EP1263544A1 - Appareil et procede d'usinage de composants de frein - Google Patents

Appareil et procede d'usinage de composants de frein

Info

Publication number
EP1263544A1
EP1263544A1 EP00916171A EP00916171A EP1263544A1 EP 1263544 A1 EP1263544 A1 EP 1263544A1 EP 00916171 A EP00916171 A EP 00916171A EP 00916171 A EP00916171 A EP 00916171A EP 1263544 A1 EP1263544 A1 EP 1263544A1
Authority
EP
European Patent Office
Prior art keywords
electrode
electrodes
machining
ring
brake rotor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP00916171A
Other languages
German (de)
English (en)
Inventor
Weston E. Dickerson
Petar Jakovljevic
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hayes Lemmerz International Inc
Original Assignee
Hayes Lemmerz International Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hayes Lemmerz International Inc filed Critical Hayes Lemmerz International Inc
Publication of EP1263544A1 publication Critical patent/EP1263544A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00—Parts or details
    • F16D65/02—Braking members; Mounting thereof
    • F16D65/12—Discs; Drums for disc brakes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H7/00—Processes or apparatus applicable to both electrical discharge machining and electrochemical machining
    • B23H7/12—Rotating-disc electrodes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H9/00—Machining specially adapted for treating particular metal objects or for obtaining special effects or results on metal objects
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H9/00—Machining specially adapted for treating particular metal objects or for obtaining special effects or results on metal objects
    • B23H9/008—Surface roughening or texturing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H9/00—Machining specially adapted for treating particular metal objects or for obtaining special effects or results on metal objects
    • B23H9/04—Treating surfaces of rolls
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2250/00—Manufacturing; Assembly
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2250/00—Manufacturing; Assembly
    • F16D2250/0092—Tools or machines for producing linings

Definitions

  • the present invention relates to rotors for caliper disc brakes and the like, and in particular to an electric discharge machine for producing brake components and a method for making same.
  • Rotors are generally well known in the art, and are used extensively in vehicle braking systems, power transmission devices, clutches, and other similar machinery and mechanisms.
  • Vehicle caliper disc braking systems slow the vehicle by inhibiting the rotation of the vehicle wheels.
  • Rotors used in typical vehicle braking systems include a central hat section for attaching the rotor to a vehicle wheel and drive member for rotation therewith, and an outer friction section having opposite friction surfaces .
  • a caliper assembly is secured to a non-rotating component of the vehicle, such as the vehicle frame.
  • the caliper assembly includes a pair of brake pads disposed adjacent the rotor friction surfaces, and a moveable piston operatively connected to one or more of the brake pads.
  • hydraulic or pneumatic forces move the piston which clamps the pads against the friction surfaces of the rotating rotor.
  • frictional forces are created which oppose the rotation of the wheels and slow the vehicle.
  • the friction converts the vehicle's kinetic energy into large quantities of heat, much of which is absorbed by the friction surfaces and conducted to the rest of the rotor and to other components to which the rotor is connected
  • Brake rotors are typically cast from a ferrous material, such as cast or grey iron, and are then machined in multiple operations to shape the rotor, to form the inner hub portion and friction surfaces.
  • ferrous material rotors are relatively heavy and they corrode during normal use.
  • Brake rotors are also cast from aluminum based metal matrix composite (MMC) containing silicon carbide particulate reinforcement.
  • MMC metal matrix composite
  • Aluminum MMC rotors have sufficient mechanical and thermal properties at a significantly reduced weight compared to ferrous metal rotors.
  • the rotor is cast from aluminum MMC and then machined in a conventional manner to form the finished rotor.
  • the particulate reinforcement in aluminum MMC parts is very hard which makes the aluminum MMC castings difficult to machine.
  • Special cutting tools made from expensive materials such as polycrystalline diamond are needed to machine aluminum MMC, yet the tools still tend to wear quickly which increases production costs.
  • brake components, such as metal rotors made from materials such as cast iron or aluminum MMC using an apparatus and technique which will reduce production costs while improving the tolerances of the parts.
  • EDM Electric discharge machining
  • the electric sparks are directed against the surface to be machined. A high temperature is reached where the spark contacts the metal surface. The high temperature vaporizes the metal at that location. A series of sparks are directed at the surface to burn away a portion of the metal resulting in a finish machined part.
  • EDM offers advantages over conventional machining in that the EDM apparatus does not physically contact the part thereby improving the tolerances of the finished part.
  • known EDM apparatus and machining techniques are slow, typically producing only about 5,000 sparks per second. The number of sparks produced per unit time in part determines how quickly the part can be machined. Conventional EDM apparatus are too slow to be cost effective for use in mass production. It is desirable to provide an apparatus and a method for machining metal brake components such as cast iron or aluminum MMC rotors using electrically discharged sparks which is quick and cost effective.
  • the apparatus includes an electrode ring adapted to be secured to a rotatable shaft.
  • the electrode ring includes a plurality of circumferentially spaced apart first electrodes adapted to be electrically connected to a first power supply, and a plurality of circumferentially spaced apart second electrodes adapted to be electrically connected to a second power supply.
  • the first and second electrodes are arranged adjacent each other in an alternating fashion around the circumference of the electrode ring so that the electrodes from the first group are not adjacent electrodes from the same group.
  • the apparatus further includes a positioning mechanism for positioning a rotating, electrically grounded brake rotor or other brake component adjacent the electrode ring until sparks are formed between the electrode ring and the rotor.
  • the sparks vaporize a portion of the rotor surface thereby creating a finished surface on the rotor having the desired dimensions.
  • the apparatus includes only one plurality of circumferentially spaced apart electrodes adapted to be electrically connected to a power supply.
  • the apparatus includes just one power supply.
  • the power supply is connected to the plurality of circumferentially spaced apart electrodes.
  • the apparatus is the same as earlier described.
  • the invention also includes a method of finish machining a brake rotor with the EDG apparatus.
  • the brake rotor is cast to produce a brake rotor casting having a radially inner hub portion with generally axially extending hat wall, a radially outer annular friction section having a radially inner edge, and an annular groove disposed adjacent the hat wall at the radially inner edge of the friction section.
  • the rotor casting is then mounted on the component mount thereby electrically connecting it to ground and rotated.
  • the electrode ring is also rotated while submerged in the dielectric oil.
  • the first electrodes are electrically connected to a first power supply and the second electrodes are electrically connected to a second power supply.
  • the rotating rotor is then at least partially submerged in the dielectric oil and moved close to the electrode ring such that sparks form between the discharge surfaces of said first and second electrodes and said rotor which vaporize a portion of the surface of said rotor.
  • the rotor and electrode ring are rotated while the sparks are generated between them until a sufficient amount of material is removed to achieve a rotor with a finished friction section having the desired dimensions.
  • the opposite friction surface may be finish machined in a variety of different ways, including using a second electrode ring adjacent that side and simultaneously finishing both sides, moving the electrode ring to the opposite side and finishing it in a similar manner as the first side described above, or by turning the rotor over on the component mount and repeating the previously described steps.
  • the previously cited alternate embodiment operates similarly to the embodiment cited above.
  • the main difference is that the alternate embodiment does not require that the second electrodes are electrically connected to the second power supply. This for the reason, that these two elements are not required to practice the alternate embodiment. Therefore the steps to manipulate these elements are not required.
  • FIG. 1 is an elevational section view of a rotor casting to be machined in accordance with the present
  • Fig. 2 is an elevational view of a portion of an electrical discharge machining apparatus in accordance with the present invention
  • Fig. 3 is a elevational sectional view of a portion of the electrical discharge machining apparatus in accordance with the present invention.
  • Fig. 4 is an elevational view of a portion of the electrical discharge machining apparatus in accordance with the present invention.
  • Fig. 5 is a perspective view of a portion of the electrode disks for use in the electrical discharge machining apparatus in accordance with the present invention
  • Fig. 6 is an elevational view of the electrode ring for use in the electrical discharge machining apparatus in accordance with the present invention.
  • Fig. 7 is a side elevational view of the electrode ring for use in the electrical discharge machining apparatus in accordance with the present invention.
  • Fig. 8 is a elevational sectional view of a portion of the electrode ring disposed adjacent the rotor during operation of electrical discharge machining apparatus in accordance with the present invention.
  • Fig. 9 is an elevational view of an alternate embodiment of the electrode ring for use in the electrical discharge machining apparatus in accordance with the present invention.
  • a rotor casting 10 is illustrated.
  • the rotor casting 10 is preferably formed by casting aluminum MMC in a conventional manner to produce the casting having physical dimensions which are close to the desired final dimensions.
  • the rotor casting may be formed from other suitable materials such as iron, including grey iron or cast iron.
  • the rotor casting 10 is then finished machined using an Electric Discharge Machining (EDM) apparatus, also referred to as an Electric Discharge Grinding (EDG) apparatus described below in a machining method described below to achieve the finished part having the desired dimensions.
  • EDM Electric Discharge Machining
  • EDG Electric Discharge Grinding
  • the rotor casting 10 includes a radially inner hub portion 12 having a central, generally circular mounting section 14 which mounts the same on an associated drive member (not shown) , such as a spindle or vehicle axle.
  • the rotor axis of rotation X typically extends through the middle of the mounting section 14.
  • a hat wall 16 extends generally axially from the periphery of the mounting section 14.
  • the hat wall 16 is preferably straight and cylindrical extending at a right angle from the mounting section 14, however, the hat wall may be inclined, forming a portion of a cone, or portions of it may be curved.
  • the central mounting section 14 has a central pilot aperture 18 cast therein, in which the drive member is closely received.
  • Fastener apertures 20 may be cast into the central mounting section 14 for receiving fasteners to secure the rotor to the drive member. Alternatively, the fastener apertures 20 may be machined into the rotor casting 10 using conventional machining techniques.
  • the rotor 10 also includes a radially outer annular friction section 22 having opposite friction surfaces 24 which interface with associated friction members (not shown) , such as brake pads or the like.
  • the friction surfaces 24 are coaxially disposed about the rotor axis of rotation X.
  • the annular friction section 22 of the rotor 10 has a radially inner edge 26 and a radially outer edge
  • the EDG apparatus 36 includes an electrode assembly 38 submerged in a tank 40 containing a dielectric oil 42 which is known in the art.
  • the EDG apparatus 36 further includes a positioning mechanism 44 for positioning the rotor 10 a predetermined distance from the electrode assembly 38 and providing a path to ground for the spark (not shown) .
  • the positioning mechanism 44 includes a component mount 46 having shaft 48 for receiving the rotor 10.
  • the component mount 46 is electrically connected to ground, the same ground to which the power supplies are also connected. When the rotor 10 is mounted to the component mount 46 it is also connected to ground.
  • a motor 53 is drivingly coupled to a pulley 50 mounted to the shaft 48 for rotating the shaft and the rotor 10. The motor 53 and shaft 48 rotate the rotor about the rotor axis X.
  • the positioning mechanism 44 also includes a dual axis positioning guide 51 having a vertical guide 52 and horizontal guide 54.
  • a positioning driver 56 moves the component mount 46 along the vertical and horizontal guides 52, 54 into the desired position adjacent the electrode assembly 38.
  • a spark sensor 58 senses for sparks between the electrode assembly 38 and the rotor 10, and communicates with the positioning driver. When the spark sensor 58 indicates to the positioning driver 56 that sufficient sparks exist, the rotor has obtained the proper position relative to the electrode assembly for machining and the positioning driver 56 stops the positioning movement of the rotor. Throughout the machining process, the spark sensor 58 continually communicates with the positioning driver 56. The positioning driver 56 uses the spark sensor information for making adjustments in the position of the rotor 10 to achieve the most sparks possible thus maximizing the machining efficiency of the EDG apparatus. Referring now to Fig. 3, the electrode assembly 38 is illustrated in detail.
  • the electrode assembly 38 includes a shaft 60 mounted for rotation in bearings 62 which are supported by the body 64 of the electrode assembly.
  • the shaft 60 is preferably constructed of steel or some other electrically conductive material.
  • An electric motor 68 is drivingly coupled to the shaft 60 for rotating the shaft and the rotor 10.
  • the shaft 60 preferably includes two similar halves 60a and 60b. Each halve of the shaft is similar in construction and function, and to avoid duplication, only one of the shaft halves 60a shall be described in detail.
  • a pair of electrode disk assemblies 70 which shall be described in detail below, are mounted to the opposite ends of each half of the shaft 60a and 60b.
  • An electrically conductive first ring 72 is mounted to the shaft 60a for rotation therewith. The first ring 72 encircles the shaft and is electrically connected thereto.
  • the first ring 72 is preferably constructed of copper, but may be made of any suitable electrically conductive material.
  • a first brush 74 abuts the first ring 72.
  • the first brush 74 is electrically conductive and known in the art.
  • the first brush 74 is connected to a voltage terminal of a first power
  • a second ring 76 encircles the shaft 60a, but is electrically insulated from the shaft by an annular insulator 78 disposed between the shaft and the second ring.
  • the second ring 76 is preferably constructed of copper, but may be made of any suitable electrically conductive material.
  • a second brush 80 abuts the second ring 76.
  • the second brush 80 is electrically conductive and known in the art.
  • the second brush 80 is connected to a voltage terminal of a second power supply 81.
  • a wire 82 is electrically connected to the second ring 76.
  • the wire 82 extends through a bore 84 formed through the middle of the shaft 60a extending from the second ring 76 to the opposite end of the shaft.
  • the wire 82 exits the bore 84 and is electrically connected to a portion of the electrode assembly 70 as described in detail below.
  • the electrode disk assembly 70 includes a first electrode disk 86 and a second electrode disk 88.
  • the first electrode disk 86 includes a central mounting hub 90 for mounting the disk to the shaft 60a.
  • the first electrode disk 86 further includes a plurality of circumferentially spaced apart electrode pads 92 extending from the radially outer periphery of the disk.
  • the electrode pads 92 are regularly spaced around the entire circumference of the first electrode disk 86.
  • the electrode pads 92 are preferably rectangular, extending along the axis of the first disk 86.
  • the second electrode disk 88 also includes a plurality of circumferentially spaced apart electrode pads 94 extending from the radially outer periphery of the second disk.
  • the second electrode pads 94 are regularly spaced around the entire circumference of the second electrode disk 88.
  • the first and second electrode disks 86 and 88, and the first and second electrode pads 92, and 94 are preferably constructed from steel , although any suitable electrically conductive material may be used.
  • the electrode pads 92, 94 may be formed integrally with the respective electrode disk 86, 88, or they may be secured thereto.
  • the first and second electrode disks 86 and 88 are mechanically secured together in a coaxial relationship such that the first and second electrode pads 92 and 94 are disposed adjacent each other in an alternating configuration forming an electrode pad ring 95.
  • the disks 86 and 88 are electrically insulated from each other by insulators (not shown) disposed between the disks.
  • the first electrode pads 92 are circumferentially spaced apart from the adjacent second electrode pads 94.
  • the shaft 60a is received in the central mounting hub 90 of the first disk 86 to secure the first and second disks 86, 88 to the shaft for rotation therewith.
  • Individual first electrodes 96 are mounted to each first electrode pad 92 by screws 98 extending through apertures 100 in the pads 92.
  • first electrodes are mounted to the first electrode disk 86, although any suitable number may be used.
  • Individual second electrodes 102 are mounted to each second electrode pad 94 by similar screws 98 extending through apertures 100 in the pads 94.
  • Approximately 18 second electrodes are mounted to the second electrode disk 86, although any suitable number may be used.
  • the first and second electrodes 96 and 102 are preferably constructed from graphite or copper, although any known suitable electrode material may be used.
  • the electrodes 96 and 102 are disposed along the ring of electrode pads 95 to form an electrode ring 103 consisting of alternating first and second electrodes 96 and 102.
  • the first and second electrodes 96 and 102 have respective flat discharge surfaces 96a and 102a.
  • the discharge surfaces 96a and 102a are circumferentially spaced apart around the electrode ring 103 such that each discharge surface forms a separate sector of the electrode ring. That is, each of these separate sectors is occupied by only a single electrode discharge surface.
  • the first electrodes 96 are electrically connected together.
  • a first electrical connection is formed from the voltage terminal of the first power supply 75, through the first brush 74, through the first ring 72, through the shaft 60a, through the first electrode disk 86, through the first electrode pads 92 to the first electrodes 96.
  • the first electrodes 96 are electrically insulated from the second electrodes 102.
  • the second electrodes are electrically insulated from the first electrodes 102.
  • the wire 82 is electrically connected to the second electrode disk 88 via a terminal 104 disposed on the disk.
  • a second electrical connection is formed from the voltage terminal of the second power supply 81, through the second brush 80, through the second ring 76, through the wire 82, through the second electrode disk 88, through the second electrode pads 94 to the second electrodes 102.
  • the first and second electrodes 96 and 102 are arranged in the electrode ring 103 such that the discharge surfaces 96a and 102a define a plane 105.
  • the electrode ring 103 has a radially outer cylindrical surface 103a and a radially outer edge 103b formed by the intersection of the cylindrical surface 103a with the discharge surfaces 96a, 102a of the first and second electrodes 96, 102.
  • the electrode assembly 38 includes a second half 60b of the shaft 60, which includes a second electrode disk assembly similar to the one described above, having a second electrode ring similar to the one described above.
  • the EDG apparatus includes a second positioning mechanism similar to the one described above.
  • the EDG apparatus can therefore, finish machine two rotors or other brake components simultaneously.
  • the electrode assembly 38 is submerged in the dielectric oil 42 as described above.
  • the voltage terminals of the first and second power supplies 75, and 81 are connected to the first and second brushes 74 and 80 respectively.
  • the shaft 60a and electrode disk assembly 70 are then rotated by the motor 68.
  • the rotor 10 is mounted on the component mount shaft 48 of the positioning mechanism 44, and rotated about the axis of rotation X by the motor 53.
  • the rotor and electrode assembly preferably rotate in opposite directions as shown at 110.
  • the positioning driver 56 moves the rotor 10 along the vertical and horizontal guides until a portion of the rotor including part of the friction surfaces is partially submerged.
  • the positioning driver 56 continues to move the rotor 10 until it is adjacent the electrode disk assembly 70 so that only a small gap exists between the first and second electrode discharge surfaces 96a, 102a and the rotor friction surface 24.
  • the gap shrinks to a predetermined distance, preferably 1/1000 to 3/1000 of an inch, the dielectric 42 no longer provides sufficient resistance, and a first spark 107 is created between one of the first electrode discharge surfaces 96a and the nearest point on the rotor friction surface 24.
  • a second spark 109 is created between one of the second electrode discharge surfaces 102a and the nearest point on the rotor friction surface 24.
  • the electrode disk assembly 70 rotates, the next pair of first and second electrode discharge surfaces 96a, 102a pass near the rotor friction surface 24 creating two more sparks, while the previous pair of first and second electrode discharge surfaces begin to move away from the rotor friction surface thereby preventing sparks from these electrodes.
  • a different set of first and second electrode discharge surfaces pass near the friction surface creating sparks, while the discharge surfaces just previously emitting the sparks are moved away from the friction surface.
  • the sparks are discharged from the first and second groups of discharge surfaces as one electrode from each group is sequentially moved near enough to the friction surface, while other electrodes from the groups are moved away from the friction surface.
  • Each spark creates a very high temperature of approximately 10,000 to 12,000 degrees Celsius at the friction surface 24 of the rotor 10.
  • the high temperatures vaporize a portion of the metal of the friction surface 24.
  • the rotor is rotated about the axis of rotation so that the sparks strike different portions of the friction surface until the entire surface is finished to the desired dimensions.
  • the opposite friction surface may be finish machined in a variety of different ways, including using a second electrode ring adjacent that side and simultaneously finishing both sides, moving the electrode ring to the opposite side and finishing it in a similar manner as the first side described above, or by turning the rotor 10 over on the component mount 46 and repeating the previously described steps.
  • the EDG apparatus is described finish machining the friction surfaces of a rotor, other surfaces of the rotor may finish machined in a similar manner. Also, other brake components may be finish machined in a similar manner by the EDG apparatus.
  • the EDG apparatus produces two sparks at a time between the electrode ring 103 and the rotor 10, resulting in twice as many sparks per unit of time as known EDM apparatus using only one group of electrodes. The EDG apparatus can thus finish machine a part more quickly than previously known EDM apparatus.
  • the EDG apparatus may use 3 or more groups of electrodes connected to 3 or more respective power supplies to achieve even more sparks per unit time.
  • the electrodes within each group are electrically connected together, and each group is electrically insulated from the other groups.
  • the electrodes of any single group are preferably disposed so as not to be adjacent each other, but rather adjacent electrodes from the other groups.
  • the friction section 24 of the rotor 10 is illustrated adjacent a portion of the electrode ring 103 comprising electrode 96 as described above.
  • the rotor 10 is preferably aligned with respect to the electrode ring 103 such that the radially outer edge 103b of the ring 103 is positioned adjacent the groove 30 thereby increasing the distance between the electrodes 96, 102 and the rotor 10 at the outer edge 103b.
  • the increased distance prevents arcing between the radially outer edge 103a and the rotor friction surface 24 which causes premature wear at the edges of the electrodes 96, 102.
  • the brake rotor is cast to produce a brake rotor casting having a radially inner hub portion with generally axially extending hat wall, a radially outer annular friction section having a radially inner edge, and an annular groove disposed adjacent the hat wall at the radially inner edge of the friction section.
  • the rotor casting is then mounted on the component mount 46 thereby electrically connecting it to ground and rotated.
  • the electrode ring 103 is also rotated while submerged in the dielectric oil 42.
  • the first electrodes are electrically connected to a first power supply and the second electrodes are electrically connected to a second power supply.
  • the rotating rotor is then at least partially submerged in the dielectric oil and moved close to the electrode ring such that sparks form between the discharge surfaces of said first and second electrodes and said rotor which vaporize a portion of the surface of said rotor.
  • the rotor 10 and electrode ring 103 are continued being rotated while separated by the predetermined distance until a sufficient amount of material is removed to achieve a rotor with a finished friction section having the desired dimensions.
  • the opposite friction surface may be finish machined in a variety of different ways, including using a second electrode ring adjacent that side and simultaneously finishing both sides, moving the electrode ring to the opposite side and finishing it in a similar manner as the first side described above, or by turning the rotor 10 over on the component mount 46 and repeating the previously described steps.
  • the method described is for finish machining the friction surfaces of a rotor, other surfaces of the rotor may finish machined in a similar manner.
  • other brake components may be finish machined in a similar manner.
  • the method described above may also include aligning the rotor with respect to the electrode ring 103 such that the radially outer edge 103b of the ring 103 is positioned adjacent the groove 30 thereby increasing the distance between the electrodes 96, 102 and the rotor 10 at the outer edge 103b.
  • the increased distance prevents arcing between the radially outer edge 103a and the rotor friction surface 24 which causes premature wear at the edges of the electrodes 96, 102.
  • the opposite friction surface 24 is machined, the radially outer edge 103b of the ring 103 is positioned radially inwardly from the radially inner edge 26 of the friction section 26 for similar reasons.
  • FIG. 9 An alternative embodiment of the EDG apparatus 36 is shown in Fig. 9, illustrated generally at 136.
  • the EDG apparatus 136 finishes a rotor in a similar manner as the EDG apparatus 36 described above.
  • the EDG apparatus 136 includes mostly the same elements as previously described regarding the EDG apparatus 36.
  • the main difference is that the electrode disk assembly 70 includes only one electrode disk 186 (as shown in Fig. 9).
  • the alternate embodiment electrode disk 186 is attached to the apparatus 38 in the same manner as the first electrode disk 86.
  • the alternate embodiment electrode disk 186 also includes a plurality of circumferentially spaced apart electrode pads 192, regularly spaced around the entire circumference of the electrode disk 186.
  • the electrode pads 192 are similar to the electrode pads 92. This embodiment does not include a second electrode disk.
  • the apparatus includes a plurality of individual electrodes 196.
  • Each electrode 196 is attached to an electrode pad 192 in the same manner as the each first electrode 96 is attached to each first electrode pad 92.
  • Each individual electrode 196 is constructed from the same material as each individual electrode 96.
  • the alternate embodiment does not include a plurality of individual second electrodes.
  • the EDG apparatus 136 also includes an electrode ring 203.
  • the electrode ring 203 is similar to the electrode ring 103, except the electrode ring 203 consists of electrodes 196 that are all connected to the same power supply.
  • the electrode ring 103 consisted of first and second electrodes 96, 102 which were connected to the first and second power supplies 75, 81 respectively. Due to the fact that all of the electrodes 196 that make up electrode ring 203 are electrically connected to the same power supply, the EDG apparatus 136 will produce only one spark at a time to machine rotor 10. In all other respects, electrode ring 203 is analogous to electrode ring 103.
  • the invention is practiced with only the first power supply as the sole power supply.
  • the alternate embodiment does not include a second power supply and its associated components.
  • This power supply in the alternate embodiment, is electrically attached to each electrode 196 in the same manner as each electrode 96 is attached to the first power supply 75.
  • the power supply of the alternate embodiment operates in the same manner as the first power supply 75.
  • the EDG apparatus 136 operates in a alike manner as the EDG apparatus 36, previously discussed.
  • the changes in the operation of the alternate embodiment mostly result from the lack of the second power supply 81.
  • the electrode assembly 38 is submerged in the dielectric oil 42 as previously stated.
  • the operation of the EDG apparatus 136 proceeds in a similar manner except that there is no connection of the voltage terminals of the second power supply 81 to the brush 80.
  • the alternate embodiment does not include a second spark 109.
  • the spark only occurs between the electrode 196 and the point on the friction surface 24 of the rotor 10 nearest the electrode 196.
  • this embodiment uses only one spark at a time to finish the rotor.
  • the method associated with this alternate embodiment is analogous to the method of the apparatus as previously described. The significant differences are the lack of the steps regarding the second power supply 81 and the finishing of the rotor 10 with the second spark 109. In all other respects, the method of the invention is the same.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
  • Turning (AREA)

Abstract

La présente invention concerne un appareil et un procédé améliorés d'usinage de finition de composants de frein. Cet appareil comprend un anneau d'électrode, qui est conçu pour être fixé à un arbre rotatif. Cet anneau d'électrode comprend au moins un ensemble d'électrodes, qui sont séparées les unes des autres de manière circonférentielle et sont conçues pour être électriquement connectées à une alimentation en énergie. Les ensembles d'électrodes sont placés de manière adjacente les uns aux autres, autour de la circonférence de l'anneau d'électrode. Cet appareil comprend également un mécanisme de positionnement qui permet de positionner un rotor rotatif, électriquement mis à la terre, de manière adjacente à l'anneau d'électrode, jusqu'à ce que des étincelles soient formées entre l'anneau d'électrode et le rotor. Ces étincelles vaporisent une partie de la surface du rotor, ce qui crée une surface finie sur le rotor, qui présente les dimensions souhaitées.
EP00916171A 2000-03-09 2000-03-09 Appareil et procede d'usinage de composants de frein Withdrawn EP1263544A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2000/006083 WO2001066294A1 (fr) 2000-03-09 2000-03-09 Appareil et procede d'usinage de composants de frein

Publications (1)

Publication Number Publication Date
EP1263544A1 true EP1263544A1 (fr) 2002-12-11

Family

ID=21741130

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00916171A Withdrawn EP1263544A1 (fr) 2000-03-09 2000-03-09 Appareil et procede d'usinage de composants de frein

Country Status (6)

Country Link
EP (1) EP1263544A1 (fr)
CN (1) CN1452532A (fr)
AU (1) AU2000237318A1 (fr)
CA (1) CA2401314A1 (fr)
MX (1) MXPA02008677A (fr)
WO (1) WO2001066294A1 (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2286106B1 (fr) 2008-05-08 2017-09-27 Rassini Frenos, S.A. De C.V. Disque de frein composite
US8183491B2 (en) * 2009-05-26 2012-05-22 General Electric Company Electric discharge machining device using rotating circular blade
CN111299728B (zh) * 2020-03-27 2021-02-02 常州工学院 一种球面斜槽数控电解加工用阴极工具

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2719902A (en) * 1953-07-22 1955-10-04 Gen Motors Corp Multi-element electrode
CH349717A (de) * 1957-03-18 1960-10-31 Agie Ag Ind Elektronik Elektroerosives Schleifverfahren und Einrichtung zu seiner Durchführung
US4341840A (en) * 1981-03-13 1982-07-27 United Technologies Corporation Composite bearings, seals and brakes

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0166294A1 *

Also Published As

Publication number Publication date
WO2001066294A1 (fr) 2001-09-13
CN1452532A (zh) 2003-10-29
MXPA02008677A (es) 2003-02-24
CA2401314A1 (fr) 2001-09-13
AU2000237318A1 (en) 2001-09-17

Similar Documents

Publication Publication Date Title
EP0945639B1 (fr) Procédé de fabriquer un frein à disque
US6296549B1 (en) Apparatus and method of machining brake components
US20040178030A1 (en) Disk-brake disk with air cooling
CA2389738A1 (fr) Disque de frein a disque amorti
WO1995002130A1 (fr) Rotor de frein a disque
US6279697B1 (en) Brake rotor with non-directional braking surface
US20080131621A1 (en) Method for fusing hard ceramic-metallic layer on a brake rotor
EP0666407B1 (fr) Ensemble rotor-aube monobloc
WO1999010125A1 (fr) Procede de fabrication d'un rotor a ventilation transversale
EP1263544A1 (fr) Appareil et procede d'usinage de composants de frein
US20040178026A1 (en) Automotive disc brake
US5353553A (en) Method and apparatus for treating brake rotors
ZA200206904B (en) Apparatus and method of machining brake components.
US4804071A (en) Carbon brake disc grooves preventing cycloidal vibration
US9120195B2 (en) Wheel assembly and method for making same
US5915747A (en) Method of making a rotor with vented hat section and an initial casting
JPS6327454B2 (fr)
EP0803315B1 (fr) Moyeu en fer ductile pour véhicule et son procédé de fabrication
EP1681137B1 (fr) Dispositif de meulage, son utilisation pour meuler des objets cylindriques, machine et procédé pour meuler des objets cylindriques
WO1999053213A1 (fr) Formage a froid de rotors a matrice metallique en aluminium
KR100361547B1 (ko) 디스크 타입 브레이크용 경량 디스크
CN107659116A (zh) 极大负荷可调磁力缓速器
EP3983694A1 (fr) Procédé de fabrication d'un disque de frein à disque
CN215786998U (zh) 一种叶盘加工用高速铣刀
US2881507A (en) Milling cutters

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20020913

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Effective date: 20040524