JPH0663920U - bolt - Google Patents

Abstract

(57) [Summary] [Purpose] It is possible to reliably prevent falling from the attached part without using accessories such as cotter pins, and it is possible to remove and reuse from the attached part. Provide a simple bolt. [Structure] A pair of captive prevention pieces 14 are attached to the tip of the screw portion 13.
And the fall-preventing pieces 14 and 14 are bendable so as to expand the tip side of the bolt.
Bolt 11.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bolt provided with a structure for preventing the bolt from falling off from a tightened portion.

[0002]

[Prior art]

 FIG. 4 shows an example of a general method of using a conventional bolt. In FIG. 4, a through hole 1a and a through hole 2a having an internal thread formed on the inner peripheral surface thereof are formed in each of the plate members 1 and 2 to be fixed, and the bolt 3 is inserted into the through hole 1a, 2a. Have been tightened. The bolt 3 has a hexagonal columnar head portion 3a having a shape suitable for tightening the bolt 3 with a hexagon wrench or a spanner, and a screw portion 3b having an external thread formed on the outer peripheral surface.

By the way, as shown in FIG. 4, even if the plate members 1 and 2 are fixed by the bolts 3, if the plate members 1 and 2 are fixed for a long period of time in an environment where vibration is applied, the bolts 3 loosen due to the vibration, and the bolt 3 causes the plate member 1 to move. , 2 from the through holes 1a and 2a. Therefore, as shown in FIG. 5, there has been proposed a bolt 4 in which a through hole 4c extending in the radial direction is formed in the vicinity of the tip of the screw portion 4b, and a split pin 5 is inserted into the through hole 4c.

[0004]

[Problems to be solved by the device]

 In the bolt 4 shown in FIG. 5, the split pin 5 is inserted into the through hole 4c, and both ends thereof have such a length that they extend outside the outer peripheral surface of the screw portion 4b. Therefore, even if the bolt 4 is loosened due to vibration or the like, the split pin 5 is locked by the lower surface 2b of the plate member 2, so that the bolt 4 is prevented from falling off.

However, since the split pin 5 as an accessory is required, the cost is high. Not only that, the through hole 4c had to be formed on the bolt 4 side in consideration of the thickness of the plate materials 1 and 2 on site. In addition, since various sizes of bolts are generally used, it is necessary to prepare split pins 5 of various sizes according to the type of bolt, and the split pins 5 must be prepared according to the bolt to be used. Pin 5 had to be selected and used.

In addition to the method of using the split pin 5 described above, the threaded portion of the bolt is made of a relatively soft material, and after screwing in, the tip of the threaded portion is crushed to expand the area and prevent it from falling off from the fixing target member. The method to do is also done in part. However, when it became necessary to remove the bolt, it was very difficult to remove the bolt, and the bolt could not be used again.

The object of the present invention is to eliminate the above-mentioned various drawbacks of the conventional bolts, to prevent the bolts from falling off without requiring separate parts, and to remove and reuse the bolts. To provide a bolt that is possible.

[0008]

[Means for Solving the Problems]

 The present invention is characterized in that a bolt having a head portion and a threaded portion having a diameter smaller than that of the head portion and having an external thread formed on an outer peripheral surface thereof is provided with the following configuration. That is, in the bolt of the present invention, a plurality of captive pieces are provided at the tip of the threaded portion, and the captive pieces are projected from the tip of the threaded part and bent so that the tip side of the bolt is widened. Is configured to be possible.

[0009]

[Action]

 The bolt of the present invention is provided with a plurality of fall-prevention pieces at the tip of the threaded portion, and since the fall-prevention pieces serve to prevent the bolt from coming off, no other component other than the bolt is required.

Further, since the plurality of captive pieces are configured to be bendable so as to expand the tip side of the bolt, by bending so as to expand the tip side of the bolt, the portion from which the bolt is attached is bent. Can be reliably prevented from falling off. Moreover, the fixed bolts can be easily removed and reused by bending back the plurality of captive prevention pieces so that the tip ends of the bolts are expanded and then bending them back. .

[0011]

[Explanation of Examples]

 A bolt according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. With reference to FIG. 2, the bolt 11 of the present embodiment is made of metal or synthetic resin and has a head portion 12 and a screw portion 13. The head 12 has a substantially hexagonal prism shape, and is shaped to be suitable for tightening the bolt 11 with a hexagon wrench, a spanner, or the like. The screw portion 13 has a cylindrical shape having a smaller diameter than the head portion 12. A male screw is formed on the outer peripheral surface of the screw 13. Note that this male screw does not necessarily have to be formed over the entire length of the screw portion 13.

At the tip of the screw part 13, a pair of captive prevention pieces 14, 14 are integrally formed with the screw part 13. The caps 14 and 14 have an elongated plate shape, but may have other shapes such as a round bar or a square bar. Of course, the fall-preventing pieces 14 and 14 need to be configured such that the tip ends of the bolts 11 can be expanded and the tip ends 14a and 14a can be easily bent. Therefore, the caps 14 and 14 are formed to have a thickness such that they can be easily bent when the bolt 11 is made of a relatively hard material, for example, a metal having high strength.

In addition, in the state before use, the drop-out preventing pieces 14, 14 are located in a cylindrical region in which the minimum diameter portion of the screw portion 13 is extended to the tip side. This is because the bolt 11 can be inserted into the hole into which the bolt 11 is inserted. However, since the fall-off preventing pieces 14, 14 can be easily bent, even if the tip side is located outside the cylindrical area, it may be bent back before use and positioned within the area.

When the bolt 11 is used, as shown by an imaginary line A in FIG. 2, for example, a driver is inserted between the fall-prevention pieces 14 and the tip of the driver A is tilted to prevent the fall-off. The distance between the pieces 14, 14 on the tip side is increased. That is, as shown in FIG. 1 (a), the inner peripheral surface has through holes 1a and 2a formed with internal threads. After inserting the bolts 11 into the through holes 1a and 2a of the plate materials 1 and 2, Bend 14 and 14 so that the space between their tips is widened as shown. Further, by continuing this bending process, as shown in FIG. 1 (b), the tips 14a, 14a of the fall-preventing pieces 14, 14 are brought into contact with the lower surface 2b of the plate member 2. In this way, since the tips 14a, 14a of the fall-preventing pieces 14, 14 are brought into contact with the lower surface 2b of the plate member 2, even if vibrations or the like are applied for a long time and the bolts 11 are loosened, the fall-preventing pieces 14 , 14 are locked to the lower surface 2b of the plate member 2, the bolt 11 does not drop out from the through holes 1a, 2a.

Further, even if the thicknesses of the plate members 1 and 2 are slightly different, it is possible to easily cope with the change by changing the length of the bendable portion of the caps 14 and 14.

Further, as shown in FIG. 1B, when the length L _{1 of the} portion of the bolt 11 inserted into the plate members 1 and 2 is shorter than the thickness L ₂ of the plate members 1 and 2, By bending the fall prevention pieces 14, 14 so as to contact the lower surface 2b of the plate member 2, the loosening prevention of the bolt 11 is also performed by the fall prevention pieces 14, 14.

The fall-preventing pieces 14 and 14 need only be integrally formed with the threaded portion 13 of the bolt 11, and are not necessarily integrally made of the same material, and a preformed bolt may be used. It is also possible to attach separate drop-preventing pieces 14, 14 to the tip of the threaded portion 13 of 11.

FIG. 3 is a schematic side view showing a modified example of the bolt 11. In the bolt 21 of FIG. 3, the screw portion 23 connected to the head portion 22 has a cylindrical shape. Then, the fall prevention pieces 24, 24 are inserted and fixed in the screw portion 23. That is, the fall prevention pieces 24, 24 are made of a member different from the bolt 11, are fixed in the cylindrical screw portion 23, and the tip side portion thereof is projected from the tip of the screw portion 22b. ing. As described above, the fall-preventing pieces 24, 24 of the present invention can have various structures as long as they are provided so as to project to the tip side of the threaded portion.

Since the drop-out preventing pieces 24, 24 are made of different members from the bolt 21, they may be made of a material different from that of the bolt 21. Further, the fall prevention pieces 14, 14, 24, 24 may be formed in three or more pieces. Furthermore, since the structure of the bolt other than the fall-preventing piece is not particularly limited, the present invention can be applied to various conventionally known bolts in general.

[0020]

[Effect of device]

 In the bolt of the present invention, a plurality of fall prevention pieces are formed at the tip of the threaded portion, and by bending the fall prevention piece so that the tip side of the bolt expands, the fall of the bolt from the fixing target member is prevented. The piece comes into contact with the member to be fixed and is reliably prevented.

Therefore, even if the bolt is loosened due to vibration or the like, the bolt is reliably prevented from falling off, so that accidents of mixing the raw material into the raw material, failure of the machine, and the like can be reliably prevented. In addition, in the conventional bolt using the split pin, complicated work such as machining the hole for inserting the split pin and selecting the split pin according to the bolt diameter is required. Then, since other parts are not necessary, the bolts can be efficiently attached.

In addition, since the fall prevention piece is configured to be bendable, it can be easily reused by bending back from the attached state. Therefore, the bolt of the present invention can be preferably used even in a portion that needs to be removed, and the bolt removed once can be reused.

Further, the bolt of the present invention is provided with the above-mentioned fall-preventing piece at the tip of the protruding portion, so that it can be manufactured extremely easily, and thus the cost of the bolt may be increased. Nor.

[Brief description of drawings]

FIG. 1A and FIG. 1B are partial cutaway sectional views showing a process of attaching a bolt to a plate material in an embodiment.

FIG. 2 is a side view showing a bolt of the embodiment.

FIG. 3 is a schematic side view showing a modified bolt.

FIG. 4 is a partially cutaway cross-sectional view showing an example of a state in which a conventional bolt is used.

FIG. 5 is a cross-sectional view for explaining a bolt provided with a conventional fall prevention structure.

[Explanation of symbols]

 11 ... Bolts 12 ... Head 13 ... Screws 14 ... Fall-out prevention piece

Claims (1)

[Scope of utility model registration request] 1. A bolt having a head portion and a screw portion having a diameter smaller than that of the head portion and having a portion on the outer peripheral surface of which a male screw is formed, wherein the bolt is projected from the tip of the screw portion, A bolt, characterized in that a plurality of captive pieces that can be bent to expand the tip side of the bolt are provided at the tip of the threaded portion.