JP2000006571A - Manufacturing device of ball-point pen tip and ball-point pen tip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a ball-point pen tip having a larger writing angle and less scratches through compression deformation by a simply configured compression tool. SOLUTION: A riveted portion 20 is profiled by being riveted by a riveting tool having a predetermined riveting angle in the tip end of a tip main body 12 with a ball 11 housed therein. An edge 21 to be a tip end outer periphery of the riveted portion 20 by means of a compression tool 40. The compression tool 40 is provided with a compression surface 42 being angled nearer a right angle than the riveting angle. Furthermore, the compression tool 40 has a ball escaping hole 41 to permit the ball 11 to be positioned when the compression surface 42 operates to compression deform the edge 21 at the nearer side of an axis than the compression surface 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the processing of the tip of a ballpoint pen tip, and more particularly to the pressing deformation of the outer edge of the tip of a caulking portion.

[0002]

2. Description of the Related Art A typical structure of a ball-point pen tip will be described with reference to FIG. Here, FIG. 8 is a front sectional view of a typical ballpoint pen tip 10. As shown in FIG. The ballpoint pen tip 10 is a component that constitutes the tip of the ballpoint pen, and the ball 11 that directly contacts the paper surface,
And a chip body 12 holding the chip body.

The tip body 12 is usually formed by cutting a metal cylindrical material such as brass, bronze, nickel silver, stainless steel, or the like. The side surface of the chip body 12 has a tapered portion 13 toward the tip. And the ball at the tip
A ball house 14, which is a space for accommodating 11, is provided. In addition, a back hole 15 extending from the rear end to the front of the ball house 14 and an ink guide hole 16 connecting the back hole 15 and the ball house 14 are also provided. Further, a radial groove 17 which is radially arranged with respect to the ink guide hole 16 and connects the back hole 15 and the ball house 14 is also provided.

[0004] The ball house 14 accommodates the ball 11 made of ceramic, cemented carbide, or the like. Further, in order to hold the ball 11 and prevent the ball 11 from dropping out of the ball house 14, a so-called caulking process is performed in which the tip end diameter of the tip body 12 is reduced by caulking. The tip portion of the chip body 12 reduced in diameter by the caulking process is referred to as a caulked portion 20. Also, this caulking part 20
The angle between the outer surface of
This is referred to as the swaging angle θ.

[0005] The caulking process is performed using a caulking tool having a contact surface having a predetermined caulking angle θ. That is, the contact surface is brought into contact with the tip of the chip body 12 on which the ball 11 is mounted and pressed, or by rotating while pressing,
A crimping portion 20 having a predetermined crimping angle θ is formed.
The caulking portion 20 has a main function of holding the ball 11 as described above, but at the same time, its shape greatly affects the writing quality of the ballpoint pen.

Here, the tip end surface of the chip body 12 is a ring-shaped surface perpendicular to the axis before crimping. However, after the crimping process, this tip surface is also caulked inward, so that the outer edge of the tip of the caulking portion 20 is located at the forefront of the chip body 12. This portion is called edge 21. The angle formed between the tangent line between the edge 21 and the ball 11 and the axis of the ballpoint pen is the maximum angle at which the ballpoint pen can be inclined with respect to the paper surface. This angle is called the tangent angle α. Also,
The greater the angle between the normal of this tangent and the axis of the ballpoint pen, the greater the area in which the ball 11 can contact the paper surface. This angle is referred to as a writing angle β. Therefore, as the tangent angle α decreases, the writing angle β increases.

Therefore, if the edge 21 can be pressed and positioned inward from the tangent, a new tangent and the ball
The contact point with 11 will move outside the original contact point. That is, the tangent angle α can be reduced by an amount corresponding to the pressing, and the area where the ball 11 can come into contact with the paper surface is increased. Further, it is possible to reduce the catch by the edge 21, and it is possible to provide comfortable writing.

Various techniques have been provided for moving or eliminating the edge 21 as described above. One of them is cutting of the edge 21. That is, the edge 21 of the caulking portion 20
By chamfering, chamfering is performed. Further, there is a so-called two-stage crimping process in which the foremost portion of the caulking portion 20 is further caulked inward.

In describing the prior art relating to the two-stage caulking process, the present application filed a patent application and utility model registration application in advance by utilizing the prior art search (Patris) of the Japan Patent Information Organization (JAPIO). Kaihei 8
-67091 and others. Here, referring to FIG. 9 created for comparison with the present invention, FIG.
The technique disclosed in Japanese Patent No. 7091 will be further described.

In the method of manufacturing the ballpoint pen tip 10 shown in FIG. 9, first, the first caulking tool 80 performs a first caulking process before mounting the ball 11 on the ball house 14 at the tip of the tip body 12. A single swaging portion 81 is formed (FIG. 9)
A). Next, after the ball 11 is mounted on the ball house 14 (FIG. 9B), a second crimping process is performed by the second crimping tool 90 to form the second crimp portion 91 (FIG. 9C).
That is.

In FIG. 9C, the second crimping tool 90 used in the second crimping process has a concave contact surface 92 and gives a convex curved surface outside the crimping portion 20. At the same time, the contact surface 92 reduces the length of the portion extending from the tip of the caulking portion 20 toward the ball 11 so that the ball
Contact with 11 is reduced.

[0012]

The area where the ball can come into contact with the paper surface can be increased by either the edge cutting or the two-stage crimping described above. However, for that purpose, the former requires a cutting tool, and the latter requires a caulking tool having a concave contact surface.

Here, in the present invention, without using a cutting tool or a specially shaped caulking tool as described above,
It is an object of the present invention to obtain the same effect as these tools by using a tool having a simple shape. That is, among the present invention, the invention according to claims 1, 2 and 3 is a manufacturing apparatus for manufacturing a ballpoint pen tip having a larger writing angle and less catching by pressing deformation with a pressing tool having a simple shape. The purpose is to provide.

It is another object of the present invention to provide a ballpoint pen tip having a larger writing angle and less catching.

[0015]

SUMMARY OF THE INVENTION In view of the above problems, the invention according to claim 1 of the present invention provides a holder 50 for holding a ballpoint pen tip 10 and a holder 50 for holding the ballpoint pen tip 10.
The tip of the tip body 12 containing the ball 11 is swaged against the ballpoint pen tip 10 held by the
Is a ball-point pen chip manufacturing device including a crimping tool 30 that forms the crimping portion, and a pressing tool 40 that presses and deforms the edge 21 that is the tip outer edge of the crimping portion 20.The crimping tool 30 that forms the crimping portion 20 includes An abutment surface 31 that forms a predetermined caulking angle with respect to the axis of the ballpoint pen tip 10 is provided.
The pressing tool 40 that presses and deforms the pressing surface 42 that forms an angle closer to a right angle than the caulking angle of the caulking tool 30 with respect to the axial direction of the held ballpoint pen tip 10, and on the axial center side of the pressing surface 42. A ball escape hole 41 for positioning the ball 11 when the pressing surface 42 presses and deforms the edge 21.
It is characterized by having.

The "holding device" is a device capable of holding the ballpoint pen tip 10 by a chuck or the like. "Caulking angle"
The term “angle” refers to an angle formed between the outer surface of the tip end of the reduced tip body 12 and the axis of the ballpoint pen tip 10. The “crimping tool” refers to a tool that forms the crimping portion 20 by caulking the tip of the tip body 12 at the above-described crimping angle.

The “edge” refers to the outermost edge of the caulking portion 20 at the forefront. "Pressing tool" refers to the edge 21
Refers to a tool for pressing and deforming. This pressing tool 40
It has a structure as described below. The “pressing surface” is a portion of the pressing tool 40 that directly contacts the ballpoint pen tip 10. The pressing surface 42 is an annular surface having an inclination, and the angle formed by the pressing surface 42 and the axis of the ballpoint pen tip 10 is larger than the caulking angle performed in the caulking step. Also,
The uppermost edge of the pressing surface 42 is located between the planar edge 21 and the ball 11 because the uppermost edge of the pressing surface 42 hits the inner periphery of a ball escape hole 41 described later. That is, the pressing surface 42 does not come into contact with the ball 11. This means that there is no restriction on the angle of the pressing surface 42 in consideration of the contact with the ball 11. Note that the angle here refers to the angle that the pressing surface 42 makes with the axis of the ballpoint pen tip 10. This makes it possible to push down the pressing surface 42 to the inside of the tangent between the edge 21 and the ball 11.

The "ball escape hole" is a vertical hole provided in the same axis as the ballpoint pen tip 10 in order to avoid contact between the pressing tool 40 and the ball 11. The inner circumference is located between the edge 21 on the plane and the ball 11. This ball escape hole 41 can be provided, for example, by piercing a rod-shaped steel material, but if the ball 11 has a depth that allows the ball 11 to escape, it is not a through hole, even if it is a blind hole or a depression. I don't care. Also, the pressing surface 42
Can be manufactured by applying a taper surface of an appropriate angle to the lower end of the ball escape hole 41. Therefore, the pressing tool
40 is a tool of a simple shape, which is easy to manufacture.

The tip of the ballpoint pen tip 10 is processed as follows by the ballpoint pen tip manufacturing apparatus according to the present invention. First, after fixing the chip body 12 with the holder 50, the ball 11 is inserted. Then, a predetermined caulking angle is given to the tip portion of the chip body 12 by the caulking tool 30, and the ball 11 is held.

Next, the pressing surface 42 of the pressing tool 40 is brought into contact with the edge 21 of the caulking portion 20. And press tool 40
Is pressed down. By doing so, the entire circumference of the edge 21 can be pressed at once. Since the pressing surface 42 comes into contact only with the edge 21, the pressing deformation does not reach the inside of the caulking portion 20. Also, as mentioned above,
Since the pressing surface 42 can be easily positioned below the tangent between the edge 21 and the ball 11, only the edge 21 can be pressed and deformed.

(Claim 2) The invention described in claim 2 is characterized in that, in addition to the features of the invention described in claim 1, the pressing tool 40 has an edge.
It is characterized in that it is rotatable around the axis of the ballpoint pen tip 10 when pressing and deforming 21. That is, in the ballpoint pen tip manufacturing apparatus according to the present invention, since the pressing tool 40 is formed to be rotatable, the edge 21 can be pressed and deformed while rotating the pressing tool 40. Thereby, the pressing deformation of the edge can be achieved more reliably.

(Claim 3) The invention according to claim 3 is characterized in that, in addition to the features of the invention described in claim 1 or 2, the holding tool 50 allows the ball-point pen tip 10 to be pressed when the pressing tool 40 presses and deforms the edge 21. Characterized in that it is rotatable about the axis of. That is, in the ball-point pen chip manufacturing apparatus according to the present invention, the holder 50 is rotatable. Therefore, the edge 21 can be pressed and deformed by the pressing tool 40 while the ballpoint pen tip 10 is rotated by the holder 50. Thereby, the pressing deformation of the edge can be achieved more reliably.

According to a fourth aspect of the present invention, there is provided a tip body in which a ball 11 is housed at the tip of a ballpoint pen tip 10.
In the ball-point pen tip 10 in which the crimping portion 20 formed by caulking the tip of 12 at a predetermined crimping angle with respect to the axis of the ball-point pen tip 10 is pressed and deformed at the edge 21 serving as the tip outer edge of the crimping portion 20, An edge surface 22 is formed at an angle closer to a right angle than the caulking angle with respect to the axial direction of the ballpoint pen tip 10.

The "edge surface" refers to a surface formed by pressing and deforming the edge 21 of the caulking portion 20. The edge surface 22 is formed by the pressing tool 40 in the ballpoint pen tip manufacturing apparatus according to the first to third aspects. The ballpoint pen tip 10 according to the present invention is manufactured as follows.

First, after fixing the chip body 12 with the holder 50, the ball 11 is inserted. Then, a predetermined caulking angle is given to the tip portion of the chip body 12 by the caulking tool 30, and the ball 11 is held. Next, the pressing surface 42 of the pressing tool 40 is brought into contact with the edge 21 of the caulking portion 20. Then, the pressing tool 40 is pressed downward. By doing so, the entire circumference of the edge 21 can be pressed at once.

Here, the edge surface 22 is located more inward than the tangent between the edge 21 before the pressure deformation and the ball 11. Therefore, in the ball-point pen provided with the ball-point pen tip 10, it is possible to reduce the engagement of the edge 21 with the paper surface. In addition, the area of the portion where the ball 11 can come into contact with the paper surface can be increased.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. In the ballpoint pen tip manufacturing apparatus according to the present embodiment, a stainless steel columnar material can be held by the holder 50 having the chuck. Further, in addition to a cutting tool for cutting this cylindrical material, a tool such as a drill having various diameters for forming a through hole or a blind hole in the cylindrical material, a crimping tool 30 and a pressing tool 40 described later are provided. . The holder 50 is movable between the above-mentioned tools while holding the columnar member. Thereby, the processing of the ballpoint pen tip 10 is automatically performed.

First, a stainless steel columnar material is held in a holder 50.
Hold with. Then, cutting is performed with a cutting tool to obtain a chip body 12 having a tapered portion 13 on the side surface toward the tip. Also, the back hole 15 from the rear end, the ball house from the front end
Drill 14. Further, the back hole 15 and the ball house 14 are cut and penetrated by a drill having a smaller diameter than the above-mentioned drill to form the ink guide hole 16 and the five radial grooves 17 radially positioned with respect to the ink hole. Let it. The ball 11 made of cemented carbide is mounted on the ball house.

Next, the caulking portion 20 is formed by performing caulking on the axis of the ballpoint pen tip 10 using a caulking tool 30 having a contact surface 31 having a predetermined caulking angle. This is the state shown in FIG. Next, press surface
The pressing deformation of the edge 21 portion is performed using the pressing tool 40 having 42. This is the state shown in FIG.

FIG. 3 is a bottom perspective view of the pressing tool 40. That is, a ball escape hole 41 serving as a through hole is provided in a round bar-shaped steel material. At the lower end of the ball escape hole 41, a pressing surface 42 which is a tapered surface is formed. The angle formed between the pressing surface 42 and the axis of the ballpoint pen tip 10 is closer to a right angle than the above-described caulking angle.

FIG. 4 is an enlarged view showing the contact between the pressing surface 42 and the edge 21. Here, assuming that the diameter of the circumference formed by the edge 21 is E and the diameter of the cross section of the ball on an imaginary plane passing through the circumference is B, this ball escape hole
The inner diameter R of 41 satisfies the following equation. B <R <E Therefore, when the pressing surface 42 is brought into contact with the edge 21,
The pressing surface 42 does not directly contact the ball 11.

Next, the above-mentioned pressing tool 40 is made to coincide with the axis of the ballpoint pen tip 10, and the pressing surface 42 is brought close to the edge 21. Then, the edge 21 is crushed by pressing with the pressing tool 40. Here, since the pressing surface 42 is not in contact with the ball 11 as described above,
The angle of the pressing surface 42 can be made larger than the caulking angle without considering contact with the pressure 11. In addition, the edge 21 can be pressed and deformed below the tangent between the original edge 21 and the ball 11. This is the state shown in FIG.

Finally, when the pressing tool 40 is moved upward, the edge surface 22 having the same inclination as the pressing surface 42 is formed at the caulking portion.
Formed at 20 tips. This is the state shown in FIG. Here, as shown in FIG. 7, the tangent angle α2 after pressing
Becomes smaller than the original tangent angle α1. Therefore, the writing angle β2 after pressing can be made larger than the original writing angle β1. That is, when the edge 21 is pressed, the ball
It is possible to increase the area where 11 can contact the paper surface.

Thus, in the ball-point pen provided with the ball-point pen tip 10 according to the present invention, comfortable writing can be achieved by increasing the writing angle and reducing the edge catching on the paper surface. In addition, by forming the pressing tool 40 so as to be rotatable about the axis of the ballpoint pen tip 10, it is possible to press and deform the edge 21 while rotating the pressing tool 40. Thereby, the pressing deformation can be more effectively achieved. The same effect can be obtained by forming the holder 50 so as to be rotatable about the axis of the ballpoint pen tip 10 instead of the pressing tool 40. Furthermore, the pressing tool 40 and the holder 50 can be formed so as to be rotatable in opposite directions.

Further, the ball escape hole 41 may be a blind hole or a dent, if it does not have to be a through hole, as long as the ball 11 has a depth exceeding the distance that the ball 11 protrudes from the tip of the chip body 12. It suffices for the purposes of the present invention. Furthermore, the above-mentioned pressing tool
In the apparatus for manufacturing a ballpoint pen tip having 40,
The object of the present invention can be achieved by a method of deforming the pressing surface 42 by hitting the edge 21 in addition to the method of pressing and deforming the pressing surface 42 in contact with the edge 21 as described above.

[0036]

With the above arrangement, the present invention has the following effects. That is, according to the first, second and third aspects of the present invention, a manufacturing apparatus for manufacturing a ballpoint pen tip having a larger writing angle and less snagging by pressing deformation with a pressing tool having a simple shape is provided. It is possible to do. In particular, claims 2 and 3
According to the description of the invention described above, in addition to the effect of the invention described in claim 1, it is possible to more reliably perform the pressing deformation of the edge.

According to the fourth aspect of the present invention, it is possible to provide a ballpoint pen tip having a larger writing angle and less catching.

[Brief description of the drawings]

FIG. 1 is a schematic view showing the formation of a caulked portion in a method of manufacturing a ballpoint pen tip according to the present invention. Note that the ballpoint pen tip is shown in a front sectional view.

FIG. 2 is a front sectional view showing a ballpoint pen tip and a pressing tool.

FIG. 3 is a bottom perspective view showing a pressing tool.

FIG. 4 is a front cross-sectional view showing contact between an edge of a caulking portion and a pressing tool.

FIG. 5 is a front sectional view showing the pressing deformation of the edge of the caulked portion by the pressing tool. Note that the original edge portion and the tangent line that have been deformed by pressing are indicated by virtual lines.

FIG. 6 is a front sectional view showing formation of an edge surface.

FIG. 7 is a front sectional view showing changes in a tangent angle and a writing angle before and after pressing an edge.

FIG. 8 is a front sectional view showing a typical shape of a ballpoint pen tip.

FIG. 9 is a schematic view illustrating a caulking process of a ballpoint pen tip according to a conventional technique in a front view. The tip body of the ballpoint pen tip is shown in cross section.

[Explanation of symbols]

10 Ballpoint pen tip 11 Ball 12 Tip body 13 Taper portion 14 Ball house 15 Back hole 16 Ink guide hole 17 Radial groove 20 Crimp portion 21 Edge 22 Edge surface 30 Crimp tool 31 Contact surface 40 Press tool 41 Ball escape hole 42 Press surface 50 Holder 80 First caulking tool 81 First caulking section 90 Second caulking tool 91 Second caulking section 92 Contact surface θ Caulking angle α Tangent angle β Writing angle α1 Original tangential angle α2 Tangent angle after pressing β1 Original writing Angle β2 Writing angle after pressing E Diameter of circumference formed by edge B Diameter of cross section of ball in imaginary plane passing through circumference formed by edge R Inner diameter of ball escape hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Muto 2-5-1-12 Irie, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Inside the Mitsubishi Pencil R & D Center (72) Inventor Yoshihide Ishii Irie-2, Kanagawa-ku, Yokohama-shi, Kanagawa No. 5-12 Mitsubishi Pencil R & D Center F-term (reference) 2C350 HA08 NE02

Claims (4)

[Claims] 1. A holding tool for holding a ballpoint pen tip, a swaging tool for caulking the tip of a tip body containing a ball with respect to the ballpoint tip held by the holding tool to form a swaging portion, And a pressing tool for pressing and deforming an edge serving as a tip outer edge of the caulking portion, wherein the caulking tool forming the caulking portion forms a predetermined caulking angle with respect to the axis of the ballpoint pen tip. The pressing tool that has an abutting surface and presses and deforms the edge includes a pressing surface that forms an angle closer to a right angle than the caulking angle of the caulking tool with respect to the axial direction of the held ballpoint pen tip, and an axial center that is larger than the pressing surface. The ball-point pen tip is characterized in that the ball-point pen tip is provided with a ball escape hole for positioning the ball when the pressing surface presses and deforms the edge. manufacturing device. 2. The ball-point pen tip manufacturing apparatus according to claim 1, wherein the pressing tool is rotatable about the axis of the ball-point pen tip when pressing and deforming the edge. 3. An apparatus for manufacturing a ball-point pen tip according to claim 1, wherein the holder is rotatable about the axis of the ball-point pen tip when the pressing tool deforms the edge. 4. A ball-point pen tip having a caulked portion formed by caulking the tip of a chip body containing a ball at a predetermined caulking angle with respect to the axis of the ball-point pen tip. A ball pen tip having an edge surface which presses and deforms an edge serving as the outer edge of the tip of the pen and forms an angle closer to a right angle than the caulking angle with respect to the axial direction of the ball pen tip.