JP3248718U - Grinding Equipment - Google Patents

Abstract

[Problem] To provide a grinding device capable of easily and thoroughly removing rust and deteriorated coatings that have developed in long, narrow gaps. [Solution] The device comprises a rotary power tool that can be rotated, a long mandrel 4 whose base end is connected to the rotary power tool and whose tip end is provided with a grinding member, and a gripping outer tube 5 that covers the mandrel 4 and can be gripped by hand, and a plurality of bearing inner tubes 51 that slidably support the mandrel 4 are provided on the inner peripheral surface of the gripping outer tube 5 at predetermined intervals in the axial direction. The bearing inner tubes 51 are made of nickel or nickel-plated material. [Selected Figure] Figure 2

Description

This invention relates to a device for grinding away rust and deteriorated coatings, and is particularly suitable for grinding away rust and deteriorated coatings that have developed in long, narrow gaps.

Conventionally, when repainting an object that has developed rust or has peeled paint, a surface preparation is carried out to remove the rust or deteriorated paint. For example, Japanese Utility Model Application Publication No. 6-61455 discloses a disk sander that is attached to a grinder for use as a surface preparation device (Patent Document 1).

Japanese Utility Model Application Publication No. 6-61455

However, in conventional grinding devices, including the disk sander described in Patent Document 1, the mounting shaft for rotating the sandpaper or the like is short. For this reason, when the long, narrow gaps formed between many fins are arranged closely together in parallel, such as in the transformer radiator shown in Figure 4, the grinding device cannot reach the entire gap, resulting in the problem that rust and deteriorated coating cannot be sufficiently removed.

This invention was made to solve this problem, and aims to provide a grinding device that can easily and thoroughly remove rust and deteriorated paint that has developed in long, narrow gaps.

The grinding device of the present invention is designed to solve the problem of easily and thoroughly removing rust and deteriorated coatings that have developed in long, narrow gaps, and includes a rotary power tool that can be rotated, a long mandrel whose base end is connected to the rotary power tool and whose tip end is provided with a grinding member, and a gripping outer tube that covers the mandrel and can be held by hand, and the inner circumferential surface of the gripping outer tube is provided with multiple bearing inner tubes spaced at predetermined intervals in the axial direction to slidably support the mandrel.

In addition, as one aspect of the present invention, in order to solve the problem of simply and reliably fixing the inner bearing cylinder to the inner peripheral surface of the outer gripping cylinder, the inner bearing cylinder may be welded to the inner peripheral surface of the outer gripping cylinder by heating the outer peripheral surface of the outer gripping cylinder with a welding tool.

Furthermore, as one aspect of the present invention, in order to solve the problem of inexpensively reducing the frictional resistance between the bearing inner tube and the mandrel, the bearing inner tube may be made of nickel or a nickel-plated material.

In one embodiment of the present invention, in order to solve the problem of preventing the gripping outer tube from shifting in the axial direction relative to the mandrel, the mandrel may be provided with a stopper member that abuts against the outer surfaces of flat washers disposed at both ends of the gripping outer tube.

Furthermore, as one aspect of the present invention, in order to solve the problem of making the grinding member easy to replace, the grinding member may be a flap wheel in which abrasive cloth is bound and fixed radially, and may be detachably screwed together by a female screw provided at the center of the flap wheel and a male screw provided at the tip of the mandrel.

In addition, as one aspect of the present invention, in order to solve the problem of easily allowing the grinding member to perform not only rotational motion but also reciprocating motion, the base end of the mandrel may be configured to be connectable to a handle that causes the grinding member to reciprocate in the axial direction, instead of the rotary power tool.

This invention makes it possible to easily and thoroughly remove rust and deteriorated paint that has developed in narrow, long gaps.

1 is a diagram showing an embodiment of a grinding device according to the present invention; FIG. 2 is a partial cross-sectional view showing the gripping outer cylinder of the present embodiment. FIG. 3 is an enlarged view showing part A in FIG. 2 . FIG. 2 is a diagram showing an example of a radiator of a transformer.

Below, one embodiment of the grinding device according to the present invention will be described with reference to the drawings.

As shown in Fig. 1, the grinding device 1 of this embodiment mainly comprises a rotary power tool 2 that can be rotated, a shaft 4 connected to the rotary power tool 2 and having a grinding member 3 at its tip, and a gripping outer tube 5 that covers the shaft 4 and can be held by hand. Each component will be explained below. In this invention, grinding is a concept that includes not only the process of scraping off the surface of an object to make it smooth, but also the process of polishing and polishing it (corresponding to abrasives).

The rotary power tool 2 rotates the grinding member 3 attached to the tip of the shaft 4. In this embodiment, the rotary power tool 2 is configured by an impact driver, drill driver, or the like, and as shown in FIG. 1, rotates and drives a bit holder 21 that is fixed and connected to the base end of the shaft 4.

The mandrel 4 transmits the rotational driving force from the rotary power tool 2 to the grinding member 3. In this embodiment, the mandrel 4 is made of nickel and is formed in a long shape that is longer than the longitudinal length of the narrow gap to be ground. The base end of the mandrel 4 is connected to the rotary power tool 2, and the grinding member 3 is provided at the tip end of the mandrel 4.

In this embodiment, the grinding member 3 is composed of a flap wheel 3 in which abrasive cloth is bundled and fixed radially, as shown in FIG. 1. A female screw (not shown) is provided at the center of the flap wheel 3, and a male screw (not shown) that screws into the female screw is provided at the tip of the mandrel 4. Therefore, the flap wheel 3 as the grinding member 3 can be easily attached and detached to the tip of the mandrel 4.

The grinding member 3 is not limited to the flap wheel 3, but may be anything capable of grinding away rust or deteriorated coating. For example, a disc-shaped grinding wheel or abrasive disk may be used as the grinding member 3.

The gripping outer cylinder 5 allows the rotating stalk 4 to be gripped by hand. In this embodiment, the gripping outer cylinder 5 is made of stainless steel and is cylindrical. As shown in FIG. 2, the inner peripheral surface of the gripping outer cylinder 5 is provided with a plurality of bearing inner cylinders 51 that slidably support the stalk 4 at a predetermined interval in the axial direction. In this embodiment, the bearing inner cylinder 51 is made of nickel, like the stalk 4, and is cylindrical with an outer diameter that is approximately the same as the inner diameter of the gripping outer cylinder 5 and an inner diameter that is approximately the same as the outer diameter of the stalk 4. In this embodiment, the gripping outer cylinder 5 has a length that covers almost the entire stalk 4, but this is not limited to this configuration, and a short gripping outer cylinder 5 may be used to cover only a position that is easy for the operator to grip.

In this embodiment, the bearing inner cylinder 51 is welded to the inner peripheral surface of the gripping outer cylinder 5 by heating its outer peripheral surface with a welding tool, as shown in FIG. 3. This allows the bearing inner cylinder 51 to be easily and reliably fixed to the inner peripheral surface of the gripping outer cylinder 5. There is no particular limitation on the welding tool, and a welding torch used in TIG (Tungsten Inert Gas) welding, for example, can be used.

The material of the bearing inner tube 51 is not limited to nickel, and may be a nickel-plated material. By using these materials, the frictional resistance between the bearing inner tube 51 and the shaft 4 can be reduced inexpensively. The bearing inner tube 51 may also be made of other materials with low frictional resistance, such as copper, aluminum, stainless steel, titanium, and molybdenum. The frictional resistance can be further reduced by applying a lubricating oil such as chain oil between the bearing inner tube 51 and the shaft 4.

In this embodiment, as shown in Figures 2 and 3, flat washers 6 are disposed on both ends of the gripping outer tube 5, and stopper members 7 that abut against the outer surfaces of these flat washers 6 are fixed to the mandrel 4. As a result, the stopper members 7 abut against the flat washers 6, preventing the gripping outer tube 5 from shifting in the axial direction relative to the mandrel 4. In this embodiment, a hexagon socket set screw is used as the stopper member 7, and is fastened to the female thread formed by tapping on the mandrel 4.

Next, the action of the grinding device 1 of this embodiment will be described. In this embodiment, the target long narrow gap is the gap between fins 11 in a transformer radiator 10 as shown in FIG. 4.

First, when using the grinding device 1 of this embodiment to remove rust or deteriorated coating that has developed in a long, narrow gap, the grinding member 3 attached to the tip of the mandrel 4 is inserted from one end of the gap, and the rotary power tool 2 is driven. This causes the grinding member 3 to rotate at high speed, removing the rust or deteriorated coating. At this time, the long mandrel 4 will vibrate, but since the bearing inner tube 51 slidably supports the rotating mandrel 4, simply gripping the gripping outer tube 5 suppresses the vibration of the mandrel 4 and stabilizes its rotation.

In addition, by applying force to the gripping outer cylinder 5, the grinding member 3 is pressed strongly against the surface of the fin 11, so that rust and deteriorated coating are deeply ground and thoroughly removed. This allows the surface of the fin 11 to be properly primed, suppressing deterioration of the newly applied coating and making it last longer. Furthermore, by adopting the bearing inner cylinder 51 as a bearing for the mandrel 4, costs are reduced compared to when bearings are used. Also, compared to when bearings are used, the gripping outer cylinder 5 has a smaller diameter and the grinding device 1 is lighter, improving workability and operability.

Then, the grinding member 3 is moved along the longitudinal direction of the gap, successively grinding the surface of the fin 11. At this time, because the mandrel 4 is long, the grinding member 3 can reach places that cannot be reached with normal tools, and rust and deteriorated paint are sufficiently removed. Then, when the grinding member 3 is moved to the other end of the gap, the preparation of the entire surface of the fin 11 that constitutes the gap is completed.

The grinding device 1 of this embodiment as described above provides the following advantages.
1. It is possible to easily and thoroughly remove rust and deteriorated paint film that has occurred in narrow long gaps.
2. By suppressing vibration of the mandrel 4 and stabilizing its rotation, the grinding accuracy can be improved.
3. Since the bearing inner cylinder 51 is welded by heating the outer peripheral surface of the gripping outer cylinder 5 with a welding tool, the bearing inner cylinder 51 can be fixed to the inner peripheral surface of the gripping outer cylinder 5 simply and reliably.
4. By forming the bearing inner cylinder 51 from nickel or a nickel-plated material, the frictional resistance between the bearing inner cylinder 51 and the mandrel 4 can be reduced inexpensively.
5. The stopper member 7 fixed to the mandrel 4 can prevent the gripping barrel 5 from being displaced in the axial direction relative to the mandrel 4.
6. The grinding member 3 can be easily replaced by making it detachable using the female screw on the flap wheel 3 side and the male screw on the axle 4 side.

The grinding device 1 according to the present invention is not limited to the above-described embodiment and can be modified as appropriate.

For example, in the above-described embodiment, the rotary power tool 2 is connected to the base end of the spindle 4 to rotate the grinding member 3, but the present invention is not limited to this configuration. Specifically, the base end of the spindle 4 may be configured to be connected to a handle that moves the grinding member 3 back and forth in the axial direction, instead of the rotary power tool 2. This allows the grinding member 3 to easily perform not only rotational motion but also reciprocation. For this reason, it is possible to remove rust and deteriorated coatings by fixing a scraper, skewer blade, cutter blade, etc. as a grinding tool to the tip of the spindle 4 and manually reciprocating the handle.

1 Grinding device 2 Rotary power tool 21 Bit holder 3 Grinding member (flap wheel)
4 Mandrel 5 Grip outer cylinder 51 Bearing inner cylinder 6 Flat washer 7 Stopper member 10 Transformer radiator 11 Fin

Claims (6)

A rotary power tool capable of being rotated;
A long mandrel having a base end connected to the rotary power tool and a grinding member provided at a tip end thereof;
a gripping outer cylinder that covers the mandrel and can be gripped by hand;
having
A grinding device, wherein a plurality of bearing inner cylinders for slidably supporting the mandrel are provided on an inner peripheral surface of the gripping outer cylinder at predetermined intervals in the axial direction. The grinding device according to claim 1, wherein the bearing inner cylinder is welded to the inner circumferential surface of the gripping outer cylinder by heating the outer circumferential surface of the gripping outer cylinder with a welding tool. The grinding device according to claim 1 or 2, wherein the bearing inner cylinder is made of nickel or nickel-plated material. The grinding device according to claim 1, wherein the mandrel is fixed with a stopper member that abuts against the outer surfaces of flat washers disposed at both ends of the gripping outer cylinder. The grinding device according to claim 1, wherein the grinding member is a flap wheel in which abrasive cloth is bound and fixed radially, and is detachably screwed together by a female screw provided at the center of the flap wheel and a male screw provided at the tip of the mandrel. The grinding device according to claim 1, wherein the base end of the shaft is configured to be connectable to a handle that reciprocates the grinding member in the axial direction instead of the rotary power tool.

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