JPS6119387B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention applies to facilities and equipment that are difficult to access, such as nuclear reactor spent fuel pools, the inner surface of reactor vessels, and equipment used therein, which are typically present in water and contain radioactive substances. This invention relates to an underwater polishing device for polishing equipment that is difficult to access while remaining underwater.

The spent fuel pool of a nuclear reactor, the inner surface of a reactor pressure vessel, and various equipment used therein usually exist underwater, and after they are manufactured or put into use, the presence of radioactive materials and other BACKGROUND ART There are facilities and devices that are difficult to access for various reasons, and it is often necessary to grind part or all of the surface of such facilities and devices. For example, in each of the above-mentioned devices, a part of one of the devices is damaged due to interaction between the devices, and a part of the broken piece remains as a protrusion on the surface of the device. If the problem is not eliminated by such means, the chances of interaction will further increase, leading to further damage to the equipment.

In such cases, conventionally, as shown in FIG. 1, a polishing head 2, usually including an air grinder or a motorized grinder (hereinafter simply referred to as a grinder), is attached to the side end of a long support hole 1, and the polishing head 2 is placed underwater. Polishing work has been carried out by manipulating the support pole 1 from the surface of the water.

However, the biggest drawback of such polishing operations is that monitoring of the polishing operations is difficult due to the remote location. Therefore, in order to solve this problem, it has been proposed to use an underwater television to observe the polished part including the surface to be ground.

However, when such a polishing implementation system is used, the following difficulties arise.

One problem is that it is difficult to attach the polishing head to the end of a long support pole and operate the other end to bring the polishing head into contact with the object to be polished.

This is because it is necessary to reduce the total weight of the jig including the pole as much as possible when operating it manually, and it is desirable to make the diameter of the pole smaller compared to the length of the pole. This is due to the fact that the rigidity is unavoidably reduced and the pole itself bends and sways when used underwater.

Another of the above-mentioned difficulties stems from the fact that an air grinder is usually selected as the grinder in order to simplify the polishing apparatus itself.

Generally, commercially available grinders supply air to the grinder impeller, transmitting the rotation of the impeller to the grinding wheel, and exhaust most of the air to the rear, that is, in the direction opposite to the grinding wheel, and some of it to the front. As a result, it is configured to be air-cooled, and when used in the air, it is used for corner polishing. In the case of underwater polishing, the part to be polished is not particularly required to be cooled because it is used underwater. In order to solve the first problem, that is, it is difficult for the polishing head to come into contact with the part to be polished, it is necessary to use the polishing head as a driving source to press the part to be polished, and to compensate for the curvature of the pole in the water. Because of this, it is often used while maintaining the above-mentioned state, and therefore, such rear exhaust generates air bubbles near the part to be polished, making it difficult to observe the part to be polished with an underwater television. Instead, the air bubbles generated by the rear exhaust disturb the area near the part to be polished, scattering polishing debris into the water, and causing water pollution.

Thus, the present invention provides an underwater polishing apparatus that solves the above-mentioned difficulties, prevents turbulence generated near the part to be polished, and eliminates the scattering of polishing debris in the water and the cause of water pollution caused by this. The purpose is to

That is, the feature of the present invention is that a polishing head including a rotating whetstone is attached to the tip of the support pole as described above, and the other end is operated to bring the rotary whetstone at the tip of the polishing head into contact with the object to be polished. In the polishing apparatus, a thrust imparting member such as a rotating screw or a water flow generating device using a submersible pump or the like is provided behind the rotating grindstone.

Another secondary feature of the present invention is that an exhaust mechanism including a relatively long exhaust pipe is attached to the thrust member.

Hereinafter, embodiments of the present invention will be described further based on the accompanying drawings.

FIG. 2 is a schematic view of the main parts of an example of the apparatus of the present invention, and shows the polishing work portion at the lower part of the support pole 1 in FIG.

Here, the first step is to attach the polishing head 2 to the lower part of the support pole 1, place it facing the object to be polished 3, and perform the polishing operation by a person on the surface of the water, that is, on land. Since it is similar to the figure,
The details are omitted. Therefore, the explanation will be given below based on the above-mentioned main parts.

In FIG. 2, reference numeral 7 indicates the lower part of the support pole 1, a polishing head 2 is attached to the tip thereof, and a rotary grindstone 4 is rotatably attached to the final end. The rotary grindstone 4 is usually formed from a material such as aluminum oxide, silicon carbide, or boron nitride, and a shaft 9 that supports it has a rotary screw 5 behind the rotary grindstone 4, which is a thrust imparting member that is a feature of the present invention. are attached coaxially and are configured to rotate synchronously with the rotating grindstone 4.

The rotary screw 5 has the function of applying thrust toward the object 3 to the polishing head, especially the rotating grindstone 4 at the tip thereof, and moving the abrasive debris backward to keep the vicinity of the surface to be polished always clean. and
When the whetstone is an air grinder, rotational motion is applied simultaneously by air pressure supplied from the lower part 7 through the air supply pipe also used by the support pole 1, and the above-mentioned function is exerted.

In the figure, the polishing head 2 including the rotary grindstone 4 and the rotary screw 5 is located in the support box 1.
1 (which may have a window hole on the back), is connected to the lower part 7 of the support pole 1 via an air pipe 6, and has an inlet in a part of the box. is attached.
The grinding debris recovery device uses the support box 11 as an exhaust box, and includes a flexible pipe 14 that is continuous with the suction port opened in the box, and a grinding debris recovery filter 12 that is interposed in the pipe 14.
and a drainage pump 13, and in addition to having a grinding debris collection function, it also has the function of a thrust imparting member separate from the rotary screw 5, and its discharge side end is appropriately connected to an underwater television or the like. Care has been taken not to affect observation.

The water flow generated in the drainage box by the rotating screw 5 flows in from the suction port provided at the front of the drainage box as shown by the arrow in FIG. 2, and is discharged to the rear via the drainage pipe 14. However, the size of the suction port on the surface facing the surface to be ground is adjusted so that the speed of the suction water flow generated at the suction port is greater than the speed of the discharge water flow generated in the drain pipe 14. At this time, if necessary, a window hole is made in the back surface of the support box 11 as described above.

The above adjustment means that the grinding avoidance side of the suction port (outer surface of the box) has a negative pressure than the drainage box side of the suction port (inner surface of the box), and the drainage box is drawn toward the object to be ground. In other words, the suction water flow generated at the suction port by the rotation of the rotary screw 5 applies a thrust force to the entire polishing head 2 including the rotary grindstone 4 in the direction of the object to be ground. In addition, grinding debris collection filter 1
2. Since the grinding piece collection mechanism consisting of the pump 13 and the flexible drainage pipe 14 also drains water to the rear, thrust is obtained by generating a suction water flow at the suction port when the pump 13 is driven, which is the effect of the rotating screw 5. It's no different than that.

Therefore, in the illustrated example, both the rotary screw 5 and the grinding piece recovery device are used together, but it is not necessary to use both together, and the thrust may be applied only by the rotating screw 5 alone, or the grinding piece recovery device may be used alone. The desired purpose can be achieved in the same way even if a thrust force is applied only by installing a polishing head, and both are within the scope of the present invention. The present invention also includes the use of a thrust imparting member that provides thrust.

In particular, if a rotary screw is not used, it is sufficient to install the drainage pump shown in Figure 2 in the latter stage.In this case, the pump can be a rotary pump or another pump, and the pump is not limited to a submersible pump. It is also possible to use a combination of a drainage pump installed on land or an ejector pump installed before the filter and a water supply pump installed on land.

When these pumps are used, a water flow is generated in the rotary grindstone 4 section in FIG. 2 from the abrasive material 3 on the left side to the drainage pump on the right side, and this water flow provides a thrust force that drives the polishing head 2 to the left side. , the grinding pieces generated near the rotary grindstone 4 are collected by a collection filter 12.

When a rotating screw is used as the above-mentioned grinding debris recovery device, thrust application and grinding debris recovery can be performed simultaneously with only the rotating screw, the drain pump 14, and the filter 12, without using the pump 13 shown in Fig. 2. It is also possible.

Thus, the pump and the rotary screw can essentially each be used independently for the same purpose;
Particularly, if they are used simultaneously as in the illustrated embodiment, it is advantageous that even if one of them fails, the desired effect can be obtained only with the other.

The support box 11, which is related to the above-mentioned thrust imparting member and grinding piece recovery device, and which houses the rotary grindstone 4, rotary screw 5, etc., also serves as a support plate used to control the amount of grinding during polishing, and is By adjusting the gap a between the surface facing the grinding surface and the tip of the grindstone 4, the amount of grinding can be adjusted.

In the illustrated example, the support box 11 is shown as a container with only the surface facing the surface to be ground opened, but its shape may be a rectangular parallelepiped with part or all of the bottom opened, or a truncated conical shape. It is possible to have a shape in which part or all of the bottom surface is open, or any other suitable shape.

In the above description, the support box 11, the pump 13, and the filter 12 are connected by the flexible pipe 14 for ease of operation, but of course, the support box 11, the pump 13, and the filter 12 are connected by the flexible pipe 14. You are free to do so.

The support box 11 divides its function into two parts,
Separating the function of setting the polishing position and the function of draining water around the surface to be polished as separate members does not impair the effects of the present invention; This is one aspect.

In the figure, reference numeral 10 denotes an exhaust port arranged at the rear of the support box 11, and an exhaust passage leading to the exhaust pipe 8 is appropriately provided so that during polishing, the exhaust port is not exhausted to the vicinity of the surface to be polished. Appropriate position,
Preferably, the exhaust is discharged from an exhaust pipe 8 via an exhaust passage of 1 m or more so as to be exhausted at a location remote from the surface to be ground, and equipment is provided to prevent disturbance around the grinding surface.

Therefore, when operating the above-mentioned polishing device from above the water surface as shown in Fig. 1 and performing polishing work,
A thrust force is applied to the grindstone surface toward the object 3 by the screw 5 rotating together with the rotary grindstone 4, and a predetermined polishing action is applied according to a preset gap a between the surface to be ground and the grindstone surface. At this time, when the pump 13 is driven, the water inside the support box 11 and the water around the surface to be ground is pumped into the flexible pipe 14.
The water is drained backward through the pump, and further generates a thrust against the grinding surface of the polishing head 2, which helps push the polishing head 2 against the surface to be ground, and at the same time collects the grinding debris around the surface to be ground into the grinding piece collection filter. .

On the other hand, in order to drive the air grinder, air is supplied through the support pole 1 and through the lower part 7 of the support pole 1 through the rear exhaust port 10 and into the exhaust pipe due to the negative pressure generated by the rotation of the rotary screw 5. The flow does not cause bubbles or other disturbances around the surface to be ground.

In this way, the tip of the polishing head can be stably brought into contact with the object 3 to be polished, and the surface of the object to be polished can be reliably polished, and observation using an underwater television can be facilitated, making it possible not only to perform smoother polishing operations, but also to improve water quality. There is no concern about contamination and promotes pollution elimination.

Although the above description has been made based on the case where an air grinder is used, it is also possible to use an electrically driven grinder in addition to an air grinder, and the desired effect can be achieved in the same way.

As described above, the present invention provides an underwater polishing device including:
A rotating screw or a water drive drive device is placed outside the rotating grindstone, and its rotation rate is used to generate thrust of the polishing head toward the surface to be ground, ensuring that the grinding wheel is in contact with the surface to be ground, and polishing is completed. Therefore, underwater polishing can be carried out reliably regardless of the ratio of the diameter of the support pole to the length, and the weight of the underwater polishing device is light and manual operation is required. You can do it easily.

In particular, in the present invention, when a drainage mechanism is attached to the rotary screw and the support box, it is easy to obtain the thrust of the polishing head by both functions, and it is a remarkable feature that makes the polishing action stable and smooth in water. In addition, when the rear exhaust mechanism is installed separately in addition to the drainage mechanism including the screw and support box, air bubbles are not generated around the surface to be polished. It makes it easier to observe the surface clearly, and at the same time prevents the vicinity of the surface to be polished from being disturbed and the abrasive debris being scattered in the water, contaminating the water quality, improving the operability of underwater polishing, which had been a concern in the past, and making it practical. The role of the device of the present invention in improving performance is extremely important.

Although the apparatus of the present invention is suitable for underwater polishing of nuclear reactor-related equipment and instruments that are difficult to access due to radioactivity, it can be similarly used for other general underwater polishing.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing how an underwater polishing device is used, and FIG. 2 is a schematic diagram showing an example of the device of the present invention. 1, 7... Support pole, 2... Polishing head, 3
...Object to be polished, 4...Rotating grindstone, 5...Rotating screw, 8...Exhaust pipe, 10...Exhaust port, 11
... Support box, 12 ... Grinding piece collection filter, 13 ... Pump, 14 ... Drain pipe.

Claims (1)

[Scope of Claims] 1. An underwater polishing device in which a polishing head including a rotary whetstone is attached to the tip of a support pole, and the other end is operated to bring the rotary whetstone at the tip of the polishing head into contact with the object to be polished for polishing, An underwater polishing apparatus characterized in that a thrust applying member for the polishing head is disposed behind the rotating grindstone. 2. The underwater polishing apparatus according to claim 1, wherein the thrust imparting member is a rotating screw, and the rotating screw is coaxial with the rotating grindstone and is attached to rotate synchronously with the rotating grindstone. 3. A grinding piece recovery mechanism in which a thrust imparting member is attached with an inlet opening near the tip of the polishing head and has a drainage pipe that generates drainage toward the rear, and this recovery mechanism applies thrust to the polishing head. An underwater polishing device according to claim 1. 4. A grinding piece recovery mechanism in which the thrust imparting member is provided with a rotating screw coaxially attached to the rotating grindstone and a suction port opened near the tip of the polishing head, and a drainage pipe that generates drainage toward the rear, The underwater polishing apparatus according to claim 1, wherein both of these provide a thrust to the polishing head. 5. Claims 1, 2, 3, or 4, wherein the polishing device is an air grinder and includes a relatively long exhaust pipe for discharging the exhaust gas at a location remote from the surface to be ground. The underwater polishing device described. 6. The underwater polishing device according to claim 1, 2, 3, or 4, wherein the polishing device is an electric grinder.