JP2017094633A - Ball-point pen tip, manufacturing method of the same, and writing instrument including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain soft writing feeling.SOLUTION: A ball-point pen tip includes: a tip body 10 made of a hard material and having a substantially cylindrical shape; a transfer ball 20 rotatably held by a front end side ball house 10a in the tip body 10; and an annular receiving body 30 which receives the transfer ball 20 in the tip body 10 from a rear side and has an ink circulation hole 31 at a center side. The receiving body 30 is formed by a soft material softer than the hard material and is integrally fixed to an inner surface of the tip body 10.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a ballpoint pen tip constituting the foremost end of a ballpoint pen refill, a method for manufacturing the ballpoint pen tip, and a writing instrument including the ballpoint pen tip.

Conventionally, in this type of invention, as described in, for example, Patent Document 1, a transfer ball made of a metal material is rotatably held on the front end side of a chip body formed entirely of a synthetic resin material, There is a ball-point pen tip in which ink supplied from the rear side of the tip body is transferred onto a writing surface such as a paper surface by the transfer ball.
In this prior art, the synthetic resin chip body is slightly elastically deformed by the pressing force when the transfer ball is pressed against the writing surface. Therefore, a general ball-point pen chip in which the transfer ball and the chip body are formed of a hard metal material. Compared to, a soft writing feel can be obtained.

JP 2008-23858 A

However, according to the above prior art, since the entire chip is formed by molding a synthetic resin material, there is a concern that dimensional accuracy may be reduced as compared with the case where a chip body is obtained by cutting a metal material. Is done.
In addition, when writing is performed in a normal writing posture in which the axis of the ball-point pen tip is appropriately inclined with respect to the writing surface, the transfer ball is held by the radial component of the pressing force that the transfer ball receives from the writing surface. There is a possibility that the peripheral wall portion on the front end side of the chip body to be held is bent.
Therefore, in the above prior art, due to the above-described decrease in dimensional accuracy, deflection on the front end side of the chip body, and the like, a partial deviation occurs in the gap dimension between the transfer ball and the chip body inner surface, and the ink discharge amount is reduced. May become unstable.

In view of such problems, the present invention has the following configuration.
A substantially cylindrical chip body made of a hard material, a transfer ball held rotatably on the front end side in the chip body, and receiving the transfer ball from the rear side in the chip body and distributing ink to the center side A ballpoint pen tip that is formed of a soft material softer than the hard material and is integrally fixed to the inner surface of the tip body.

  Since the present invention is configured as described above, a soft writing feel can be obtained and ink can be ejected satisfactorily.

It is a longitudinal section showing an example of a ball-point pen tip concerning the present invention. It is a principal part enlarged view of FIG. An example of a material is shown, (a) is a plan view, and (b) is a longitudinal sectional view. It is a longitudinal cross-sectional view which shows the chip | tip main body in the middle of a process. The chip | tip main body in the middle of the process is expanded and shown, (a) is a fragmentary top view, (b) is a fragmentary longitudinal cross-sectional view. It is a longitudinal cross-sectional view which shows the chip | tip main body immediately after an ink guide groove was formed. The chip body immediately after the ink guide groove is formed is shown enlarged, (a) is a partial plan view, and (b) is a partial longitudinal sectional view. It is a longitudinal cross-sectional view which shows an example of the writing instrument which comprised the ball-point pen tip which concerns on this invention.

One of the features of the ball-point pen tip in the present embodiment is that a substantially cylindrical tip body made of a hard material, a transfer ball held rotatably on the front end side in the tip body, and the transfer ball An annular receiver having an ink circulation hole on the center side and received from the rear side in the chip body, and the receiver is formed of a soft material softer than the hard material and integrated with the inner surface of the chip body Fixed.
Here, the “soft material softer than the hard material” means that the material of the receiver is soft relative to the material of the chip body. Therefore, in the above configuration, the chip body is formed of a metal material, the receiver is formed of a synthetic resin material, the chip body is formed of a synthetic resin material, and the receiver is the chip body. And a mode in which the chip body is formed of a metal material and the receiver is formed of a metal material softer than the metal material of the chip body.
According to the above configuration, since the transfer ball is received by the receiver made of the soft material, a soft writing feel can be obtained, and the dimensional accuracy of the front portion of the chip body from the receiver is lowered. And the deformation can be suppressed, and as a result, the ink can be ejected satisfactorily.

  As another feature, the inner diameter of the chip body is provided with a reduced diameter portion constricted with respect to the front and rear portions, and the receiver is fixed in a substantially cylindrical shape on the inner circumference of the reduced diameter portion. (See FIG. 2).

  As another feature, an annular inclined surface that is reduced in diameter toward the rear is formed from the front end surface of the reduced diameter portion to the front end surface of the receiver (see FIG. 2).

  As another feature, the transfer ball is not in contact with the front end surface of the reduced diameter portion made of the hard material, but is brought into contact with the front end portion of the receiver made of the soft material (see FIG. 2). ).

  Further, as a feature of the method of manufacturing the ballpoint pen tip, a removal process is performed on a material integrally including a soft layer continuous in the axial direction and a hard layer covering the outer periphery of the soft layer and continuous in the axial direction. By applying, the said chip | tip main body which consists of the said hard layer, and the said receiver which consists of the said soft layer were formed (refer FIGS. 3-5).

  Furthermore, as another feature, as a pre-process for performing the removal process, the soft layer is molded into a cylindrical member made of the hard layer to form the material (see FIG. 3).

  Other features include a step of removing the center side of the soft layer to form the ink circulation holes, and a portion of the front side of the ink circulation holes to the hard layer. Forming a front end surface of the body (see FIGS. 4 and 5).

  Further, as another feature, a writing instrument was configured with the ballpoint pen tip (see FIG. 8).

<Specific Embodiment>
Next, specific embodiments having the above characteristics will be described in detail with reference to the drawings.
In the present specification, “front” means the tip direction of the ball-point pen tip, and “rear” means the opposite direction. Further, the “outer diameter direction” means a direction away from the center in the radial direction of the ball-point pen tip, and the “inner diameter direction” means the opposite direction.

  The ballpoint pen chip 1 includes a substantially cylindrical chip body 10 made of a hard material, a transfer ball 20 rotatably held in a ball house 10a on the front end side in the chip body 10, and the transfer ball 20 as a chip body 10 And an annular receiving body 30 having an ink circulation hole 31 on the center side.

The chip body 10 is formed of a hard material into a substantially cylindrical shape having a tapered conical portion on the tip side. Examples of the hard material include stainless steel (Vickers hardness HV 100 to 450), brass (brass: HV 80 to 150), or white (HV 105 to 270), and alloys containing these metals.
In the chip body 10, a ball holding wall surface 11, a reduced diameter portion 12, a tapered hole 13, and a large diameter hole 14 are formed sequentially from the front side, and these internal spaces communicate with each other in the front-rear direction.

The ball holding wall surface 11 is a substantially cylindrical inner wall surface, and has an inward annular protrusion 11 a that is bent in the radially inward direction and contacts the front outer surface of the transfer ball 20 on the front end side.
Further, a constricted diameter reducing portion 12 is provided on the rear side of the ball holding wall surface 11.

  The diameter-reduced portion 12 is a cylindrical hole having a diameter smaller than that of the front-side ball holding wall 11 and a diameter smaller than that of the front end portion of the tapered hole 13 on the rear side of the diameter-reduced portion 12. It is. A receiving body 30 to be described later is fixed to the inner peripheral surface of the reduced diameter portion 12 in a substantially cylindrical shape.

Further, the tapered hole 13 is a substantially truncated cone-shaped hole continuously reduced in diameter toward the front, and a large-diameter hole 14 is continuous at the rear end side of the tapered hole 13. .
The large-diameter hole 14 is formed in a substantially cylindrical shape that continues backward from the rear end of the tapered hole 13.

The receiver 30 is formed in a cylindrical shape from a soft material softer than the hard material forming the chip body 10, and is integrally fixed to the inner peripheral surface of the reduced diameter portion 12 in the chip body 10.
For the soft material, for example, a synthetic resin material such as POM (polyacetal) or PE (polyethylene) is used.
The receiver 30 is integrally formed on the inner peripheral surface of the reduced diameter portion 12 by a manufacturing process described later. The inner peripheral surface of the receiver 30 functions as an ink circulation hole 31 that circulates ink from the rear to the front.

Further, a plurality of ink guide grooves 10b (five in the illustrated example) are formed on the inner peripheral surface of the receiver 30 at equal intervals in the circumferential direction.
Each ink guide groove 10b penetrates the receiver 30 in the front-rear direction. In addition, each ink guide groove 10b penetrates the receiver 30 in the radially outward direction. The bottom portion of the ink guide groove 10b is positioned so as to be recessed in the radially outward direction from the inner peripheral surface of the reduced diameter portion 12. A two-dot chain line in FIG. 2 indicates a radial position of the bottom of the ink guide groove 10b.
As another example of the ink guide groove 10b, a groove formed only in the front portion of the receiver 30 without penetrating the receiver 30 in the front-rear direction may be used.

The front end surface 12a of the reduced diameter portion 12 is formed in an inclined surface shape that is reduced in diameter toward the rear. Similarly, the front end surface 32 of the receiver 30 is also formed in an inclined surface shape whose diameter is reduced toward the rear.
And these two front end surfaces 12a and 32 are connected substantially flush, and comprise the substantially flat cyclic | annular inclined surface diameter-reduced toward back.
The annular inclined surface (front end surfaces 12a and 32), the ball holding wall surface 11 and the like constitute a ball house 10a that rotatably accommodates the transfer ball 20.

The transfer ball 20 is formed in a spherical shape from a hard metal material such as a sintered body mainly composed of tungsten carbide or silicon carbide.
The outer diameter of the transfer ball 20 is set to be larger than the inner diameter of the reduced diameter portion 12 (in other words, the outer diameter of the receiving body 30) and slightly smaller than the inner diameter of the ball holding wall surface 11.

The front half of the transfer ball 20 is pressed against the inward annular protrusion 11 a on the front end side of the ball holding wall surface 11.
The rear half of the transfer ball 20 is received in contact with the front end portion of the receiving body 30 made of a soft material without contacting the front end surface 12a of the reduced diameter portion 12 made of a hard material. The illustrated example will be described in more detail. The rear half of the transfer ball 20 is in contact with the corner where the front end face 32 and the ink circulation hole 31 intersect.

Next, a manufacturing method of the ballpoint pen tip 1 having the above configuration will be described in detail.
The chip body 10 is formed by removing the solid cylindrical material A. Specifically, the removing process is a cutting process (including a grinding process and a polishing process).
The material A integrally includes a soft layer a1 that is continuous in the axial direction and a hard layer a2 that covers the outer periphery of the soft layer a1 and is continuous in the axial direction.
The soft layer a1 is formed in a long cylindrical shape from the soft material (synthetic resin material) described above. The hard layer a2 is formed in a long cylindrical shape from the hard material (metal) described above.
This material A is formed by injecting the soft material into the cylindrical member a2 made of the hard layer a2 and integrally forming the soft layer a1 as a pre-process for performing the removal process.

  The material A having the above-described configuration is first formed into a substantially long shaft shape with the tip side tapered, by removing the outer shape portion.

Furthermore, the material A is processed into a substantially long cylindrical shape by removing the inside.
More specifically, by inserting a plurality of drills or reamers whose diameters are gradually reduced from the rear side of the substantially long shaft-shaped material A, the tapered hole 13 and the large diameter are provided. A hole 14 or the like is drilled.

Next, a drill is inserted into the material A processed as described above in order from the front and the back, and the ink circulation holes 31 are formed through.
Furthermore, by inserting a thicker drill from the front, the ball holding wall surface 11, the front end surface 12 a of the reduced diameter portion 12, the front end surface 32 of the receiver 30, and the like are formed (see FIGS. 4 and 5). ). In addition, the dashed-two dotted line in FIG. 4 shows a drill.

  Next, broaching for inserting the radial sagittal cutting tool b from the front is performed on the material A processed as described above. According to this broaching process, the receiving body 30 and the reduced diameter portion 12 are cut into a vertical groove shape to form a plurality of ink guiding grooves 10b, and the chip body 10 is completed.

  Then, the transfer ball 20 is inserted into the chip body 10 from the front, and the front end side outer peripheral portion of the chip body 10 is crimped. The transfer ball 20 is rotatably held on the front end side in the chip body 10 while partially protruding from the chip body 10.

Next, the writing instrument 100 using the ball-point pen tip 1 having the above configuration will be described (see FIG. 8).
The writing instrument 100 causes the ball-point pen tip 1 at the front end of the ball-point pen refill 120 to protrude from the front end of the shaft tube 110 by a pressing operation of the knock unit 140, and the protruding state is released by an operation of bending the clip 111 toward the center of the shaft tube. It is a retractable ballpoint pen.
The ballpoint pen refill 120 is formed by connecting the ballpoint pen tip 1 to the front end of the ink containing tube 121 and filling the inside thereof with ink.

According to the ballpoint pen tip 1 and the writing instrument 100 having the above-described configuration, when writing is performed by pressing the transfer ball 20 protruding from the front end of the chip body 10 against a writing surface such as a paper surface, the rear side of the transfer ball 20 is soft. Since it is received by the receiver 30 made of a material, a soft writing feel can be obtained.
In addition, since the portion other than the receiver 30 is made of a hard material, the ball holding wall surface 11 and the inwardly facing annular protrusion 11a have relatively high dimensional accuracy and are not easily deformed when subjected to writing pressure. For this reason, the ink discharge amount can be stabilized as well as ink leakage hardly occurs.
In addition, if the writing pressure is too strong and the transfer ball 20 retracts too much, the receiver 30 (soft material) that receives the rear end side of the transfer ball 20 is elastically deformed, and the rear end of the transfer ball 20 The side comes into contact with the front end surface 12a (hard material) of the reduced diameter portion 12. For this reason, the retraction amount of the transfer ball 20 can be regulated, and as a result, it is possible to prevent ink leakage due to the retraction of the transfer ball 20 or the front end surface 32 of the receiver 30 from being sagged. it can.
Furthermore, if writing is performed while the writing pressure is too strong and the transfer ball 20 is retracted too much, the foremost end of the chip body 10 (the corner portion on the outer diameter side of the inwardly facing annular projection 11a) The writing surface may be rubbed, the front end may be worn, the writing surface may be damaged, or the writing feeling may be reduced due to frictional resistance. Can also be resolved.

  In addition, according to the said embodiment, although the receiving body 30 was provided in the inner peripheral surface of the diameter reducing part 12 as a particularly preferable example, as another example, without providing the diameter reducing part 12, a ball holding wall surface It is also possible to adopt a mode in which the receiving body 30 is provided in an annular shape on the inner peripheral surface of the chip body 10 that continues to the lower side of the chip 11.

Further, according to the above embodiment, the front end surfaces 12a and 32 are connected substantially flush with each other and are formed into a substantially flat annular inclined surface that is reduced in diameter toward the rear side. It is also possible to adopt a mode in which the front end surface 12a protrudes forward in a stepped manner, or a mode in which the front end surface 32 is recessed rearwardly from the front end surface 12a.
Further, as another example, one or both of the front end surface 12a and the front end surface 32 are formed in a flat surface substantially orthogonal to the axis, or one or both of the front end surface 12a and the front end surface 32 are recessed. It is also possible to adopt a form formed in a curved surface.

  Further, according to the example shown in FIG. 2, the outer surface of the transfer ball 20 is brought into contact with only the corner portion where the front end face 32 and the ink circulation hole 31 intersect, but as another example, the corner portion on the front end face 32 is used. It is also possible to adopt a mode in which a surface other than that is in contact with the transfer ball 20.

  Moreover, according to the said embodiment, although the ball-point pen tip 1 and the receptacle 30 were formed by cutting, as another example, the ball-point pen tip 1 and the removal by processing other than cutting, such as plasma processing and laser processing, etc. It is also possible to form the receiver 30.

  Moreover, according to the said embodiment, although the soft layer a1 was shape-processed in the inside of the cylindrical member a2 which consists of hard layers, the raw material A was formed, as another example, the cylindrical member which consists of hard layers The material A is formed by press-fitting a shaft-shaped member made of a soft layer into the inside thereof, and the material A is formed by inserting and bonding the shaft-shaped member made of a soft layer inside the cylindrical member made of a hard layer. It is also possible to adopt a formed aspect or the like.

  Further, according to FIG. 8, a monochromatic ballpoint pen is configured as an example of the writing instrument 100 provided with the ballpoint pen tip 1, but other examples of the writing instrument 100 include a multicolored writing instrument provided with a plurality of colors of ballpoint pen refills, and a ballpoint pen refill. It is also possible to constitute a multifunctional writing instrument having a plurality of types of refills such as a pencil refill and a mechanical pen refill.

  Further, the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention.

1: Ballpoint pen tip 10: Chip body (hard material)
10a: Ball house 10b: Ink guide groove 11: Ball holding wall surface 11a: Inward annular protrusion 12: Reduced diameter portion 12a: Front end surface (annular inclined surface)
20: Transfer ball 30: Receptor (soft material)
31: Ink flow hole 32: Front end surface (annular inclined surface)
100: Writing instrument A: Material a1: Soft layer a2: Cylindrical member

Claims (8)

A substantially cylindrical chip body made of a hard material, a transfer ball held rotatably on the front end side in the chip body, and receiving the transfer ball from the rear side in the chip body and distributing ink to the center side An annular receiver having a hole,
The ballpoint pen tip is formed of a soft material softer than the hard material, and is integrally fixed to an inner surface of the tip body.   The reduced diameter part of the shape constricted with respect to the front-and-rear part is provided in the inner peripheral surface of the said chip | tip main body, and the said receiver is being fixed to the inner peripheral surface of this reduced diameter part in the substantially cylindrical shape. Ballpoint pen tip   The ball-point pen tip of Claim 2 in which the cyclic | annular inclined surface which diameter-reduces toward back is formed from the front-end surface of the said diameter reduction part to the front-end surface of the said receiver.   4. The ballpoint pen tip according to claim 3, wherein the transfer ball is brought into contact with a front end portion of the receiver made of the soft material without contacting a front end surface of the reduced diameter portion made of the hard material.   The chip main body made of the hard layer is formed by subjecting a material integrally including a soft layer continuous in the axial direction and a hard layer covering the outer periphery of the soft layer and continuous in the axial direction; The method of manufacturing a ballpoint pen tip according to any one of claims 1 to 4, wherein the receiver made of the soft layer is formed.   The manufacturing method according to claim 5, wherein the material is formed by molding the soft layer inside a cylindrical member made of the hard layer as a pre-process for performing the removing process.   Removing the central side of the soft layer to form the ink circulation hole, and removing the portion on the front side of the ink circulation hole until reaching the hard layer to form the front end surface of the receiver The manufacturing method of Claim 5 or 6 including the process to do.   A writing instrument comprising the ballpoint pen tip according to any one of claims 1 to 4.

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