JP2001221215A - Detachment prevention structure for insertion member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple detachment prevention structure for an insertion member excellent in workability and handleability, certainly preventing detachment of a shaft body such as a nut screwed on a bolt without using an additional detachment prevention tool such as a split pin. SOLUTION: A screw shaft 8 of the bolt 7 is formed with a slit-like groove, while a flexible member 2 projecting formed with a lock part 5 is housed in the groove 1. When inserting the nut 9, a thread of the nut 9 presses the flexible member 2 to house the flexible member 2 into the groove 1. When the nut 9 is inserted in a prescribed position, the flexible member 2 gets in a free state, and the lock part 5 abuts on an end face of the nut 9 to function as the detachment prevention structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a retaining structure for an insertion member to be inserted into a shaft, and more particularly, to a retaining structure for an insertion member which can be easily detached and securely retained.

[0002]

2. Description of the Related Art As shown in FIG.
2 and the bolt 14 and the nut 1
5 is generally used. In this case, a stopper is used at a place where the nut 15 is not likely to come off. As a typical stopper, a split pin 16 is shown as shown. The split pin 16 is a standard product, and its shape, material and the like are determined. The split pin 16 is inexpensive and convenient. In particular, it is difficult to remove the split pin 16 at a rusting point, and a special punching tool is required. Further, as shown in FIG. 14, the detached split pin 16 has a problem that its tip is bifurcated or chipped, making it difficult to reuse. Also,
In places where outdoor work is required, particularly in outdoor work in winter, where tightening of the bolts 14 and nuts 15 is required, the work of attaching and detaching the split pins 16 is extremely poor and hated.

In many cases, a snap ring 17 shown in FIG. 15 is used as a retaining pin instead of the split pin 16. This is often used when it is necessary to fix the ring-shaped member 19 inserted in the shaft 18 at that position as shown in FIG. Snap ring 1
7 is effective as a retaining member, but it is difficult to attach and detach it without a special tool. In addition, it is more expensive than the split pin 16. Also, the snap ring 17
In general, it is difficult to use the shaft body 18 such as a screw shaft.

FIGS. 17 and 18 show a conventional simple retaining structure for retaining an inserted member without using a separate member, such as a split pin 16 and a snap ring 17. FIG. ing. This is provided with a turning piece 22 rotatably supported by a pin 21 on a shaft body 20,
The turning piece 22 is asymmetric with respect to the pin 21, the base end side is made heavier, and a locking portion 23 for preventing the insertion member from coming off is formed integrally with the distal end side. As shown in FIG. 17, the insertion member 24 is inserted in a state where the turning piece 22 is manually turned around the pin 21. When the insertion is completed, the turning piece 22 turns naturally, and as shown in FIG. Locking part 2
Reference numeral 3 denotes an abutment on the end face of the insertion member 24 to prevent the insertion member 24 from coming off.

[0005]

As described above, the retaining structure using the split pin 16 and the snap ring 17 is inferior in workability, and may be difficult to reuse, and is difficult to handle because it is a separate product. . 17 and 18 are good in workability and handleability, but a gap 27 required for turning the turning piece 22 between the end face 25 of the shaft 20 and the end face 26 of the insertion member 24. And the like, and the insertion position of the insertion member 24 becomes unstable. Further, since the rotation of the rotating piece 22 uses gravity, it cannot be applied to an arbitrary place.

The present invention has been made in view of the above circumstances, has good workability and handleability, can be applied to various types of shafts including a screw shaft, can reliably prevent slipping, and is relatively inexpensive. It is an object of the present invention to provide an insertion member retaining structure that can be implemented at a time.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a retaining structure for engaging an end face of an insertion member inserted into a shaft body to prevent the insertion member from coming off.
The retaining structure includes a slit-shaped groove formed on an outer surface of the shaft, and a locking portion having a base end inserted into the groove and protruding from the outer surface of the shaft in a free state at the distal end. And a resiliently deformable flexible member which is entirely accommodated in the groove by the pressing force applied to the locking portion.

[0008] Further, one or more grooves are formed in the shaft body, and the plurality of grooves have the same shape or different shapes. Also,
The flexible member has a locking portion formed at one or two places, and abuts on a rear surface or a front and rear surface of the insertion member to prevent the insertion member from coming off. I do.

Further, the shaft is a screw shaft, and the insertion member is a nut-like member screwed to the screw shaft. The shaft is formed of a shaft rod, and the insertion member is the shaft. It is a hollow member inserted into a rod.

According to the first aspect of the present invention, when the insertion member is inserted into the shaft, the locking portion projecting from the outer surface of the shaft is pressed by the inner surface of the insertion member to lock. The part sinks in the groove. Therefore, the insertion member is easily inserted into the shaft. When the insertion is completed, the retaining portion of the retaining member returns to a free state due to its elasticity, and the retaining portion engages, that is, comes into contact with the end face of the insertion member. Thereby, the retaining is surely performed. That is, the retaining operation is performed only by the insertion operation of the inserting member without using a special separate retaining device.
Therefore, workability and handleability can be improved.

According to the insert member retaining structure according to the second aspect of the present invention, since the grooves are formed at a plurality of positions, the insertion members can be reliably prevented from coming off, and the shape of the plurality of grooves ( By making the lengths different, it is possible to cope with insertion members having different dimensions.

According to the insertion member retaining structure of the third aspect of the present invention, by forming two retaining portions for retaining the insertion member, the insertion member is retained on both the front and rear surfaces, so that it is more reliable. A retaining is performed.

According to the insertion member retaining structure according to the fourth aspect of the present invention, a more widespread retaining structure at a position using a screw shaft most commonly used as a fastener and a nut-like member screwed to the screw shaft. Attachment and detachment of the retaining member can be facilitated at a suitable fastening point, and workability can be greatly improved.

According to the structure for preventing the insertion member from falling out according to the fifth aspect of the present invention, the structure is also applied to the prevention of the removal of the empty member inserted into the shaft rod, and the applicable range can be expanded.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of an insertion member retaining structure according to an embodiment of the present invention. FIGS. 1, 2, 4 and 8 show an embodiment in which a bolt is used as a shaft body and a nut screwed to a screw shaft of the bolt is used as an insertion member. Further, two grooves are formed in the present embodiment, and one groove has a shorter length along the axial length direction than the other groove, but is not limited to this.

At a suitable place on the screw shaft 8 of the bolt 7, a dimension a
And the groove 1 'of A> a is formed. The groove width t (FIG. 2) of the grooves 1 and 1 'is constant in the present embodiment, but is not limited to this. It should be noted that only the groove 1 described below is used, but the same contents are applied to other grooves 1 ′ and the like.

A flexible member 2 having a retaining structure of the present invention is accommodated in the groove 1. The flexible member 2 is made of an elastically deformable material, and is, for example, shown in FIGS.
The shape shown in FIG. The flexible member 2 includes a base plate 3 having a length a ″ on the base end side, a flexible plate 4 having a length b <a ″ that is connected to the base plate 3 at one end and is cantilevered, The flexible plate 4 includes a locking portion 5 and the like protruding from the distal end side of the flexible plate 4, and is formed of a plate member having a thickness t1. A gap 6 is formed between the base plate 3 and the flexible plate 4. With the above structure,
When the locking portion 5 is pressed, the front end side of the flexible plate 4 is bent by the gap 6. It should be noted that the flexible member 2 is of such a size as to be completely accommodated in the groove 1 in this bent state.

The flexible member 2 is made of, for example, an elastically deformable member made of a spring material, and the length a ″ of the base plate 3 is formed to be slightly longer than the length a of the bottom surface of the groove 1. The thickness t1 is slightly thinner than the groove width t of the groove 1. As described above, the dimension a ″ of the base plate 3 of the flexible member 2 is slightly longer than the length a of the bottom surface of the groove 1. When the flexible member 2 is inserted into the groove 1, the base plate 3 is slightly deformed in the groove width direction or the vertical direction as shown in FIGS. Thereby, the flexible member 2 is stably held in the groove 1, and
Does not fall off easily. In addition, the flexible member 2 is stored in a free state in which only the locking portion 5 protrudes from the outer surface of the screw shaft 8 in the free state, as shown in FIG.

Next, the operation of the insertion member retaining structure of the present embodiment will be described with reference to FIGS. The flexible member 2 is fitted in the groove 1 of the screw shaft 8 of the bolt 7 in advance. When the nut 9 is screwed into the screw shaft 8 and tightened, the locking portion 5 of the flexible member 2 is pressed by the inner screw of the nut 9, and the entire flexible member 2 is in the groove 1 as shown in FIG. Is stored in. Therefore, the screwing of the nut 9 can be continued. As shown in FIG. 5, when the screwing of the nut 9 advances to a predetermined position, the pressing force of the locking portion 5 by the internal screw of the nut 9 is released, and the flexible member 2 returns to the original free state. For this reason, the locking portion 5 comes into contact with the end face of the nut 9, and as a result, the nut 9 is prevented from being pulled out. In this case, since the base plate 3 is fitted in the groove 1 as described above, the flexible member 2 is fixed to the groove 1 and falls off during the above operation and after the operation. I will not do it.

In the above-described embodiment, the shaft is the screw shaft 8 of the bolt 7. FIGS. 8 and 9 show a shaft that is a shaft 10 and a hollow member 11 as an insertion member. An embodiment in the case of insertion is shown. First, the flexible member 2 shown in FIG. 3 and the like is fitted in the groove 1 formed in the shaft rod 10. When the empty member 11 is inserted into the shaft 10 in this state, the locking portion 5 of the flexible member 2 is pressed by the inner hole of the empty member 11, and the entire flexible member 2 is stored in the groove 1. The shaped member 11 is inserted to a predetermined position. By setting the shapes of the groove 1 and the flexible member 2 so that the flexible member 2 returns to the free state in this state, the empty member 11 is prevented from falling off at a predetermined insertion position. In the present embodiment, the case where the shaft rod 10 is used as the shaft body has been described. However, a similar structure of the retaining structure is applied to shaft bodies of other forms.

FIGS. 10 and 11 show several examples of other embodiments relating to the flexible member. The flexible member 2a shown in FIG. 10 is provided with locking portions 5a, 5a at the front and rear, and the locking portions 5a, 5a are brought into contact with the insertion member at the front and rear to make sure that the insertion member is more securely retained. It has been improved. The flexible members 2b and 2c in FIGS. 11 and 12 are formed by forming a flexible member with a single wire member. The flexible member 2b in FIG. The flexible member 2c shown in FIG. 12 is formed by fixing a separate locking portion 5c to a wire member. 10, 11 and 12, the lower side of the base plate 3a of the flexible member 2a and the wire members of the flexible members 2b and 2c are fitted in such a manner that they protrude from the bottom side of the groove 1 in the figure. 2b and 2c are formed so as to be held in the groove 1. The shape and structure of the flexible member are not limited to those described above.

[0022]

According to the insert member retaining structure of the present invention, the screw member such as a bolt and the nut inserted into the screw shaft and other various shaft members can be reliably prevented from being removed. In addition to this, it is not necessary to use a separate stopper as in the prior art, so that it can be implemented at low cost, and the workability and handleability can be improved.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a retaining structure for an insertion member according to the present invention, in which a bolt having a screw shaft is used as a shaft body and a nut is used as an insertion member. FIG.

FIG. 2 is a top view of FIG. 1;

FIGS. 3A and 3B are a front view, an A side view (b), and a top view (c) showing one embodiment of a flexible member used for the retaining structure of the insertion member of the present invention.

FIG. 4 is a partial axial sectional view for explaining a retaining function of the retaining structure of the insertion member shown in FIGS. 1 and 2;

FIG. 5 is a partial axial cross-sectional view for explaining a retaining function of the retaining structure of the insertion member shown in FIGS. 1 and 2;

FIG. 6 is a schematic diagram showing a state in which a flexible member is fitted into a groove.

FIG. 7 is a schematic view showing a state in which a flexible member is fitted into a groove.

FIG. 8 is a partial axial sectional view showing an embodiment of an insertion member retaining structure according to the present invention when a shaft rod is used as a shaft body and a hollow member is used as an insertion member.

FIG. 9 is a partial axial sectional view showing a state in which the insertion member is prevented from coming off by the flexible member in FIG. 8;

FIG. 10 is a front view showing an embodiment of a flexible member provided with locking portions at the front and rear.

FIG. 11 is a front view showing a flexible member using a wire member.

FIG. 12 is a front view showing a flexible member using a wire member and having a locking portion fixed to the wire member.

FIG. 13 is an axial sectional view showing a retaining structure using a conventional split pin.

14 is a front view showing a form of a split pin taken out from a screw shaft or the like in the case of FIG. 13;

FIG. 15 is a plan view of a snap ring.

FIG. 16 is a partial axial sectional view showing a conventional retaining structure in which a snap ring is retained.

FIG. 17 is a schematic view of a conventional retaining structure using a one-touch rotating piece.

FIG. 18 is a schematic view illustrating the operation of the retaining structure of FIG. 8;

[Explanation of symbols]

 Reference Signs List 1 groove 1 'groove 2 flexible member 2a flexible member 2b flexible member 2c flexible member 3 base plate 4 flexible plate 5 locking portion 5a locking portion 5b locking portion 5c locking portion 6 gap 7 bolt 8 screw 9 Nut 10 Shaft bar 11 Empty member

Claims (5)

[Claims] 1. A retaining structure for engaging an end face of an insertion member inserted into a shaft body to prevent the insertion member from coming off, the retaining structure comprising a slit formed on an outer surface of the shaft body. And a locking portion that is fitted on the base end side into the groove and protrudes from the outer surface of the shaft body in the free state on the distal end side, and is entirely formed in the groove by pressing force applied to the locking portion. And an elastically deformable flexible member housed in the insertion member. 2. The retaining structure for an insertion member according to claim 1, wherein one or more of the grooves are formed in the shaft body, and the plurality of grooves have the same shape or different shapes. . 3. The flexible member has a locking portion formed at one or two places, and abuts on a rear surface or a front and rear surface of the insertion member to prevent the insertion member from falling off. The retaining structure for an insertion member according to claim 1, wherein the structure is provided. 4. The retaining structure for an insertion member according to claim 1, wherein the shaft body is a screw shaft, and the insertion member is a nut-like member screwed to the screw shaft. 5. The retaining structure for an insertion member according to claim 1, wherein the shaft body is formed of a shaft bar, and the insertion member is a hollow member inserted into the shaft bar.