JP5703540B2 - Connecting structure between shafts - Google Patents

Description

  The present invention relates to a shaft-shaft connection structure in which the other shaft body is inserted and connected to the inner diameter portion of a cylindrical member.

As an example, a mechanical pencil in which a metal eraser holder is connected to the rear portion of a resin core tank is known. More specifically, the relationship between the inner diameter of the core tank and the outer diameter of the eraser holder is such that the outer diameter of the eraser holder is slightly larger and is connected in a state where it is firmly pressed into the core tank. . Thus, when the eraser is used, the eraser and the core tank are prevented from shaking.
JP2003-165294A.

  However, in the above-described conventional technology, the lead tank and the eraser holder are firmly press-fitted, so that the lead tank may be whitened during assembly depending on the dimensional variation of each member. There was a risk that cracking would occur if it was loose or somewhat.

The present invention is a shaft-shaft connection structure in which the other shaft body is inserted and connected to the inner diameter portion of the cylindrical member, and is connected to the inner surface of the cylindrical member and the large diameter portion. A reduced diameter portion is formed on one side, an inner step portion is formed on the other side, and the large diameter portion of the other shaft body is brought into contact with and pressed into the large diameter portion, and the end portion of the large diameter portion of the other shaft body The inner step portion is formed in the vicinity, a gap is formed between the reduced diameter portion of the cylindrical member and the other member, and the reduced diameter portion is sandwiched by the other shaft body The gist is that the cylindrical member and the other shaft body are connected by a clamping force in the circumferential direction and the longitudinal direction.

The present invention is a shaft-shaft connection structure in which the other shaft body is inserted and connected to the inner diameter portion of the cylindrical member, and is connected to the inner surface of the cylindrical member and the large diameter portion. A reduced diameter portion is formed on one side, an inner step portion is formed on the other side, and the large diameter portion of the other shaft body is brought into contact with and pressed into the large diameter portion, and the end portion of the large diameter portion of the other shaft body The inner step portion is formed in the vicinity, a gap is formed between the reduced diameter portion of the cylindrical member and the other member, and the reduced diameter portion is sandwiched by the other shaft body Since the cylindrical member and the other shaft body are connected by the clamping force in the circumferential direction and the longitudinal direction, a connecting structure between the shaft and the shaft that prevents whitening and cracking can be provided.

The longitudinal half sectional view showing the 1st example. The principal part enlarged view of FIG. The principal part enlarged view of FIG. AA sectional view taken on the line AA of FIG. The longitudinal half cross-section perspective view of a front shaft. FIG. The external appearance perspective view of a lead tank. The principal part longitudinal cross-sectional view which shows a 2nd example. FIG. 9 is a top view of FIG. 8. The principal part perspective view of FIG. The principal part longitudinal cross-sectional view which shows a 3rd example. FIG. 12 is a top view of FIG. 11. The principal part longitudinal cross-sectional view which shows a 4th example. The principal part longitudinal cross-sectional view which shows a 5th example. The top view of FIG. The principal part longitudinal cross-sectional view which shows the modification of a 5th example. The external appearance perspective view which shows the 6th example. The front view which shows the 7th example.

  The operation will be described. Even if the pressure input in the circumferential direction is weakened, the vibration between the shafts is prevented by the vertical clamping force.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As a first example, a connection structure between a clip and a shaft tube in a writing instrument will be described. The shaft cylinder 1 includes a front shaft 2 and a rear shaft 3, and the front shaft 2 and the rear shaft 3 are detachably fixed by screwing. Further, a grip member 4 made of a rubber-like elastic body is inserted on the surface of the front shaft 2, and a protrusion 5 having an elliptical cross section is formed on the surface of the grip member 4. An outer cylinder 6 made of a metal material is inserted on the surface of the grip member 4, and a plurality of through holes 7 are formed in the outer cylinder 6. The protrusion 5 of the member 4 is exposed. Further, the surface of the outer cylinder 6 is finely knurled, and an anti-slip effect is generated by the knurled portion and the protrusion 5 of the grip member 4.
Reference numeral 8 denotes a tip member that is detachably attached to the tip of the front shaft 1, and the tip of the tip member 8 is a tip opening 9 in which a later-described cursive unit appears and disappears.

A substantially rectangular front window hole 10 and a rear window hole 11 having a contracted portion at a substantially central part are formed on the side surface of the rear part of the rear shaft 3. A connecting member 13 for connecting the clip 12 made of a metal material and the rear shaft 3 is inserted into the rear window hole 11. The connecting member 13 is formed by bending a plate-like member made of a metal material.
The clip 12 has a curved shape in which a rear portion approaches the direction of the shaft tube 1, and the curved portion makes the finger feel good, and the rear portion of the clip 12 is disposed on the shaft tube. By approaching 1, the sense of unity between the clip 12 and the shaft tube 1 is improved. The surface of the curved portion of the rear portion of the clip 12 is provided with a convex pattern having a low height by rolling or the like to improve the aesthetics, and slip when operating the curved portion. It also has a stopping effect.
Further, on both sides of the front portion of the clip 12, a semicircular arc-shaped ball portion 14 that protrudes toward the axial tube 1 is formed. The ball portions 14 are slightly approaching each other in the direction of the shaft tube 1. Entry into the front window hole 10 formed in the rear shaft 3 is facilitated. That is, even if the axis of the clip 12 is slightly distorted with respect to the axis of the barrel 1, the ball portion 14 is tapered, so that it can be easily guided to the front window hole 10.
On the other hand, ridges 15 are formed on both sides of the intermediate rear portion of the clip 12 so as to bulge in the direction of the shaft tube 1, and through holes 16 are formed in the ridges 15.
The connecting member 13 that connects the clip 12 and the shaft tube 1 is mounted between the raised portions 15 formed at the opposing positions. The connecting member 13 has a box shape and is formed by bending a plate-like member into a quadrangle.

  A through hole 17 is formed in a substantially central portion of the side surface of the connecting member 13, and a support shaft 18 is inserted into the through hole 17. Further, the support shaft 18 also penetrates the through hole 16 of the clip 12. Further, a torsion coil spring 19 having a coil portion mounted between the shaft tube 1 and the clip 12 is also inserted into the support shaft 18. That is, the ball portion 14 of the clip 12 is urged toward the shaft tube 1 by the torsion coil spring 19.

A cursive unit 20 is arranged in the shaft cylinder 1 so as to be able to move back and forth and to be able to protrude from the tip of the tip member 8. In this example, the cursive unit 20 is a mechanical pencil unit that extends a pencil lead. Details will be described below. A resin core tank 23 accommodating a plurality of cores is disposed in the middle shaft 22 urged rearward by a resilient member 21 such as a coil spring so as to be movable back and forth. A chuck body 25 for holding and releasing the core is fixed to the base via a joint 24. A chuck ring 26 that opens and closes the chuck body 25 is surrounded in front of the chuck body 25. Further, a tip 27 is fixed to the front of the middle shaft 22 by means such as screwing, and a lead detent member 28 made of a rubber-like elastic body that prevents the lead from retreating is provided on the tip 27. It is installed internally. Reference numeral 29 denotes a guide pipe that guides the lead that has been fed out, and reference numeral 30 denotes an elastic member such as a coil spring that urges the lead tank 23 and the chuck body 25 toward the rear.
A vertical protrusion 31 is formed in the longitudinal direction of the front inner peripheral surface of the front shaft 2, and a vertical groove 32 formed on the front outer peripheral surface of the middle shaft 22 is fitted in the vertical protrusion 31. Is engaged. The vertical protrusions 31 and the vertical grooves 32 are formed at four equally spaced locations, but may be at three locations or at five locations. That is, the relative rotation between the front shaft 2 and the middle shaft 22 is prevented by the engagement between the vertical protrusions 31 and the vertical grooves 32.

On the other hand, an eraser receiving member 33 is fixed behind the lead tank 23, and an eraser 34 is detachably attached to the rear of the eraser receiving member 33. A knock member 35 is detachably press-fitted behind the eraser receiving member 33 so as to cover the eraser 34. Hereinafter, the connection means between the lead tank 23 and the eraser receiving member 33 will be specifically described.
The core tank 23 is formed of a resin material such as polyacetal or polypropylene, and a large diameter portion 36 is formed on the inner surface of the rear portion of the core tank 23, and the rear portion of the large diameter portion 36 is shrunk. Although the diameter portion 37 is formed, the large diameter portion 36 and the reduced diameter portion 37 are connected by a conical inner shape portion 38 having an inclined surface. A tapered opening 39 having an inclined surface that expands outward is formed at the rear end of the reduced diameter portion 37.
A flange 40 is formed behind the lead tank 23, and a notch 41 is partially formed in the front of the flange 40. By forming the notch 41, for example, when the core tank 23 is a resin molded product, the occurrence of a recess called “shrink” is prevented, and an accurate collar 40 is obtained.

On the other hand, the eraser receiving member 33 is formed by pressing a metal material such as stainless steel or iron, and a large-diameter cylindrical portion 42 is formed in front of the eraser receiving member 33. A small-diameter cylindrical portion 43 is formed behind the large-diameter cylindrical portion 42, and the large-diameter cylindrical portion 42 and the small-diameter cylindrical portion 43 have a conical first inner shape portion 44 having an inclined surface. It is connected with. In addition, a receiving cylindrical portion 45 larger in diameter than the large-diameter cylindrical portion 42 is formed behind the small-diameter cylindrical portion 43. The small-diameter cylindrical portion 43 and the receiving cylindrical portion 45 are inclined. It is connected by a second inner shape part 46 having a surface. In addition, an inner surface flange portion 47 whose diameter decreases toward the inner diameter direction is formed on the front end surface of the large-diameter cylindrical portion 42. A through hole 47 a is formed in the inner surface flange portion 47, and the diameter of the through hole 47 a is larger than the inner diameter of the core tank 23. That is, the lead stored in the lead tank 23 is not caught by the inner surface flange 47.
The large-diameter cylindrical portion 42 is formed larger than the large-diameter portion 36 of the core tank 23, and is in a press-fit state at this portion. On the other hand, the small diameter cylindrical portion 43 is formed smaller than the reduced diameter portion 37 of the core tank 23, and a gap 48 is formed on the circumference in this portion. By forming this gap 48, even if a slight dimensional variation occurs in the small diameter cylindrical portion 43 or the reduced diameter portion 37, the relative press-fitting between the small diameter cylindrical portion 43 and the reduced diameter portion 37 is achieved. The action is prevented.
Further, the distance from the first inner shape portion 44 of the eraser receiving member 33 to the second inner shape portion 46 is shorter than the distance of the reduced diameter portion 37 of the core tank 23. That is, the reduced diameter portion 37 of the core tank 23 is sandwiched between the first inner shape portion 44 and the second inner shape portion 46.

A large diameter portion 49 is formed at the rear portion of the middle shaft 22, and the rear end portion of the large diameter portion 49 is an engaging portion with the ball portion 14 of the clip 12. That is, when the cursive unit 20 protrudes, the rear end portion of the large-diameter portion 49 is engaged with the ball portion 14 of the clip 12 to prevent the cursive unit 20 from retreating. The protruding state of the body unit 31 is maintained.
Here, when the rear portion of the clip 12 is pressed in the direction of the shaft tube 1 with a finger or the like, the front of the clip 12 is separated from the shaft tube 1 and widened. At this time, the ball portion 14 and the large diameter portion 49 of the middle shaft 33 The engagement is released and the cursive unit 20 moves rearward by the urging force of the elastic member 21. As a result, the cursive unit 20 is immersed in the barrel 1.

A second example will be described with reference to FIGS. This is an example in which a longitudinal groove 50 is formed in the reduced diameter portion 37 formed in the core tank 23 of the first example. The longitudinal groove 50 is formed at a position of a weld (resin joint) generated when the core tank 23 is formed by injection molding. When the eraser receiving member 33 is assembled to the core tank 23, the large-diameter cylindrical portion of the eraser receiving member 33 gets over the reduced diameter portion 37 of the core tank 23. As a result, whitening and cracking in the reduced diameter portion 37 are further prevented. That is, by forming the vertical groove 50 in the weld line portion where cracking is likely to occur, damage during assembly is prevented as much as possible.
In this second example, the entire vertical flutes of about ¼ arc on the circumference are formed at opposing positions. However, as shown in FIGS. It may be provided at a location (third example), or the distance in the vertical direction of the reduced diameter portion 52 may be shortened as shown in FIG. That is, the rear portion of the reduced diameter portion 52 is a groove portion 53 on the entire circumference (fourth example). Further, the reduced diameter portion 52 may be shortened, and the vertical groove 54 may be formed in the reduced diameter portion 52 (fifth example; FIGS. 14 and 15). Note that a conical portion 52a having an inclined surface may be formed on the shortened diameter-reduced portion 52 from the middle portion to the rear portion or from the vicinity of the front end of the diameter-reduced portion 52 to the rear portion (see FIG. 16). . The outer peripheral portion of the distal end of the large diameter portion 36 of the eraser receiving member 33 is guided by the conical portion 52a, and the insertion into the core tank 23 is facilitated.

A sixth example will be described with reference to FIG. The large-diameter cylindrical portion 55 of the eraser receiving member 33 is formed with a longitudinal groove 56 having an approximately 1/3 circular arc, and the protruding large-diameter cylindrical portion 55 formed by forming the longitudinal groove 56 is replaced with the core. This is an example in which a press-fitting portion with respect to the large diameter portion 36 of the tank 23 is used. In this example, pressure input at the press-fitting portion is reduced, and whitening or cracking of the large-diameter portion 36 of the core tank 23 is further prevented.
In the example shown in FIG. 18, the inner surface flange portion 57 formed in front of the large-diameter cylindrical portion 42 of the eraser receiving member 33 extends forward and is reduced in diameter conically toward the front. Yes (seventh example) By providing the conical inner surface flange portion 57 at the front end portion of the eraser receiving member 33, the assembly to the core tank 23 is further facilitated.

DESCRIPTION OF SYMBOLS 1 Shaft cylinder 2 Front axis | shaft 3 Rear axis | shaft 4 Grip member 5 Protrusion part 6 Outer cylinder 7 Through-hole 8 Tip member 9 Front-end opening part 10 Front window hole 11 Back window hole 12 Clip 13 Connection member 14 Ball | bowl part 15 Raised part 16 Through-hole DESCRIPTION OF SYMBOLS 17 Through-hole 18 Support shaft 19 Torsion coil spring 20 Cursive unit 21 Repelling member 22 Middle shaft 23 Core tank 24 Joint 25 Chuck body 26 Chuck ring 27 Tip 28 Core detent member 29 Guide pipe 30 Repelling member 31 Vertical protrusion 32 Longitudinal groove 33 Eraser receiving member 34 Eraser 35 Knock member 36 Large diameter portion 37 Reduced diameter portion 38 Inner shape portion 39 Taper opening portion 40 Gutter portion 41 Notch portion 42 Large diameter cylindrical portion 43 Small diameter cylindrical portion 44 First inner shape portion 45 Receiving cylindrical portion 46 Second inner shape portion 47 Inner surface flange portion 48 Clearance 49 Large diameter portion 50 Vertical groove 51 Vertical groove 52 Reduced diameter portion 53 Groove portion 5 4 Longitudinal groove 55 Large-diameter cylindrical part 56 Longitudinal groove 57 Inner collar

Claims (1)

A connecting structure of a shaft and a shaft for inserting and connecting the other shaft body to the inner diameter portion of the cylindrical member, the inner diameter of the cylindrical member is connected to the large diameter portion and the large diameter portion, and the diameter is reduced to one side. And forming an inner step portion on the other side, contacting and press-fitting the large diameter portion of the other shaft body into the large diameter portion, and in the vicinity of the end of the large diameter portion of the other shaft body A stepped portion is formed, and a gap is formed between the reduced diameter portion of the cylindrical member and the other member, and the reduced diameter portion is sandwiched by the other shaft body, thereby the cylindrical shape. A shaft-shaft connection structure in which a member and the other shaft body are connected by a clamping force in the circumferential direction and the longitudinal direction.

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