METHOD FOR THE PRODUCTION OF METAL DISKS AND APPARATUS FOR CARRYING OUT THE METHOD

Abstract

In a method for the production of rotation-symmetric metallic disks, several metal disks are punched out from a metal sheet, mounted in a rotary drive of a grinding machine and subsequently refinished. The metal disks are placed side-by-side between two clamping devices of the rotary drive, with each of the clamping devices having a circular bearing surface. Refinishing is implemented by a rotating adjustable grinding wheel.

Description

The invention relates to a method for the production of metal disks, in particular throttle valves, according to the preamble of patent claim 1, and to an apparatus for carrying out the method according to patent claim 5.

STATE OF THE ART

Throttle valves or exhaust flaps are made of circular metal disks which are punched out from a metal plate having two holes and typically two adjacent bosses. Subsequently, the punched out metal disks are either milled individually about the circumference on a milling machine or placed upon one another into a stack, placed upon a receiving mandrel and machined with a lathe chisel on a lathe in order to provide the correct diameter. During turning on a lathe, the precision of the surface being treated lies in a tolerance range of 20 to 50 μm. When a throttle valve is involved, the disk edge should not extend perpendicular in relation to the disk surface but rather at an angular range of 80° to 100°, preferably at a sharp angle of about 83°, so that precise positioning of the metal disks on the mount is especially important in order to maintain the specified dimensional and positioning precisions of the individual metal disks. When compliance is required with especially narrow tolerance specifications of less than 20 μm, or stainless steel should be used as material for the metal disks provided as throttle valve, only individual processing becomes possible. Otherwise, the high demands on diameter and roundness precisions cannot be met. Suffice to say that the individual processing of such metal disks is time-consuming and therefore cost-intensive.

OBJECT OF THE INVENTION

It is therefore an object of the present invention to provide a method and apparatus for the production of metal disks, in particular high-precision throttle valves and those made of stainless steel, requiring less time while yet maintaining the required high precision.

SUMMARY OF THE INVENTION

This object is attained by a method for the production of metal disks having the features of patent claim 1, and by an apparatus for the production with the features of patent claim 5.

In the method according to the invention for the production of rotation-symmetric metallic parts, in particular metal disks, which are punched out from a metal sheet, the parts are mounted in a rotary drive of a grinding machine and subsequently refinished. Several metal disks are hereby placed side-by-side between two clamping devices of the rotary drive, with each of the clamping devices having a circular bearing surface, and with the refinishing being implemented by an adjustable grinding wheel.

The method according to the invention has the great benefit of permitting the circumferential surfaces of a great number of metal disks to be simultaneously machined, and of attaining a very high dimensional precision and very even surface quality of the ground circumferential surfaces.

According to claim 2, the circular bearing surface of the clamping devices has advantageously a diameter which is greater than half the diameter of the metal disks.

According to claim 3, a grinding wheel is further used which has a diameter of at least four times the diameter of the metal disks being processed so as to machine the edges of the metal disks in an optimum manner.

According to claim 4, the metal disks are mounted between the clamping devices preferably at an angle of 0 to 20°, in particular 5° to 10°.

The apparatus according to the invention for carrying out the method includes according to claim 5 a grinding machine having a rotary drive, which includes two clamping devices that can be positioned in relation to one another and have a circular bearing surface, for clamping the metal disks. Furthermore, the grinding machine includes a rotatable grinding wheel which is adjustable with respect to the region between the clamping devices.

According to claim 6, the circular bearing surfaces of the clamping devices have advantageously a diameter which is greater than half the diameter of the metal disks to be processed.

The grinding wheel has hereby in accordance with claim 7 a circular-cylindrical grinding surface.

According to an especially preferred embodiment of the apparatus as set forth in claim 8, the circular-cylindrical grinding surface has a width which corresponds at least to the width of the mounted metal disks.

DESCRIPTION OF AN EXEMPLIFIED EMBODIMENT OF THE INVENTION

Further advantages of the invention will be more readily apparent from the dependent patent claims and the following description of an exemplified embodiment of the invention with reference to the schematic drawings. It is shown in:

FIG. 1 a grinding machine with clamping devices and metal disks mounted onto a clamping device,

FIG. 2 the same grinding machine with clamping devices as viewed from another angle,

FIG. 3 the grinding machine with metal disks clamped between the clamping devices,

FIG. 4 a perspective illustration of a stack of metal disks,

FIG. 5 the same stack as in FIG. 4, as viewed from another angle, and

FIG. 6 a single metal disk.

FIGS. 1 and 2 show perspective illustrations of a part of a grinding machine 1 having a rotary drive 2 which includes two clamping devices 3 and 4, with the clamping device 3 on the left-hand side of the figures having two pins 5 projecting out in axis direction and with the right clamping device 4 being provided with bores 6. The pins 5 can be inserted into the bores 6 without play. As shown, a stack of metal disks 7 are placed upon the pins 5 in a row. FIG. 3 shows the left clamping device 3 and the right clamping device 4 being moved towards one another so that the metal disks 7 are clamped between the two clamping devices. For that, the clamping devices 3 and 4 have each a circular bearing surface 8 defined by a diameter which corresponds to at least half the diameter of the clamped metal disks 7. Further provided are a grinding wheel 10 and a cooling and cleaning device 11 with several nozzles 12 to cool the grinding wheel 10 and the metal disks 6 and at the same time to clean the grinding wheel 10 from grinding residues. The grinding wheel 10 is made of fine-grained grinding material and has a diameter which normally is at least four times the diameter of the metal disks 7 to be processed.

FIGS. 4 and 5 show perspective illustrations of a stack of metal disks 7 having two punched-out bores 13 which lie on a line through the circle center. As a result, the metal disks 7 are mounted at this angle of 0 to 20°, in particular 5° to 10°, on the pins 5 of the clamping device 3 (see FIGS. 1 and 2). In the present case, the angle amounts to about 7°. Furthermore, the metal disks 7 have on one side projecting protuberances 14 (FIG. 5) in proximity of the two bores 13 and on the other side recessed bosses 15 (FIG. 4) so that the metal disks 7 can be aligned when stacked. FIG. 6 shows a single metal disk 7, with the projecting protuberance 14 being clearly visible. The metal disks 7 shown in FIGS. 4 to 6, have already been ground in the grinding machine 1 so that the circumferential surfaces 16 of the metal disks 7 have a smooth surface and are aligned in relation to the side surfaces of the metal disks 7 at a defined angle—here about 83° or 97°.

The metal disks 7 are machined as follows: The punched-out metal disks 7 are lined up on the left clamping device 3 with the pins 5 and clamped between the clamping devices 3 and 4. The types of present protuberances 14 and bosses 15 ensure hereby a perfect alignment of the metal disks 7 within one another. The metal disks 7 are then radially moved by the rotary drive 2 at a high rotation speed, and the rotating grinding wheel 10 is pressed against the juxtaposed rotating metal disks 7. As a result, the circumferential surfaces 16 are ground with very high precision and surface quality. This method has been especially proven for the production of throttle valves of stainless steel.

The metal disks 7 have normally a diameter of 15 to 90 mm and may be made of brass, aluminum alloys, or stainless steel. The precision of diameter is below 20 μm in the method described herein. The method described herein is suitable for all rotation-symmetric metallic parts which can thus be machined in a shortest time.

Claims

1.-8. (canceled)

9. A method, comprising: punching out from a metal sheet a rotation-symmetric metallic part;mounting a plurality of said rotation-symmetric metallic part side-by-side between circular bearing surfaces of two confronting clamping devices of a rotary drive of a grinding machine; andsubsequently refinishing the plurality of rotation-symmetric metallic parts, using a positionally adjustable grinding wheel.

10. The method of claim 9, wherein the metallic part is a metal disk.

11. The method of claim 9, wherein the circular bearing surface of the clamping devices has a diameter which is greater than half a diameter of the metallic part.

12. The method of claim 9, wherein the grinding wheel is defined by a diameter which is at least four times a diameter of the metallic part.

13. The method of claim 9, wherein the metallic parts are mounted between the clamping devices at an angle of 0 to 20°.

14. The method of claim 9, wherein the metallic parts are mounted between the clamping devices at an angle of 5° to 10°.

15. Apparatus, comprising: a grinding machine having a rotary drive and two clamping devices operated by the rotary drive so as to be rotatable, said clamping devices being constructed for movement in relation to one another for clamping a plurality of metallic parts between circular bearing surfaces of the clamping devices; anda rotatable grinding wheel which is positionally adjustable with respect to a region between the clamping devices for machining the metallic parts.

16. The apparatus of claim 15, wherein the metallic parts are metal disks.

17. The apparatus of claim 15, wherein the circular bearing surface of each of the clamping devices has a diameter which is greater than half a diameter of the metallic parts.

18. The apparatus of claim 15, wherein the grinding wheel has a circular-cylindrical grinding surface.

19. The apparatus of claim 18, wherein the circular-cylindrical grinding surface has a width which corresponds at least to a width of the metallic parts mounted between the clamping devices.

20. The apparatus of claim 15, wherein the bearing surface of one of the clamping devices has a pin for lining up the metallic parts, and the bearing surface of the other one of the clamping devices has a bore for engagement by the pin.

21. The apparatus of claim 15, wherein each said metallic part has a protuberance on one side and a boss on an opposite side so that the metallic parts are aligned when clamped between the clamping devices by engagement of the protuberance of one of the metallic parts in the boss of another one of the metallic parts.