Form dressing roller

Abstract

A form dressing roller with a carrier body and a freestanding cover ring containing diamond grains and/or diamond rods configured in ceramic, metallic, or resin bond. The form dressing roller is made and used for dressing diamond and CBN grinding wheels as well as conventional wheels with abrasives made of corundum or silicon carbide. The form dressing roller includes clamping screws for securing the cover ring between the carrier body and an attachment ring, and includes a receiving hole in the center of the carrier body. The cover ring has at least three recesses.

Claims

1. A form dressing roller for dressing grinding wheels, comprising: a carrier body; a cover ring containing at least one of diamond grains and diamond rods configured in ceramic, metallic, or resin bond according to a predefined setting pattern; clamping screws that secure the cover ring between the carrier body and a clamping ring; and a receiving hole in the center of the carrier body, wherein the cover ring has at least three recesses.

2. The form dressing roller according to claim 1, wherein the cover ring has three to twelve recesses.

3. The form dressing roller according to claim 1, wherein the cover ring has four to six recesses.

4. The form dressing roller according to claim 1, wherein the recesses have a width of 1 mm to 10 mm.

5. The form dressing roller according to claim 1, wherein a depth of the recesses corresponds to a usable cover height.

6. A form dressing roller according to claim 1, wherein a diameter of the form dressing roller is 80 mm to 250 mm.

7. The form dressing roller according to claim 1, wherein a diameter of the receiving hole is 8 mm to 120 mm.

8. A form dressing roller for dressing grinding wheels, comprising: a carrier body; a cover ring containing at least one of diamond grains and diamond rods configured in ceramic, metallic, or resin bond; clamping screws that secure the cover ring between the carrier body and a clamping ring; and a receiving hole in the center of the carrier body, wherein the cover ring has at least three recesses, wherein the cover ring includes at least one layer; and wherein, in each layer, closely-sized individual diamond grains are arranged in a plane perpendicular to an axis of rotation of the form dressing roller according to a predefined setting pattern.

9. The form dressing roller according to claim 8, wherein the cover ring includes a first layer and a second layer; and wherein the diamond grains of the first layer lie in gaps between the diamond grains of the second layer and partially extend into the second layer such that a circumferential surface geometry of the dressing roller remains virtually constant as wear progresses.

10. A method for producing a cover for a form dressing roller, comprising: producing at least one diamond layer, including setting diamond grains according to a predefined setting pattern on a base with an adhesive layer; adding bonding powder to the at least one diamond layer; cold pressing and sintering the at least one diamond layer onto the base to form a cover, wherein a cover width is equal to or less than a diamond grain size; and cutting recesses out of the cover.

11. The method according to claim 10, prior to cold pressing and sintering the at least one diamond layer onto the base to form a cover, stacking at least two diamond layers with at least one of relative displacement and rotation of the at least two diamond layers to from a layer package; and cold pressing and sintering the layer package onto the base to form the cover.

12. The method according to claim 10, further including grinding and finishing the at least one diamond layer.

13. A method for producing a cover for a form dressing roller, comprising: producing a at least one diamond layer, including setting diamond grains according to a predefined setting pattern on a base with an adhesive layer; forming recesses in the base; adding bonding powder to the at least one diamond layer; and cold pressing and sintering the at least one diamond layer onto the base to form a cover.

14. The method according to claim 13, prior to cold pressing and sintering the at least one diamond layer diamond layer onto the base to form a cover, stacking at least two diamond layers with at least one of relative displacement and rotation of the at least two diamond layers to form a layer package; and cold pressing and sintering the layer package onto the base to form the cover.

15. The method according to claim 13, further including grinding and finishing the at least one diamond layer.

16. A method of using a form dressing roller, comprising: producing a form dressing roller, including a carrier body, a cover ring containing at least one of diamond grains and diamond rods configured in ceramic, metallic, or resin bond, clamping screws that secure the cover ring between the carrier body and a clamping ring, and a receiving hole in the center of the carrier body, wherein the cover ring has at least three recesses; and dressing a grinding wheel with the form dressing roller.

17. A method of using a form dressing roller according to claim 16, wherein dressing a grinding wheel with the form dressing roller includes dressing a diamond or CBN grinding wheel configured in ceramic, Bakelite, metallic, or resin bond.

18. A method of using a form dressing roller according to claim 16, wherein dressing a grinding wheel with the form dressing roller includes dressing a grinding wheel with abrasives made of corundum or silicon carbide.

Description

(1) The invention is explained in detail in the following with reference to drawings. They depict:

(2) FIG. 1 a plan view of the front side of the form dressing roller;

(3) FIG. 2 a plan view of the back side of the form dressing roller;

(4) FIG. 3 an enlarged detail Y of the cover with one recess according to FIG. 1 and FIG. 2;

(5) FIG. 4 a cross-section through the form dressing roller;

(6) FIG. 5 an enlarged detail Z of the cross-section according to FIG. 4;

(7) FIG. 6 a graphic representation of the actual surface roughness of workpieces after dressing, with the use of a prior art form dressing roller DDS without recesses in comparison with a form dressing roller DDS cut with recesses according to the invention;

(8) FIG. 7 a graphic representation of the surface roughness of workpieces after dressing, with the use of a prior art form dressing roller DDS without recesses in comparison with a form dressing roller DDS cut with recesses according to the invention;

(9) FIG. 8 a graphic representation of the roundness of workpieces after dressing, with the use of a prior art form dressing roller DDS without recesses in comparison with a form dressing roller DDS cut with recesses according to the invention;

(10) FIG. 1 depicts a plan view of the front side of a form dressing roller 10 for dressing diamond and CBN grinding wheels (not shown) in ceramic, Bakelite or resin, and/or metallic bond as well as conventional grinding wheels with abrasives made of corundum or silicon carbide. The form dressing roller 10 is an example of a diamond dressing system (DDS). The form dressing roller 10 enables high precision dressing of ceramically bonded diamond and boron nitride grinding wheels. The form dressing roller 10 includes a set one layer diamond sinter cover 2, which is clamped into a two-part steel base consisting of a carrier body 1 and a clamping ring 6. The cover 2 is made of individual diamond grains that have virtually the same size. The diamond grains lie in rays that pass through a common center of the form dressing roller 10. The diamonds are bonded into a matrix that is made of a suitable bonding material, for example, a galvanic or sinter bond with high tungsten content. The cover ring 2 in FIG. 1 has five recesses 3. FIG. 1 depicts the receiving hole 5 and the clamping screws 4.

(11) FIG. 2 depicts a plan view of the back side of the form dressing roller 10. The inner edge 6A and outer edge 6B of the clamping ring 6 are visible.

(12) FIG. 3 depicts an enlarged detail Y of the cover 2 with one recess 3 according to FIG. 1 and FIG. 2. The recess 3 has a width of 5 mm and a depth of 5 mm with a cover height of 5 mm. The recess 3 can be cut out or incorporated during the shaping operation.

(13) FIG. 4 depicts a cross-section through the form dressing roller 10 and FIG. 5 depicts an enlarged detail Z of the cross-section according to FIG. 4 in the region of the clamping ring 6 and of the cover ring 2. It is readily discernible that the carrier body 1 and the clamping ring 6 are held together by the clamping screws 4. Both the carrier body 1 and the clamping ring 6 are customarily made of stainless steel. The clamping ring 6 is inserted with precise fit of the inner edge 6A into the carrier body 1. The cover ring 2 is set on the carrier body 1. The cover ring 2 is clamped between the carrier body 1 and the clamping ring 6. The outer edge 6B of the clamping ring 6 is flush with the outer edge 6B of the carrier body 1. The usable height of the cover ring 2 is 5 mm.

EXAMPLES

(14) FIG. 6 is a graphic representation of the actual surface roughness of a ceramic CBN (cubic crystalline boron nitride) grinding wheel after dressing. In the grinding process, the restoration of concentricity, of the geometric shape as well as the optimalen actual surface roughness of the grinding wheel plays an important role. The actual surface roughness R.sub.ts [m] of a dressed grinding wheel is shown. For this, a grinding wheel was dressed with a form dressing roller (DDS CUT) according to the invention and a second grinding wheel was dressed with a prior art form dressing roller (DDS). It was demonstrated that with the form dressing roller according to the invention, an actual surface roughness depth of 3.5 m was achieved on the grinding wheel. With the prior art form dressing roller, a actual surface roughness of only 1.8 m was achieved on the dressed grinding wheel. The actual surface roughness of the grinding wheel dressed with the form dressing roller according to the invention is greater than with the standard dressing roller. This implies higher performance grinding wheel topography. This result was surprising and unexpected.

(15) FIG. 7 is a graphic representation of the surface roughness of a grinding wheel after dressing. In the grinding process, the restoration of the desired surface roughness of the workpiece plays an important role. The surface roughness Ra [m] of ground workpieces is shown. For this, grinding wheels were dressed with a form dressing roller (DDS CUT) according to the invention and with a prior art form dressing roller (DDS). It was demonstrated: By means of dressing with the form dressing roller according to the invention DDS CUT, a somewhat higher surface roughness of 0.23 m was obtained in the workpieces than with the prior art form dressing roller DDS of 0.22 m.

(16) With the form dressing roller according to the invention DDS CUT, in 400 workpieces, a somewhat lower surface roughness of 0.25 m was obtained than with the prior art form dressing roller DDS of 0.32 m. The surface roughness was, to be sure, somewhat higher with the prior art form dressing roller DDS; however, with the prior art form dressing roller, only 400 workpieces could be ground with the predefined surface roughness. Consequently, only one dressing cycle of 400 workpieces could be obtained with the prior art form roller DDS.

(17) With the form dressing roller according to the invention DDS CUT, a surface roughness of 0.26 m was obtained in 600 workpieces and 0.25 m in 800 workpieces. The surface roughness was virtually constant over the 800 workpieces. The performance was doubled with the form dressing roller according to the invention (DDS CUT). A substantially better constant in the surface roughness of the ground workpieces was obtained. This result was surprising and unexpected.

(18) FIG. 8 is a graphic representation of the roundness of the workpieces after dressing of the grinding wheel. In grinding, roundness is a measure of the accuracy with which an ideal round shape (circular shape) is obtained. There is a better roundness profile; consequently, few shape deviations occur. In the grinding process, the optimum roundness of the workpiece plays an important role. The roundness in [m] of the workpieces is depicted. For this, grinding wheels were dressed with a form dressing roller (DDS CUT) according to the invention and with a prior art form dressing roller (DDS). It was demonstrated:

(19) With the form dressing roller according to the invention DDS CUT, a lower roundness of 1.2 m was obtained in the ground workpieces than with the prior art form dressing roller DDS of 2.8 m.

(20) With the form dressing roller according to the invention DDS CUT, a lower roundness of 1.3 m was obtained than with the prior art form dressing roller DDS of 2.7 m. The roundness error was higher with the prior art form dressing roller. With the prior art form dressing roller DDS, only 400 workpieces could be ground with the required accuracy. With the form dressing roller according to the invention DDS CUT, in 600 workpieces, a roundness of 1.3 m was obtained and in 800 workpieces, a roundness of 1.2 m was obtained. The roundness was virtually constant over the 800 ground workpieces. The performance as doubled with the form dressing roller according to the invention (DDS CUT). A substantially better constant in the roundness of the ground workpieces was obtained. The roundness results demonstrate that with the form dressing roller according to the invention (DDS CUT), constant roundness values can be achieved over the entire dressing cycle. The grinding wheels dressed with the prior art form dressing roller DDS had to already be dressed again after 400 workpieces since the surface roughness as well as the roundness fell outside the workpiece tolerance. This result was surprising and unexpected.

LIST OF REFERENCE CHARACTERS

(21) 10 form dressing roller 1 carrier body 2 cover ring/cover/diamond sinter cover 3 recesses 4 clamping screws 5 receiving hole 6 clamping ring 6A inner edge of the clamping ring 6B outer edge of the clamping ring Y enlargement according to FIG. 1 and FIG. 2/enlarged detail Y Z enlargement according to FIG. 4/enlarged detail Z