JP2011177879A - Cup-type rotating grinding wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To completely grind the old coating film over a wide area in a short time period and prevent peeled-off materials from adhering to a rotating grinding wheel by improving the rotating speed and the grinding force of a grinding tip. <P>SOLUTION: A ring-shaped projection part 3 having a flat part 4 is provided on the under surface of a whole outer peripheral edge of a cup-type base metal 2 having a diameter of 15-30 cm in the cup-type rotating grinding wheel. A plurality of grinding tips 5 having a cutting edge directed toward the rotating direction of a grinding wheel 1 are mounted to the flat part 4 separated in the circumferential direction along coaxial circles having large and small different diameters. The angle θ formed by the front side surface of the cutting edge of the grinding tip 5 and the flat part 4 is set to be 0<θ<90°. The lower part of the grinding tip 5 is formed in a circular arc shape when viewed from the front side of the cutting edge, and is formed in a vault shape having a central part swollen downward as a whole. The base metal 2 is provided with a recessed groove 10 having a circular arc-shaped cut edge recessed from the outer peripheral edge to the radially inward direction at predetermined intervals in the peripheral direction. A cutting blade 11 having the cutting edge directed toward the grinding wheel rotating direction is provided on the outer peripheral surface of the ring-shaped projection part 3 in the peripheral direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a cup-type rotary grindstone used for surface grinding of an object to be ground, and by fitting and attaching a rotary shaft of a power tool such as a grinder or an air tool to a mounting hole drilled in the center, a concrete structure, a metal The present invention relates to a cup-type rotary grindstone used for grinding and peeling off an old coating film deposited on the surface of a steel structure or a stone structure.

Steel structures, concrete structures, concrete blocks, and the like include those having a waterproof coating film or resin film on the surface of steel or concrete, or a reinforcing FRP (fiber reinforced plastic) sheet attached. When repairing the surface of these structures, it is necessary to remove some or all of the coating film and FRP. Conventionally, for this type of coating film removal work, a grinding tip is separated in the circumferential direction on the lower surface of a cup-shaped base metal having a diameter of about 10 cm, which is provided with a drill for attaching a power tool such as a grinder in the center, and further on the lower surface. The thing which arrange | positioned the grinding | polishing chip | tip intermittently also on the outer side was used. Then, the cup-type base metal is rotated while the segment chip is in sliding contact with the surface of the material to be ground, and the chips ground by the contact of the continuous grinding chip with the material to be ground are discharged outside between the grinding chips. I was trying to use it.
In Patent Document 1 and Patent Document 2, a ring-shaped convex portion formed of a flat lower surface is formed on an inner concentric circle in addition to the outer peripheral lower surface of the disk-shaped metal wheel having flat upper and lower surfaces, and the outer peripheral lower surface, A grinding tip is provided on the lower surface of the ring-shaped convex portion at a predetermined interval in the circumferential direction, and the grinding tip is arranged so that the radial outer end side at the front end side in the grindstone rotation direction faces slightly outward without following the outer peripheral edge of the wheel. Attached to is disclosed. Each of the grinding tips described in Patent Document 1 and Patent Document 2 has a rectangular parallelepiped grinding tip disposed in a groove formed by a vertical groove wall and an inclined groove bottom recessed in a diamond grindstone, and is attached by brazing. Therefore, the angle formed by the flat bottom surface of the ring-shaped convex portion of the disc-shaped metal wheel and the front side surface of the grinding tip in the grinding wheel rotation direction is an obtuse angle exceeding 90 degrees, and the blade having a cutting edge angle of 90 degrees is in the grinding wheel rotation direction. The lower end surface of the grinding tip is attached to the flat surface of the ring-shaped convex portion of the disk-shaped metal wheel with a flat inclined surface inclined downward toward the rear in the direction of rotation of the grindstone. In addition, the three grinding tips provided on the outer surface of the metal wheel described in Patent Document 1 also have a tangent line with a contact point at the intersection of the front side surface of the grinding tip with a cutting edge angle of 90 degrees and the metal wheel and the grinding tip. Since the angle formed with the front side surface is inclined at an obtuse angle of 90 degrees or more with respect to the grinding wheel rotation direction, there has been a problem in that the grinding tip may be scattered and dropped due to impact during use of the rotary grinding stone.
The bottom surface of the outer periphery of the cup-type base metal is made a flat surface with an inclination angle θ of 5 to 20 ° upward, and a rectangular parallelepiped grinding tip is attached to the flat surface to grind the rotating wheel during work. There has been proposed a rotating grindstone that is used in a state where the grindstone axis is inclined with respect to the material surface in correspondence with θ (see, for example, Patent Document 3). In the rotating grindstone described in Patent Document 3, only the outer edge (edge) portion of the grinding tip cutting edge acts on the material to be ground in the tilting process, and the lower surface of the rectangular parallelepiped tip is simply inclined outward. The angle formed between the front side surface in the rotational direction and the flat lower surface of the entire outer periphery of the cup-type base metal is 90 degrees. For this reason, there has been a problem in that the durability of the grinding tip is low due to a situation in which the grinding tip scatters and falls off due to an impact while using the rotating grindstone.
In the rotating grindstone described in Patent Document 4, a rectangular parallelepiped grinding tip having a change in the concentration of diamond abrasive grains is attached to the lower surface of the outer peripheral edge of the cup-shaped base metal. The angle formed by the flat lower surface of the entire outer periphery of gold is 90 degrees. For this reason, there has been a problem that a situation occurs in which the grinding tip is scattered and dropped while using the rotating grindstone.
In addition, there has been proposed a disk-type grindstone in which a grindstone portion is continuously provided by brazing with diamond abrasive grains or CBN abrasive grains on the outer peripheral portion of a flat tool body, and a cutting edge is provided on the outer peripheral side portion of the grindstone portion. (For example, refer to Patent Document 5). When the side cutting edge of the grindstone described in Patent Document 5 is used, the side surface height direction and the cutting edge width are formed to the same width, so the sintered product ground with the side cutting edge sticks to the cutting edge. was there.
Moreover, since the grinding tip of the rotating grindstone described in Patent Literature 1 to Patent Literature 5 is in line contact with the object to be ground, the grinding force is weak and the number of continuous contact of the grinding tip to the same place of the material to be ground is increased. There was a problem that there was a necessity and work efficiency was bad.
JP 2006-321006 A JP 2004-74318 A Kaihei 11-165262 Japanese Patent No. 3623085 JP 2008-149395 A

  The present invention was devised in view of the above-mentioned problems of the prior art, and the base metal has a diameter of about 15 cm to 30 cm, and is ground on the circumference of a concentric circle having a different diameter on the lower surface of the outer peripheral surface. A grinding wheel is in use by providing a flat part with a width that can be attached to the chip, and arranging the grinding chip on the flat part with an acute angle between the flat part and the front side surface of the grinding chip edge in the direction of grinding wheel rotation. An object of the present invention is to provide a cup-type rotary grindstone that prevents the grinding chip from falling off and adheres exfoliation to the peripheral surface, increases the rotational speed of the grinding chip, and has high durability and high grinding force.

In order to achieve the above object, an invention according to claim 1 of the present application is for grinding and removing a coating film, a resin film or an FRP film applied to the surface of concrete, metal or stone for repairing. It is a cup-shaped rotating grindstone that is circular in plan view, and has a mounting hole for mounting a tool in the center of the cup-type base metal, and a ring-shaped convex part on the entire outer periphery of the cup-type base metal. A cup-type rotating grindstone in which a flat portion having a predetermined width is provided on the lower surface of the disc, and a plurality of grinding chips with blade edges facing in the grindstone rotating direction are attached to the flat portion at a distance in the circumferential direction. Is formed in a size of 15 to 30 cm, and the grinding tip has an angle θ between the front surface of the grinding tip rotation direction and the flat portion at the tip of the grinding tip set to 0 <θ <90 °. Tilted forward in the wheel rotation direction Characterized in that it is formed to the blade.
The invention described in claim 2 is a cup-type rotary grindstone having a circular shape in plan view for grinding and removing a coating film, a resin film or an FRP film applied on the surface of concrete, metal or stone material for repair. A hole for attaching a tool to the center of the cup-shaped base metal, and a ring-shaped convex portion is provided on the entire outer periphery of the cup-shaped base metal, and a flat portion having a predetermined width on the lower surface of the ring-shaped convex portion. In the cup-type rotary whetstone in which a plurality of grinding chips with the cutting edge directed in the grindstone rotation direction are attached to the flat portion at a distance in the circumferential direction, the cup-type base metal is formed with a diameter of 15 cm to 30 cm. In the flat portion, the center of the cup-type base metal is provided as a center of the circle so that the grinding tips are not juxtaposed in the inner and outer directions on the concentric circles having different diameters. The front of the grinding wheel rotation direction Serial the angle theta between the flat portion 0 <theta <is set to 90 °, characterized in that formed on the blade tilted forward in the grinding wheel rotational direction as viewed from the side of the grindstone.
According to a third aspect of the present invention, the grinding tip edge lower portion is formed in an arc shape that bulges downward as viewed from the grinding wheel rotation direction so that the cutting edge of the grinding tip is in point contact with the material to be ground. Features.
The invention according to claim 4 is characterized in that a plurality of cutting blades whose blade tips are directed in the grinding wheel rotation direction are arranged on the outer surface of the ring-shaped convex portion so as to be spaced apart in the circumferential direction.
According to a fifth aspect of the present invention, the outer peripheral edge of the base metal provided with the ring-shaped convex part is provided with a concave groove that opens to the outer peripheral edge of the ring-shaped convex part and that is recessed in the radial inward direction of the base metal. It is characterized by being provided with a predetermined interval in the circumferential direction.

Since the present invention has an unprecedented size of 15 cm to 30 cm in diameter, more grinding tips can be provided, the grinding range is wide, the speed of the grinding tips is increased, and the old coating film is applied. The destructive force for destructive grinding is increased, and the grinding workability can be improved.
In the present invention, since the flat portion provided on the lower surface of the entire outer peripheral edge of the base metal is wide, the grinding chips are alternately arranged along concentric circles having large and small diameters around the center of the base metal in the flat portion. Therefore, there is an effect that the grinding tip is continuously brought into contact with the surface of the material to be ground, and the grinding operation time can be shortened.
In the present invention, the cutting edge of the grinding tip is oriented in the direction of rotation of the grinding wheel, the angle formed by the front side surface of the cutting edge and the flat portion of the ring-shaped convex portion is set to less than 90 °, and the lower part of the grinding tip is viewed from the direction of rotation of the grinding wheel. Therefore, the cutting edge of the grinding tip makes point contact with the material to be ground. By making point contact between the cutting edge and the material to be ground, a large force is applied to the shape of the cutting edge portion so as to reduce the contact area with the material to be ground, and the object to be ground can be reliably ground with a larger force. effective.
In the present invention, since a plurality of cutting blades whose blade edges are directed in the rotational direction of the grindstone are arranged apart from each other in the circumferential direction on the outer surface of the ring-shaped convex portion, when the position is moved in the lateral direction while rotating the rotating grindstone. First, the cutting blade provided on the outer surface of the ring-shaped convex portion first comes into contact with the material to be ground coated with the old coating film, and the old coating film is peeled off by the cutting blade. There is an effect that the old coating film peeled off from the side surface is not sticky.
Since the present invention forms a concave groove recessed inward on the outer peripheral edge of the base metal, chips can be discharged outward from the concave groove, and a sintered product of the object to be ground such as resin is applied to the grinding chip. There is an effect of not sticking.

  The movement speed of the grinding tip is increased by making the diameter of the base of the cup-type rotary grindstone larger than the existing diameter of 15 to 30 cm, and the width of the flat portion provided on the lower surface of the ring-shaped convex portion In the flat portion, the grinding tips are alternately arranged along the concentric circles having different diameters within the flat portion so as not to be juxtaposed in the radial direction. As a result, the number of contacts was significantly increased so that the grinding tip was ground continuously on the workpiece, and the grinding area was increased and the grinding time was shortened. By making the angle between the flat part and the front side of the cutting edge of the grinding tip less than 90 °, the reaction force received from the material to be ground of the grinding tip is reduced, and the grinding tip is scattered from the ring-shaped convex part or peeled off. It became difficult and realized a long life.

A first embodiment shown in FIGS. 1 to 7 will be described.
The cup-type rotating grindstone 1 is a rotating grindstone for grinding and removing a coating film, a resin film, or an FRP film applied to the surface of concrete, metal, or stone material for repair. A ring-shaped convex portion 3 is provided on the entire outer peripheral lower surface of the base metal 2. The lower surface of the ring-shaped convex portion 3 is a flat portion 4. The flat portion 4 is formed in a ring shape so as to be interposed between the circumferences of concentric circles having different diameters with the center of the base metal 2 being the center of the circle, and the flat portion 3 has at least two grinding chips 5 in the inner and outer directions. Are provided with inner and outer widths that can be juxtaposed.

The base metal 2 has a linear distance of 15 cm to 30 cm that passes through the center of a circular circle in plan view and connects the opposing outer peripheral edges of the flat portion 4. That is, the base metal 2 is formed in a perfect circle in a plain view having a diameter of about 15 cm to 30 cm. The diameter of the base metal 2 is set to 15 cm to 30 cm. First, when the velocity of an object that is rotating on the circumference of a radius r on a plane is v, the acceleration is α, and the angular velocity is ω, Formula α = v ² (m / s) ² / r (m) = r (m) ω ² (1 / s) ² is established, and this formula rotates on the circumference corresponding to the length of radius r. It turns out that the velocity v of the object to be increased becomes large, and as a result, the force that the grinding tip or cutting edge acts on the material to be ground increases, and the destructive force of the material to be ground on the old paint film increases significantly. Second, the metal base 2 is made of metal and has a weight and size and weight that can be handled by an adult male. Third, grinding is performed while visually checking the location of the old paint film. This is because of the above three reasons. An attachment hole 6 for attaching an electric tool such as a grinder or a rotary shaft of an air tool is formed in the center of the base metal 2. A portion extending from the hole edge of the attachment hole 6 to a predetermined distance is formed on a flat surface 7 having a donut shape so that the electric tool or the air tool can be fastened and attached. On the side of the flat surface 7, an inclined surface that inclines so as to gradually increase in diameter as it goes downward is continuously provided, and the base metal 2 is formed in a dish shape as a whole. A chip discharge hole 8 is provided on the inclined surface. The chip discharge hole 8 is formed for the purpose of discharging the face and reducing the weight of the rotating grindstone 1.

  A plurality of grinding tips 5 whose cutting edges are directed in the rotation direction of the grindstone 1 are attached to the flat portion 4 separately in the circumferential direction along concentric circles having different diameters. In FIG. 1, in the flat portion 4, three grinding tips 5 are arranged on the small-diameter circumference, and six grinding tips 5 are arranged on the large-diameter circumference with the cutting edge in the grinding wheel rotation direction. . An angle θ formed by the front surface of the cutting edge of the grinding tip 5 and the flat portion 4 is set to 0 <θ <90 °. The angle θ is most preferably set to 45 ° ≦ θ <90 °. As shown in FIGS. 6 and 7, the lower portion of the grinding tip 5 is formed in an arc shape when viewed from the front side of the cutting edge, and is formed in a bowl shape whose center bulges downward as a whole. The front part of the cutting edge is formed in a U shape when viewed from the front side in the rotational direction. The cutting edge is brought into point contact with the material 9 to be ground, and the force acting on the material 9 to be ground from the cutting edge is increased to increase the grinding force. This is to reduce the vibration and noise during use of the cup-type rotary grindstone 1 by reducing the contact area. The grinding tip 5 disposed on the circumference of the large diameter in the flat portion 4 is disposed so that the cutting edge slightly faces outward. In Example 1, the outer surface of the grinding tip 5 is disposed along the tangent line of the outer peripheral edge of the ring-shaped convex portion 3 when viewed from the bottom surface. If the outer surface of the grinding tip 5 is arranged along the tangent line of the outer peripheral edge of the ring-shaped convex portion 3 because the object moving circularly on the circumference has a line of force acting in the tangential direction. This is because the grinding tip 5 can be applied to the workpiece 9 most efficiently. The grinding tip 5 has a U-shaped longitudinal section, and the lower surface of the grinding tip 5 is formed in an inclined surface that is gradually inclined upward from the front side to the rear side in the grinding wheel rotation direction to reduce the height. . The lower surface of the grinding tip 5 is formed as an inclined surface that is gradually inclined upward with respect to the grinding wheel rotation direction. First, since the old coating film of the material to be ground is ground on the front side of the cutting edge of the grinding tip 5, the rear side is This is because it is unnecessary, and secondly, the air resistance can be reduced. The grinding tip 5 is provided with a groove in which the front groove wall of the grinding wheel rotation direction is inclined so as to incline forward in the rotation direction in the flat portion 4 of the ring-shaped convex portion 3, and the grinding tip 5 is inclined forward in the groove. Are fixed and attached by brazing. The method for attaching the grinding tip 5 is not limited to brazing.

  The base metal 2 having the ring-shaped convex portion 3 is provided with a concave groove 10 having an arc-shaped cut edge that is recessed radially inward from the outer peripheral edge at predetermined intervals in the circumferential direction. The concave groove 10 is provided for discharging chips and reducing the weight.

  On the outer peripheral surface of the ring-shaped convex portion 3, cutting blades 11 whose blade tips are directed in the grindstone rotating direction are arranged at a predetermined interval along the circumferential direction. In this embodiment, four cutting blades 11 are provided with an angle of 90 ° in the circumferential direction. The cutting edge 11 is provided with a vertical length of about 3 mm from the lower end of the outer periphery of the ring-shaped convex portion 3. The front side surface of the cutting blade 11 in the direction of grindstone rotation is disposed along an extension line of the diameter of the base metal 2. In the first embodiment, an example is described in which the cutting blade 11 is continuously formed to protrude outward from the lower peripheral edge of the outer periphery of the ring-shaped convex portion 3. If it is provided on the outer periphery, the arrangement position is not limited. Specifically, the present invention includes a case where the cutting edge is provided at a position located about 1 mm above the lower surface of the outer peripheral surface of the ring-shaped convex portion 3. Further, the front side surface of the cutting blade 11 in the rotation direction of the grindstone is not limited to being disposed along the extended line of the diameter of the base metal 2. The case where the cutting edge 11 is formed as a protrusion on the outer peripheral surface of the ring-shaped convex portion 3 is also included in the present invention. Moreover, the number of attachments to the outer peripheral surface of the ring-shaped convex part 3 of the cutting blade 11 is not limited to four, and the number of attachments is arbitrary.

  As an example of the dimensions of each part, when the diameter of the cup-type rotating grindstone 1 is 20 cm, the diameter of the flat surface 7 is about 7 cm, the diameter of the chip discharge hole 8 is about 2.2 cm, and the ring-shaped convex part 3 The height of the flat part 4 is about 0.9 cm, the height from the flat part 4 of the grinding tip 5 is about 0.3 cm, and the front side and the flat part of the grinding chip 5 in the direction of rotation of the grindstone 4 is 85 °, the height of the cutting edge 11 from the peripheral surface of the ring-shaped convex portion 3 is 0.1 cm, and the vertical length is 0.3 cm.

削チップ５の速度ｖが増し、被研削材９へ次から次へと研削チップ５が連続的に当接し、又、等速円運動をする研削チップや切刃の作用力が増大し、被研削材に対する破壊力が著しく大となり、極めて短時間で完璧な研削作業が出来る。カップ型回転砥石１の外周に内方に窪む凹溝１０を設けているので、切粉排出用孔８と凹溝１０の双方から切粉の排出が行われ、切粉の排出が瞬時になされ、研削チップ５や切刃１１やリング状凸部周面に合成樹脂等の焼結物が付着しない。平坦部４に於いて、大小異径の同心円上に研削チップ５を設けているので、研削面積が拡大されるという作用効果がある。通常、旧塗膜は表面が平滑ではなくデコボコしている。リング状凸部３の外周面に切刃を設けているので、ブラシ及び電動或はエアー工具が取り付けられた回転砥石を、次の研削予定場所へ回転しながら横方向に移動すると、先ず、旧塗膜を有する被研削材にリング状凸部３の外周面が回転しながら当接し、切刃１１で旧塗膜を剥離する。剥離物は回転砥石の回転中の円心力により接線方向へと飛び散らされ、回転砥石に付着しない。次に、リング状凸部３の平坦部４に設けた研削チップ５により研削され、更に研削された剥離物は切粉排出用孔８や内方に窪む凹溝１０より外方へ排出される。Next, the operation will be described. The cup-type rotating grindstone of the present application is rotated inside the annular brush so that a rotating shaft such as an electric tool or air tool is fitted into the mounting hole 6 and the brush is disposed outside the entire outer peripheral surface of the ring-shaped convex portion 3. A grindstone is provided, and the flat portion 4 is used so as to abut against the workpiece 9 horizontally.
Since the cup-type rotating grindstone 1 has a large diameter of 15 to 30 cm, the acceleration is α, half

The speed v of the cutting tip 5 is increased, the grinding tip 5 is continuously brought into contact with the workpiece 9 from one to the next, and the acting force of the grinding tip or the cutting blade that moves at a constant speed is increased. The destructive force on the abrasive is remarkably large, and perfect grinding can be performed in an extremely short time. Since the concave groove 10 recessed inward is provided on the outer periphery of the cup-type rotating grindstone 1, the chips are discharged from both the chip discharge hole 8 and the concave groove 10, and the discharge of the chips is instantaneous. Thus, a sintered product such as a synthetic resin does not adhere to the grinding chip 5, the cutting edge 11, or the ring-shaped convex portion peripheral surface. Since the grinding tip 5 is provided on concentric circles having different diameters in the flat portion 4, there is an effect that the grinding area is enlarged. Normally, the surface of the old coating is not smooth but uneven. Since the cutting edge is provided on the outer peripheral surface of the ring-shaped convex portion 3, when the rotating grindstone attached with the brush and the electric or air tool is moved to the next grinding place while moving in the lateral direction, The outer peripheral surface of the ring-shaped convex portion 3 abuts on the material to be ground having a coating film while rotating, and the old coating film is peeled off by the cutting blade 11. The peeled material is scattered in the tangential direction by the center force of the rotating grindstone during rotation, and does not adhere to the rotating grindstone. Next, the peeled material ground by the grinding chip 5 provided on the flat portion 4 of the ring-shaped convex portion 3 and further ground is discharged outward from the chip discharging hole 8 and the concave groove 10 recessed inward. The

  The embodiment shown in FIG. 8 will be described. Grinding tips 12 and 13 formed on the flat portion 4 with inclined surfaces whose lower surfaces are inclined upward from the front side to the rear side are arranged on the circumference of a concentric circle. Among concentric circles having different diameters, a grinding tip 12 is disposed on the circumference of the small diameter, and a grinding tip 13 is spaced apart on the circumference of the large diameter. The angle formed between the flat portion 4 and the front side surface of the grinding chips 12 and 13 in the direction of the grindstone rotation is set to be less than 90 °, and the outer surface of the grinding tip 13 is on the outer circumferential surface of the ring-shaped convex portion 3 when viewed from the bottom surface side. It is arranged and attached along. The grinding tips 12 and 13 are formed in a rectangular parallelepiped as viewed from the front side in the grinding wheel rotation direction so that the material to be ground and the cutting edges of the grinding tips 12 and 13 are in line contact. On the outer peripheral surface of the ring-shaped convex portion 3, a cutting blade 11 having a cutting edge directed in the grinding wheel rotation direction is provided.

The embodiment shown in FIGS. 9 and 10 will be described. In the flat portion 4, grinding tips are arranged on concentric circles having large and small diameters with the cutting edge directed in the direction of grindstone rotation. The grinding tip 14 disposed on the circumference of the small diameter among the concentric circles is disposed such that the angle formed by the front side surface of the blade edge and the flat portion 4 is inclined forward to less than 90 °. The inner surface of the grinding tip 14 is disposed so as not to protrude from the inner edge of the ring-shaped convex portion 3 toward the inner side of the base metal 2.
Two types of grinding tips 15 and 16 are arranged on the circumference of the large diameter of the concentric circles. The grinding tips 15 and 16 are disposed in a forward inclined state in which the cutting edge is directed in the direction of rotation of the grindstone, and the angle between the front side surface of the cutting edge and the flat portion 4 is set to be less than 90 °. The grinding tip 15 is disposed so that the outer surface of the grinding tip 15 is located inside the outer peripheral edge of the ring-shaped convex portion 3. The grinding tip 16 is formed slightly wider than the grinding tip 15, and the outer surface of the grinding tip 16 protrudes outward from the outer peripheral edge of the ring-shaped convex portion 3. The front side surface of the cutting edge of the grinding tip 16 is continuously arranged from the flat portion 4 to the midway position in the outer portion height direction of the ring-shaped convex portion 3. The center of the grinding tip 16 in the width direction may be located slightly outside the center of the grinding tip 15 in the width direction. In other words, the flat portion 4 is provided with grinding tips 14, 15 and 16 on the circumference of a circle of 3 with large, medium and small diameters, and the grinding tip 14 is arranged on the circumference of the small diameter circle. The grinding tip 15 is disposed on the circumference of the medium-diameter circle, and the grinding tip 16 is disposed on the circumference of the large-diameter circle. The grinding tips 14 and 15 are disposed without protruding from the flat portion 4 to the outside. The grinding tip 16 protrudes outward from the flat portion 4, and the protruding portion has the same function as the cutting edge 11. The lower portions of the grinding tips 14, 15, 16 are arc-shaped when viewed from the front side of the cutting edge, and are formed in a bowl shape with the center bulging downward as a whole. The reason why the front part of the cutting edge is formed in a U shape when viewed from the front side in the rotation direction is to allow the cutting edge to come into point contact with the material to be ground. On the outer peripheral surface of the ring-shaped convex portion 3, there is provided a cutting blade 11 having a cutting edge directed in the grinding wheel rotation direction. The cutting edge 11 is provided with a length in the vertical direction of several millimeters from the lower end of the outer periphery of the ring-shaped convex portion 3. The front side surface of the cutting blade 11 in the direction of grindstone rotation is disposed on an extension line of the diameter of the base metal 2.
In Example 3, since three types of grinding tips 14, 15, and 16 are disposed on the flat portion 4, the total width of the grinding tips 14, 15, and 16 becomes an area that can be ground by rotating the grindstone, thereby reducing the grinding area. Since the number of grinding tips that are further expanded and continuously contact the material to be ground is large, and the time between the grinding tips that come into contact with each other is shortened, the grinding operation is performed efficiently. In addition, since the disposition distances of the grinding tips 14, 15, 16 from the center of the base metal 2 are slightly different, the grinding area is wide, the number of contact of the grinding tips is made uniform, and the old coating film of the material to be ground is obtained. Can be completely peeled off in a short time. Further, since the outer portion of the front side surface of the grinding tip 15 protrudes, the protruding portion performs the same function as the cutting edge 11.

It is a bottom view of a cup type rotating grindstone. Example 1 It is a top view of a cup type rotating grindstone. Example 1 It is a front view of a cup type rotating grindstone. Example 1 It is the sectional view on the AA line of FIG. Example 1 It is an expansion side explanatory view of a grinding tip. Example 1 It is an expansion perspective view explanatory drawing of a grinding tip. Example 1 It is explanatory drawing which shows the contact state of the grinding chip front side seen from the grindstone rotation direction, and the to-be-ground body surface. Example 1 It is a partial expansion perspective view which shows the arrangement | positioning relationship between a ring-shaped convex part, a grinding tip, and a cutting blade. (Example 2) It is a bottom view of a cup type rotating grindstone. (Example 3) It is a partial expansion perspective view which shows the arrangement | positioning relationship between a ring-shaped convex part, a grinding tip, and a cutting blade. (Example 3)

DESCRIPTION OF SYMBOLS 1 Cup type grindstone 2 Base metal 3 Ring-shaped convex part 4 Flat part 5, 12, 13, 14, 15, 16 Grinding chip 6 Mounting hole 9 Material to be ground 10 Groove recessed inward 11 Cutting blade

Claims (5)

A circular cup-type rotating grindstone with a flat view for grinding and removing a coating film, a resin film or an FRP film applied to the surface of concrete, metal or stone,
An attachment hole for attaching a tool is formed in the center of the cup-shaped base metal, a ring-shaped convex portion is provided on the entire outer periphery of the cup-shaped base metal, and a flat portion having a predetermined width is provided on the lower surface of the ring-shaped convex portion. In the cup-type rotating grindstone in which a plurality of grinding chips with the cutting edges directed in the grindstone rotating direction are attached to the flat portion with being spaced apart in the circumferential direction,
The cup-type base metal is formed in a size of 15 cm to 30 cm in diameter,
The grinding tip has an angle θ between the front surface of the grinding wheel rotating direction at the cutting tip edge and the flat portion set to 0 <θ <90 °, and the blade is tilted forward in the grinding wheel rotation direction when viewed from the side of the grinding wheel. A cup-type rotary whetstone characterized by being formed into A circular cup-type rotating grindstone with a flat view for grinding and removing a coating film, a resin film or an FRP film applied to the surface of concrete, metal or stone,
An attachment hole for attaching a tool is formed in the center of the cup-shaped base metal, a ring-shaped convex portion is provided on the entire outer periphery of the cup-shaped base metal, and a flat portion having a predetermined width is provided on the lower surface of the ring-shaped convex portion. In the cup-type rotating grindstone in which a plurality of grinding chips with the cutting edges directed in the grindstone rotating direction are attached to the flat portion with being spaced apart in the circumferential direction,
The cup-type base metal is formed in a size of 15 cm to 30 cm in diameter,
The center of the cup-type base metal in the flat part is provided as a center of a circle so that grinding tips are not juxtaposed in the inner and outer directions on concentric circles of different diameters,
In the grinding tip, the angle θ formed between the front surface of the grinding wheel rotation direction at the cutting edge of the grinding tip and the flat portion is set to 0 <θ <90 °, and the grinding tip is tilted forward in the grinding wheel rotation direction as viewed from the side of the grinding wheel. A cup-type rotary grindstone formed on a blade.   The lower part of the cutting edge of the grinding chip is formed in an arc shape that bulges downward as viewed from the grinding wheel rotation direction so that the cutting edge of the grinding chip makes point contact with the workpiece. The cup-type rotary grindstone as described.   The cup-shaped rotation according to claim 1, 2 or 3, wherein a plurality of cutting blades whose cutting edges are directed in the grinding wheel rotation direction are spaced apart in the circumferential direction on the outer surface of the ring-shaped convex portion. Whetstone.   On the outer peripheral edge of the base metal provided with the ring-shaped convex part, a concave groove that opens to the outer peripheral edge of the ring-shaped convex part and is recessed in the radial inward direction of the base metal has a predetermined interval in the circumferential direction. The cup-type rotary grindstone according to claim 1, 2, 3, or 4, wherein the cup-type rotary grindstone is provided at a distance.

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