JP2014105724A - Stopper structure for screw member and writing instrument with stopper structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stopper structure for a screw member in which it may be easily manufactured in less-expensive cost.SOLUTION: This invention relates to a stopper structure for a screw member (1) for stopping releasing from each other after a male threaded part (33) formed at the outer wall of a male threaded member (3) that can be resiliently deformed is threadably engaged with a female threaded part (54) formed at the inner peripheral wall of an opening (51) opened at the female threaded member (5). When the male threaded part is threadably engaged with the female threaded part, an annular protrusion (35) receiving an external force from the inner peripheral wall of an annular feeding groove (59) is resiliently deformed and released from the annular feeding groove and enters into an annular fitting groove (57) and the annular protrusion entered into the annular fitting groove is resiliently returned back to abut against a step (58) between the annular fitting groove and the annular feeding groove to perform a stopping action. Since its structure is simple, it can be manufactured in less-expensive cost.

Description

  The present invention relates to a screw member retaining structure and a writing instrument having the retaining structure.

  A screw member retaining structure (conventional retaining structure) for retaining a screw member, in which the head and the threaded portion are connected by a shaft portion thinner than the threaded portion, rotatably supported in a mounting hole of a resin molded product. Patent Document 1 discloses this. More specifically, the mounting hole of the resin molded product is provided with an elastic claw that is elastically deformable on the outer peripheral side with an inner diameter smaller than the outer diameter of the screw portion and the head, and the elastic claw is When the screw member is inserted into the mounting hole, the screw member is pushed and widened to allow passage of the screw portion, and is restored after the screw portion passes and is engaged with the screw portion and the head. Thus, the screw member is prevented from coming off.

  On the other hand, in Patent Document 2, a core mechanical pencil and a plurality of refills having different colors are accommodated in a shaft cylinder so that they can be moved in and out, and mechanical pencils and refills of different colors are received from the shaft cylinder according to the user's request. There has been disclosed a writing instrument structure (conventional writing instrument structure) that can be used for writing. More specifically, a refill holding pipe (12) formed by inserting and holding the refill (11) is inserted into a part of the outer wall so that it can be freely inserted into the refill holding groove (17) from the side surface direction. A notch (18) is drilled in the front-rear direction, and an elastic locking claw (19) protruding from the left and right in the circumferential direction is provided at the substantially tip of the notch (18). The refill holding pipe (12) formed by holding the refill (11) integrally is held together with the spring (15) in the holding groove (17) of the refill holding pipe guide (10).

JP 2002-39145 A (paragraphs 0007 and 0008, FIG. 1) JP 2001-129189 A (paragraph 0015, FIG. 2)

  However, the conventional retaining structure is prevented by the deformation and elastic return of the elastic claw at the time of insertion. Such an elastic claw is functionally possible, but it is not possible because the structure becomes complicated. It may not be a shape that can be easily molded. Therefore, the molding die becomes complicated, and as a result, the manufacturing cost increases. Therefore, there is a problem that it is difficult to realize the conventional retaining structure in terms of cost even if it is applied to the writing instrument described below.

  In addition, the above-mentioned writing instruments can be reassembled and reattached by disassembling the shaft cylinder or removing the tip mechanism from the core pipe each time a sharp core (lead core) is refilled or the refill is replaced. It is very troublesome, and if the shaft tube is disassembled, other parts housed in the shaft tube are often lost. In this respect, according to the conventional writing instrument structure, since the refill holding pipe and the spring are integrally held, at least the spring is less likely to be lost. However, the conventional writing instrument structure has a problem in that it is expensive because it has a large number of parts and a complicated structure for the purpose of preventing the loss of the spring.

  The technical problem to be solved by the present invention is to eliminate the above-described problems, and to provide a screw member retaining structure that is easy to manufacture and inexpensive, and a writing instrument having the retaining structure.

  In order to achieve the above object, the present invention employs the following configuration. It should be noted that the definitions and the like made in explaining the invention described in any claim are applicable to the inventions of other claims as far as possible in the nature, regardless of the order of description.

(Characteristics of the invention of claim 1)
The screw member retaining structure according to the first aspect of the present invention (hereinafter referred to as “structure of claim 1”) includes a male screw portion having an outer diameter R1 formed on the outer wall of the elastically deformable male screw member. This is a screw member retaining structure for retaining each other after being screwed into a female thread portion having an inner diameter r1 formed on an inner peripheral wall of the opening portion opened in the female screw member. The male screw member is generally made of a resin, but may be a metal or the like as long as it can be elastically deformed. Here, an annular protrusion having an outer diameter R2 (R2> R1) that is substantially concentric with the male screw portion is provided in a portion of the male screw member that is farther from the female screw portion than the male screw portion. At least one escape hole for allowing the annular projection to be reduced to a maximum outer diameter R3 (not shown, R3 ≦ R1) is formed by penetrating elastically by an external force, and the female screw on the inner peripheral wall of the opening is formed. An annular fitting groove having an inner diameter r2 (r2> r1) is provided on the opening end side from the portion, and an annular introducing groove having an inner diameter r3 (R1 <r3 <r2) is provided on the opening end side from the annular fitting groove. Is formed. The structure according to claim 1 having the above-described configuration is such that when the male screw portion is screwed into the female screw portion, the annular protrusion receiving an external force from the inner peripheral wall of the annular introduction groove is elastically deformed to pass through the annular introduction groove. The annular protrusion entering the annular fitting groove is elastically restored so as to be inserted into the fitting groove, thereby coming into contact with the stepped portion between the annular fitting groove and the annular introduction groove to prevent it from coming off. It is characterized by.

  According to the structure of the first aspect, the male screw member and the female screw portion are coupled with each other by screwing the male screw portion and the female screw portion, and the coupling release due to the disconnection is suppressed. In other words, when the male screw part is inserted into the opening and screwed into the female screw part, the annular protrusion is elastically deformed into the male screw member by receiving external force from the inner peripheral wall of the annular introduction groove abutted by the screw advancement. Thus, the size is reduced to a size that can pass through the annular introduction groove. It is the escape hole that enables this reduction. If there is no escape hole, the annular protrusion that has received an external force is deformed but difficult to reduce, but at least a part of the meat of the annular protrusion is released to the escape hole as the escape hole is deformed. Further progress of the screw causes the annular protrusion to enter the annular fitting groove, where it elastically returns to a state having a larger diameter than the inner diameter of the annular introduction groove. As a result, even if an external force in the direction opposite to the direction of screw advancement is applied to the male screw member, the annular protrusion comes into contact with the stepped portion and is prevented from coming off. Since the above-described effects are realized by a very simple structure, the structure of claim 1 is a screw member retaining structure that is easy to manufacture and inexpensive.

(Characteristics of the invention described in claim 2)
The screw member retaining structure (hereinafter referred to as "structure of claim 2") according to the invention of claim 2 is the structure of claim 1, wherein the inner peripheral wall of the annular introduction groove is the female screw portion. And an inclined surface (tapered surface) whose radius gradually decreases toward the surface.

  According to the structure of claim 2, in addition to the operational effect of the structure of claim 1, the annular protrusion comes into contact with the inclined surface that narrows toward the male screw portion, so that the reduction accompanying the progress of the screw is gradually and smoothly performed. Can be done.

(Characteristics of Claim 3)
The screw member retaining structure (hereinafter referred to as "structure of claim 3") according to the invention of claim 3 is the structure of claim 1 or 2, wherein the annular fitting groove, the female screw portion, A connecting groove surrounded by an inclined surface which is continuous with the inner peripheral wall of the annular fitting groove and gradually decreases in radius toward the female screw portion is formed between the connecting groove and the inner groove.

  According to the structure of claim 3, in addition to the function and effect of the structure of claim 1 or 2, the tip of the male screw part to be inserted into the female screw part is guided by the inclined surface surrounding the connecting groove. Can be performed smoothly. This action is not directly related to the retaining of the screw member, but if the insertion is not performed smoothly, there is a possibility that the male screw part and the female screw part may not be screwed correctly, and this may be wiped off. It is a premise for proper retention. That is, the smooth insertion indirectly exerts the retaining action.

(Feature of the invention of claim 4)
The writing section according to the invention of claim 4 (hereinafter referred to as “writing instrument of claim 4”) includes a shaft cylinder having a tip end portion and a rear end portion, and a direction of the rear end portion by a return spring in the shaft cylinder. And at least one refill provided so as to be slidable by a knocking operation of the knock member, and the spring member in which the knock member and the refill are coupled, and the return spring and the lock mechanism are accommodated And a refill pressing member that immerses into the spring housing body and returns with the urging force of the return spring while compressing the return spring, wherein the refill pressing member is a male screw member according to any one of claims 1 to 3. And the knock member is constituted by the female screw member according to any one of claims 1 to 3. It is characterized in.

  According to the writing instrument of the fourth aspect, the refill slides against the return spring by knocking the knock member, and writing is possible with the tip protruding from the tip of the shaft tube by the locking action of the lock mechanism. become. The return of the refill is performed by the return force of the return spring. Here, since the retaining structure according to any one of claims 1 to 3 is included between the refill pressing member and the knocking member, the refilling member is prevented from slipping out of the knocking member (or vice versa). As a result, even if the writing instrument is disassembled during replacement of the refill member (for example, replacement of a used ballpoint pen core or refilling the mechanical pencil), the return spring or knock member in the spring housing is lost. The fear of doing is dispelled.

  According to the present invention, it is possible to provide a screw member retaining structure that is easy to manufacture and inexpensive, and a writing instrument having the retaining structure.

It is a top view (a female screw part is a longitudinal section) showing a screw member before screwing. It is a top view which shows the screw member after screwing (a female screw part is a longitudinal section). It is a top view of a writing instrument. It is sectional drawing of the writing instrument shown in FIG. It is a top view of a spring container. It is a fragmentary sectional view of the spring container shown in FIG.

  A mode for carrying out the invention (hereinafter referred to as “this embodiment” as appropriate) will be described with reference to the drawings. Here, first, a retaining structure for a screw member will be described as the present embodiment, and then a writing instrument will be described as an application example of the present embodiment.

(Outline of screw member retaining structure)
As shown in FIGS. 1 and 2, the screw member 1 of this embodiment includes a male screw member 3 and a female screw member 5 that are screw-connected to each other. The screw member 1 may be a member for connecting members not shown in the figure, attaching another member to a certain member, or having a specific function. In this embodiment, as the application example shows, it has a function as a part of writing instrument.

(Configuration of male screw member)
The male screw member 3 is entirely made of synthetic resin and is configured to be elastically deformable at least in the radial direction. The male screw member 3 has a cylindrical large-diameter portion 31a and a small-diameter portion 31b having a smaller diameter than the large-diameter portion 31a by a stepped portion 31c. A male thread portion 33 having an outer diameter R1 is formed on the outer wall of the small diameter portion 31b. Reference numeral 31d indicates a tip portion of the small diameter portion 31b. A portion of the male screw member 3 that is farther from the female screw portion 54 than the male screw portion 33 (a portion on the opposite side of the distal end portion 31d across the male screw portion 33 of the small diameter portion 31b) is substantially concentric with the male screw portion 33. An annular protrusion 35 having an outer diameter R2 (R2> R1) (provided in the circumferential direction of the male screw member) is provided. The shape of the annular protrusion 35 is not particularly limited. However, in order to reduce the contact resistance with the inclined surface 59a of the annular introduction groove 59, which will be described later, a substantially semicircular cross section having a curved outer peripheral surface is preferable.

  In the small diameter portion 31b, a long relief hole 37 is formed penetratingly formed in the axial direction crossing the annular protrusion 35. In FIGS. 1 and 2, only one escape hole 37 is shown, but it is hidden and cannot be seen, but there is another one on the back side of the figure, and there are a total of two. If necessary, one or three or more may be used. The escape hole 37 is a hole for allowing the annular projection 35 to be elastically deformed by an external force F (FIG. 1) and allowing the annular projection to be reduced to a maximum outer diameter R3 (not shown, R3 ≦ R1). Although the escape hole 37 of this embodiment is elliptical, the shape is not limited as long as the above object is achieved. The shape, number, formation location, and the like of the escape holes 37 may be appropriately selected in order to efficiently reduce the outer diameter of the annular protrusion 35.

(Configuration of female screw member)
The female screw member 5 is formed in a cylindrical shape having a diameter larger than that of the male screw member 3, and the constituent material is not limited, but is made of synthetic resin in the present embodiment. An opening 51 having a predetermined depth is formed at the center of the female screw member 5 on the side facing the male screw member 3. The openings 51 are arranged in order from the innermost side to the outside (from the right to the left in FIG. 1) in order, the storage part 53, the female screw part 54, the connection groove 55, the annular fitting groove 57, and the annular introduction groove 59. It has. The storage portion 53 is formed so that the distal end portion 31d of the male screw member 3 when screwed can be stored without contacting the surroundings. The female screw portion 54 is formed in an inner peripheral wall portion connected to the inner peripheral wall of the storage portion 53, and an inner diameter r1 thereof is a dimension capable of screwing with the male screw portion 33 having an outer diameter R1. The connecting groove 55 is smoothly inserted since the tip of the male screw portion 33 (that is, the tip portion 31d) to be inserted into the female screw portion 54 is guided by the inclined surface surrounding the connecting groove 55. it can.

  The annular fitting groove 57 is a groove having an inner diameter r <b> 2 (r <b> 2> r <b> 1) at a position closer to the opening end side than the female screw part 54 of the peripheral wall in the opening 51. The annular introduction groove 59 is further on the open end side than the annular fitting groove 57 via the connection groove 55. The inner peripheral wall of the annular introduction groove 59 includes an inclined surface 59a whose radius gradually decreases toward the female screw portion 54 (minimum inner diameter r3 (R1 <r3 <r2)).

(Operation of retaining structure)
According to the retaining structure 7 of the screw member 1 according to the present embodiment, the male screw member 3 and the female screw member 5 are coupled by the male screw portion 33 and the female screw portion 54 being screwed together, and the coupling release by the disconnection is released. It is suppressed. That is, when the male screw portion 33 is inserted into the opening 51 and screwed into the female screw portion 54, an external force is received from the inner peripheral wall (inclined surface 59a) of the annular introduction groove 59 abutted by the screw progression. 35 is elastically deformed into the male screw member 3 and is reduced to the maximum outer diameter R3 (R3 ≦ R1) that can pass through the annular introduction groove 59. It is the escape hole 37 that enables this reduction. Reduction is realized by at least a part of the meat of the annular protrusion 35 being released to the escape hole 37 along with the deformation of the escape hole 37. As the screw advances further, the annular protrusion 35 enters the annular fitting groove 57, where it elastically returns to a state of a larger diameter (that is, R2) than the minimum inner diameter r3 of the annular introduction groove 59. As a result, even if an external force in the direction opposite to the screw traveling direction (from right to left in FIG. 1) is applied to the male screw member 3, the annular protrusion 35 is formed between the annular fitting groove 57 and the annular introduction groove 59. Is prevented from coming off by coming into contact with a stepped portion 58 formed by the inner diameter difference.

(Application example of this embodiment)
A writing instrument which is an application example of the present embodiment (hereinafter referred to as “this application example”) will be described with reference to FIGS. As shown in FIG. 1, the writing instrument 101 according to this application example has an external configuration including a shaft cylinder 103 having a front end portion 101a and a rear end portion 101b, and a knock member 105 protruding from the rear end portion 101b along the axis. In addition, the following member group is provided in the shaft cylinder 103.

  Reference numeral 107 shown in FIG. 4 indicates a spring accommodating body accommodated in the shaft cylinder 103, and similarly, reference numeral 115 indicates a refill. As shown in FIG. 5 and FIG. 5, the spring accommodating body 107 is a cylindrical member, and the lock mechanism 111 and the return spring 109 are accommodated therein. The lock mechanism 111 is interlocked with a refill pressing member 113 provided so as to be able to protrude and retract with respect to the spring accommodating body 107, while sliding the refill 115 while compressing the return spring 109 and projecting the tip from the tip portion 103 a. It is configured to be lockable. A knock member 105 is screwed to the open end of the refill pressing member 113 by a method to be described later, and the locking mechanism 111 is locked by the knocking operation of the knocking member 105 and is locked by re-operating the knocking member 105. Release is to be made. When the lock is released, the refill is pulled into the shaft tube 103 by the return force of the return spring 109. In this application example, there is only one refill 115, but when there are a plurality of refills 115, the above mechanism is required for each refill.

  Here, the refill pressing member 113 is constituted by the male screw member 3 of the present embodiment, and the knock member 105 is similarly constituted by the female screw member 5. Accordingly, since the above-described retaining structure 7 is included between the refill pressing member 113 and the knocking member 105, the refilling member is securely prevented from coming off from the 113 knocking member 105 (or vice versa). As a result, even if the writing instrument 101 is disassembled when the refill member is replaced, the possibility of losing the return spring 109, the knock member 105, etc. in the spring housing 107 is eliminated.

DESCRIPTION OF SYMBOLS 1 Screw member 3 Male screw member 5 Female screw member 7 Retaining structure 31a Large diameter part 31b Small diameter part 31c Step part 31d Tip part 33 Male screw part 35 Annular projection 37 Escape hole 51 Opening part 53 Storage part 54 Female screw part 55 Connection Groove 55a inclined surface 57 annular fitting groove 58 step portion 59 annular introduction groove 59a inclined surface 101 writing instrument 103 shaft tube 103a front end portion 103b rear end portion 105 knock member 107 spring accommodating body 109 return spring 111 lock mechanism 113 refill pressing member 115 refill

Claims (4)

After the male screw portion having the outer diameter R1 formed on the outer wall of the elastically deformable male screw member is screwed into the female screw portion having the inner diameter r1 formed on the inner peripheral wall of the opening portion formed in the female screw member, A screw member retaining structure for retaining,
An annular protrusion having an outer diameter R2 (R2> R1) that is substantially concentric with the male screw portion is provided at a portion of the male screw member that is farther from the female screw portion than the male screw portion, and is elastic by an external force. At least one escape hole is formed so as to allow the annular projection to deform and to reduce to the maximum outer diameter R3 (R3 ≦ R1),
An annular fitting groove having an inner diameter r2 (r2> r1) is formed closer to the opening end side than the female threaded portion of the inner peripheral wall of the opening, and an inner diameter r3 (R1 <r3 <is arranged closer to the opening end side than the annular fitting groove). each of the annular introduction grooves of r2) is formed,
When the male threaded portion is screwed into the female threaded portion, the annular projection that has received an external force from the inner peripheral wall of the annular introduction groove is elastically deformed, passes through the annular introduction groove, and enters the annular fitting groove, and A screw member retaining structure characterized in that an annular protrusion entering the annular fitting groove is elastically restored to come into contact with a step portion between the annular fitting groove and the annular introduction groove to prevent the screw member from coming off. . The screw member retaining structure according to claim 1, wherein an inner peripheral wall of the annular introduction groove includes an inclined surface whose radius gradually decreases toward the female screw portion. A coupling groove is formed between the annular fitting groove and the female threaded portion, which is continuous with the inner peripheral wall of the annular fitting groove and surrounded by an inclined surface whose radius gradually decreases toward the female threaded portion. The screw member retaining structure according to claim 1 or 2, wherein: A shaft cylinder having a front end portion and a rear end portion;
At least one refill urged in the axial direction by a return spring in the shaft cylinder and slidable by a knocking operation of a knocking member;
A spring housing body that connects the knock member and the refill, and that houses the return spring and the lock mechanism;
A refill pressing member that immerses in the spring housing while compressing the return spring and returns with the urging force of the return spring,
The refill pressing member is constituted by the male screw member according to any one of claims 1 to 3, and the knock member is constituted by the female screw member according to any one of claims 1 to 3. .

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