WO2013100749A1

WO2013100749A1 - Apparatus and method for providing improved grinding lines on an aluminium substrate disc

Info

Publication number: WO2013100749A1
Application number: PCT/MY2012/000074
Authority: WO
Inventors: Eng Seong HONG; Masrini Binti Halim ELMA
Original assignee: Kobe Precision Technology Sdn. Bhd.
Priority date: 2011-12-27
Filing date: 2012-04-03
Publication date: 2013-07-04
Also published as: AU2012343353A1; AU2012343353B2; MY179417A; JP2015503457A

Abstract

A grinding apparatus for establishing grinding lines on an aluminium substrate disc, said apparatus including; a central rotatable shaft; a rotatable peripheral ring; a pair of circular grinding plates wherein each plate includes a central bore hole positionable about the central rotatable shaft wherein each of the circular grinding plates are free to rotate independently of the other and/or the central rotatable shaft; a plurality of carrier plates adapted to be sandwiched in between the pair of circular grinding plates wherein each carrier plate includes a series of pockets to which aluminium substrate discs are nestable therein such that the upper and lower surfaces of the aluminium discs are in contactable communication with each of the circular grinding plates; wherein the central rotatable shaft, peripheral ring and the plurality of carrier plates include a series of teeth and/or gears along their angular edges so as to establish an epicyclic gearing so as to increase and create a degree of rotation upon each of the central rotatable shaft, peripheral ring and each of the carrier plates such that the ability to impart rotation upon the carrier plates to which the aluminium discs rest therein results in an elliptical criss-cross grinding line pattern.

Description

DESCRIPTION

Title. APPARATUS AND METHOD FOR PROVIDING IMPROVED GRINDING LINES ON AN ALUMINIUM SUBSTRATE DISC

FIELD OF THE INVENTION [001] This invention relates to an apparatus or an arrangement which is adapted to establish grinded lines upon an aluminium substrate disc.

[002] More particularly this invention relates to a very unique arrangement wherein the grinding pattern upon the aluminium substrate disc includes an improved surface roughness uniformity compared to conventional parallel grinding lines.

BACKGROUND ART DISCUSSION

[003] This invention focuses more on disc grinding processes associated with high production rates wherein the aluminium disc is sandwiched into a machine between two rotatable abrasive plates. [004] More specifically these conventional types of machinery associated with the grinding process include four types of gears, a sun gear, a ring gear, a lower plate gear and an upper plate gear.

[005] Common terminology applied to conventional processes also makes reference to the RPM ratio which is referred to as the rotation ratio of a grinder plate against the sun gear. [006] The RPM ratio is associated with the disc revolution. A higher grinder plate rotation will increase disc revolution and wherein a higher sun gear rotation will also increase disc self-rotation.

[007] For the most part current grinding processes have been unable to consistently provide a surface roughness upon the aluminium substrate that is uniform.

[008] Therefore it is an object of this invention to provide an apparatus and/or method which is able to provide the means of establishing grinding lines upon an aluminium substrate disc that will have better roughness uniformity by way of establishing a grinding pattern with a cross hatch configuration.

[009] Further objects and advantages of the invention will become apparent from a complete reading of this specification.

SUMMARY OF THE INVENTION

[010] In one form of the invention there is provided a grinding apparatus for establishing grinding lines on an aluminium substrate disc, said apparatus including;

a central rotatable shaft;

a rotatable peripheral ring;

[011] a pair of circular grinding plates wherein each plate includes a central bore hole positionable about the central rotatable shaft wherein each of the circular grinding plates are free to rotate independently of the other and/or the central rotatable shaft; [012] a plurality of carrier plates adapted to be sandwiched in between the pair of circular grinding plates wherein each carrier plate includes a series of pockets to which aluminium substrate discs are nestable therein such that the upper and lower surfaces of the aluminium discs are in contactable communication with each of the circular grinding plates;

[013] wherein the central rotatable shaft, peripheral ring and the plurality of carrier plates include a series of teeth and/or gears along their angular edges so as to establish an epicyclic gearing so as to increase and create a degree of rotation upon each of the central rotatable shaft, peripheral ring and each of the carrier plates such that the ability to impart rotation upon the carrier plates to which the aluminium discs rest therein results in an elliptical criss-cross grinding line pattern.

[014] Advantageously, the applicant for this invention has realised that by establishing a planetary or epicyclic gearing type arrangement between the main central rotatable shaft and the peripheral ring through the geared teeth arrangement of the carrier plates holding the aluminium substrate discs means that as these carrier plates for the aluminium discs are sandwiched there in between the pair of circular grinding plates, not only are they moving in the general direction of the main central rotating shafts and the lower plates to which it rests thereon, it is also undergoing its own internal rotation upon its own axis.

[015] The situation is very similar to the way the earth rotates about the sun, not only is there a general rotation of the carrier plate containing the aluminium substrate disc moving in orbit about the central rotating shaft, where it is then being grinded both on its upper and underside by being sandwiched within the pair of grinding plate with each of the upper and lower grinding plates rotation in an anti direction, due to the establishment of the gearing arrangement between the central rotating shaft and the peripheral ring means that what is established is the unique phenomenon of the carrier plates holding the aluminium substrate discs revolving themselves as they move in their general orbit about the main central rotating shaft.

[016] Advantageously through the establishment of a gearing mechanism it is now possible to change the RPM ratio in order to provide different roughness uniformity as required depending on the application and use of the relevant aluminium disc.

[017] As the carrier plates are able to self rotate and spin and are no longer held generally stationary, the grinding pattern which is created using this self type rotation creates a cross hatch configuration of grind lines upon the disc. [018] The ability to establish this cross hatch grinding pattern leads to a direct correlation between roughness uniformity.

[019] In preference the central rotatable shaft is the central and/or sun gear.

[020] In preference the peripheral ring is an outer ring with inward facing teeth.

[021] In preference the central and/or sun gear includes outward facing teeth. [022] In preference each carrier plate wherein the aluminium substrate discs rest therein have annular pointing outward facing teeth adapted to mesh with the annulus and/or central/sun gear. [023] In preference the apparatus is adjustable such that the pair of grinding plates can be separated wherein an upper grinding plate is raisable relative to the lower grinding plate such that carrier plates wherein the aluminium substrate discs nested therein can be placed there upon the lower grinding plate during times of inoperation of the grinding apparatus.

[024] In preference the plurality of carrier plates are configured about the lower circular plate such that there is a maximising of contact area between the aluminium substrate discs nested in the carrier plate and each of the respective circular grinding plates to which the carrier plates are sandwiched therein between.

[025] In preference the abrasive stresses from the upper and lower grinding plates imparted upon the aluminium substrate discs nesting within the plurality of carrier plates during operation are equal on both sides.

[026] In preference the apparatus further includes sufficient cooling to minimise the heat generated during the disc grinding process.

[027] In preference the grinding apparatus includes a main external housing body such that the pair of circular grinding plates are enclosed within the apparatus so that the grinding process is not viewable from the outside of the machine thereby minimising any exposure to dust and airborne metal filings created.

[028] In one form of the invention there is provided a grinding arrangement wherein the grinding apparatus referred to precedingly includes a series of steps wherein individual such apparatus are positioned to establish firstly a rough grind and then a more finer grind.

[029] Advantageously by using an arrangement whereby two or more grinding apparatuses referred to above are responsible for various stages in the grinding process from rough through to fine means that those grinding apparatus associated with the rough grind can focus on larger stock removal and so forth and wherein finer grained apparatuses can focus on surface quality wherein the use of two or more multiple apparatuses therefore will be able to produce improved grinding lines overall. [030] For example, a rough grind apparatus could focus on aluminium stock removal of 42 microns and wherein a finer apparatus could focus on the grinding on surface quality/polishing for smoothness and so forth wherein stock removal would be expected to be 5 microns

[031] In order now to describe the invention now in greater detail a preferred embodiment will be presented through the use of the following illustrations and text:

BRIEF DESCRIPTION OF THE INVENTION

[032] Figure 1 is a schematic view of the main components shown using a conventional grinding process wherein the upper grinding plate to which the carrier plate would be sandwiched therein between during operation is not shown for clarity reasons. [033] Figures 2a illustrates the path taken by the carrier plate and its relevant movement to the lower plate when the conventional arrangement of Figure 1 is put into operation wherein the sun gear and the ring impart no rotation into the carrier plate which is not undergoing any self-rotation and figure 2b illustrates the disc grinding lines.

[034] Figures 3a and 3b provide representations of the path of the carrier plate relative to the lower plate and the grinding line pattern established upon the grinder disc after the grinding process wherein the sun gear and the ring gear rotates the carrier plate has a partial degree of self rotation due to the relative movement of the carrier to the sun gear and the ring gear rotation.

[035] Figure 4 shows a schematic representation of the main components associated with the apparatus that provides for a cross hatch grinded line pattern during the grinding process in a preferred embodiment of this invention.

[036] Figures 5a and 5b show respectively the path of carrier movement relative to the lower plate and the cross hatch grinded line pattern upon the aluminium substrate discs after the grinding process.

DETAILED DESCRIPTION OF THE ILLUSTRATIONS

[037] Referring to the drawings now in greater detail wherein as shown in Figure 1 purely for illustrative purposes in order to provide a distinction between the features associated with the preferred embodiment of this invention as illustrated in Figure 4, there is provided a more conventional arrangement shown generally as (10) that includes a main rotatable shaft (12) a lower grinding plate (14) which includes a series of striations (15) which imparts an abrasive means to grind a pattern line upon aluminium substrate discs (24) which nest in carrier pockets (25) of the carrier plate (22).

[038] The lower plate (14) has an internal bore hole (18) and a peripheral edge (16) which is independent of the main driveable or central shaft (12) and the external rim (20).

[039] Although not shown in the illustrations there is an upper grinding plate which when the machine is in operation would see that both the upper and lower grinding plates which sandwich therein between the carrier plates (22) to which the aluminium substrate discs (24) rest therein carrier pockets (25).

[040] Figure 2a shows the path (26) that the carrier plate moves relative to the lower plate. This is when the main central shaft (12) and the external or annulus ring (20) do not impart any rotation onto the carrier plate (22) and therefore there is no self rotation of the carrier plate (22) as it moves in its defined direction. [041] As the carrier plate (22) does not rotate in its general movement, the Aluminium substrate discs (24) that are located withinside the carrier pockets (25) upon the carrier plate (22) will not rotate as well as one would expect and the resulting grinding line pattern as illustrated in Figure 2b will be parallel (28).

[042] In Figure 3a the path (30) of the carrier movement relative to the lower plate is different to that shown in Figure 2a because in this embodiment the main central shaft (12) and the annulus ring (20) rotates and there is a slight degree of self rotation of the carrier plate (22) due to the fact that there would be some relative degree of internal spinning of the carrier plate as it is free to rotate relative to the main central rotating shaft (12) and the annulus ring (20) albeit from a mechanical or input connection such as the gearing arrangement shown in Figure 4 which is the preferred embodiment of this invention there is no such interaction.

[043] Accordingly as a result of this scenario the Aluminum discs (24) are imparted with a grinding line pattern (31 ) to have a generally or substantial annular or curved parallel configuration.

[044] Figure 4 illustrates the grinding process of this preferred embodiment of the invention shown generally as (32).

[045] The main rotatable central shaft of conventional arrangements has become the sun gear (34) with its outwardly pointing teeth or gears (36).

[046] The annulus or outer ring (50) with its inwardly pointing teeth or gears (52). [047] The carrier plate (46) rests upon the lower grinding plate (38) with outer peripheral edge (40) and inner peripheral edge (42)

[048] The carrier plate (46) with its annular teeth (48) is able to establish a meshed gearing relationship between the annulus ring (50) and the sun gear (34) whereby not only will there be general movement of the carrier plate (46) but there will also be internal self rotation to which the degree of that rotation will be dependent upon the gearing relationship between the sun gear, carrier plate and the annulus or outer ring. 1049] Advantageously as introduced above as there is now mechanical interaction through the planetary gear defined by the meshed teeth arrangement between the sun gear, carrier plate and the annulus or outer ring means that by being able to establish self rotation of the carrier plate with the higher degree of rotation of the carrier plate now established results in an elliptical type cross configuration as shown by the path taken now by the carrier plate (46) which then establishes upon the aluminium substrate disc a cross hatch type grinding line pattern.

[050] As the person skilled in the art will appreciate the aluminium substrate disc (45) nesting inside the carrier plate (46) will have a higher rotation that does conventional arrangements and result in a grinding line pattern to be crisscrossed (56) achieved by the grinding path (54) as best seen upon the disc (45) in Figure 5b.

[051] As the applicant has found by increasing the carrier plate self rotation through the unique gear mechanism they are able to obtain a more uniform surface rather than as compared to existing grinding processes.

[052] During testing the applicant was able to determine that roughness uniformity correlates by referring to the standard deviation value of the disc. The lower the standard deviation the better uniformity.

[053] Using the scenarios introduced above and shown in the illustrations, the grinding process provided in Figure 4 had a lower standard deviation range compared to those scenarios that were illustrated in Figures 2a, 2b, 3a and 3b whereby this invention provided for aluminium substrate discs to have a better roughness uniformity.

Claims

A grinding apparatus for establishing grinding lines on an aluminium substrate disc, said apparatus including; a central rotatable shaft; a rotatable peripheral ring; a pair of circular grinding plates wherein each plate includes a central bore hole positionable about the central rotatable shaft wherein each of the circular grinding plates are free to rotate independently of the other and/or the central rotatable shaft; a plurality of carrier plates adapted to be sandwiched in between the pair of circular grinding plates wherein each carrier plate includes a series of pockets to which aluminium substrate discs are nestable therein such that the upper and lower surfaces of the aluminium discs are in contactable communication with each of the circular grinding plates; wherein the central rotatable shaft, peripheral ring and the plurality of carrier plates include a series of teeth and/or gears along their angular edges so as to establish- an epicyclic gearing so as to increase and create a degree of rotation upon each of the central rotatable shaft, peripheral ring and each of the carrier plates such that the ability to impart rotation upon the carrier plates to which the aluminium discs rest therein results in an elliptical criss-cross grinding line pattern.

2. The grinding apparatus of claim 1 wherein the central rotatable shaft is the central and/or sun gear.

3. The grinding apparatus of claim 2 wherein the peripheral ring is an outer ring with inward facing teeth.

4. The grinding apparatus of claim 3 wherein the central and/or sun gear includes outward facing teeth.

5. The grinding apparatus of claim 4 wherein each carrier plate wherein the aluminium substrate discs rest therein have annular pointing outward facing teeth adapted to mesh with the annulus and/or central/sun gear.

6. The grinding apparatus of claim 5 wherein the apparatus is adjustable such that the pair of grinding plates can be separated wherein an upper grinding plate is raisable relative to the lower grinding plate such that carrier plates wherein the aluminium substrate discs nested therein can be placed there upon the lower grinding plate during times of inoperation of the grinding apparatus.

7. The grinding apparatus of claim 6 wherein the plurality of carrier plates are configured about the lower circular plate such that there is a maximising of contact area between the aluminium substrate discs nested in the carrier plate and each of the respective circular grinding plates to which the carrier plates are sandwiched therein between.

8. The grinding apparatus of claims 6 or 7 wherein the abrasive stresses from the upper and lower grinding plates imparted upon the aluminium substrate discs nesting within the plurality of carrier plates during operation are equal on both sides.

9. The grinding apparatus of claim 1 wherein the apparatus further includes sufficient cooling to minimise the heat generated during the disc grinding process.

10. The grinding apparatus of claim 1 wherein the grinding apparatus includes a main external housing body such that the pair of circular grinding plates are enclosed within the apparatus so that the grinding process is not viewable from the outside of the machine thereby minimising any exposure to dust and airborne metal filings created.

11. A grinding arrangement wherein the grinding apparatus referred to in any one of the preceding claims includes a series of steps wherein individual such apparatus are positioned to establish firstly a rough grind and then a more finer grind.