JPH05249246A - Device for wiping off dirt from upper end face of drum can - Google Patents

Abstract

PURPOSE:To temporarily raise and separate a dirt wiping-off pad from the upper end face of a drum can so that the shock to the pad when the pad is separated from the lid of the drum can be reduced. CONSTITUTION:A drum can 1 is placed and rotated on a turntable 5 rotated by means of a main section 4 with its axis in the vertical direction and each lid which closes the opening of the can 1 is provided almost on the same circumference on the upper end face. A pad 17 is installed to the front end section of a pad moving mechanism 18 and, at the same time, moved over an extent R in the radial direction of the can 1 or raised at the moving time so as to prevent the pad 17 from coming into contact with the lids. The raising extent of the pad 17 is decided based on the measured results of a noncontact distance measuring instrument 20 installed to the front end of a fitting frame 19 and constituted of a distance sensor which detects that the distance to an object is smaller than a set value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for wiping dirt off the upper end surface of a drum for radioactive waste when a drum for radioactive waste is rotated about the axis with the axis perpendicular to the drum. A dirt wiping device for the upper end surface of a drum can in which the contact pad is temporarily lifted and separated from the upper end surface of the drum can so as to avoid contact with the lid for closing the opening and to reduce impact during avoidance. ..

[0002]

2. Description of the Related Art In a conventional example, a drum for radioactive waste is rotated around an axis perpendicular to the drum.
The horizontal arm of the wiping device is provided with a traveling base movable in the longitudinal direction thereof, and a dirt wiping pad is attached to the traveling base. In order to avoid the pad from avoiding contact with the lid for closing the opening at the top surface of the drum during wiping, one method is to attach a preceding roller near the pad holder and use this as a tip guide to get over the lid. At the same time, the system was adopted to get over the lid and avoid it. As another method, the presence of the lid is detected by a sensor of contact type limit switch type, and the horizontal arm of the wiping device is raised in parallel or swing based on the detection signal, and the pad lifts the lid. A method was adopted in which the elevator is moved up and down in two positions with a lift amount that allows it to be lowered after passing.

[0003]

In the first conventional method, the abutment of the preceding roller over the lid causes
Since the pad holding portion is impacted and the preceding roller is contaminated, there is a risk that the stains at one place will be diffused. Further, in the second method, the sensor is contaminated when it comes into contact with the lid, and the horizontal arm of the wiping device moves in parallel or swinging in two positions, so that the lifting motion is inevitable. It becomes shocking and eventually the pad is also shocked. It is not preferable in terms of mechanism that the pad holding portion is impacted by the first and second methods, but in the case where the GM counter is stored inside the pad holding portion, there is a possibility that actual damage may occur. is there.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems of the prior art and to prevent the dirt wiping pad from abutting against the opening sealing lid, and to reduce the impact at the time of avoiding. Another object of the present invention is to provide a dirt wiping device for the upper end surface of a drum can, which is temporarily raised and separated from the upper end surface of the drum can.

[0005]

According to a first aspect of the present invention, there is provided an apparatus for cleaning dirt on the upper end surface of a drum can, which wipes off dirt on the upper end surface of the drum for radioactive waste when the drum can is rotated about the axis of the drum can. In the apparatus, a non-contact type distance measuring device for measuring the distance between the opening provided at the upper end surface of the drum can and the upper surface of the sealing lid; and the dirt wiping pad based on the output of the distance measuring device. A pad drive section for temporarily raising and separating from the upper end surface of the drum can with a predetermined lift amount and acceleration so that contact with the lid is avoided and the impact at the time of avoidance is small.

According to a second aspect of the present invention, there is provided a device for removing dirt from the upper end surface of a drum according to the first aspect, wherein the distance measuring device has a plurality of lids which are fixed by gradually changing the measurement reference plane level. A distance sensor that detects that the distance to the upper surface is within a set value is provided. A dirt wiping device for an upper end surface of a drum according to claim 3 is the device according to claim 1,
The distance measuring device includes one distance sensor capable of moving up and down so as to change the measurement reference plane level stepwise, and detecting that the distance from the lid upper surface is within a set value.

According to a fourth aspect of the present invention, there is provided a device for cleaning the upper surface of a drum of a drum according to the first aspect, in which the distance measuring device detects that the distance from the upper surface of the lid is within a set value. One stationary distance sensor whose set value is variable stepwise is provided.

[0008]

In the dirt removing device for the drum can upper end surface according to any one of claims 1 to 4, the non-contact type distance measuring device is used to connect the opening provided at the drum can upper end surface to the upper surface of the sealing lid. The distance is measured in a non-contact manner, and then the pad drive unit causes the dirt-wiping pad to avoid contact with the lid based on the output of the distance measuring device, and to reduce the impact at the time of avoidance. It is temporarily lifted and separated from the upper end surface of the drum with a predetermined lift amount and acceleration.

According to a second aspect of the present invention, there is provided a device for cleaning dirt on the upper end surface of a drum, wherein a plurality of distance sensors forming a distance measuring device determines the distance between the upper surface of the lid and the upper surface of the lid. It is measured in a contactless manner as an intermediate value of the levels of the adjacent distance sensors when changing. Particularly, in the dirt removing device for the upper end surface of the drum according to claim 3, when the distance from the upper surface of the lid is changed by the distance sensor constituting the distance measuring device, the signal state of the output changes,
It is measured in a non-contact manner as an intermediate value between the adjacent stepwise elevation levels.

Particularly, in the dirt removing device for the upper end surface of the drum according to the fourth aspect, the distance from the upper surface of the lid is changed by the distance sensor constituting the distance measuring device when the output signal state changes. It is measured in a non-contact manner as the intermediate value of each stepwise set value.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a dirt wiping device for the drum can upper end surface according to the present invention will be described below with reference to the drawings. FIG. 1 is a side view of the embodiment, and FIG. 2 is a plan view of a drum can in the embodiment. In FIG. 1, a drum can 1 is installed and rotated with a vertical axis on a rotary table 5 that is rotated by a main part 4 that stores main parts of the device such as a controller and an operation part. In the course of this rotation, the radioactive dirt adhering to the upper end surface of the drum can 1 is wiped off by the pad 17 for contamination inspection. The lower end surface and the outer peripheral surface of the drum can 1 are also wiped off as a separate step. In FIG. 2, the upper end surface of the drum 1 is
The respective lids 2 and 3 for sealing the opening are provided on substantially the same circumference. Returning to FIG. 1, the pad 17 is installed at the tip of the pad moving mechanism 18, and is moved or moved by the pad moving mechanism 18 in the radial direction of the drum can 1 over a range of R, as will be described later in detail. At this time, the lids 2 and 3 are moved up and down to avoid contact with the lids 2 and 3. The time and degree of this ascending / descending is determined by the pad moving mechanism 18 based on the measurement of the surface level of each of the lids 2 and 3 of the drum 1 by the distance measuring device 20 installed at the tip of the mounting frame 19. The height of the drum 1 is defined as 880 mm by the JIS standard, but there is usually a variation of ± 10 mm.
Further, the pad 17 is spring-biased so as to press the upper end surface of the drum can 1, so that the pad 17 is slightly movable in the vertical direction, and the impact at the time of contact is mitigated. This pad 17
Since the GM counter tube for the radioactivity measurement may be stored in the holding part of, the impact relaxation is especially required.

FIG. 3 is a perspective view of the pad moving mechanism in the embodiment. In FIG. 3, the pad moving mechanism 18 mainly includes an actuator 7 as a drive source for moving the pad 17 up and down, a rotating frame 9 for holding a main part including the pad 17,
A moving frame 13 for moving the pad 17 in a straight line and a pad 15 for the shaft 15
Actuator 14 as a drive source to rotate around
And a mounting frame 16 for holding the pad 17. To describe the configuration and operation in more detail, the rotating frame 9 is supported rotatably around the shaft 8 in the upper part, and the guide shaft 11 can be linearly moved in one part in order to move the moving frame 13 straight in the lower part. The screw shaft 12 is screwed to the other. This guide shaft
11, The screw shaft 12 holds the moving frame 13 at each right end thereof.
This moving frame 13 is guided so as to be able to move straight with respect to the rotating frame 9 via a guide shaft 11, and moves straight through a screw shaft 12 rotated by a motor 10 fixed to the rotating frame 9, that is, as shown in FIG. Move drum can 1 in the radial direction. Moving frame
An actuator 14 of a pneumatic cylinder type is installed on the upper end surface of 13, and a mounting frame 16 is provided on the right end portion thereof so as to be rotatable around a shaft 15. The output shaft of the actuator 14 is joined to the mounting frame 16 via a universal joint not labeled,
The linear movement of the output shaft causes the mounting frame 16 and
Is rotated counterclockwise at a right angle from the position shown. At this rotational position, the radioactivity of the dirt on the pad 17 is measured.
Returning again, the rotating frame 9 is joined at its lower end to the output shaft of the hydraulic cylinder type actuator 7, which is rotatably supported around the shaft 6. The pad 17 is rotated to move up and down. Each drive of the actuator 7, the motor 10, and the actuator 14 is controlled by a controller (not shown) based on the overall work command and the signal from the distance measuring device 20 in FIG.

By the way, the distance measuring device 20 is generally considered to be a non-contact type optical or ultrasonic type measuring device capable of continuous analog measurement, but the cost is high and the distance accuracy is not so high. Since it is not necessary to make details, a simplified form having the following three configuration examples is used in this embodiment. FIG. 4 is a front view of the first configuration example. Here, the three distance sensors 21, 22, 23 are attached to the base 24 in such a manner that the lower end surface as the measurement reference surface is vertically displaced by L. The base 24 is fixed to the right end of the mounting frame 19 in FIG.

The distance sensors 21, 22 and 23 are based on the principle of triangulation. For example, when the object comes within a certain set value, the output signal is turned on, and the distance exceeds the set value. A kind of on / off operation is performed according to the distance so that the output signal turns off. Where L is 10 mm
Therefore, it corresponds to the above-mentioned variation in the height of the drum can.
The lower end surface of the intermediate distance sensor 22 is aligned with the upper end surface of the drum having the reference height, and the distance sensors 21 and 23 are positioned by shifting the lower and upper sides by 10 mm. Now, when the surface of each lid of the drum (hereinafter referred to as the target surface) is at a distance exceeding the lower end surface of the lowermost distance sensor 21 beyond the set value, the output of any distance sensor is in the off state, When the distance between the surface and the lower end surface of the distance sensor 21 is within the set value and the distance between the target surface and the lower end surface of the distance sensor 22 exceeds the set value, only the output of the distance sensor 21 is turned on. Furthermore, when the distance between the target surface and the lower end surface of the distance sensor 22 is within the set value, and the distance between the target surface and the lower end surface of the distance sensor 23 exceeds the set value,
Both outputs of the distance sensors 21 and 22 are turned on. Furthermore, when the distance between the target surface and the lower end surface of the distance sensor 23 is within the set value, all the outputs of the distance sensors 21, 22, 23 are turned on.

As described above, since the set value of the distance sensor comes in the middle of the lower end surface level of the adjacent distance sensors when the output ON / OFF state changes, the output of each distance sensor Based on this, the distance to the target surface can be obtained in stages. In other words, it is required to determine whether the level of the upper end surface of the drum can is within the standard height of 880 mm to (880 + 10) mm or the standard height of 880 mm to (880-10) mm. Moreover, the accuracy of the distance measurement is sufficient for the purpose of the embodiment. Based on this distance measurement,
The initial level of the pad 17 related to the upper end surface of the drum in FIG. 3 is determined by the lifting operation of the entire pad moving mechanism 18 by another lifting mechanism. Next, when the pad 17 approaches the lid as the drum can rotates, the actuator 7
The pad 17 is operated to move up and down with a stroke necessary and sufficient to avoid the lid of the drum and an acceleration that does not give a shock. In addition, from the safety of operation, 10
The level within mm is sufficiently absorbed by the spring structure of the holding portion of the pad 17. This type of distance sensor is advantageous in terms of cost, and is not affected by dirt on the lens surface, color difference of the object, presence or absence of a background object, etc. It has features.

FIG. 5 is a front view of a second configuration example of the distance measuring device. The second configuration example is different from the first configuration example in that only one distance sensor is provided and the level is changed stepwise by the elevating means. Ie one distance sensor
31 is attached to a table 32 that is moved up and down by a lifting mechanism 33. The elevating mechanism 33 is fixed to the right end portion of the mounting frame 19 in FIG. The elevating operation is performed by gradually shifting three positions corresponding to the first configuration example, in which the lower end surface as the measurement reference surface of the distance sensor 31 is vertically displaced by L from the level corresponding to the reference height of the drum can. It is carried out as follows. Therefore, in the operation of the second configuration example, when the level of the distance sensor 31 is changed stepwise, and the signal state of the output changes, the set value related to the distance comes between the adjacent levels. Become. The elevating mechanism 33 has a known structure in which a motor is built in and the table 32 is moved straight by rotation of a screw shaft directly connected to the motor.

FIG. 6 is a front view of a third configuration example of the distance measuring device. The third configuration example is a configuration in which one distance sensor is fixedly installed and the set value related to the distance is changed stepwise. That is, the base 42 is the mounting frame in FIG.
The distance sensor 41 fixed to the right end of 19 and fixed to the base 42 has a built-in variable resistor for changing the set value related to the distance. The axis of this variable resistor is rotated stepwise by the motor 43, and the set value relating to the distance is changed stepwise, which has the same meaning as the stepwise elevation of the distance sensor 31 in the second configuration example. Therefore, according to the third configuration example, when the set value is changed stepwise by the rotation of the variable resistor and the signal state of the output changes, there is a measurement distance in the middle of each adjacent set value. Become.

[0018]

According to the dirt wiping device for the drum can upper end surface according to any one of claims 1 to 4, the upper surface of the lid for sealing the opening provided at the drum can upper end surface by the non-contact type distance measuring device. The distance from the upper end surface of the drum can is temporarily measured by the pad drive unit with a predetermined lift amount and acceleration based on the output of the distance measuring device. As a result, it is lifted and separated, and as a result, contact with the lid is avoided and the impact at the time of avoidance is small. Therefore, the pad does not contaminate the lid, and the periphery of the pad holding portion is free from the possibility of mechanical damage or operation inhibition, thus improving the reliability of the device.

According to a second aspect of the present invention, there is provided a device for wiping the upper surface of a drum can, wherein a plurality of distance sensors constituting a distance measuring device determines the distance from the upper surface of the lid and the output signal state, for example, ON or OFF. It is measured in a contactless manner as an intermediate value of the levels of the adjacent distance sensors when changing. Therefore, since the distance measuring device has no movable portion, operational reliability can be improved.

Particularly, in the dirt-cleaning device for the upper surface of the drum according to the third aspect, the distance sensor forming the distance measuring device measures the distance between the upper surface of the lid and the upper surface of the lid when the output signal state changes. It is measured in a non-contact manner as the intermediate value of each stepped ascending / descending level. Therefore, especially when the measurement accuracy is narrow or the measurement range is wide, the number of distance sensors can be significantly reduced compared to claim 2, so that the cost of the distance measuring device can be reduced by devising the moving mechanism.

Particularly, in the apparatus for wiping off the dirt on the upper surface of the drum according to claim 4, the distance sensor forming the distance measuring device measures the distance from the upper surface of the lid when the output signal state changes. It is measured in a non-contact manner as the intermediate value of each stepwise set value. Therefore, since there are almost no moving parts in the distance measuring device, operational reliability can be improved, and the number of distance sensors can be significantly reduced, especially when there are many stages of setting values, which reduces the cost of the distance measuring device. Can be achieved.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment according to the present invention.

FIG. 2 is a plan view of a drum according to an embodiment.

FIG. 3 is a perspective view of a pad moving mechanism in the embodiment.

FIG. 4 is a front view of a first configuration example of the distance measuring device.

FIG. 5 is a front view of a second configuration example of the distance measuring device.

FIG. 6 is a front view of a third configuration example of the distance measuring device.

[Explanation of symbols]

 1 Drum Can 2, 3 Lid 4 Main Part 5 Turntable 6 Shaft 7 Actuator 8 Shaft 9 Rotating Frame 10 Motor 11 Guide Shaft 12 Screw Shaft 13 Moving Frame 14 Actuator 15 Shaft 16 Mounting Frame 17 Pad 18 Pad Moving Mechanism 19 Mounting Frame 20 Distance measuring devices 21, 22, 23 Distance sensor 24 Base 31 Distance sensor 32 33 Lifting mechanism 41 Distance sensor 42 Base 43 Motor

Claims (4)

[Claims] 1. An upper surface of a lid for sealing an opening provided in an upper end surface of a drum in a device for wiping off dirt on an upper end surface of a drum for radioactive waste when the drum can is rotated about the axis of the drum. A non-contact type distance measuring device for measuring the distance between the lid and the lid for avoiding contact with the dirt wiping pad based on the output of the distance measuring device,
In addition, a pad drive unit that temporarily raises and separates from the upper end surface of the drum can with a predetermined lift amount and acceleration so that the impact during avoidance is small; .. 2. The apparatus according to claim 1, wherein the distance measuring device is arranged such that the distances from a plurality of fixed upper surfaces of the lid are changed within a set value. A dirt wiping device for an upper end surface of a drum can, comprising a distance sensor for detecting. 3. The apparatus according to claim 1, wherein the distance measuring device has a distance to one upper lid surface that can be raised and lowered so as to change the measurement reference plane level stepwise within a set value. A device for wiping dirt off the upper end surface of a drum can, which is provided with a distance sensor for detecting. 4. The device according to claim 1, wherein the distance measuring device detects that the distance to the upper surface of the lid is within a set value, and the set value is stepwise variable. Device for removing dirt from the upper end surface of a drum can, which is provided with a distance sensor provided.