JP2010173243A - Barrel structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shaft cylinder structure of a writing instrument in which a front shaft and a rear shaft can be connected through a separate joint member without rattling and a highly accurate dimension is not required at the connection portion. There is.
In a shaft structure of a writing instrument in which a front shaft and a rear shaft are connected in an axial direction via a joint member, the joint member is connected to one of the front shaft and the rear shaft. The other member of the front shaft 11 and the rear shaft 12 is screwed into the joint member 13 and brought into contact with the one member. Thus, the minute movement is disabled.
[Selection] Figure 1

Description

  The present invention relates to a shaft tube structure of a writing instrument such as a ballpoint pen, a mechanical pencil, and a sign pen, and more particularly to a shaft tube structure of a writing instrument in which a front shaft and a rear shaft are connected via a joint member.

Conventionally, in this type of shaft tube structure, as shown in Patent Document 1, a middle shaft (1 ′) is screwed and connected to the rear side of the front shaft (1 ″), and the middle shaft (1 ′) is further connected. There is one in which the rear shaft (2) is fitted and connected to the rear side.
In the shaft cylinder structure in which the front shaft (1 ″) and the rear shaft (2) are connected by the middle shaft (1 ′) therebetween as in this prior art, the middle piece (6 in the middle shaft (1 ′)). ) To guide each of the refills (cursive body 4) in the axial direction, or to receive a resilient member (5) for urging the refills backward by the middle piece (6). It is common to have an additional function in 1 ′).

  However, according to the prior art, a structure in which a plurality of cylindrical members are connected in the axial direction may cause rattling in the axial direction or the circumferential direction. More specifically, for example, in a fitting portion between the middle shaft (1 ′) and the rear shaft (2), there is a possibility that one member may rattle in the axial direction or the circumferential direction with respect to the other. . Therefore, in the prior art, in order to prevent the rattling, it is necessary to maintain the size of the fitting portion with high accuracy, which causes a decrease in productivity.

JP 2007-296699 A

  The present invention has been made in view of the above-described conventional circumstances, and the subject of the present invention is that the front shaft and the rear shaft can be connected to each other through a separate joint member without rattling. An object of the present invention is to provide a writing tube shaft structure that does not require high-precision dimensions at a location.

The technical means for solving the above-mentioned problem is a shaft cylinder structure of a writing instrument in which a front shaft and a rear shaft are connected in an axial direction via a joint member, and the joint member is connected to the front shaft and the rear shaft. Fitted to one of the members in a finely movable state, and then the other member of the front shaft and the rear shaft is screwed into the joint member and brought into contact with the one member Thus, the minute movement is disabled.
According to this configuration, first, the joint member is fitted into one of the front shaft and the rear shaft in a state in which the joint member can move minutely. Thereafter, the other member of the front shaft and the rear shaft is screwed into the joint member and abuts against one member. Due to the contact force at this time, the joint member cannot move minutely relative to the one member.

Further technical means is characterized in that the joint member is fitted to one of the front shaft and the rear shaft in a state in which the joint member is minutely movable in the axial direction.
According to this configuration, the joint member is fitted to one member of the front shaft and the rear shaft so as to be movable in the axial direction. After that, the other member of the front shaft and the rear shaft is screwed into the joint member and abuts against the one member, so that the minute movement of the joint member in the axial direction becomes impossible.

In a further technical means, the joint member is fitted to one member of the front shaft and the rear shaft in a state in which the joint member can be slightly moved in the circumferential direction.
According to this configuration, the joint member is fitted to one of the front shaft and the rear shaft in a state in which the joint member can be slightly moved in the circumferential direction. Thereafter, the other member of the front shaft and the rear shaft is screwed into the joint member and abuts against the one member, so that the minute movement of the joint member in the circumferential direction becomes impossible.

Further technical means is characterized in that the front shaft and the rear shaft are brought into contact with each other through a ring member that is annularly attached to the joint member.
According to this configuration, when the other member of the front shaft and the rear shaft is screwed into the joint member, the ring member is sandwiched between the other member and the one member like a washer. Therefore, it is possible to effectively increase the tightening force of the screwed portion by the ring member.

In a further technical means, the one member is used as a rear shaft, the other member is used as a front shaft, and a female screw portion is formed on the inner peripheral surface of the front shaft to be screwed into the joint member. The shaft member structure of the writing instrument in which a male screw part for screwing into the female screw part is formed on the outer peripheral surface of the joint member, the front part of the inner peripheral surface of the front shaft on the front side of the female screw part Is provided with an inclined surface that is reduced in diameter toward the front so that the front end portion of the joint member is slidably contacted when the female screw portion and the male screw portion are moved forward. Features.
According to this configuration, if the female screw portion and the male screw portion are forcibly tightened, the front end portion of the joint member is in sliding contact with the inclined surface of the inner peripheral surface of the front shaft. The female screw portion and the male screw portion are disengaged by elastic deformation or the like (the male screw portion rotates in opposition to the female screw portion). Therefore, it is possible to prevent the fitting member and the rear shaft from being disengaged or the rear shaft from being damaged by the forcible tightening.

Since the present invention is configured as described above, the following effects can be obtained.
Since the joint member and one of the front shaft and the rear shaft are fitted in such a manner that they can be moved minutely during assembly, the dimensional accuracy of the fitting portion can be relatively lowered. it can.
Moreover, since the other member of the front shaft and the rear shaft is finally screwed into the joint member and brought into contact with the one member, the fitting portion is not rattled by the minute movement. Can be in a state.
Therefore, it is possible to connect the front shaft and the rear shaft without rattling through separate joint members, and it is not necessary to provide a highly accurate dimension at the connection portion between the front shaft and the rear shaft.

It is a longitudinal cross-sectional view which shows the axial cylinder structure of the writing instrument which concerns on this invention. An example of the coupling member used for a coaxial cylinder structure is shown, (a) is a side view, (b) is a rear end view. It is a principal part half sectional view for demonstrating the assembly procedure of a coaxial cylinder structure, (a) shows the state before the engaging part 12a climbs over the to-be-engaged part 13c, (b) is engaging. A state where the portion 12a is fitted over the engaged portion 13c is shown. It is a principal part half sectional view for demonstrating the effect | action of a coaxial cylinder structure, (a) shows the state which the engaging part was located in the rear end side of the annular recessed part, (b) is an engaging part in an annular recessed part Shows the state of moving forward. It is principal part half sectional drawing for demonstrating the assembly procedure of a coaxial cylinder structure, (a) shows the state which assembled | attached the ring member, (b) shows the state which screwed the front shaft. It is the (VI)-(VI) sectional view taken on the line in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The writing instrument A includes a shaft tube 10, a slide operation body 20 that can be advanced and retracted while being exposed on the outer periphery of the shaft tube 10, and a pusher that can be moved forward by being pushed by the slide operation body 20. And a urging member 50 for urging the pusher 30 and the refill 40 rearward, and the pusher 30 and the refill as the slide operation body 20 advances. 40 is a retractable writing instrument in which the writing part 41 at the front end of the refill 40 is protruded from the front end part of the shaft tube 10 by moving forward.

In the present specification, “front” means the direction in which the writing portion 41 protrudes (downward according to FIG. 1) in the axial direction of the barrel 10, and “rear” refers to the “front”. It shall mean the reverse direction.
Further, in this specification, “shaft centripetal direction” means a direction approaching the center of the shaft tube 10 (in other words, a reduced diameter direction), and “shaft tube centrifugal direction” means from the center of the shaft tube 10. It means the direction away (in other words, the diameter expansion direction).

  Further, a plurality of (eg, three) slide operating bodies 20, pushers 30, refills 40, and urging members 50 are provided at intervals in the circumferential direction. However, according to FIG. By omitting, the characteristic internal structure of the writing instrument A is clearly expressed.

  The shaft tube 10 is formed by connecting a front shaft 11 and a rear shaft 12 in the axial direction via a joint member 13 and a ring member 15.

The front shaft 11 is formed from a synthetic resin material, has a tapered cylindrical tip 11a on the front end side, and a female screw portion for screwing and connecting a joint member 13 described later to the inner peripheral surface on the rear end side. 11b.
According to a preferred example of the present embodiment, the screw shape of the female screw portion 11b is a screw having a trapezoidal cross section (so-called trapezoidal screw).
An annular inclined surface 11c (see FIG. 5B) that gradually decreases in diameter toward the front is provided on the front side of the inner peripheral surface of the front shaft 11 relative to the female screw portion 11b.

  The inclined surface 11c is arranged at a predetermined interval in front of the outer peripheral edge 13f of the front end of the female screw portion 11b.

The rear shaft 12 is formed in a substantially cylindrical shape from the same synthetic resin material as the front shaft 11. An engagement portion 12 a having a convexly curved cross section is provided on the inner peripheral surface of the front end side of the rear shaft 12.
The engaging portion 12a protrudes in the shaft tube centripetal direction over the entire circumference of the rear shaft 12, and rides over and engages with an engaged portion 13c of the joint member 13 described later.

Further, on the rear side of the engagement portion 12a on the inner peripheral surface of the front end side of the rear shaft 12, a convex portion 12d that fits the concave portion 13e on the outer peripheral surface of the joint member 13 so as to be movable in the circumferential direction is provided. (See FIG. 3).
The projecting portion 12d is a protrusion that protrudes from the inner peripheral surface of the rear shaft 12 in the shaft tube centripetal direction and extends in the shaft tube shaft direction, and when the rear shaft 12 is put on the joint member 13 from the rear side, The member 13 is inserted from the rear into the recess 13e on the rear end side of the outer peripheral surface.

Further, a stepped portion 12e is provided on the rear side of the front end side inner peripheral surface of the rear shaft 12 so as to receive the joint member 13 when it is slightly moved rearward.
According to the illustrated example, the stepped portion 12e is a front end portion of a protrusion formed on the inner peripheral surface of the rear shaft 12, and a plurality of the stepped portions 12e are provided at intervals in the axial tube circumferential direction.

  The peripheral wall on the rear end side of the rear shaft 12 is formed with a guide hole 12b that penetrates in the axial cylinder radial direction and guides the slide operation body 20 and the pusher 30 to advance and retreat (see FIG. 1). The rear end opening of the rear shaft 12 is closed by a tail plug 14.

  The guide hole 12b is a through hole formed so as to engage the slide operation body 20 and the pusher 30 so as to be able to advance and retreat. According to the illustrated example, the guide hole 12b is formed in a long shape extending in the axial direction.

In the guide hole 12b, two latching portions 12f are provided on the peripheral wall of the shaft tube 10 so as to sandwich the advance / retreat path of the pusher 30 therebetween.
Each latching portion 12f is formed in a stepped shape on the peripheral wall of the shaft tube 10 so that the rear end portion of the pusher 30 is locked when the pusher 30 moves forward and sinks in the shaft tube centripetal direction. Has been.

  Further, the joint member 13 is a substantially bottomed cylindrical member that extends from the rear end side inside the front shaft 11 to the front end side inside the rear shaft 12, and is formed on the front end side outer peripheral surface as shown in FIG. A male screw portion 13a, a ring locking portion 13b formed on the rear end side of the male screw portion 13a, an engaged portion 13c formed on the rear end side of the ring locking portion 13b, A rear end wall portion 13d provided so as to intersect the shaft center on the rear end side with respect to the engaged portion 13c, and a convex portion 12d on the inner peripheral surface of the rear shaft 12 at the outer peripheral portion of the rear end wall portion 13d. And a recess 13e that fits into the.

  The male screw portion 13 a is a trapezoidal screw (so-called trapezoidal screw) that is screwed with the female screw portion 11 b on the inner peripheral surface of the rear end side of the front shaft 11.

The ring locking portion 13b is an annular recess for fitting a ring member 15 described later.
Note that, according to the illustrated example, the ring member 15 is fitted to the concave ring locking portion 13b. However, as another example, the ring locking portion 13b is formed in a convex shape, and the inside of the ring member 15 is formed. The peripheral surface may be formed in a concave shape, and these may be fitted together.

  The engaged portion 13c includes an annular convex portion 13c1 for getting over and fitting the engaging portion 12a in the rear shaft 12, and an annular concave portion for fitting the engaging portion 12a after getting over the annular convex portion 13c1. 13c2 (see FIG. 3).

The annular protrusion 13c1 includes an annular inclined surface 13c11 that gradually increases in diameter toward the front, and an annular flat surface 13c12 that protrudes in a substantially cylindrical outer peripheral surface on the front side of the inclined surface 13c11.
According to this configuration, when the rear shaft 12 is fitted to the joint member 13, the annular engaging portion 12a is gradually expanded in diameter elastically along the inclined surface 13c11, overcoming the flat surface 13c12, It will fit into the recess 13c2.

The annular recess 13c2 is formed so as to fit the engaging portion 12a when the annular recess 13c1 is overcome.
More specifically, the annular recess 13c2 includes an annular flat surface 13c21 serving as a bottom surface portion, and an annular inclined surface 13c22 that gradually increases in diameter toward the front side of the flat surface 13c21. (See FIG. 2A).
The annular recess 13c2 has an axial total length w2 (see FIG. 3A) composed of the flat surface 13c21 and the inclined surface 13c22, which is larger than the axial dimension w1 of the engaging portion 12a of the rear shaft 12. It is set large. According to this configuration, the rear shaft 12 can be moved minutely in the axial direction relative to the joint member 13.

  The rear end wall portion 13d is provided so as to be substantially orthogonal to the axial center of the shaft so as to close the rear end opening of the cylindrical rear shaft 12, and has a guide rod 13d1 protruding rearward at the center thereof. In addition, the guide rod 13d1 has guide holes 13d2 through which the plurality of refills 40 are inserted (see FIG. 2).

The guide bar 13d1 is a long bar-shaped portion having a triangular cross section and extending in the axial direction of the shaft cylinder.
The guide hole 13d2 is a plurality of through holes provided around the guide rod 13d1 at intervals in the circumferential direction.
The guide bar 13d1 and the guide hole 13d2 prevent the plurality of refills 40 from interfering with each other, and smoothly advance and retract each refill 40.

  The rear end surface around each guide hole 13d2 in the rear end wall portion 13d functions as a surface that receives the front end of the biasing member 50.

Moreover, the recessed part 13e is a groove | channel recessed in the axial direction at the rear-end side outer peripheral surface of the coupling member 13. As shown in FIG. The rear end portion of the concave portion 13e is opened so that the convex portion 12d on the inner peripheral surface of the rear shaft 12 can be inserted from the rear side (see FIG. 3).
A width w3 of the concave portion 13e in the axial tube circumferential direction is set larger than a width w4 of the convex portion 12d in the axial tube circumferential direction.
A plurality (three in the example of FIG. 6) of the recesses 13e are provided at intervals in the circumferential direction. And the productivity at the time of connecting the rear axis | shaft 12 with respect to the joint member 13 is made favorable by enabling fitting of the convex part 12d with respect to either of these some recessed parts 13e.

  As other examples, it is also possible to adopt a mode in which the number of the concave portions 13e is made to correspond to the number of the convex portions 12d, a mode in which the plurality of concave portions 13e and the plurality of convex portions 12d are respectively fitted, or the like.

  The slide operating body 20 is engaged with the guide hole 12b on the rear end side of the rear shaft 12 so as to advance and retract substantially parallel to the center line of the shaft tube 10 while being exposed on the outer peripheral portion of the shaft tube 10. Yes.

  In addition, the pusher 30 is pushed by the slide operation body 20 in a state in which the pusher 30 is in the shaft 10, and moves forward and retracts by the urging force of the urging member 50. 12b is engaged.

  The guide hole 12b penetrates the peripheral wall on the rear end side of the rear shaft 12 in the axial cylinder axial direction in the axial cylinder radial direction, and engages with the slide operating body 20 and the pusher 30 so that these slide operating bodies 20 are engaged. And the pusher 30 is formed to slide in the axial direction.

Further, according to the illustrated example, the refill 40 is a ballpoint pen refill including a writing unit 41 that is a ballpoint pen tip and an ink tank 42 connected to the rear end side of the writing unit 41. The rear end portion is connected to the front end of the presser 30 in a state where the biasing member 50 is annularly mounted.
The refill 40 can be a mechanical pencil refill instead of the ballpoint pen refill.

  The urging member 50 is a coil spring that is annularly mounted on the rear end side of the refill 40. The front end side of the urging member 50 is received by the joint member 13, and the pusher 30 and the refill 40 are urged rearward by the rear end portion. ing.

Next, the characteristic effect of the writing instrument A having the above configuration will be described in detail.
In the manufacturing process of the writing instrument A, as shown in FIG. 3A, the rear shaft 12 is annularly covered on the rear end side of the joint member 13 (in other words, the rear end of the rear shaft 12 is connected to the rear end of the joint member 13). When the rear shaft 12 is pressed against the joint member 13 by inserting the end side), the engaging portion 12a on the inner peripheral surface of the rear shaft 12 is inclined on the rear end side of the engaged portion 13c on the outer peripheral surface of the joint member 13. It abuts on the surface 13c11 (see FIG. 2).

  When the rear shaft 12 is further pushed forward and moved, as shown in FIG. 3B, the engaging portion 12a rides on the annular convex portion 13c1 of the engaged portion 13c while elastically expanding its diameter. Thereafter, the elastic member is elastically reduced in diameter, gets over the engaged portion 13c, and fits into the annular recess 13c2.

In this fitted state, the dimension w2 of the annular recess 13c2 in the axial cylinder axis direction is larger than the dimension w1 of the annular projection 13c1 in the axial cylinder axis direction. A minute movement is possible.
More specifically, the rear shaft 12 is opposed to the joint member 13 and can move back and forth between the state shown in FIG. 4A and the state shown in FIG.

In addition, the state of Fig.4 (a) shows the state which the engaging part 12a contacted the cyclic | annular convex part 13c1 in the rearmost end side in the cyclic | annular recessed part 13c2.
4B, when the rear shaft 12 moves forward relative to the joint member 13, the engaging portion 12a is separated from the annular convex portion 13c1, and the step portion 12e in the rear shaft 12 is connected to the joint member. The state which contact | abutted to the rear-end surface of 13 is shown.

  And in the said fitting state, as shown in FIG. 6, since the dimension w3 of the axial cylinder circumferential direction of the recessed part 13e is larger than the dimension w4 of the axial cylinder circumferential direction of the convex part 12d, the rear axis | shaft 12 is a joint member. 13 is in a state that can be finely moved (smallly rotated) in the circumferential direction of the shaft cylinder.

  Next, the ring member 15 is fitted to the ring locking portion 13 b on the outer peripheral surface of the joint member 13. In this state, the ring member 15 is slightly movable back and forth within the ring locking portion 13b.

  Then, the female screw portion 11b on the inner peripheral surface of the rear end side of the front shaft 11 is screwed into the male screw portion 13a of the joint member 13, and the front shaft 11 is tightened, so that the rear end portion of the front shaft 11 becomes a ring. The ring member 15 is pressed against the member 15, and the ring member 15 is pressed against the front end portion of the rear shaft 12.

Therefore, in the state where the front shaft 11 is tightened, as shown in FIG. 5B, the ring member 15 is positioned in the ring locking portion 13b, and the engaging portion 12a is on the rear end side in the annular recess 13c2. The state comes into contact with the annular projection 13c1, and this contact state is maintained by the pressure contact force between the front shaft 11 and the rear shaft 12, and the rear shaft 12 is fixed so as not to rattle in the front-rear direction.
Further, the rear shaft 12 is fixed to the joint member 13 so as not to rattle in the circumferential direction by the pressure contact force between the front shaft 11 and the rear shaft 12.

  That is, according to the writing instrument A having the above-described configuration, before the front shaft 11 is fastened to the joint member 13, the rear shaft 12 is fitted to the joint member 13 in a state in which the rear shaft 12 can be slightly moved in the axial direction and the circumferential direction. Therefore, it is not necessary to maintain the dimensions of the engaging portion 12a, the engaged portion 13c, the convex portion 12d, the concave portion 13e, and the like, which are the fitting portions of the rear shaft 12 and the joint member 13, with the front shaft. 11, the productivity of the rear shaft 12 and the joint member 13 can be improved.

Further, as described above, the front shaft 11 is forcibly tightened against the joint member 13 by mischief or the like in a state where the front shaft 11, the rear shaft 12, the joint member 13, and the ring member 15 are assembled. In this case, the joint member 13 moves forward, and the rear end surface 15a of the ring member 15 abuts against the rear end portion 13b1 of the ring locking portion 13b, so that the joint member 13 is prevented from moving forward.
In this state, when the front shaft 11 is further forcibly tightened, the ring member 15, the front shaft 11, and the like are elastically deformed, and the joint member 13 further moves forward, and the front end of the joint member 13 is Since the outer peripheral edge 13f (see FIG. 5B) is in sliding contact with the inclined surface 11c, elastic deformation of the rear end side portion of the front shaft 11 in the axial tube centrifugal direction is promoted, and the female screw portion 11b and the male screw portion 13a (In other words, the female screw portion 11b is idle with respect to the male screw portion 13a).
Therefore, due to the forceful tightening, the engaging portion 12a on the inner peripheral surface of the rear shaft 12 gets over the annular convex portion 13c1 on the outer peripheral surface of the joint member 13 in the reverse direction (upward in the drawing), and the rear shaft 12 and the joint member 13 Can be prevented from coming off.

  According to the above-described embodiment, the joint member 13 is fitted to the rear shaft 12 so as to be slightly movable, and then the front shaft 11 is screwed into the joint member 13 and brought into contact with the rear shaft 12. However, as another example, the joint member 13 is fitted to the front shaft 11 in a state where the joint member 13 can be slightly moved, and then the rear shaft 12 is screwed to the joint member 13. It is also possible to adopt a configuration in which the minute movement is made impossible by contacting the front shaft 11.

  Moreover, according to the said embodiment, it was set as the structure which contact | abuts the front axis | shaft 11 and the rear axis | shaft 12 via the ring member 15 with which the joint member 13 is mounted | worn cyclically | annularly. The ring member 15 may be omitted, and the front shaft 11 and the rear shaft 12 may be in direct contact with each other.

  Moreover, although the said embodiment was applied to the structure which connects the front axis | shaft 11 and the rear axis | shaft 12 with the coupling member 13 in the writing instrument which has the some refill 40 as a particularly preferable example, as another example, You may apply to the structure which connects the front axis | shaft and rear axis | shaft of a writing instrument which has a refill by a coupling member.

DESCRIPTION OF SYMBOLS 10: Shaft cylinder 11: Front shaft 11b: Female screw part 12: Rear shaft 12a: Engagement part 13: Joint member 13c: Engagement part 13c1: Annular convex part 13c2: Annular concave part 15: Ring member A: Writing instrument

Claims (5)

In the shaft tube structure of the writing instrument in which the front shaft and the rear shaft are connected in the axial direction via a joint member,
The joint member is fitted to one of the front shaft and the rear shaft in a state of being minutely movable, and then the other member of the front shaft and the rear shaft is screwed onto the joint member. A shaft cylinder structure of a writing instrument, wherein the minute movement is made impossible by being brought into contact with the one member.   The shaft cylinder structure of a writing instrument according to claim 1, wherein the joint member is fitted to one member of the front shaft and the rear shaft in a state of being minutely movable in the axial direction.   The shaft cylinder structure of a writing instrument according to claim 1 or 2, wherein the joint member is fitted to one member of the front shaft and the rear shaft in a state in which the joint member is minutely movable in the circumferential direction.   The shaft cylinder structure of a writing instrument according to any one of claims 1 to 3, wherein the front shaft and the rear shaft are brought into contact with each other through a ring member that is annularly attached to the joint member. . The one member is a rear shaft, the other member is a front shaft, and a female screw portion is formed on the inner peripheral surface of the front shaft to be screwed into the joint member. A shaft tube structure of a writing instrument in which a male screw part for screwing into the female screw part is formed,
A front end portion of the joint member when the female screw portion and the male screw portion are moved forward is slidably contacted with a portion on the front side of the female screw portion on the inner peripheral surface of the front shaft. The shaft cylinder structure of a writing instrument according to any one of claims 1 to 4, further comprising an inclined surface that decreases in diameter toward the front.

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