JPS5949877B2 - bolt tensioning machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is suitable for use in 7-lunge joints of large pressure vessels such as chemical reaction tubes and heat exchangers, installation of large machines, and assembly of main cable bands of long suspension bridges. This relates to a bolt tensioner that applies the required tightening force to the bolt.

In the conventional bolt tensioner, as shown in FIG. 1, the hydraulic output of the piston 16 is generated by a tension rod 28 attached to a flange plate 30 that is in contact with the spherical surface 14 on the upper surface of the piston 16.
It has a structure in which the power is transmitted to the bolt 3 through a large number of components, and its external dimensions are large, resulting in a large weight, poor work efficiency, and high cost.

In addition, there are design constraints such as the need for wide bolt spacing in the equipment to be tightened, and furthermore, if the upper tightening flange 1 surface is inclined due to tightening, the tension rod 2B
If the space 29 around the bolt 3 is not made large enough, there are drawbacks such as an undesirable bending force being applied to the bolt 3 and the tightening nut 4 being unable to rotate due to this bending force.

The present invention aims to improve the drawbacks of conventional bolt tensioners, and to provide a bolt tensioner that is small and lightweight, has good workability, and does not apply excessive bending force to the bolt.

This will be explained with reference to the diagram.

1 is an upper tightening flange, 2 is a lower tightening flange, and 3 is a bolt inserted between the two.

5 is its lower nut, and 4 is a tightening nut.

B is the base part of the machine, and C is the cylinder part.

In the base portion B, a socket 8 is rotatably housed in the base 7, and a plurality of plungers 9 are attached to the socket 8 via springs 10.

11 is a retaining ring for the spring 10. 12 is a hole into which the nut rotation lever 13 provided in the socket 8 is inserted;
indicates an opening provided in the base 7.

A spherical part 14 is formed on the upper surface of the base 7, and this spherical part 1
4, the lower surface of the cylinder 15 of the cylinder portion C having a shape compatible with the spherical portion, which will be described later, is brought into contact.

In the cylinder portion C, 15 is a cylinder into which a piston 16 is fitted.

A bolt grip screw 6 for coupling with the bolt 3 is provided at the center of the piston 16.

At the top of the cylinder 15, attach the top cover 19 with screws 22.
A return spring 20 is installed between the top cover 19 and the piston 16.

21 is a bundle formed on the upper part of the top cover 19.

The oil guide pipe 23 is attached to the piston 16, and the top cover 1 is attached.
An oil guide passage 25 connects a pressure oil inlet 24 provided outside of the oil pressure chamber 9 and a pressure oil chamber 26 .

17.18 is the backing.

The action and effect will be explained.

A base part B consisting of a base 7, a socket 8, a plunger 9, a spring 10, etc. is fitted onto the outer periphery of the tightening nut 4 and brought into contact with the upper surface of the upper tightening flange 1.

Next, a piston fitted inside a cylinder part C consisting of a cylinder 15, a piston 16, a top cover 19, a return spring 20, etc., whose lower surface is in contact with the spherical part 24 on the upper surface of the base T of the base part B. 16 onto the top of the bolt 3 while rotating the bundle 21.

Pressure oil is introduced into pressure oil inlet 2 from a hydraulic pump unit (not shown).
When the pressure oil is fed from 4, it passes through the pressure oil guide path 25 and enters the pressure oil chamber 2.
Leads to 6.

The piston 16 moves by the pressure oil and stretches the bolt 3.

The reaction force is transmitted from the cylinder 15 to the base T via the spherical portion 14 and further to the upper tightening flange 1.

Therefore, move the nut rotation lever 13 to the base 7.

It is inserted through the opening 27 and into the hole 12 of the socket 8, and the tightening nut 4 is rotated to bring it into close contact with the surface of the upper tightening flange 10.

Next, when the pressure oil in the pressure oil chamber 26 is released, an axial tensile force remains in the bolt 3, and the upper and lower parts of the bolt 3 remain in tension.

A strong tightening condition occurs between the tightening flanges 1 and 2, the bolt 3, the tightening nut 4, and the lower nut 5.

The piston 16 releases the pressure oil and the return spring 2
It is pushed back to its starting position with a force of 0.

Next, the cylinder portion C is removed from the bolt 3, and the base portion B is removed from the tightening nut 4, thereby completing the tightening work.

The base part B is provided with a plunger 9 that presses the socket 8 against the tightening nut 4 with a spring 10, so when assembling this machine, the bolt 3 installed horizontally There is no need to worry about the machine falling off due to its own weight, and alignment is easy.

In this way, even when the present invention is formed from two parts, the base part and the cylinder part, and the flange surface is inclined,
The base part and the cylinder part can contact each other at any angle along the spherical part at a low position very close to the tightening nut. It is no longer necessary to provide a pull rod and a space around it, which is required for the machine, and the external dimensions of the machine can be made smaller and the weight can be reduced accordingly.

Therefore, it is inexpensive, easy to handle, and has extremely good workability.

[Brief explanation of drawings]

Figure 1 is a vertical side view of the conventional machine, Figure 2 is a vertical side view of the main parts of a typical tightening flange, Figure 3 is a vertical side view of this machine, and Figure 4 is a cross-sectional side view of the base part. It is. B: Base part, C: Cylinder part,
3...Bolt, 4...Tightening nut, 6
...Bolt grip screw, 7...Base, 14...Spherical part, 15...Cylinder, 16...Piston. 215-

Claims (1)

[Claims] 1. A spherical part is formed on the upper surface of the base of the base part to be fitted to the outer periphery of the tightening nut, and the lower surface of the cylinder of the cylinder part having a shape compatible with the spherical part is brought into contact with this spherical part, and the cylinder part is A piston is fitted inside the cylinder, and a bolt tensioner is provided at the center of the piston with a bolt gripping thread for connection with the tip of the bolt.