JPH0334392B2 - - 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 the upper head of a nuclear reactor pressure vessel.

During periodic inspections of the reactor and fuel replacement, the upper mirror must be removed, but in order to prevent radioactive contamination when the upper mirror is removed, the well installed at the top of the pressure vessel must be Water filling is done. 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 how to clean stud bolts. The stud bolt 3 passes through the flange 1a of the upper mirror 1 and is connected to the flange 2a of the pressure vessel main body 2, and a nut (not shown) is connected to a threaded portion 3a of the bolt 3, which is a threaded portion of the nut. Conventionally, when cleaning a bolt, first cover the threaded part 3a with a plastic bag 4,
Cleaning was carried out manually by a worker who put his/her hand into the plastic bag 4 and used a wire brush. Plastic bag devices are used to prevent the scattering of radioactive dust generated during cleaning work, but the effect of preventing scattering is not always sufficient, and there is a risk that workers may be exposed to internal radiation by inhaling it. It is expensive and it is difficult to collect dust. In addition, as nearly 100 stud bolts are attached to one pressure vessel, manual cleaning takes a long time.
This poses a higher risk of exposure.

In order to solve the above problems, the inventors provided a device in which a brush attached to a support is mechanically rotated in a cylindrical container around the bolt, and the dust removed from the bolt is collected by a suction device. (Patent application 1982-182120 - Patent application 1982-182129).

As shown in FIG. 2, in this device, a brush 17 is attached to a support 18 formed around a bolt 3, and a rotating shaft 22 of a motor 23 is engaged with an engaging groove 21, whereby The support 18 and the brush 17 are rotated around the bolt 3 to clean the bolt 3. This cleaning is performed inside the cylindrical main body 11, which prevents dust from scattering and is structured to suck the dust from a suction port 27 provided at the bottom of the main body 11'. On the other hand, a sliding plate 14 is provided at the upper end of the support 18.
is attached, and by pulling up the handle 13, the support 18 and brush 17 move in the X direction (radial direction of the bolt), making it easy to attach and detach the entire device and the bolt 3. has the following problems:

(a) Handle 1 to open and close support 18 and brush 17
3, the handle 13 must be moved up and down by the operator directly.

(b) When attaching and detaching the entire device to the stud bolts 3, it is necessary to lift the handle 13, and the weight of the entire device (excluding the motor 23) exceeds 20 kg, so when attaching and detaching the entire device to a large number of bolts 3 in succession. It requires a lot of effort.

(c) When lifting the entire device, attaching and detaching it to the bolt 3, and transporting it, attach and detach the motor 23 and the device body,
It is necessary to handle them separately, which makes the work complicated.

The purpose of this invention is to solve the above-mentioned problems, and to enable a worker to attach and detach the entire device and stud bolts and open and close the support by remote control without having to approach the pressure vessel and directly handle the device. The object of the present invention is to provide a device that can reduce worker labor and radiation exposure.

In short, the present invention enables a bolt cleaning device to be operated remotely.The rotating motor is fixed to the main body of the device, and the support to which the brush is attached can be opened and closed without removing the motor. This is what I did.

Examples of the present invention are shown in FIGS. 3 to 5 below.

3 and 4, reference numeral 11 is a bolt cleaning device having a mechanism according to the present invention, which is attached to the upper mirror flange 1a along the annular pedestal 7 fixed to the upper mirror 1 of the reactor pressure vessel. A station 8 that can be driven by remote automatic control in the circumferential direction and radial direction of the
It is suspended from the lifting arm 9 and attached to the stud bolt 3. Further, a stud tensioner 10 and a nut attaching/detaching device 12 are suspended from the station 8 at the same time.

FIG. 5 shows the overall structure of a bolt cleaning device showing an embodiment of the present invention, and the entire structure is suspended by a lifting arm 9 and attached to and detached from a stud bolt 3.
In this figure, a cylindrical cleaning device 11 is arranged on the threaded portion 3a of the stud bolt 3 protruding from the flange 1a of the upper mirror so that its central axis is located on the centerline of the threaded portion 3a. . Reference numeral 18 denotes a support disposed in an annular space formed between the cleaning device main body 11 and the threaded portion 3a, and a brush 17 is attached to the threaded portion 3a side. A guide 15 is fixed to the upper end of the support 18, and the guide 15 is inserted into the engagement hole 16a of the rotary disk 16. A central portion of the rotary disk 16 is engaged with a motor 23 via a rotary shaft 24 that is extendable and retractable in the axial direction. Further, the motor 23 is fixed to the main body 11 of the apparatus by a fixing member 30.

By rotating the motor 23, the rotational force is transmitted to the rotary disk 16 via the rotating shaft 24, and further rotates the support 18 via the guide 15.
At this time, the brush 17 attached to the support 18 slides on the surface of the threaded portion 3a to remove generated rust. A lower guide 19 provided at the lower end of the support 18 is a wheel connected to the lower guide 20 through an engagement hole, and each support is supported at its upper and lower ends by a rotary disk 16 and a wheel 19. As a result, it rotates around the threaded portion 3a.

In the bolt cleaning device described above, when installing the device on the bolt, the brush 17 gets caught on the threaded portion 3a, making the installation work difficult, so the support 18
performs the following operations to facilitate attachment and detachment of the device.

First, when attaching the device body to the stud bolt, the device body is inserted into the hanging screw portion 3a by the lifting arm 9. At this time, the lifting plate 26 is inflated with air as shown in the left half of Fig. 4. It is pulled upward by the cylinder 25 and the lifting plate 26
The rotating plate 16 that is engaged with the rotating plate 16 is simultaneously pulled upward. As a result, the sliding plate 14 attached to the upper part of the guide 18 slides down the slope portion 16b of the rotary disk 16, and the support 18 moves in the X direction.
Thereby, even if the brush 17 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 elevating plate 26 is moved by the air cylinder 25 as shown in the right half of FIG.
As a result, the rotary disk 16 is lowered, and the support 18 approaches the Y direction, that is, the threaded portion 3a. On the other hand, when the elevating plate 26 and the rotary disk 16 are moved up and down by the air cylinder 25, the relative distance between the motor 23 and the rotary disk 16 changes. On the other hand, the rotating shaft 24 has a spline structure and can be expanded and contracted in the axial direction.

When the installation of the bolt cleaning device main body is completed, the motor 23 is rotated as described above to clean the bolts.

By implementing this invention, workers do not need to approach the reactor pressure vessel and directly operate tools, and all work can be done remotely, so the labor required for work can be significantly reduced. and safe.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the stud bolt insertion part of a reactor pressure vessel, Figure 2 is a cross-sectional view of a conventional bolt cleaning device, and Figure 3 is an automatic nut removal/removal device equipped with a bolt cleaning device having the mechanism of the present invention. FIG. 4 is a plan view of the device, FIG. 4 is a front view of the device shown in FIG. 3, and FIG. 5 is a sectional view of a bolt cleaning device showing an embodiment of the present invention. 3...Stud bolt, 11...Device main body, 1
7... Brush, 18... Guide, 23... Motor, 24... Rotating shaft, 25... Air cylinder.

Claims (1)

[Scope of Claims] 1. A device that has a support that rotates around the bolt and has a cleaning member such as a brush attached thereto in the main body of the device for cleaning a bolt placed against an upright bolt. A lifting device that lifts and lowers the support and opens and closes the support accordingly;
A bolt cleaning device characterized by being equipped with a motor that rotates a support. 2. Claim 1, characterized in that the rotating shaft that transmits the power of the motor to the support has a spline structure, and is configured to accommodate relative displacement between the rotating plate and the motor as the support moves up and down.
Bolt cleaning device described in section. 3. The bolt cleaning device according to claim 1, wherein the elevating device is an air cylinder.