 43 advances upward in the figure to reach a position beyond the first vertical wall 44b and then the restriction by the first vertical wall 44b is released, so the coil spring 40 As a result, as shown in FIG. 8 (b), it is rotated to the right as shown in FIG.

Then, when the finger is released, the cam 43 further rotates and passes through the first vertical movement to reach the position shown in FIG. Let the vertical movement distance in this first vertical movement be the first vertical movement distance α. At this time, the slope of the cam 43 collides with the front half portion of the third slope of the strip 44 (hereinafter referred to as “front half slope”) 44 d, and the impact is transmitted to the refill 3.
Furthermore, the cam 43 slides and rotates the inclined surface 44d of the first half of the strip 44, and then passes through the second vertical movement to reach the position shown in FIG. 8 (d). The vertical movement distance in this second vertical movement is taken as a second vertical movement distance β. At this time, the slope of the cam 43 collides again with the second half of the third slope of the strip 44 (hereinafter referred to as the “second half slope”) 44 e, and the impact is transmitted to the refill 3.

Thereafter, the cam 43 rotates by sliding on the second half slope 44e of the strip 44, abuts against the second vertical wall 44f of the strip 44 and stops, and the pen point at the time of writing not shown in FIG. It reaches the storage position.
Conventionally, the above-mentioned collision has occurred only once, and the vertical movement distance at that time was approximately equal to the sum of the first vertical movement distance α and the second vertical movement distance β in the above-mentioned configuration. Thus, by providing an axial step in the front and rear half of the third slope of the strip 44 and shortening the vertical movement distance per time of the cam 43, the impact applied to the refill 3 can be mitigated. .

In the ballpoint pen 1 shown in the first, second and third embodiments, the diameter A of the writing ball used for the ballpoint pen tip 32 is 0.38 mm, and a commercially available water-based ballpoint pen (UM-101ER, manufactured by Mitsubishi Pencil, Inc.) is used as an ink. The writing distance was measured under the following conditions using the black ink used in
In a state where the ink storage tube 30 is filled with the ink, using a writing tester compliant with JIS Standard S6039, using a writing speed of 4.5 m / min, a writing angle of 60 °, and a writing load of 0.98 N, JIS Standard P3201 The writing test was conducted by spiral writing on a writing test paper in accordance with the above, and the writing distance was measured.

  As a result of measuring the writing distance, at least 200 m of the writing distance could be secured in all the ballpoint pens 1.

  The present invention is applicable to a knock-type ballpoint pen employing an ink containing particles of relatively large diameter.

1 Ballpoint pen 2 axis main body 20 axis cylinder
21 spout member 22 clip member 23 tip shaft
24 rear axle 3 refill 30 ink storage tube
31 Fittings 32 Ballpoint pen tip 33 Writing ball
34 Holder 34a Taper 34b Crimp
34c Outer diameter of the caulked part 35 Ball house 35a Cylindrical surface
35b bottom 35c ball seat 36 ink induction hole
36a ink groove 37 back hole 37a inward convex portion
38 resilient member 38a biasing portion 4 knock mechanism
40 coil spring 41 knock portion 41a erasing member
42 Rotor 42a Expanded diameter portion 42b Reduced diameter portion
42c pressure chamber 42d diameter expansion surface 42e diameter expansion surface
42f reduced diameter surface 42g most reduced diameter surface 43 cam
44 striae 44a first slope 44b first vertical wall
44c second slope 44d first half slope 44e second half slope
44f second vertical wall 45 back cylinder 5 pressure mechanism
50 rubber holder 51 pressure spring 52 O ring A writing ball diameter B writing ball C clearance D cylindrical surface inner diameter E ink guiding hole inner diameter F ball receiving ring outermost diameter G biasing portion wire diameter α 1 Vertical moving distance β second vertical moving distance

Claims (1)

Refill with a ballpoint pen tip which is a writing unit at the tip,
A shaft body for containing the refill;
A coil spring for urging the refill backward;
And a knock portion provided at the rear of the shaft main body and disposed behind the refill and interlocking with the refill.
A knock-type ballpoint pen that is in a writing position by pressing the knocking portion forward to cause the refill to protrude from the tip of the shaft main body,
The ballpoint pen tip includes a writing ball, and a holder for holding the writing ball at its tip,
The tip of the holder is provided with a caulking portion for holding the writing ball, and in the internal space of the holder, a ball house provided at the tip of the holder and into which the writing ball is inserted; A back hole provided from the tip to the vicinity of the ball house and an ink guiding hole connecting the back hole and the ball house,
The ball house has a cylindrical surface substantially parallel to the axis, a bottom surface which is a conical surface which is continuously reduced in diameter continuously to the cylindrical surface, and a ball seat on which the curved surface of the writing ball is transferred And have, and
At a plurality of locations equally spaced around the ink guiding hole, ink grooves, which are radial grooves bored from the side of the ball house toward the rear, are formed.
A resilient member for biasing the writing ball in the distal direction is inserted into the back hole, and a tip portion of the resilient member linearly extends in the distal direction and passes through the ink guiding hole. It is formed as an urging part that abuts on the back end of the writing ball and urges it.
The maximum volume of ink contained in the refill is 0.5 ml or more, the sphericity of the writing ball is 0.5 μm or less, and the writing ball is in the holder in the axial direction of the ballpoint pen tip in the holder. The clearance which is a movable amount is less than 30 μm, and the average particle diameter of the pigment used in the ink is 0.3 μm or more and less than the clearance, and the force for holding the writing ball of the caulking portion is the knock portion Not more than the knock load when pressing
The pressing load of the resilient member is less than the weight of the shaft body,
The diameter of the writing ball is A, the writing ball dimension which is the distance that the writing ball protrudes from the tip of the holder is B, the clearance is C, the inner diameter of the cylindrical surface of the ball house is D, the ink guiding hole Assuming that the inner diameter is E, the outermost diameter of the ball seat is F, and the wire diameter of the biasing portion is G,
The writing ball is held in the caulking portion so that (B + C) <0.4A,
The ball house is formed such that D ≧ (A + 0.03 mm) and F <0.65 A,
The ink guiding hole is formed to satisfy E ≦ 0.6A,
The biasing portion is formed to satisfy 0.4E ≦ G ≦ 0.6E,
The knock load is 5 N or more
The ballpoint pen is characterized in that the writing distance is 200 m or more.