JP2003103469A - Straight cup grinding wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance discharge capability of chips during grinding by a straight cup grinding wheel, particularly, to further enhance chip discharge capability of the grinding wheel itself in the straight cup grinding wheel provided with a hole for collecting dust in a base material. SOLUTION: In the grinding wheel 10, an abrasive material layer 12 using diamond abrasive grains is attached to a flat part 11a of an outer circumferential portion of the base material 11. In the substrate 11, a through hole 14 for collecting dust with an inner diameter of 13 mm is provided on an inclined face 11c between the flat part 11a and a hole 11b for attachment. Recessed parts 14a and 14b for forcibly forming a flow of air by rotation of the grinding wheel 10 and encouraging discharge of chips are respectively formed on a base material front face side (a base material inner face side) and a base material back face side (a base material outer face side) of the through hole 14. By forming the recessed parts 14a and 14b, the flow of air coming from the recessed part 14b of the back face side through the through hole 14 and out from the recessed part 14a of the front face side is forcibly formed during rotation of the grinding wheel, and the discharge of chips is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cup type grindstone used for grinding stone materials, concrete, bricks and the like.

[0002]

2. Description of the Related Art Cup-type grindstones are widely used for grinding highly brittle materials such as stone materials, concrete and bricks.
The basic structure of the cup-shaped grindstone is one in which an abrasive material layer is provided intermittently or continuously along the outer peripheral edge of a cup-shaped substrate. It is brought into sliding contact with and surface-ground.

A grindstone in which an abrasive layer is intermittently provided along the outer peripheral edge of a cup-shaped substrate has good discharge of chips from between the intermittent abrasive layers and is less likely to be clogged. Further, since the contact area with the material to be ground is small, it has the advantage that the abrasive material layer bites well into the material to be ground and has excellent sharpness. On the other hand,
It also has the disadvantages of large vibration during grinding, large chipping, and rough surface.

In a grindstone in which an abrasive layer is continuously provided along the outer peripheral edge of a cup-shaped substrate, since the continuous abrasive layer contacts an object to be ground, vibration during grinding is small and chipping does not occur. Few. Further, it has the advantages that the ground surface roughness is fine and the surface accuracy is good. On the other hand, because the discharge of chips is bad,
Clogging is likely to occur, and since the contact area with the material to be ground is large, grinding burn is likely to occur, the grinding stone part does not bite into the material to be ground poorly and sharply, it is difficult to supply the grinding fluid and cooling air, It also has the disadvantage.

In these cup-shaped grindstones, the abrasive grains forming the abrasive material layer are composed mainly of alumina oxide A.
-Based abrasive grains, C-based abrasive grains containing silicon carbide (SiC) as a main component,
Superabrasive grains such as diamond grains and cBN (cubic boron nitride) grains are used depending on the material of the workpiece and the grinding conditions.

By the way, in a cup-type grindstone in which an abrasive layer is continuously provided along the outer peripheral edge of a substrate, clogging is likely to occur due to poor discharge of cutting chips, and it is difficult to supply a grinding liquid. On the other hand, a space is formed inside the substrate, and an opening is formed on the outer surface of the substrate that communicates with this space, and the outside air is sucked into the cavity as the substrate rotates and is introduced into the cavity. With blade structure,
Further, there is disclosed a cup-shaped grindstone which communicates with a cavity and opens at an end face of a substrate, and in the middle of which a grinding fluid supplied to the inside of the substrate merges with air to form a gas passage for leading out from the end face is disclosed in JP-A-5-69339. Has been proposed to.

Further, the present applicant also installed openings penetrating the outer peripheral edge of the substrate and the abrasive material layer at a plurality of positions in the circumferential direction of the abrasive material layer that were continuously installed, or intermittently, respectively. Japanese Unexamined Patent Publication No. 2000-84858 proposes a cup-type grindstone with a through hole which is provided for each abrasive material layer and whose inner wall of the opening is inclined rearward or frontward in the grindstone rotating direction.

[0008]

According to the cup-type grindstone proposed in the above publication, it is possible to improve the discharge property of the chips and the supply property of the grinding fluid. However,
In these whetstones, since the through hole is provided in the portion where the abrasive layer is present, vibration occurs when the peripheral edge of the through hole hits the material to be ground, and chipping easily occurs in the material to be ground.

On the other hand, there is a grindstone in which a through hole is formed in a base plate of a cup-shaped grindstone to enhance a dust collecting effect when a dust collecting device is attached. By providing through holes in the substrate,
The air resistance at the time of sucking the air around the grindstone by the dust collection duct is reduced, and the dust collection efficiency, that is, the chip discharge property is improved. In this case, the dust collection duct should be installed toward the grinding part so that air flows from the outer surface side (back surface side) of the substrate to the inner surface side (front surface side), and from the inner surface side to the outer surface side of the substrate. In some cases, it is arranged toward the outer surface of the substrate so that air flows. However, in any case, the dust collection effect depends only on the suction capacity of the dust collector, and the substrate of the grindstone has almost no function of positively improving the air flow,
The ability to discharge chips as a grindstone is not so high.

The problem to be solved by the present invention is to enhance the ability to discharge chips during grinding with a cup-type grindstone, and particularly to the chip-discharging ability of the grindstone itself in a cup-type grindstone having holes for dust collection on a substrate. Is to further increase.

[0011]

According to the present invention, in a cup-shaped grindstone in which a through hole for collecting dust is provided in a substrate, air on the outer surface side or the inner surface side of the substrate is drawn into the through hole when the grindstone rotates. It is characterized in that a concave portion or a convex portion, which creates a flow of air from the through hole to the inner surface side or the outer surface side of the substrate, is formed in the peripheral portion of the through hole of the substrate.

By forming the concave portion or the convex portion at the peripheral portion of the through hole of the substrate, the air on the outer surface side of the substrate is drawn into the through hole by the concave portion or the convex portion on the outer surface side of the substrate when the grindstone rotates, and the convex portion on the inner surface side of the substrate is projected. The air that has flowed through the through hole is forced to be generated by the portion or the concave portion from the through hole to the inner surface side of the substrate. As the air flows, the chips are sucked together with the air into a dust collecting duct installed around the grindstone, and the discharge of the chips is improved. As the recesses or protrusions formed on the peripheral edge of the through hole, the following shapes are preferable.

A recess is formed by grinding the groove toward the rear side in the grindstone rotating direction from the peripheral edge of the through hole on the substrate inner side, and a recess formed by grinding the groove toward the front side in the grinding wheel rotating direction from the peripheral edge of the through hole on the substrate outer surface side. When each is formed, a flow of air that enters the through hole from the concave portion on the outer surface side of the substrate and exits to the inner surface side of the substrate is forcibly created when the grindstone rotates.

A curved surface portion is formed on the front side in the grindstone rotation direction starting from the peripheral edge of the through hole, the inner surface of the substrate being convex and the outer surface side of the substrate being concave, and from the peripheral edge of the through hole to the rear side in the grinding wheel rotation direction. When a curved surface with a concave side and a convex outer surface is molded, a negative pressure is generated on the inner surface of the through-hole due to the presence of a convex portion on the inner surface of the substrate when the grindstone rotates, and at the same time, a convex portion on the outer surface of the substrate is formed. Due to the existence of the air flow, the air flow forced into the through hole from the outer surface side of the substrate and exiting to the inner surface side of the substrate is forced. By setting the relationship between the concave portion and the convex portion in the above relationship to be opposite, the flow of the air flowing out from the substrate inner surface side to the substrate outer surface side is forcibly created.

The cup-shaped grindstone of the present invention can also be a cup-shaped grindstone in which an inclined surface having a slope toward the rear side in the grindstone rotation direction is formed between the through holes on the inner surface side of the substrate. By forming the above-mentioned inclined surface in the middle of the through holes on the inner surface side of the substrate, the rear side of the inclined surface becomes a negative pressure when the grindstone rotates, and the air on the outer surface side of the substrate is drawn into the through hole and the inner surface side of the substrate The outgoing air flow is forced to be created. Furthermore, the cup-shaped grindstone of the present invention may be a cup-shaped grindstone in which openings are formed by bending two short pieces separated and formed by a V-shaped slit formed on the substrate to the back side and the front side, respectively. . By forming such an opening, a flow of air that enters the opening from the outer surface side of the substrate and exits from the inner surface side is forcibly created when the grindstone rotates. Also in the case of the above-mentioned two grindstones, the direction of the inclined surface and the bending direction of the short piece can be set so that the flow direction of the air when the grindstone rotates is from the inner surface side of the substrate toward the outer surface side.

[0016]

FIG. 5 is a view showing a basic shape of a cup-shaped grindstone which is an embodiment of the present invention, in which (a) is a front view,
(B) is a N-O-P line sectional view of (a).

The grindstone 1 has a ring-shaped abrasive material layer 12 made of diamond abrasive grains bonded and attached to a flat portion 11a of an outer peripheral portion of a cup-shaped substrate 11 by brazing. The substrate 11 is a cup-shaped substrate made of a 3.2 mm-thick steel plate by press drawing, and has a mounting hole 11b for mounting the rotating shaft of the electric tool in the center. The substrate 11 has an outer diameter of 95 mm, and the abrasive layer 12 has a width of 7 mm and a thickness of 4 mm.

The substrate 11 is provided with a through hole 13 for dust collection extending from the inside to the outside of the substrate 11 on the inclined surface 11c between the flat portion 11a and the mounting hole 11b. By providing the through hole 13, the air resistance is reduced when connected to the dust collecting device, and the dust collecting efficiency is improved. In this grindstone 1, the substrate 11 is made of one steel plate, but the substrate may be a laminated substrate made of two steel plates in order to reduce the vibration of the substrate. Further, although the abrasive layer 12 is an annular abrasive layer continuously provided along the outer peripheral edge of the substrate 11, it may be a chip-like abrasive layer provided intermittently.

FIG. 1 is a view showing a cup-shaped grindstone according to a first embodiment of the present invention. (A) is a front view, (b) is a rear view, and (c) is (A) -B- of (a). It is a C line sectional view. 1, the same members as those in FIG. 5 are designated by the same reference numerals as those in FIG.

The grindstone 10 of this embodiment is similar to the grindstone 1 of the basic shape shown in FIG. 5, in which the flat portion 11a of the outer peripheral portion of the substrate 11 is provided with the abrasive material layer 12 using diamond abrasive grains. Is. The substrate 11 is provided with a through hole 14 for collecting dust having an inner diameter of about 13 mm on the inclined surface 11c between the flat portion 11a and the mounting hole 11b.

Here, in the grindstone 10 of the present embodiment, the flow of air is forced by the rotation of the grindstone 10 on the substrate front side (substrate inner surface side) and the substrate rear side (substrate outer surface side) of the through hole 14, respectively. To form chips and form recesses 14a and 14b for promoting the discharge of chips. Recess 1 on the front side of the substrate
4a is a rear surface of the through hole 14 in the grindstone rotation direction (direction of arrow D in the figure), and a triangular groove of about 6 mm is ground in the grindstone rotation direction starting from the peripheral edge of the through hole 14.
The groove at the starting point has a depth of about 1.5 mm and a width of about 8 m.
m. The concave portion 14b on the rear surface side of the substrate is formed by grinding a triangular groove of about 10 mm in the direction opposite to the grindstone rotating direction from the peripheral edge of the through hole 14 on the front side in the grindstone rotating direction of the through hole 14. The depth of the groove at the starting point is about 1.5
The width in mm is about 8 mm.

The recesses 1 are formed on the front side and the back side of the substrate of the through hole 14.
By forming 4a and 14b, when the grindstone 10 rotates, a flow of air that enters the through hole 14 from the recess 14b on the back side and exits from the recess 14a on the front side is forcibly created. Along with this air flow, chips are sucked and discharged by a dust collecting duct (not shown) installed around the grinding section, and chips are discharged well.

2A and 2B are views showing a cup-shaped grindstone according to a second embodiment of the present invention. FIG. 2A is a front view and FIG.
It is the EF sectional view taken on the line of FIG.

The grindstone 20 is formed by attaching the abrasive layer 12 to the flat portion 21a of the outer peripheral portion of the cup-shaped substrate 21. The substrate 21 is a cup-shaped substrate formed by press-drawing two steel plates each having a thickness of 1.6 mm, and has a mounting hole 21b for mounting the rotating shaft of the electric tool in the center. In the substrate 21, a through hole 24 for collecting dust is formed on an inclined surface 21c between the flat portion 21a and the mounting hole 21b.

In the grindstone 20 of the present embodiment, the projections for promoting the discharge of the chips by forcibly creating a flow of air by the rotation of the grindstone 10 on the substrate front side and the substrate backside of the through hole 24 respectively. 24a and 24b are formed. The convex portion 24a on the front surface side of the substrate has a convex shape on the front surface side of the substrate and a concave shape on the rear surface side of the substrate on the front side of the through hole 24 in the grindstone rotation direction.
A semi-circular curved surface portion of about 10 mm is formed by press molding in the grindstone rotation direction with the peripheral edge of No. 4 as the starting point. The height of the convex portion at the starting point is about 1.0 mm and the width is about 10
mm. The convex portion 24b on the rear surface side of the substrate is formed with a convex portion similar to the convex portion 24a on the front surface side of the substrate from the peripheral edge of the through hole 24 as the starting point, on the rear side of the through hole 24 in the grindstone rotating direction.

The convex portions 2 are formed on the front side and the rear side of the substrate of the through hole 24.
By forming 4a and 24b, a negative pressure is generated on the front side of the through-hole 24 due to the presence of the front side convex portion 24a when the grindstone 20 rotates, and at the same time from the back side due to the presence of the rear side convex portion 24b. The flow of air entering the through hole 24 and exiting from the front side is forcibly created. Dust collecting duct (not shown) in which chips are installed around the grinding part along with this air flow
Will be sucked into and discharged, and the discharge of chips will be good.

Although the above embodiment is an example of forcing the flow of the air coming out from the substrate outer surface side to the substrate inner surface side, the concave and convex portions formed on the outer surface side and the inner surface side of the substrate are By setting the relationship opposite to the case of the above-described embodiment, it is possible to forcibly create the flow of air that emerges from the substrate inner surface side to the substrate outer surface side.

FIGS. 3A and 3B are views showing a cup-shaped grindstone according to a third embodiment of the present invention. FIG. 3A is a front view and FIG.
3 is a sectional view taken along line GH-I of FIG. 3C, and FIG. 6C is an end view taken along line JK of FIG. In FIG. 3, the same members as those described in FIG. 5 are designated by the same reference numerals.

The grindstone 30 is formed by attaching the abrasive layer 12 to the flat portion 31a of the outer peripheral portion of the cup-shaped substrate 31. The substrate 31 is a cup-shaped substrate formed by pressing and drawing a steel plate having a thickness of 3.2 mm, and has a mounting hole 31b for mounting it on the rotating shaft of the electric tool in the center. The board 31 has a flat portion 31a and a mounting hole 31b.
A through hole 13 for collecting dust is formed on the inclined surface 31c between the two.

In the grindstone 30 of this embodiment, the substrate 3
A blade 35 having a slope surface having a slope toward the rear side in the grindstone rotation direction between the through holes 13 on the front side of the blade 35.
Is provided. The blades 35 are for attaching a steel plate to the substrate 31 by brazing to make a negative pressure on the substrate front side to create a flow of air from the substrate rear side when the grindstone rotates. The inclination of the blades 35 is selected at an angle suitable for producing the negative pressure.

By providing such a blade 35,
A flow of air entering the through hole 13 from the back side of the substrate and exiting from the front side is forcibly created. Along with this air flow, chips are sucked and discharged by a dust collecting duct (not shown) installed around the grinding section, and chips are discharged well.

FIG. 4 is a diagram showing a substrate of a cup-shaped grindstone according to a fourth embodiment of the present invention. FIG. 4A is a diagram of the substrate seen from the back side, and FIG. 4B is a line LM of FIG. FIG. 6C is an end view in a cross section, and FIG. 6C is a diagram showing a slit formation state before forming an opening of the substrate shown in FIG.

The abrasive layer is attached to the front side of the flat portion 41a of the substrate 41, but the abrasive layer is not shown in FIG. In the substrate 41 of the grindstone of the present embodiment, the opening 43 is formed in the inclined surface 41c between the flat portion 41a and the mounting hole 41b. This opening 43 is shown in FIG.
As shown in, three slits 41f, 41g, 41h
Is formed on the inclined surface 41c, and two short pieces 41d, 4 separated by these slits are formed.
The through hole 13 is formed by bending 1e on the back side and the front side as shown in FIG. The bending angles of the short pieces 41d and 41e are 15 degrees to 80 degrees.
Within the range of degrees.

By thus bending the two short pieces 41d and 41e to form the opening 43, a flow of air that enters the opening 43 from the back side of the substrate and exits from the front side is forcibly created when the grindstone rotates. Along with this air flow, chips are sucked and discharged by a dust collecting duct (not shown) installed around the grinding section, and chips are discharged well.

[0035]

In the cup-type grindstone having the substrate provided with the through holes for collecting dust, the air on the outer surface side or the inner surface side of the substrate is drawn into the through holes when the grindstone rotates, and the inner surface side or the outer surface of the substrate is drawn from the through holes. By forming a concave or convex portion on the periphery of the through-hole of the substrate, where the flow of air that flows out to the side is created, the flow of air through the through-hole is forcibly created when the grindstone rotates, and with this air the chips Will be sucked and discharged by the dust collector, and the discharge of chips will be good.

[Brief description of drawings]

FIG. 1 is a diagram showing a cup-shaped grindstone according to a first embodiment of the present invention, in which (a) is a front view, (b) is a rear view, and (c).
FIG. 7A is a sectional view taken along the line ABC of FIG.

2A and 2B are diagrams showing a cup-shaped grindstone according to a second embodiment of the present invention, in which FIG. 2A is a front view and FIG.
It is a -F line sectional view.

FIG. 3 is a view showing a cup-type grindstone according to a third embodiment of the present invention, (a) is a front view, and (b) is a GH of (a).
-I line sectional drawing, (c) is an end view in the JK line cross section of (a).

FIG. 4 is a diagram showing a substrate of a cup-shaped grindstone according to a fourth embodiment of the present invention, in which (a) is a diagram of the substrate seen from the back side;
(B) is an end view in the LM line cross section of (a), (c)
FIG. 4A is a diagram showing a slit formation state before forming an opening of the substrate shown in FIG.

5A and 5B are diagrams showing a basic shape of a cup-shaped grindstone according to an embodiment of the present invention, FIG. 5A is a front view, and FIG. 5B is a cross-sectional view taken along the line NOP of FIG.

[Explanation of symbols]

1,10,20,30 Whetstone 11,21,31,41 substrate 11a, 21a, 31a, 41a Flat part 11b, 21b, 31b, 41b Mounting holes 11c, 21c, 31c, 41c Inclined surface 12 Abrasive layer 13, 14, 24 Through holes 14a, 14b recesses 24a, 24b convex part 35 feathers 41d, 41e short piece 41f-41h slit 43 openings

Continued front page    F term (reference) 3C063 AA02 AB05 BA02 BB02 BB03                       BB04 BG04 BG10 EE16 FF20

Claims (5)

[Claims] 1. A cup-shaped grindstone in which a through hole for collecting dust is provided in a substrate, air on the outer surface side or the inner peripheral side of the substrate is drawn into the through hole when the grindstone rotates, and the inner surface of the substrate passes through the through hole. The cup-shaped grindstone is characterized in that a concave portion or a convex portion that creates a flow of air flowing toward the side or the outer peripheral side is formed in the peripheral portion of the through hole of the substrate. 2. A recess formed by grinding a groove toward the rear side in the grindstone rotation direction from the peripheral edge of the through hole on the substrate inner surface side, and a groove toward the front side in the grindstone rotation direction from the peripheral edge of the through hole on the substrate outer surface side. The cup-shaped grindstone according to claim 1, wherein each of the ground recesses is formed. 3. A curved surface portion having a convex inner surface of the substrate and a concave outer surface of the substrate is formed on the front side in the grindstone rotation direction starting from the peripheral edge of the through hole, and rearward in the grindstone rotating direction from the peripheral edge of the through hole. The cup-shaped grindstone according to claim 1, wherein a curved surface portion having a concave inner surface side and a convex outer surface side is formed on the side. 4. A cup-shaped grindstone in which a through hole for collecting dust is provided in a substrate, and a sloped surface having a slope toward the rear side in the wheel rotating direction is formed in the inner surface of the substrate between the through holes. The cup-shaped grindstone that is characterized. 5. A cup-shaped grindstone characterized in that an opening is formed by bending two short pieces, which are separated and formed by an E-shaped slit formed on a substrate, to the back side and the front side, respectively.