ES2242669T3 - ABRASIVE SHEET AND ABRASIVE DISK THAT INCLUDES A PLURALITY OF SUCH SHEETS. - Google Patents

Abstract

The abrasion laminates (1) have a first straight edge (2) and an opposite, parallel edge (3) with a convex edge and first middle point (M1) and circular third edge (4) with a second middle point (M2) surrounded by a fourth edge (5). A straight line (g) is parallel runs parallel to the first and second edge.

Description

Abrasive sheet and abrasive disk comprising a plurality of such sheets.

The invention relates to an abrasive sheet and to an abrasive disk comprising a plurality of such sheets on a disc-shaped carrier, especially for tools for sharpen that can be rotatably operated.

Publication DE 295 10 727 U1 describes a abrasive disc which comprises a disc-shaped carrier centered on an axis and that can rotate around it with a hub section arranged around the shaft and with a section of ring carrier arranged around it. At the same time, the cube section presents a drill for the passage of an element of clamping for clamping a working spindle of a machine of work. On the bearer section is attached by a adhesive an annular lining, which is formed by sheets individual abrasives At the same time, abrasive sheets are trapezoidally formed and arranged overlapping each other to tile mode over the ring carrier section. Due to the trapezoidal shape of the abrasive sheets, these cannot be cut by consecutive cutting from a continuous band. further a very large number of abrasive sheets of this type is needed to cover the annular carrier section, which has as consequence a relatively large angle of attack of each individual abrasive sheet and, consequently, that the disc abrasive be relatively thick throughout its entire section cross.

The present invention poses the problem of, on the one hand, propose an abrasive sheet in whose manufacture produce the least possible waste and, on the other hand, create a abrasive disc that requires a small number of abrasive sheets and that has a high degree of coating in the edge area of abrasive sheets.

This problem is solved according to the invention. thanks to the abrasive sheet being circumscribed by

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a first straight song,

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a second song parallel to the first song,

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a third convex edge in the form of a circular arc with a given radius around a first center as well as

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a fourth concave edge in the form of a circular arc with a radius that corresponds to the radius of the third song about a second center,

the first center and the second being arranged center, displaced relative to each other, on a parallel to the First song and second song.

This problem is further resolved according to the invention by means of an abrasive disk which is characterized because the abrasive sheets are circumscribed in each case by

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a first straight song,

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a second song parallel to the first song,

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a third convex edge in the form of a circular arc with a given radius around a first center as well as

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a fourth concave edge in the form of a circular arc with a radius that corresponds to the radius of the third song about a second center

the first center and the second being arranged center, offset from each other, on a straight line parallel to the first song and the second song,

and because its outer contour is formed by the third convex edges of the abrasive sheets that overlap. At the same time, the outer contour defines the radius nominal outside of the tool for sharpening.

The advantage of this form of abrasive sheets is It is based on the fact that for its manufacture these can be separated from a band continues in consecutive court since the songs that limit in each case a sheet and are opposite each other run in each case parallel to pairs. It is also advantageous that - due to circular arc-shaped edges - only one number needed Small abrasive sheets to coat the carrier section ring the carrier with them superimposed as tiles. Thank you to this the manufacture of an abrasive disk according to the invention is It makes it simpler and therefore more economical. It also turns out, due to the reduced number of abrasive sheets per abrasive disc, a smaller angle of attack of the abrasive sheets with respect to a plane that runs perpendicular to the axis, which gives rise to also to a better abrasion behavior and makes possible a flat constructive shape of the abrasive disk. Another advantage is in which the degree of coating of an abrasive disk comprising abrasive sheets of this type is maximum in the edge area, it is say where where during tool operation the highest speeds appear and also where the work zone. This means that where the main request (in the largest diameter), is where it is available most of the material while there where gives only a small contribution to abrasion removal (in the smaller diameter), there is also less material. Thanks to that a high duration of the abrasive disc is achieved.

In another refinement of the invention, the abrasive sheets are characterized because the radii of the arches circular blades that describe the third edges and the fourth songs correspond approximately to the outer radius nominal abrasive disc. Especially it is planned that a tangent to the third song is approximated to it at the point of transition to the second song. In addition, it is planned that second edges of in each case an abrasive sheet are arranged adjacent to and within the outer contour of the disc abrasive. Thanks to the mentioned characteristics it is achieved that the degree of coating of the overlapping abrasive sheets mutually be maximum in the vicinity of the disk contour abrasive. Especially, thanks to the chosen embodiment, the second straight edges are also in the vicinity of the outer contour of the abrasive disk and contribute to the process of abrasion. This is especially advantageous because during the abrasion process is precisely in this area, in the proximity of the outer contour of the abrasive disc, where the processing zone with the highest relative speeds and with The highest abrasion rate. Consequently durations are possible high for simultaneously high abrasion rates. It is also conceivably an arrangement of the abrasive sheets in such a way that the third edges slightly protrude from the outer radius of the disk-shaped carrier so that, during the use of the useful for sharpening with the use of a large angle of attack, the Workpiece is not damaged by the bearer edge in shape of disk.

In another improvement of the invention is provided that the distances between the first edge and the straight line parallel, which is defined by the centers of the arches circulars that describe the third and fourth edges, as well as between This and the second song have different sizes. In this improvement is advantageous for abrasive sheets to receive a sickle shape whose sharp ends, formed between the second and fourth songs, are, unlike the ends blunt fixed by the first edge, further away from the axis of the disc abrasive. According to a particular preferred form of the invention is provided that the distance between the first song and the second song equal to or larger than the radius of the arches circulars that describe the third song and the fourth song. The advantage of wide abrasive sheets with great distance between the first and second songs are based on what is necessary only a small number of sheets to achieve a degree of given coating and a determined coating thickness for abrasive discs formed by abrasive sheets. However it is conceivable also the use of abrasive sheets in the which the distance between the first and second edges is less that the radius of the circular arcs that describe the third and Fourth songs In order to avoid oscillations or vibrations of the abrasive disc during operation is provided that the first edge is not contained in the defined parallel straight line through the centers, but present a distance from this.

A preferred improvement of the invention It is characterized in that the length of the first or second edges corresponds approximately to the width of the section of ring carrier. This ensures that during the process of abrasion can take advantage of the entire width of the carrier  disk-shaped

According to a particular form of the invention it is provided that the number of abrasive sheets connected to the disc-shaped carrier is between 10 and 40. By the number of abrasive sheets used is influenced, depending of the application case, on the thickness of the abrasive disc and the angle of attack of the individual abrasive sheets. How many more abrasive sheets are arranged on a carrier, all the more The abrasive disk will be thicker, the greater the angle of attack of each individual abrasive sheets and the longer will be the duration of the tool.

A preferred embodiment is characterized in that the abrasive sheets are connected to the carrier section of the carrier by adhesion or a resin of molding At the same time, the sickle shape of the abrasive sheets offers the special advantage that abrasive sheets can be fixedly bonded with the carrier section approximately over the entire length of the fourth songs concave

A simple and economical manufacture of individual abrasive sheets results because these are cut from a continuous band, with a defined width, using a cutting tool. At the same time, the width of the band corresponds to the distance formed between the first and the second edges of the abrasive sheet.

In the drawing it is represented schematically a preferred embodiment.

In the drawing, the figures show:

Figure 1, a top view of a sheet abrasive according to the invention,

Figure 2, a top view on a band as a starting product for abrasive sheets according to the invention,

Figure 3, a four-sheet arrangement abrasives on a circular ring, and

Figure 4, a perspective view of a disk abrasive according to the invention with abrasive sheets, partially sectioned

Figure 1 shows an abrasive sheet 1. This presents a first straight 2 edge, a second straight 3 edge, opposite to this one and that runs parallel, a third song 4 convex and that runs in a circular arc around a first center M_ {1}, as well as a fourth 5 concave edge, opposite parallel to that and that runs in the form of a circular arc around a second center M_ {2}. At the same time, the circular arcs of the third song 4 and fourth song 5 have the same radius R. The centers M_ {1}, M_ {2} are arranged on the line (parallel) g displaced with respect to the first 2 or second edge edge 3, so that the length of these edges 2, 3 corresponds at the distance of the centers M_ {1}, M_ {one} with respect to the other.

The abrasive sheet 1 is structured such so that the third song 4 convex becomes the second straight singing 3. At the same time, the second song 3 is arranged within the circle, which is described by an arc of radius R and with center M_ {1}, although directly adjacent to it. The distance A of the first edge 2 with respect to the second edge 3 is greater than the radius R of the circle, so that between the first edge 2 and the parallel line g is formed a displacement B.

Figure 2 shows a band 6 with two edges 7, 8 constraints arranged parallel to each other, which define the band width A. For the manufacture of abrasive sheets 1, 1``, 1 '' 'the band 6 is separated, for a constant advance, of intermittently using a cutting tool. The same time the third edge 4, of the abrasive sheet 1 cut first place, at the same time represents the fourth edge 5 'of the sheet 1 'abrasive which is then separated. In addition, the length of the first song 2, that is to say the second song 3, corresponds to the length of the feed between two cuts. The cutting tool is structured in a circular arc with radius R around the center M_ {1} (= M_ {2}). The center M_ {1} of the radius circle R described by the circular arc is in the width A of Band 6, adjacent to the second song 8.

Figure 3 shows the provision of four abrasive sheets 1, 1 ', 1' ', 1' '' relative to a ring 9. At the same time, the abrasive sheets 1, 1 ', 1' ', 1' '' are arranged overlapped in such a way that the third songs 4 in circular arc shape form the outer contour of ring 9. The inner radius of ring 9 is defined by the shortest distance of the fourth songs 5 concave with respect to the center M_ {1}. Be appreciate that the fourth songs 5, starting from the point of contact with the inner radius, they move away from the center M_ {1} towards the second edge 3. It follows that the coating area 10 of two 1, 1 '' 'abrasive sheets, which overlap as tiles, are found in the outer zone of ring 9. Consequently it increases -in the case of a large number of abrasive sheets- the degree of coating, that is, the number of abrasive sheets 1 that are overlap each other, starting from the inner radius to the radius outer ring 9.

Figure 4 shows an abrasive disk 11 according to the invention with abrasive sheets 1 in perspective view and partially sectioned This comprises a carrier 12 in the form of disk, which is arranged centered on an x axis and which it has a hub section 13, with a hole 14 arranged centered on the x-axis, as well as an annular carrier section 15 connected to it, in addition to an annular protection element 16 like this as abrasive sheets 1. The disc-shaped carrier 12 can be made of metal, of layers of abrasive fiber fabric bonded by resin or a vulzanized fiber. It can Actively rotate around the x axis of a machine job. The bore 14 of the hub section 13 is intended for the passage of a fastener, not shown, for the holding the abrasive disk 11 to a working spindle of the working machine The annular protection element 16 is arranged around the outer perimeter of the carrier 12 in shape of disk. It has an essentially shaped cross section of L, so that it limits the carrier 12 in the form of a disk in radial direction The protection element 16 is made in plastic and serves to prevent damage to the surface of the piece of work to be processed, especially in the case of large angles of attack of the abrasive disc.

About the annular bearer section 15 of the carrier 12, the abrasive sheets 1 are held together, overlapping like tiles, by adhesion or resin molding The outer diameter of the ring formed by the sheets abrasives 1 is slightly larger than the outer diameter of the carrier 12 together with the annular protection element 16. This it has the advantage that during the abrasion process, with the use of large angles of abrasive disk 11, the disc-shaped carrier 12 or protection element 8 does not They come into contact with the workpiece to be processed. Be appreciate that the degree of coating of the abrasive sheets 1 that they overlap each other increases, starting from the x axis, towards the radius outer abrasive disk 11. This is especially advantageous because, precisely in the area of the edge of the abrasive disc 11, the highest trajectory speeds take place and, for consequently, the main processing zone. The shape of the cross section of the coating area 10 of the sheets abrasives 1 is adapted according to the above to the degree of wear during the operation of the abrasive disk 11. This has as consequently a high duration of the abrasive disc 11.

List of reference signs

1, 1 ', 1' ', 1' '' sheet abrasive 2 first singing 3 second singing 4 third singing 5 quarter singing 6 band 7 first singing 8 second singing 9 ring 10 zone overlay eleven disk abrasive 12 carrier in the form of disk 13 section from Cube 14 drill fifteen section ring carrier 16 element of protection g straight line (parallel) x axis TO distance / width of the band B displacement M_ {1} first center M_ {2} second center R radio

Claims (12)

1. Abrasive sheet (1), especially for abrasive discs (11) that can be rotatably driven, characterized in that it is circumscribed by

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a first straight (2) edge,

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a second song (3) parallel to the first song (2),

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a third edge (4) convex in the form of a circular arc with a radius (R) given around a first center (M_ {1}), as well as

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a fourth concave edge (5) in the form of a circular arc with a radius (R) corresponding to the radius (R) of the third edge (4) around a second center (M_ {2}),

the first center (M_ {1}) being arranged and the second center (M_ {2}), displaced relative to each other, on a straight line parallel (g) to the first edge (2) and the second singing (3). 2. Abrasive disc (11) with a disc-shaped carrier (12), which can be rotatably driven around the axis (x), and comprising a plurality of abrasive sheets (1), which are partially secured overlapping on an annular carrier section (15), centered on the axis, of the carrier (12), characterized in that the abrasive sheets (1) are circumscribed in each case by

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a first straight (2) edge,

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a second song (3) parallel to the first song (2),

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a third edge (4) convex in the form of a circular arc with a radius (R) given around a first center (M_ {1}), as well as

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a fourth concave edge (5) in the form of a circular arc with a radius (R) corresponding to the radius (R) of the third edge (4) around a second center (M_ {2})

the first (M_ {1}) and the second center (M_ {2}), displaced relative to each other, over a straight line parallel (g) to the first edge (2) and the second edge (3), and because its external contour is formed by third parties edges (4) convex of the abrasive sheets (11) that are overlap. 3. Abrasive disc according to claim 2, characterized in that the radii (R) of the circular arcs of the abrasive sheet describing the third edge (4) and the fourth edge (5) correspond approximately to the nominal outer radius of the abrasive disk (11 ). 4. Abrasive sheet according to claim 1 or abrasive sheet for an abrasive disk according to claim 2, characterized in that a tangent of the third edge (4) is located at the point of transition towards the second edge (3) approximated thereto. 5. Abrasive disc according to claim 2, characterized in that the second edges (3) of in each case an abrasive sheet (1) are arranged adjacent to and within the outer contour of the abrasive disc (11). 6. Abrasive sheet according to claim 1 or abrasive sheet for an abrasive disc according to claim 2, characterized in that the distance (A) between the first edge (2) and the second edge (3) is equal to or larger than the radius (R) of the circular arcs that describe the third edge (4) and the fourth edge (5). 7. Abrasive sheet according to claim 1 or abrasive sheet for an abrasive disk according to claim 2, characterized in that the distances between the first edge (2) and the parallel straight line (g), which is defined by the centers (M_ { 1}, M 2 of the circular arcs that describe the third and fourth edges (4, 5), as well as between it and the second edge (3), have different sizes. 8. Abrasive disc according to claim 2, characterized in that the length of the first or second edges (2, 3) corresponds approximately to the width of the annular carrier section. 9. Abrasive disc according to claim 2, characterized in that the number of abrasive sheets (1) connected to the disc-shaped carrier (12) is between 10 and 40. 10. Abrasive disc according to claim 2, characterized in that the abrasive sheets (1) are connected to the carrier section (15) of the carrier (12) by adhesion or a molding resin. 11. Abrasive sheet according to claim 1 or abrasive sheet for an abrasive disc according to claim 2, characterized in that the sheet is cut from a continuous band (6), with a defined width (A), by a cutting tool. 12. Abrasive sheet according to claim 1 or abrasive sheet for an abrasive disk according to claim 2, characterized in that the width (A) of the band (6) corresponds to the distance formed between the first and second edges (2, 3) of the abrasive sheet (1).