JPS634616Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a bolt/nut tightening machine for tightening a nut onto a bolt, and its purpose is to prevent the bolts from rotating together when tightening the nut.

Conventionally, nuts on high-strength bolts were tightened by rotating the nuts using a tightening machine.
The bolts sometimes rotate when the nut is rotated, making it difficult to confirm whether they have been tightened correctly and strongly. Furthermore, if it was discovered that the bolts were not rotating together, it was necessary to tighten them again (tighten them twice).

The present invention was devised to deal with such problems, and includes a bolt/nut tightening machine that has a socket that fits onto the nut that is screwed onto the bolt, and that drives the socket to rotate. A non-rotatable rod is provided at the center of rotation of the socket, and an engaging portion is provided at the tip of the rod to be able to engage and detach from a groove formed on the end surface of the male thread of the bolt that projects toward the nut. By engaging the engaging portion at the tip of the rod with the groove on the end surface of the male threaded portion of the bolt, it is possible to prevent the bolts from rotating together during tightening, and there is no need to check that the bolts are rotating together. To provide a bolt/nut tightening machine that does not require double tightening.

The present invention will be explained below based on drawings showing embodiments. First, the first embodiment shown in FIGS. 1 to 3 will be explained. In the figures, 1 and 2 are high-strength bolts and nuts that firmly fix two members 3 and 4, and the nuts are tightened by a tightening machine 5. It can be tightened by turning 2. The tightening machine 5 has two parallel piston parts 7 and 8 that are operated by fluid pressure such as oil or air supplied inside through a hose 6.
A pinion part 9 rotates when the piston parts 7 and 8 operate by meshing with racks 7a and 8a formed on the piston parts 7 and 8, and a pinion part 9 is connected to the pinion part 9 through a cylindrical part 10. The inner socket 11 to be coupled, the outer socket 12 that is provided so as to be unfixable so as to surround the inner socket 11, and the pinion part 9, the cylindrical part 10, and the inner socket 11.
It consists of a rod 13 which is installed so that it cannot rotate when it is fitted into the rod. Said inner socket 11
is fitted onto the nut 2 so that the rotation of the inner socket 11 causes the nut 2 to be rotated in the tightening direction, and the outer socket 12 is fitted onto the nut 2.
It is fitted onto the washer 14 interposed between the member 4 and the washer 14 to prevent the washer 14 from rotating together. Further, one end of the rod 13 has an engaging portion 17 that can be freely engaged with and disengaged from a groove 16 formed in the end surface of the male threaded portion 15 of the bolt 1 that protrudes toward the nut 2 side. It is located within the socket 11. The other end of the rod 13 has a small diameter, and a cap-shaped support member 19 screwed onto the tightening machine body 18 is inserted through the rod 13 and fixed to the end face of the small diameter portion 21 within a recess 20 of the support member 19 with a screw 22. The support member 19 is supported by a stopper 23 so as not to come off. Further, the recess 20 and the stopper 23 are formed into square shapes so as to fit into each other.
The stopper 23 located inside is designed not to rotate. Therefore, the rod 13 is also not rotatable. A coil spring 24 is provided so as to surround the small diameter portion 21, and is designed to impart elasticity to the rod 13 in the axial direction. 25 is a handle portion attached to the tightening machine main body 18.

Therefore, when the inner socket 11 is fitted over the nut 2 and the nut 2 is tightened to the bolt 1, the engaging portion 17 at one end of the rod 13 is engaged with the groove 16 on the end surface of the male threaded portion 15 of the bolt 1. By matching them together, it is possible to prevent the bolt 1 from rotating together when the nut 2 is rotated.

In the above embodiment, a straight groove 16 was formed on the end face of the male threaded portion 15 of the bolt 1, but as shown in FIG. It is also possible to provide a matching engagement part.

The bolt/nut tightening machine of the present invention can be implemented as described above, and by engaging the engaging part at the tip of the rod with the groove on the end surface of the male threaded part of the bolt, the bolt can rotate together during tightening. Also, there is no need to check that the bolts rotate together, and there is no need to tighten them twice.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway overall side view showing the first embodiment of the present invention, FIG. 2 is a view taken along the line X-X in FIG.
The figure is a front view of the end face of the male threaded portion of the bolt, and FIG. 4 is a front view of the end face of the male threaded portion of the bolt showing a second embodiment of the present invention. 1... Bolt, 2... Nut, 3, 4... Member, 5... Tightening machine, 6... Hose, 7, 8... Piston part, 7a, 8a... Rack part, 9... Pinion part , 11...inner socket, 13...rod,
15...Male thread part, 16...Groove, 17...Engaging part, 18...Tightening machine body, 19...Support member, 2
0... recess, 21... small diameter section, 23... stopper, 24... coil spring.

Claims (1)

[Scope of utility model registration request] In a bolt/nut tightening machine that has a socket that fits externally onto a nut that is screwed onto a bolt, and that rotates the socket, a non-rotatable rod is provided at the center of rotation of the socket. A bolt/nut tightening machine characterized in that the tip of the rod is provided with an engaging part that can be freely engaged with and detached from a groove formed in the male threaded end surface of the bolt that projects toward the nut.