JPS6351751B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a large bolt cleaning device, and more particularly to a bolt cleaning device suitable for cleaning stud bolts that tighten an upper mirror, which is the upper cover of a nuclear reactor pressure vessel.

When performing periodic inspections of the reactor and replacing fuel, the upper mirror must be removed. When the upper mirror is removed, water is filled in the well provided at the top of the pressure vessel to prevent radioactive contamination. will be held. In this case, the stud bolts that attach the upper mirror to the pressure vessel body also become soaked in water, causing rust, and the bolts must be cleaned before and after removing and attaching the nuts.

Figure 1 shows a method for cleaning stud bolts. The stud bolt 3 is inserted through the flange 1a of the upper mirror 1 and is threadedly engaged with the flange 2a of the pressure vessel main body 2, and the nut (not shown) is threadedly engaged with the threaded portion 3a of the bolt 3, which is the threaded portion of the nut. . When cleaning a bolt, first, a plastic bag 4 is placed over the threaded portion 3a, and the cleaning is carried out manually by a worker who puts his/her hand into the plastic bag 4 and uses a wire brush. Wearing plastic bags is intended to prevent the scattering of radioactive dust generated during cleaning work, but the effect of preventing scattering is not necessarily sufficient, and there is a high risk that workers will be exposed to radiation internally if they inhale it. Moreover, it is difficult to collect the dust. Additionally, as more than 100 stud bolts are attached to each pressure vessel, manual cleaning takes a long time and increases the risk of exposure to radiation.

A device for cleaning large stud bolts was devised in Utility Model Application No. 58283/1983. In the device according to this invention, the wire brush is rotated in contact with the bolt screw as in the present application, but there are the following problems.

(1) The wire brush is always pressed against the stud using a coil spring 48 shown in FIG.

This forces the device to be pushed into the stud in opposing contact with the stud, which can cause cracking and damage to the stud in large studs made of special materials that are sensitive to scratches.

(2) Air is taken in from the middle of the outer cylinder of the device, and air is extracted from the middle of the outer cylinder of the device. In addition, the inner cylinder is provided with a plurality of air intake ports 3c, and the resistance to air flow is large. Dust collects at the bottom of the device.

(3) The brush 4 has approximately the same length as the outer cylinder 2. To replace the brush, remove bolts 11 and 12.
It is necessary to take out a heavy device including a rotating body from the outer cylinder, and it takes time and effort to replace the brushes.

The purpose of this invention is to eliminate the above-mentioned problems and provide a device that automatically cleans bolts. More specifically, the motor that rotates the support to which the brush is attached and the main body of the cleaning device are separated. It is an object of the present invention to provide a bolt cleaning device which is formed to be easy to handle.

In short, this invention forms an engagement groove in the upper part of the bolt cleaning device, and is structured so that the rotating shaft of the motor is inserted into the engagement groove, thereby making it possible to separate the motor and the device body, and also making it possible to separate the motor and the device body. This is done so that the type of information does not matter.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, a cylindrical cleaning device 11 is attached to the threaded portion 3a of the stud bolt 3 protruding from the flange 1a of the upper mirror.
It is arranged so that it is located on the central axis of. 13
is a support placed in an annular space formed between the cleaning device main body 11 and the threaded portion 3a;
A brush 12 is attached to the a side. A guide 9 is fixed to the upper end of the support 13, and the guide 9 is inserted into the engagement hole 10a of the rotary disk 10. An engagement groove 21, which is a key groove, is formed in the center of the rotary disk 10 (see also FIG. 3).
It is configured so that the rotating shaft _M1 of the motor M is inserted therein. With this configuration, it is not necessary to always attach the motor to the cleaning device main body, and the entire device can be made lightweight. In addition to the hand drill type motor shown in the figure, various types of motors can be used by attaching a rotating shaft _M1 that engages with the engagement groove 21.

By fitting the rotating shaft M ₁ into the engagement groove 21 , the rotational force of the motor M is transmitted to the rotary disk 10 and further rotates the support 13 via the guide 9 . The brush 12 attached to the guide 9 slides on the surface of the threaded portion 3a due to the rotation of the support 13, and removes generated rust. 15 is a lower guide provided at the lower end of the support 13; 14 is a wheel connected to the lower guide 15 through an engagement hole 14a; It rotates around the threaded portion 3a by being supported by.

In the bolt cleaning device described above, when attaching the device to the bolt, the brush 12 gets caught on the threaded portion 3a, making the attachment work difficult. Therefore, the support 13 operates as shown below to facilitate attachment and detachment of the device. Make it.

First, when attaching the device body to the stud bolt, suspend the device body using the handle 7 and tighten the threaded portion 3a.
By suspending the main body of the device, the handle 7 is pulled upward as shown in the left half of FIG. 2. As a result, the sliding plate 8 attached to the upper part of the guide 9 slides down the slope portion 10b of the rotary disk 10, and the support 13 moves in the X direction.
Thereby, even if the brush 12 is hard, the entire body can be easily inserted into the threaded portion 3a. When the installation of the device main body 11 is completed, the handle 7 descends due to its own weight, and as a result, the support 13 approaches the Y direction, that is, the threaded portion 3a, as shown in the right half of FIG.

When the installation of the bolt cleaning device main body is completed, the rotating shaft _M1 of the motor M is inserted into the engagement groove 21 as described above, and the bolt cleaning operation is performed.

By implementing this invention, a conventional motor can be freely used for operating the bolt cleaning device, making it economical.

Further, since no motor is fixed to the main body of the device, the entire device can be made lightweight and the device can be easily handled.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a stud bolt insertion portion of a reactor pressure vessel, FIG. 2 is a sectional view of a bolt cleaning device according to the present invention, and FIG. 3 is a view taken along line AA in FIG. 10...Rotating disk, 12...Brush, 13...Support, 21...Engagement groove, M...Motor, _M1 ...Rotating shaft.

Claims (1)

[Claims] 1 The lower end of the cylindrical device body has a dust suction passage, the lower end is located in the engagement hole of the rolling wheel provided at the bottom of the device body, and the engagement hole of the rotary disk through which the guide connected to the upper end is rotationally driven. In an apparatus for cleaning a large stud, which is provided with a plurality of supports with brushes that are inserted through the studs, and when the apparatus is suspended by the handles of the supports with brushes, the supports are displaced toward the wall side of the main body of the apparatus. A removable motor bolt cleaning device, characterized in that an engagement groove for shaft insertion is provided, and a motor is detachably attached to the device body.