JP2024055281A - Wet type grinding device - Google Patents

Abstract

To provide a wet type grinding device which enables uniform grinding work to be performed with good workability.SOLUTION: A grinding device includes: a housing body 10 into which an air motor 2 is incorporated; a disc-like cover 9 which is fixed to one end side of the housing body 10 and in which a rotary shaft of the air motor 2 protrudes at its center; a grinding disc 8 connected to the rotary shaft at the inner side of the cover 9; a water supply port 6 for supplying water to the interior of the cover 9; a drain port 12 for draining turbid water containing grinding dust occurring in the cover 9; and a cylindrical joint part 11 which is fixed to the drain port 12 on an outer surface of the cover 9 and used to attach the other end of a drain hose 5 connected at one end side to suction means. The joint part 11 has a length along a diameter direction of the cover 9 and forms a grip part 11a configured to be held by a worker. An extension line of a center axis L of the grip part 11a passes through a rotation center O of the grinding disc 8.SELECTED DRAWING: Figure 2

Description

This invention relates to a wet grinding device that grinds wall surfaces while supplying water.

A known grinding device has a cover to prevent the scattering of powdery grinding chips generated when grinding a concrete wall, etc., and performs grinding while spraying water toward the object to be ground inside the cover.
Patent Document 1 describes a wet grinding device equipped with a means for discharging turbid water containing grinding chips generated inside the cover to the outside of the cover.
Specifically, a drainage port is formed in a cover surrounding the grinding disk at a position away from the water inlet, and a drainage pipe is connected to the drainage port. Furthermore, the drainage hose connected to the drainage pipe is connected to the suction means.
Additionally, a casing incorporating an air motor for rotating the grinding disc is attached to the outside of the cover, and the operator can hold this casing in one hand.

Figure 4 is a plan view of this conventional wet grinding device, showing the positional relationship of the casing 3 and drainage pipe 4 in the cover 1. As shown in the figure, the cover 1 has a cylindrical casing 3 with an air motor 2 built in its center and a drainage pipe 4 arranged approximately parallel to each other. A drainage hose 5 connected to suction means (not shown) is connected to the drainage pipe 4. In the figure, reference numeral 6 denotes a water supply port formed in the cover 1, and reference numeral 7 denotes a water supply hose for supplying water from the water supply port 6 into the cover 1. Inside the cover 1, a grinding disk 8 is connected to the rotating shaft of the air motor 2.

JP 2018-059394 A

A drainage hose 5 is connected to the drainage pipe 4, and this drainage hose 5 is connected to a suction means (not shown) for discharging turbid water containing grinding chips. In addition, the drainage hose 5 may be worn down and damaged by being dragged along the floor during operation. For this reason, the drainage hose 5 must have sufficient pressure resistance and abrasion resistance. Therefore, the drainage hose 5 has a large inner diameter and wall thickness, and is made of a rubber material that is highly resistant to pressure and abrasion. The length of the drainage hose 5 must be long enough to reach the suction means and long enough for the worker to move freely. For this reason, the weight of the drainage hose 5 connected to the drainage pipe 4 becomes very large.

In this way, the drainage pipe 4, to which the heavy drainage hose 5 is connected, is provided along the side of the cylindrical casing 3, which extends from the center O of the cover 1 in the diametric direction of the cover 1. In other words, the drainage pipe 4 is provided at a position that is off the center O, not in the diametric direction of the cover 1. In the state shown in FIG. 4, the weight of the drainage hose 5 acts only on the left side of the cover 1, so the device has a large weight difference between the left and right sides of the axis of the casing 3.

When grinding a wall surface using such a device, the worker holds the casing 3 aligned vertically with one hand as shown in Figure 4, and presses the grinding disk 8 against the surface to be ground. In this case, with the device shown in Figure 4, there is a difference in the weight acting on the cover 1 between the left and right, so the center of rotation of the grinding disk 8, i.e., the center O of the cover 1, can wobble from side to side. In particular, if the cover 1 wobbles when the grinding disk 8 is moved while being pressed against the surface to be ground, the pressing force of the grinding disk 8 becomes uneven, making it impossible to perform uniform grinding work and causing problems with poor workability.

The purpose of this invention is to provide a wet grinding device that can perform grinding work uniformly and with good workability.

The first invention comprises a housing body incorporating an air motor as a driving source, a disk-shaped cover fixed to one end of the housing body with the rotation shaft of the air motor protruding from the center, a grinding disk connected to the rotation shaft on the inside of the cover opposite the housing body with the cover as a boundary, a water supply port formed in the cover to supply water into the cover, a drainage port formed in the cover to discharge turbid water containing grinding chips generated in the cover, and a cylindrical joint portion fixed to the drainage port on the outer surface of the cover and for attaching the other end of a drainage hose connected to suction means, the other end of which is fixed to the drainage port on the outer surface of the cover, and the joint portion constitutes a grip portion configured to be held by an operator, and an extension of the central axis of the grip portion passes over the center of rotation of the grinding disk.

In the second invention, the angle formed by the line segment connecting the center of the drainage port to the center of rotation of the grinding disk and the line segment connecting the center of the water supply port to the center of rotation of the grinding disk is between 80° and 180° when measured from the drainage port in the direction of rotation of the grinding disk, and all of the openings of the water supply port are positioned within the rotational trajectory of the grinding disk.

In the third invention, a brush-like seal member with bristles facing the object to be ground is provided on the outer periphery of the cover.

According to the first invention, when the cylindrical joint is positioned vertically and the grip is held, the relatively heavy drainage hose can be lowered vertically. In addition, because the extension line of the central axis of the joint (grip) to which the heavy drainage hose is connected passes through the center of rotation of the grinding disc, the grip is less likely to be pulled left and right or to wobble due to weight imbalance. This allows the worker to stably control the position of the grinding disc and perform work stably.

According to the second aspect of the present invention, the water supplied into the cover efficiently turns into droplets and spreads, so that the moisture reaches the entire grinding chips, thereby producing turbid water.
In particular, since water can be supplied from the water inlet to the part of the grinding disc opposite the grip portion, water can be supplied more reliably to the grinding area when the grinding operation is performed by gripping the grip portion located at the bottom and pressing firmly upward.

According to the third invention, the brush-like sealing member can prevent muddy water from splashing outside the cover while sucking in external air. If external air cannot be sucked in, excessive negative pressure may be created inside the cover when the waste liquid is sucked in, which may prevent the grinding disk from moving freely. In this invention, the brush-like sealing member allows an appropriate amount of external air to be sucked into the cover, so such a problem does not occur.

FIG. 2 is a plan view of the wet grinding apparatus according to the embodiment. FIG. 2 is a bottom view of the wet grinding apparatus according to the embodiment. FIG. 2 is an external perspective view of a cover according to the embodiment. FIG. 1 is a plan view of a conventional wet grinding device.

[Embodiment]
An embodiment of the present invention will now be described with reference to FIGS.
Fig. 1 is a plan view of the wet grinding device according to the embodiment, Fig. 2 is a bottom view of the embodiment, and Fig. 3 is a perspective view of the appearance of the cover.
In this embodiment, the same components as those in the conventional device are designated by the same reference numerals as those in FIG.

In the embodiment of the grinding device, a grinding disk 8 is attached to the rotating shaft 2a of an air motor 2 that protrudes from the center of a disk-shaped cover 9. The air motor 2 is the driving source of the grinding disk 8. The center O of the cover 9 is the rotation center O of the grinding disk 8. The grinding disk 8 is called an abrasive disk, grinding machine, etc., and has one or more grinding blades arranged on the disk surface along the outer periphery.

One end of the housing body 10, into which the air motor 2 is assembled, is fixed to the outer surface of the cover 9, with the rotating shaft 2a protruding inside the cover 9 as described above. The housing body 10 is cylindrical and extends along the diameter of the cover 9. An air hose (not shown) is connected to the other end of the housing body 10, allowing compressed air for driving the air motor 2 to pass through the housing body 10 and be supplied to the air motor 2.

1 and 2, the cover 9 is formed with a circular water inlet 6 and a circular drainage port 12. However, the opening shapes of the water inlet 6 and the drainage port 12 are not limited to circles and may be oval or the like.
A water supply hose 7 is connected to the water supply port 6 on the outer surface of the cover 9, making it possible to supply water to the inside of the cover 9 via the water supply hose 7 and the water supply port 6, and a cylindrical joint part 11 for attaching the other end of the drainage hose 5 is fixed to the drainage port 12. One end of the drainage hose 5 is connected to suction means (not shown).
Therefore, the water supplied from the water supply port 6 during grinding operation becomes turbid water containing grinding debris and is discharged from the drain port 12.

The cylindrical joint 11 has a length that extends from the outer periphery of the cover 9 along the diameter of the cover 9 on the outside of the cover 9, forming a grip 11a that allows the operator to hold it in his/her hand. The grip 11a is not only thick and long enough to be easily gripped, but may also have a non-slip material or a non-slip treatment on its surface. In addition, the grip 11a extends in a different direction from the joint 11 on the outside of the cover 9 and is spaced apart from the joint 11, allowing the operator to easily hold it in his/her hand. The joint 11 and the cover 9 are formed to be integrated, for example, from a metal material.

The joint portion 11 is fixed to the drain port 12 so that an extension line of its central axis L passes through the rotation center O of the grinding disk 8 .
In this embodiment, the joint 11 has a larger diameter from the drainage port 12 toward the grip portion 11a. However, the joint 11 only needs to have an inner diameter that allows the smooth flow of turbid water, and may have a uniform diameter throughout.

The positional relationship between the water supply port 6 and the drain port 12 is set as follows.
The center of the drainage port 12 is on the central axis L of the grip portion 11a and opens at a position close to the outer periphery of the cover 9, while the center of the water supply port 6 is located at a position shifted by an angle θ in the rotational direction (arrow α) of the grinding disk 8 (see Figure 2).

The angle θ is the angle formed by the line segment s1 connecting the center of the drainage port 12 to the center of rotation O and the line segment s2 connecting the center of the water supply port 6 to the center of rotation O, measured in the direction of rotation of the grinding disk 8 (arrow α), and is set to 100° in this embodiment. In addition, the entire opening of the water supply port 6 is positioned within the rotation trajectory of the grinding disk 8, i.e., inside the grinding disk 8.

Furthermore, the cover 9 of the embodiment is provided with a brush-like seal member 13 on its outer periphery (see Figs. 2 and 3). As shown in Fig. 3, the cover 9 has a circular bottom surface portion 9a and a side wall portion 9b that stands up along the outer periphery of the bottom surface portion 9a and faces the grinding object side. The seal member 13 is formed by fixing the base of a tuft of bristles 13b to a support tape 13a.
The support tape 13a of this sealing member 13 is adhered to the outer periphery of the side wall portion 9b of the cover 9, with the tips of the bristles of the bristle bundles 13b facing the object to be ground, such as a wall surface.

The center of the bottom surface 9a of the cover 9 is provided with a mounting hole 9c for mounting the housing body 10 by projecting the rotating shaft 2a of the air motor 2 into the cover 9. However, in FIG. 3, the water supply port 6 and the drain port 12 formed in the cover 9 are omitted.

[Actions and Effects]
In this embodiment, the grip portion 11a is provided on the joint portion 11, so that the operator can hold the grip portion 11a during the grinding operation. Since the extension line of the central axis L of the grip portion 11a passes through the rotation center O of the grinding disk 8, when the cover 9 is placed on the upper side and the grip portion 11a is held vertically, the drainage hose 5, which is heavy, will drop straight down. Therefore, the cover 9 can be prevented from being pulled left and right or swung by the weight of the drainage hose 5. Therefore, the rotation of the grinding disk 8 is stabilized, and the workability and work quality of the grinding operation are improved. In addition, since there is no other configuration of the grinding device around the grip portion 11a, the operator can easily hold the grip portion 11a and easily operate the grinding device.

In addition, the housing body 10 of this embodiment does not need to be held by hand, as with the conventional casing 3. All that is required is that the air motor 2 is incorporated in the housing body 10 and a flow path for compressed air is secured. Therefore, there is no need to consider ease of holding it, and the housing body 10 can be made smaller and lighter by forming it from a resin material, etc., to further reduce weight imbalance.

Furthermore, in this embodiment, the positional relationship between the water supply port 6 and the drainage port 12 is as described above, so that the water supplied from the water supply port 6 spreads efficiently throughout the cover 9, and murky water containing grinding debris is produced.
The reasons are as follows:
If the water inlet 6 and the drainage port 12 are too close, the water supplied from the water inlet 6 may flow directly into the drainage port 12 and may not spread sufficiently inside the cover 9. However, if a phase difference of an appropriate angle θ is provided in the direction away from the drainage port 12 as in this embodiment, the water supplied from the water inlet 6 will spread sufficiently before being sucked into the drainage port 12 and become turbid water.

In this embodiment, the angle θ is set to 100°, however, it has been confirmed that the water supplied from the water supply port 6 spreads sufficiently within the cover 9 if the angle θ is in the range of 80° to 180°.
When the grinding disk 8 is brought into contact with the surface to be ground during actual grinding work, the portion farther from the grip portion 11a held by hand, i.e., the upper portion in Figures 1 and 2, tends to be pressed more strongly against the surface to be ground. Therefore, a lot of grinding debris is generated in the upper portion. In order to supply sufficient water to the upper portion where grinding debris is likely to be generated, it is preferable that the angle θ is 80° to 180°.

Furthermore, since all of the openings of the water supply port 6 are provided within the rotation path of the grinding disk 8, the entire amount of water supplied from the water supply port 6 collides with the rotating grinding disk 8 and immediately turns into water droplets, which spread throughout the cover 9, making it easy to capture grinding chips.
In addition, since the drain port 12 is formed on the central axis of the grip portion 11a and near the outer periphery of the cover 9, it is easy to drain the turbid water that falls due to gravity when working with the grip portion 11a facing downward, and it is also possible to efficiently drain the turbid water that is thrown outward by the centrifugal force of the rotating grinding disk 8.

In addition, the bristle bundle 13b of the sealing member 13 seals the gap between the cover 9 and the surface to be ground, preventing the cloudy water generated inside the cover 9 from escaping and scattering around. It is particularly important to prevent cloudy water containing harmful substances such as asbestos from scattering.

The sealing member 13 of this embodiment prevents the liquid from splashing as described above, while allowing outside air to flow into the cover 9 through the gaps between the individual bristles of the bristle bundle 13b. This prevents the inside of the cover 9 from becoming excessively negative pressure due to the suction force of the suction means (not shown). If negative pressure were to occur inside the cover 9 and the cover 9 were to stick to the surface to be ground, the grinding disk 8 would not be able to move smoothly, which would make grinding work less efficient, but this does not happen in this embodiment.

The turbid water discharged from the wet grinding device of the above embodiment can be recovered and treated using a conventionally known wastewater treatment system. In particular, if the turbid water contains asbestos, it can be treated using a treatment system such as that described in JP 2022-124510 A, and the filtered water can be discharged.

Useful in various grinding work sites where dust is generated.

2 Air motor 2a Rotating shaft 5 Drain hose 6 Water supply port 8 Grinding disc 9 Cover 10 Housing body 11 Joint 11a Grip 12 Drain port 13 Seal member 13b Brush bristles O (Rotation) center L (Grip) central axes s1, s2 (of grip) Line θ (connecting centers) Angle α Rotation direction

Claims (3)

A housing body incorporating an air motor as a driving source;
a disk-shaped cover fixed to one end of the housing body and having a rotary shaft of the air motor protruding from the center;
a grinding disk connected to the rotating shaft on the inside of the cover, which is on the opposite side of the cover from the housing body;
a water supply port formed in the cover for supplying water into the cover;
A drainage port formed in the cover for discharging turbid water containing grinding chips generated in the cover;
a cylindrical joint portion fixed to the drainage port on an outer surface of the cover and for attaching one end of a drainage hose having one end connected to a suction means;
The above joint portion is
A grip portion having a length along a diameter direction of the cover and configured to be held by an operator is configured;
A wet grinding device, characterized in that an extension line of the central axis of the grip portion passes over the center of rotation of the grinding disk. the angle formed by the line segment connecting the center of the drainage port and the center of rotation of the grinding disk and the line segment connecting the center of the water supply port and the center of rotation of the grinding disk is 80° or more and 180° or less when measured from the drainage port in the direction of rotation of the grinding disk,
2. The wet grinding device according to claim 1, wherein all of the openings of said water supply ports are positioned within the rotational path of said grinding disk. The wet grinding device according to claim 1 or 2, in which a brush-like seal member with bristles facing the object to be ground is provided on the outer periphery of the cover.

Images