JP2011240607A - Ball-point pen refill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make sure, quick gas filling and sure tail plug attachment possible by adopting a tail plug in a shape which can carry out a provisional stop in an ink storage tube in a state without trouble in pressurized gas filling in a pressurized environment when a ball-point pen refill used for a pressurized ball-point pen is produced.SOLUTION: The ball-point pen refill 10 has the ink storage tube 20 which stores ink 11 and in which the pressure gas is enclosed, a ball-point pen tip 30 which is attached to the tip of the ink storage tube 20, and the tail plug 40 which seals the rear end of the ink storage tube 20. A large diameter part 42 engaging with the inner diameter of the ink storage tube 20, a small diameter part 43 loosely engaging with the inner diameter of the ink storage tube 20, a fitting part 45 which is fitted to the rear end edge of the ink storage tube 20 before the small diameter part 43 is inserted and the large diameter part 42 is press-fitted, and a notch part 46 which is notched from the fitting part 45 to a position near the rear end are provided in the side face part of the tail plug 40.

Description

  The present invention relates to a ballpoint pen refill in which a pressurized gas is filled in an ink containing tube.

Conventionally, there has been provided a ballpoint pen in which a pressurized gas is filled and enclosed in an ink storage tube of a ballpoint refill. As an example of the method of sealing the pressurized gas into such a ballpoint pen refill, the ink storage tube after filling with ink is placed in a pressurized environment filled with the gas to be sealed, and the tail plug is crimped there. And sealing.
In this method, when the outer diameter of the tail plug is approximately the same as or slightly larger than the inner diameter of the ink storage tube and is attached by press fitting, the tail plug is attached to the ink storage tube before being placed in a pressurized environment. I can't. Therefore, in this case, it is necessary to handle the tail plug in a pressurized environment.
On the other hand, it is also conceivable that the tail plug is temporarily inserted into the ink storage tube before being placed in a pressurized environment. However, in this case, the outer diameter of the tail plug and the inner diameter of the ink containing tube are substantially the same shape, and since these are joined, it becomes a state close to sealing. Therefore, the gas cannot be efficiently sealed in the ink storage tube.

In order to solve these problems, the following techniques are disclosed.
JP-A 61-27298 JP 2005-212393 A

In the invention described in Patent Document 1, a tail plug is welded to a tube to prevent gas leakage. However, the outer diameter of the tail plug is made considerably larger than the inner diameter of the tube in order to increase the fitting force between the tail plug and the tube. Thereby, the tube of the portion into which the tail plug is press-fitted is pushed out. Thereby, a crack is easy to generate | occur | produce in a tube after welding, and pressurized gas may leak.
The invention described in Patent Document 2 is an assembling method in which the tail plug is inserted after filling the pressurized gas while temporarily fixing the tail plug. However, the passage connecting the inside of the ink storage tube and the outside during temporary fixing is extremely narrow, and the flow path of the pressurized gas is easily closed. Therefore, since it may take time to sufficiently fill the pressurized gas, it is difficult to employ in the production line.

  In view of the above-described problems, the present invention temporarily fixes an ink containing tube in a manner that does not hinder pressurized gas filling in a pressurized environment when manufacturing a ballpoint pen refill used in a pressurized ballpoint pen. It is an object of the present invention to enable reliable and quick gas filling and reliable mounting of a tail plug by adopting a tail plug having a shape that can be used.

In order to solve the above-described problems, the present invention provides an ink storage tube 20 that stores ink 11 and contains pressurized gas, a ballpoint pen tip 30 that is attached to the tip of the ink storage tube 20, and the ink storage A ballpoint pen refill 10 with a tail plug 40 for sealing the rear end of the tube 20,
On the side part of the tail plug 40,
A large-diameter portion 42 fitted to the inner diameter of the ink containing tube 20,
A narrow-diameter portion 43 loosely fitted into the inner diameter of the ink containing tube 20,
A locking portion 45 for locking to the rear end edge of the ink containing tube 20 before the small diameter portion 43 is inserted and the large diameter portion 42 is press-fitted,
A cutout portion 46 is provided that is cut out to a position closer to the rear end than the locking portion 45.

In the present invention, the writing pen tip side of the ballpoint pen refill 10, that is, the side where the ballpoint pen tip 30 is located is referred to as the leading end, and the opposite side is referred to as the trailing end.
In the present invention, the “large diameter portion 42” and the “small diameter portion 43” are formed on the side surface portion of the tail plug 40. Here, when the tail plug 40 is attached to the rear end of the ink containing tube 20, the small diameter portion 43 is inserted first, and then the large diameter portion 42 is inserted. That is, the small diameter portion 43 is located on the distal end side of the large diameter portion.
The large-diameter portion 42 has an outer diameter that fits with the inner diameter of the ink containing tube 20. In other words, the outer diameter of the large-diameter portion 42 is large enough to be inserted so that it does not move easily when it is completely attached to the ink storage tube 20. In other words, the large diameter portion 42 cannot be inserted into the ink containing tube 20 unless it is press-fitted.

On the other hand, the small-diameter portion 43 has an outer diameter enough to loosely fit with the inner diameter of the ink containing tube 20. In other words, the outer diameter of the small diameter portion 43 is large enough to be inserted so loosely that it can be easily moved when temporarily secured to the ink storage tube 20. In other words, the small-diameter portion 43 can be easily inserted into the ink storage tube 20 without being press-fitted.
The tail plug 40 of the present invention is provided with a “locking portion 45” as a structure for temporarily fixing the rear end edge of the ink containing tube 20 in a state where the large diameter portion 42 is not press-fitted. A “notch 46” is provided from the locking portion 45 to a position closer to the rear end. The notch 46 serves as a gas passage between the ink storage tube 20 and the outside in a state where the tail plug 40 is locked.

As the locking portion 45, for example, a step portion 44 between the large diameter portion 42 and the small diameter portion 43 can be used. In this case, the notch 46 is formed as a slit-like notch that vertically cuts the narrow-diameter portion 43 from the tip of the tail plug 40 and extends to the tip of the large-diameter portion 42 beyond the stepped portion 44. become.
On the other hand, the locking portion 45 can be formed as a protrusion protruding from the small diameter portion 43. In this case, it is sufficient that the cutout portion 46 is formed as a slit-like cutout so as to reach a portion closer to the rear end than the projection position from the tip end of the tail plug 40 by selecting a position avoiding the projection. Therefore, in this case, the rear end of the notch 46 can be kept within the range of the small-diameter portion 43 so as not to reach the large-diameter portion 42. By doing so, the length of the notch 46 can be kept to the minimum necessary, and the strength of the tail plug 40 can be secured to some extent.

  In the ballpoint pen refill 10 according to the present invention, the filling of the pressurized gas is performed as follows. First, the small diameter portion 43 of the tail plug 40 is inserted into the rear end of the ink containing tube 20 with the ballpoint pen tip 30 attached and filled with the ink 11, and temporarily fixed when the locking portion 45 is press-fitted. . In this state, the notch 46 reaches the rear side of the ink containing tube 20, and the inside of the ink containing tube 20 communicates with the outside from here. When the ink storage tube 20 in this state is placed in an environment filled with pressurized gas, the pressurized gas enters the ink storage tube 20 from the notch 46. Then, by pressing the tail plug 40 and press-fitting the large-diameter portion 42, the tail plug 40 is fixed to the ink storage tube 20, and pressurized gas is sealed.

  In the present invention, the tail plug 40 is preferably welded and fixed after being press-fitted into the ink storage tube 20. By doing so, the tail plug 40 and the ink containing tube 20 are more reliably joined. Here, the method of welding is not particularly limited, but for example, the welding can be performed by various methods such as welding by heating, welding by ultrasonic vibration, and welding by laser irradiation. When employing laser irradiation, for example, the tail plug 40 is formed of a laser-impermeable material, and the tail plug 40 attached to the ink storage tube 20 is welded to the ink storage tube 20 by laser irradiation. It may be fixed. In this way, the tail plug 40 is welded so that the press-fitting allowance of the tail plug 40 is sufficient to be in close contact, and it is not necessary to make it too large. As a result, the ink storage tube 20 can be prevented from cracking, and the change in the external dimension due to the press-fitting can be minimized.

  Further, in the present invention, the tail plug 40 is preferably formed by injection molding of resin, and the gate position at the time of injection molding is preferably provided at a position avoiding the large diameter portion 42. That is, the large diameter portion 42 is a portion that is press-fitted into the ink storage tube 20, and the surface thereof is in close contact with the ink storage tube 20. Therefore, when a gate at the time of injection molding is used on the surface, there is a possibility that the smoothness of the surface is impaired due to protrusion or depression of the gate portion after molding. This reduces the certainty of press fitting and increases the possibility of gas leakage from the gate portion. Therefore, such a problem can be avoided by designing the mold so that the gate comes to the position avoiding the large diameter portion 42, for example, the surface of the small diameter portion 43.

  Note that the ballpoint pen tip 30 of the present invention may be mounted by being directly inserted into the tip of the ink storage tube 20, or the ink storage tube via a joint mounted at the tip of the ink storage tube 20. It may be attached to 20.

  Since the present invention is configured as described above, when manufacturing a ballpoint pen refill for use in a pressurized ballpoint pen, the ink containing tube is temporarily fixed in a manner that does not hinder pressurized gas filling in a pressurized environment. By adopting a tail plug having a shape capable of being handled, the tail plug can be easily handled in a pressurized environment, and reliable and quick gas filling and reliable mounting of the tail plug are possible.

It is (A) front view, (B) front sectional view, (C) front perspective view, and (D) rear perspective view of the ballpoint pen refill according to one embodiment of the present invention. However, ink to be filled is omitted in (B). It is front sectional drawing of the ball-point pen refill which concerns on 1 embodiment of this invention. (A) Front view, (B) Bottom view, (C) Top view, (D) Front perspective view, and (E) Back perspective view of an ink storage tube used for a ballpoint pen refill according to one embodiment of the present invention. (F) FF sectional view in the figure and a front view of (A), (G) GG sectional view, and (H) HH sectional view. It is the (A) front view, (B) side view, (C) front perspective view, and (D) back perspective view of the tail plug used for the ball-point pen refill according to one embodiment of the present invention. It is side surface sectional drawing (AD) and front view (EH) which show the procedure in which the tail plug in the ball-point pen refill which concerns on 1 embodiment of this invention is mounted | worn with an ink storage tube. It is a partial cross section figure which expands and shows the tip part of the ink storage tube used for ball-point pen refill concerning one embodiment of the present invention. It is a partial cross section figure which shows the metal mold | die for shape | molding the ink accommodating pipe | tube in the ball-point pen refill which concerns on one embodiment of this invention. It is a partial cross section figure which shows the fitting state of the ball-point pen tip and the ink storage tube in the ball-point pen refill according to the one embodiment of the present invention.

Embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a ballpoint pen refill 10 according to an embodiment of the present invention includes a hollow tubular ink containing tube 20, a metal ballpoint pen tip 30 attached to the tip thereof, and a tail end thereof. A resin tail plug 40 to be mounted and an ink 11 (see FIG. 2) omitted in FIG. The rear end portion of the ballpoint pen tip 30 is an insertion portion 31 with a reduced outer diameter.
The ink storage tube 20 is divided into an ink filling portion 21 in the first half portion with a small inner diameter and a pressurized gas filling portion 22 in the second half portion with a large inner diameter (FIG. 1B). On the outer surface from the position slightly behind the position where the ball-point pen tip 30 is mounted in the ink filling unit 21 to the pressurized gas filling unit 22, a plurality of ribs 23 along the axial direction are formed with respect to the axis. It is equally distributed radially (FIGS. 1A, 1C, and 1D). In this embodiment, eight ribs 23 are provided. The outer diameter of the ink filling portion 21 considering the rib 23 is equal to the outer diameter of the pressurized gas filling portion 22. Further, the outer diameter of the portion near the tip where the rib 23 is not provided in the ink filling portion 21 is formed smaller than the portion where the rib 23 is provided.

  As shown in FIG. 2, the ink 11 is filled in an ink filling portion 21 having a small inner diameter in the ink storage tube 20. The ink 11 to be filled is not particularly limited, but an oil-based ballpoint pen ink having a low viscosity is desirable. The pressurized gas is filled in the pressurized gas filling unit 22 having a large inner diameter, and diffuses to the ink filling unit 21 as the ink 11 is consumed. In addition, at the time of manufacturing the ballpoint pen refill 10, the ink 11 is not filled in all areas of the ink filling portion 21, and the ink 11 does not exist in some areas of the rear end portion as shown in the figure. There can also be a site. Naturally, a part of the gas filled in the pressurized gas filling part 22 is diffused and present in this part.

FIG. 3 shows an overall view and a sectional view of the ink containing tube 20 again. As is apparent from the bottom view (FIG. 3B) and sectional views (FIGS. 3F and 3G) viewed from the front end direction, eight ribs 23 are provided on the outer periphery of the ink filling portion 21. It has been. The portion where the rib 23 is provided is thick, and this portion is the thick portion 24. On the other hand, a portion between the rib 23 and the rib 23 is thinner than the thick portion 24, and this portion is a thin portion 25 (FIGS. 3F and 3G). The outer diameter of the boundary portion between the ink filling portion 21 and the pressurized gas filling portion 22 is substantially the same and is smoothly continuous (FIGS. 3A and 3H).
The ink containing tube 20 is formed by injection molding of a resin that has a relatively low gas permeability and is resistant to moisture, such as polybutylene terephthalate or polyethylene naphthalate. Here, since the ribs 23 are provided, the resin is sufficiently filled in the outer peripheral portion of the ink filling portion 21. Further, depending on the thickness of the resin in the thick portion 24, the gas permeability of the ink filling portion 21 as a whole is drastically reduced as compared with the case where the rib 23 is not provided. From the viewpoints of the advantages in molding and gas permeability, the number of ribs 23 is desirably eight as described above. Incidentally, if the number of the ribs 23 is larger than this, the area ratio occupied by the thin-walled portion 25 becomes small, and molding defects are likely to occur. On the other hand, if the number of the ribs 23 is smaller than this, the area ratio occupied by the thin portion 25 increases, and the gas permeability cannot be lowered.

As shown in FIG. 4, the tail plug 40 has a flange portion 41 that contacts the rear end edge of the ink storage tube 20, a large-diameter portion 42 that fits the inner periphery of the ink storage tube 20, and a tip end side thereof. However, it is composed of a smaller diameter portion 43 having a smaller diameter. At two locations on the front surface and the back surface of the small-diameter portion 43, a notch portion 46 is formed by notching from the leading edge to the step portion 44 between the large-diameter portion 42 and the small-diameter portion 43 (FIG. 4A). ), (C)). Further, protrusion-like locking portions 45 are provided on both side surfaces of the small-diameter portion 43, that is, at a position 90 ° away from the notch 46 with respect to the axis (FIGS. 4A and 4B). . Note that a gate into which resin is injected at the time of injection molding is provided on the bottom surface of the fitting recess 47 in the center portion of the flange portion 41 (FIG. 4D).
The filling of the pressurized gas when the tail plug 40 is assembled to the tube body will be described with reference to FIG.

  In the closed space of the pressure-type writing instrument assembly machine, the small diameter portion 43 of the tail plug 40 is inserted into the rear end hole 27 of the ink containing tube 20 (FIGS. 5A and 5E), and further insertion is advanced. The locking portion 45 formed on the narrow diameter portion 43 of the stopper 40 is brought into contact with the inner peripheral surface of the ink containing tube 20 to temporarily fix it (FIGS. 5B and 5F). Fill. At this time, the pressurized gas is filled into the ink containing tube 20 from the notch 46. From here, the tail plug 40 is further pressed forward to bring the large diameter portion 42 into contact with the inner peripheral surface of the ink containing tube 20 (FIGS. 5C and 5G). Then, the tail plug 40 is completely press-fitted, and the flange portion 41 is brought into contact with the rear end edge of the ink containing tube 20 (FIGS. 5D and 5H). In this state, the cutout portion 46 is located in the ink containing tube 20, so that the communication between the pressurized gas filling portion 22 and the outside is blocked, and the pressurized state of the gas is maintained. In this state, ultrasonic welding is performed, and the assembly of the tail plug 40 is completed.

A convex portion 28 is formed on the inner peripheral surface of the tip portion of the ink containing tube 20 as shown in FIG. The rear end edge 28a of the convex portion 28 is substantially perpendicular to the inner peripheral surface.
The ink containing tube 20 is formed using a mold 60 as shown in FIG. That is, the mold 60 includes a cavity 61 that forms the outer shape of the ink storage tube 20 and a core pin 62 that is inserted into the cavity 61 and forms the internal space of the ink storage tube 20. Resin is injected into the space 66 between the cavity 61 and the core pin 62 to form the ink containing tube 20.
The core pin 62 is divided into a first half part 63 and a second half part 64. The outer diameter of the rear end of the front half 63 is formed slightly smaller than the outer diameter of the front end of the rear half 64, and a step 65 is formed at a place where these abut each other. The step 65 forms a rear end edge 28a of the convex portion 28.

  On the outer periphery of the insertion part 31 of the ball-point pen chip 30, a strip-shaped recess 32 is formed as shown in FIG. The convex portion 28 of the ink containing tube 20 is fitted into the concave portion 32. That is, when the insertion portion 31 of the ballpoint pen tip 30 is press-fitted into the tip hole 26 of the ink storage tube 20, the convex portion 28 of the ink storage tube 20 is fitted into the concave portion 32 of the insertion portion 31. Here, the ball-point pen tip 30 is constantly pressed in the tip direction by the pressurized gas. However, the rear end edge 32a of the concave portion 32 is locked at this position by coming into contact with the rear end edge 28a of the convex portion 28 that stands up substantially at a right angle, and is prevented from coming off in the front end direction.

  The present invention can be used as a ballpoint pen refill for a pressurized ballpoint pen.

10 Ballpoint pen refill 11 Ink
20 Ink storage tube 21 Ink filling part 22 Pressurized gas filling part
23 Rib 24 Thick part 25 Thin part
26 Tip hole 27 Rear hole 28 Projection
28a Rear edge of convex part
30 Ballpoint pen tip 31 Insertion section 32 Recess
32a Rear edge of recess
40 Tail plug 41 Flange part 42 Large diameter part
43 Small diameter part 44 Stepped part 45 Locking part
46 Notch 47 Fitting recess
60 Mold 61 Cavity 62 Core pin
63 First half 64 Second half 65 Step
66 Space between cavity and core pin

Claims (6)

A ballpoint pen refill comprising an ink containing tube that contains ink and contains pressurized gas, a ballpoint pen tip attached to the tip of the ink containing tube, and a tail plug that seals the rear end of the ink containing tube. There,
On the side part of the tail plug,
A large diameter portion that fits into the inner diameter of the ink containing tube;
A small diameter portion loosely fitted to the inner diameter of the ink containing tube;
A locking portion for locking the rear end edge of the ink containing tube before the small diameter portion is inserted and the large diameter portion is press-fitted,
A ballpoint refill comprising a notch portion that is notched to a position closer to the rear end than the locking portion.   2. The ballpoint pen refill according to claim 1, wherein the locking portion is formed as a protrusion protruding from a position avoiding the notch portion in the small diameter portion.   3. The ballpoint pen refill according to claim 1, wherein the tail plug is welded and fixed after being press-fitted into the ink storage tube.   4. The ballpoint pen according to claim 3, wherein the tail plug is made of a laser-impermeable material, and the tail plug attached to the ink storage tube is welded and fixed to the ink storage tube by laser irradiation. Refill.   5. The tail plug is formed by resin injection molding, and a gate position at the time of injection molding is provided at a position avoiding the large diameter portion. Ballpoint pen refill.   6. The ballpoint pen refill according to claim 1, wherein the ballpoint pen tip is attached to the ink containing tube via a joint attached to a tip of the ink containing tube.

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