JP2009008255A - Fixing structure for internal and external member and method for forming fixing structure for internal and external member used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve high fixing force in a fixing structure for a member recess-projection fitted by deforming a wall surface of an inner hole. <P>SOLUTION: In the fixing structure of the member recess-projection fitted by inserting at least a part of one of members into an inner hole of the other member and deforming the wall surface of the inner hole, a partial recession is formed on a distal end of an insertion part to the inner hole of the one member, and a protrusion is formed in the rear of the recession, and the wall of the inner hole of the other member is positioned in the recession. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inner / outer member fixing structure in which at least a part of an inner member is inserted into an inner hole of an outer member and is fitted by an uneven relationship between wall surfaces facing each other.

Conventionally, as a method for inserting and fixing the inner member into the inner hole of the outer member, there are known methods such as press-fitting by making the inner and outer diameters into a press-fitting relationship, and fitting by overcoming by forming convex portions on each outer surface and inner surface. It has been.
Japanese Patent Laid-Open No. 2006-015061 discloses that an indentation burr is generated by pressing a jig on an insertion portion of a member to be inserted into the inner hole of the other member, and a biting portion against the wall of the inner hole of the other member is provided. A fixing method is disclosed (see Patent Document 1).
JP 2006-015601 A

  In the invention described in Patent Document 1, a strong fixing cannot be obtained only by a convex portion that bites into the outer member.

  The present invention provides a fixing structure for an inner / outer member in which at least a part of the inner member is inserted into an inner hole of the outer member and is fitted by a concave / convex relationship between wall surfaces facing each other. The gist is a fixing structure of the inner and outer members in which a concave portion is formed, a convex portion is formed behind the concave portion, and the wall of the inner hole of the outer member is positioned in the concave portion.

Since the concave portion is formed at the distal end of the insertion portion, the meat of the outer member is deformed during insertion and escapes into the concave portion, and the meat for the press-fitting overlap enters the concave portion in a press-fit manner. Press-fit state can be obtained. Further, since the meat of the outer member also wraps around the convex portion, a state in which the protrusion is pressed from the periphery is formed. Since the partial press-fitted state in the concave portion and the state in which the convex portion is pressed from the periphery are alternately formed, a higher fixing force than that obtained by forming the concave-convex relationship or the convex portion is obtained. In other words, rather than pressing only in the radial direction, such as a press-fit relationship between cylindrical materials, a press-fit relationship is formed even in the meat portion that enters the recess, so that the surface area of the press-in wall increases and becomes looser. It is difficult to fix. In particular, it is preferable to use a relatively soft material for the member serving as the outer member because the force of the resin entering the recess increases.
Further, since the concave portion is formed at the tip of the inner member, the concave portion can be easily formed by shearing the end portion of the inner member, and the convex portion is formed by bringing the meat in the concave portion. Therefore, the material of the portion to be the convex portion is compressed, work hardening occurs and it can be made a hard convex portion, and a high convex portion corresponding to the concave portion can be formed, which is preferable. Furthermore, a shear burr can be generated so as to surround the periphery of the recess, and a high fixing force can be obtained by biting into the inner wall of the outer member. Further, there is no cutting residue that forms the convex portion by cutting.

  Since the fixing structure of the member of the present invention is fixed by the relationship in which the concave and convex portions of both members are fitted together, it is a combination of a relatively soft member and a relatively hard member in the sense of absorbing the dimensional accuracy of both. It is preferable. And since it is easier to endure damage in the case of expanding the diameter than in the case of reducing the diameter, it can be said that the relatively soft member that undergoes deformation is preferably an outer member. For example, as a member having an inner hole to be an outer member, a synthetic resin such as polypropylene, polyethylene, polybutylene terephthalate is an inner member, and a member to be inserted into the inner hole is an alloy such as stainless steel or white, It is preferable that it is a hard member compared with an external material.

  The difference between the inner and outer diameters of the outer member and the inner member is an overlap margin part, and the inner wall of the outer member is deformed, but the inner member is formed at the tip of the insertion portion into the inner hole of the outer member. In order to position the outer member in the partial concave portion, it is preferable to set the inner diameter of the outer member so that the inner diameter is a position corresponding to the bottom of the concave portion.

  As a method of forming the above-mentioned partial concave portion and a convex portion behind the concave portion in the inner member inserted into the inner hole of the outer member, a shearing blade that is partially in contact with the tip of the inner member is used. By pushing and pushing in the longitudinal direction of the member, the meat pushed away to the processing end position can be formed in a raised state while the meat of the part is pushed away while being sheared to form a recess. At this time, the meat brought to the periphery of the recess may protrude and rise like a burr.

FIG. 1 shows an example in which the present invention is applied to a ballpoint pen tip and its connecting member in a ballpoint pen.
In other words, it is a so-called refill in which a ballpoint pen tip 1 as a pen tip is connected to an ink tank 3 via a tip holder 2 as a connecting member. It is provided. Of course, since it has the minimum function as a writing instrument that can be gripped and written even in the state of this refill, it has been devised to make it easy to grasp the shape of the member or to write it, and this component configuration will be established as a writing instrument It can also be made.
An insertion portion 1a formed by reducing the diameter of the ballpoint pen tip 1 in a step shape is inserted into the inner hole 2a of the tip holder 2 as an external material.
The ball-point pen tip 1 has an inclined portion 1b that serves as an insertion guide for the inner hole 2a of the tip holder 2 at the rear end. The minimum outer shape portion of the inclined portion 1b is the rearmost end portion of the ball-point pen tip 1. The diameter is smaller than the opening diameter of the inner hole 2 a of the chip holder 2.

  As shown in FIG. 2 which shows the state before the connection between the ball-point pen tip 1 and the tip holder 2, and FIG. 3 which is an enlarged view of the portion I in FIG. 2, the ball-point pen tip 1 (half-sectional view) is an inclination of the insertion portion 1a. A concave portion 1c is formed from the middle of the portion 1b, and the convex portion 1d surrounds the concave portion 1c. The tip of the tip holder 2 (longitudinal sectional view), which is an external material, is made of a synthetic resin such as polypropylene and has a cylindrical shape. The inner surface of the hole 2a is positioned. As shown in FIG. 4 in which the portion II in FIG. 1 in which the ballpoint pen tip 1 and the tip holder 2 have been connected is enlarged, a tip holder 2 in which the insertion portion 1a of the metal ballpoint tip 1 is relatively soft. It is inserted while deforming the inner part of the. While the deformed meat portion is deformed in the direction of swelling outward, the deformed material enters the recessed portion 1c, which is a space portion, in a press-fit manner. In addition, the flesh of the chip holder 2 also wraps around the convex portion 1d and presses the convex portion 1d from the periphery, and the convex portion 1d surrounding the concave portion 1c bites into the inner wall of the chip holder 2 and is high. Fixing force can be obtained.

Next, a part of manufacturing method of the ball-point pen tip 1 in the above example will be described. The process of forming the concave portion 1c and the convex portion 1d surrounding the periphery in the insertion portion 1a will be described.
That is, as shown in FIG. 5, the ball 4 is held by holding the ball 4 and sandwiching the ball-point pen tip 1 having the insertion portion 1a and the inclined portion 1b between the upper pressing jig 5 and the side pressing chuck 6, and from below. The recess forming jig 7 is raised and processed. As shown in FIG. 6, which is an enlarged view of the processed portion (III portion), the recess forming jig 7 has an inclined portion 7 a having a funnel-like diameter as a processed portion, and at the boundary with the inner hole 7 b. A rolling process is performed while applying a shearing force at a certain corner portion 7c, and the outer portion of the insertion portion 1a is pushed up to be deformed to form a recess 1c. FIG. 7 shows a perspective view of the recess forming jig 7. In the inclined portion 7a, horizontal holes 7d from four directions are opened, and the concave portion 1c is formed by the inclined portion 7a between the horizontal holes 7d. By adjusting the number, shape, position, and size of the horizontal holes, it is possible to appropriately adjust the number, shape, position, and size of the recesses 1c. The insertion portion 1a and the portion that is the front portion thereof are formed by a conventionally known method such as cutting or plastic deformation. However, the insertion portion 1a may be formed before forming the concave portion 1c and the convex portion 1d. You may make (however, it is necessary to form the insertion part 1a beforehand).

FIG. 8 shows another example. It is shown as a figure corresponding to the above-mentioned FIG.
The ball tip side surface 1f of the convex portion 1d formed on the ballpoint pen tip 1 is formed upright, and in the state where the connection with the chip holder 2 is completed, the material portion of the chip holder 2 located around the surface 1f is the chip holder. 2 and the ball-point pen tip 1 become a large obstacle part in the direction in which they are separated. As a method for forming such a surface 1f, as shown in FIG. 9, a cylindrical portion 6b having a wall portion 6a at the tip formed integrally with a partial pressing chuck 6 sandwiching the ball-point pen chip 1 is provided along the insertion portion 1a. The process which forms the recessed part 1c is performed. The material deformed by forming the concave portion 1c rises as the convex portion 1d, but it cannot move forward by contacting the wall portion 6a, and an upright surface 1f is formed. is there.

FIG. 10 shows still another example. Similar to the above example, the diagram corresponds to FIG.
In this example, the concave portion 1c is formed by inclining the bottom surface 1e so as to become deeper toward the ball side. That is, since the tip of the bottom surface 1e of the recess 1c is the shallowest portion as the recess, the material of the chip holder 2 that has entered the recess is obstructed when moving in the direction of separating the ball-point pen tip 1 and the chip holder 2. It is formed as a part to become. In order to form such a bottom surface 1e, the bottom surface 1e can be easily formed by applying the slanted inner hole 7b of the recess forming jig 7 and pressing it obliquely. In that case, the recessed part formation jig | tool 7 does not need to be a member with an integrated process part.

The principal part sectional drawing which shows an example. The principal part expanded sectional view which shows an example. The I section enlarged view of FIG. The II section enlarged view of FIG. The longitudinal cross-sectional view which shows a manufacturing method. The III section enlarged view of FIG. The perspective view of a recessed part formation jig | tool. FIG. 4 is a view corresponding to FIG. 4 showing another example. The longitudinal cross-sectional view which shows a manufacturing method. FIG. 4 is a view corresponding to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ball-point pen tip 2 Tip holder 3 Ink tank 4 Ball 5 Upper side pressing jig 6 Side part pressing chuck 7 Recessed part forming jig 1a Insertion part 1b Inclined part 1c Recessed part 1d Convex part 1e Bottom face 1f Ball tip side face 6a Wall part 6b Tube part 7a Inclined part 7b Inner hole 7c Corner part 7d Horizontal hole

Claims (3)

Inserting at least part of the inner member into the inner hole of the outer member, and forming a partial recess on the outer surface of the distal end of the insertion portion of the inner member in the inner / outer member fixing structure that fits by the concave / convex relationship of the wall surfaces facing each other And a fixing structure for the inner and outer members in which a convex portion is formed behind the concave portion and the wall of the inner hole of the outer member is positioned in the concave portion. The member fixing structure according to claim 1, wherein an outer member into which the member is inserted is a soft material rather than the inner member. The recess of the inner member is formed by rolling, a burr of processing deformation that is larger than the inner diameter of the outer member is formed as a protrusion around the recess, the inner member is placed in the inner hole of the outer member, 3. The method for forming an inner / outer member fixing structure according to claim 1, wherein the inner member is pressed while being deformed, and the material of the outer member pushed away enters the concave portion of the inner member.