US 3751346 A
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Description (OCR text may contain errors)
Aug. 7, 1973 ET AL 3,751,346
COMBINED PLATING AND HONING METHOD AND APPARATUS Filed Aug. 16, 1971 a. M ,7} E
United States Patent O 3,751,346 COMBINED PLATING AND HONING METHOD AND APPARATUS Myron P. Ellis, Royal Oak, and Richard J. Gavasso,
Detroit, Mich, assignors to Micromatic Industries, Inc, Detroit, Mich.
Filed Aug. 16, 1971, Ser. No. 172,120
Int. Cl. B23p 1/00, 1/02; C23b 5/56 U.S. Cl. 20426 6 Claims ABSTRACT OF THE DISCLOSURE BRIEF SUMMARY OF THE INVENTION This invention relates to the plating and honing arts and, more particularly, to an improved combined plating and honing method and apparatus effective to plate a surface of a workpiece and simultaneously and/or sequentially mechanically hone such surface so as to provide an improved plated and honed workpiece having an improved surface finish.
Heretofore, various methods and apparatus have been utilized for the purpose of plating and simultaneously honing the surface of a workpiece. For example, various methods and apparatus have been provided for simultaneously burnishing and plating a surface of a workpiece while the workpiece is immersed in a plating solution and the workpiece is functioning as an electrical cathode while the honing tool is functioning as an electrical anode. For example, such methods and apparatus of the indicated character are disclosed in the U.S. applications of Myron P. Ellis and Richard J. Gavasso Ser. No. 838,113 filed July 1, 1969 now Pat. No. 3,616,289, and Ser. No. 864,086 filed Oct. 6, 1969 now Pat. No. 3,637,469, and both entitled Electroplate Honing Method.
An object of the present invention is to overcome disadvantages in prior plating and honing methods and apparatus of the indicated character and to provide an improved combined plating and honing method and apparatus utilizing a rotatable sleeve type anode, positionable in very close proximity to the workpiece surface, and a plurality of honing stones mounted for coaxial rotation with and reciprocation relative to the sleeve type anode, the anode being rotatable relative to the workpiece surface to effect the plating thereof, and the honing stones being movable into engagement with the plated surface to simultaneously mechanically hone such surface during the plating operation, the workpiece surface being exposed to a pressurized conventional plating solution during the plating and honing operation.
Another object of the invention is to provide an improved plating and honing method and improved plating and honing apparatus that are economical and commercially feasible to practice and manufacture, durable, eiiicient and reliable in operation.
In accordance with the present invention, an improved honing method and improved apparatus are provided, the improved method utilizing the improved apparatus which includes a honing tool that is mounted for coaxial rotation with and reciprocation relative to a sleeve type anode, the honing tool carrying a plurality of honing stones projectable beyond the periphery of the sleeve type anode and into engagement with the workpiece surface. The sleeve type anode is disposed in very close but spaced relationship with respect to the surface of the workpiece and in such manner that the sleeve acts as an electrical anode and the workpiece as an electrical cathode, and during high current density electroplating, an electrolyte is circulated between the sleeve and the workpiece whereby metal is deposited on the surface of the workpiece. The sleeve type anode is normally held in an axially fixed position relative to the work surface and rotated during the plating operation while the honing tool is rotated coaxially with the sleeve type anode and simultaneously reciprocated during the plating operation 50 as to provide an improved plated and honed surface having surface characteristics superior to those heretofore obtainable. The improved honing method and apparatus may also be utilized to electroplate and simultaneously hone a semiblind or stepped bore as well as a straight cylindrical bore.
The above as well as other objects and advantages of the present invention will become apparent from the following description, the appended claims and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic, elevational view, with portions in cross-section, of a combined honing and plating machine embodying the present invention;
FIG. 2 is a cross-sectional view of the structure illustrated in FIG. 1, taken on the line 22 thereof; and
FIG. 3 is a fragmentary, enlarged elevational view of a portion of the structure illustrated in FIG. 1.
DETAILED DESCRIPTION Referring to the drawings, the present invention is illustrated embodied in apparatus for honing and plating stepped or semi-blind end and straight cylindrical bores of a workpiece although it will be understood that the present invention is applicable to other uses. FIG. 1 illustrates a honing machine, generally designated 10, having a reciprocating quill 12 to which a honing and plating tool, generally designated 14, is drivably connected for reciprocation with the quill 12 and rotation relative to the quill 12. A work holding fixture 16 is provided which is mounted beneath the tool 14 as illustrated in FIG. 1 and supports a workpiece 18 in axial alignment with the tool 14.
Details of an electrochemical honing machine of a type in which the present invention may be incorporated are more fully disclosed in U.S. Pat. No. 3,390,068 issued to M. P. Ellis et al. on June 25, 1968. It will be understood that a wide variety of honing tools may be mounted to the reciprocating quill 12 for both reciprocating and rotational movement in any manner well known in the art.
As shown in FIG. 1, the honing and plating tool 14 is positioned relative to the workpiece 18 for combined plating and honing, the workpiece 18 being disposed in a fixed position relative to the fixture 16 forming a part of the machine 10. The illustrated workpiece 18 has a stepped bore 20 in which the lower portion of the bore is partially closed, as at 22. Such a bore may be described generally as a modified blind bore but it will be understood that the present invention may also be utilized with straight cylindrical bores.
The combined honing and plating tool 14 comprises a tool support 24 which includes a plurality of honing stones 26, four of such stones 26 being illustrated although any desired number of such honing stones may be utilized. The stones 26 are mounted relative to the tool support 24 so that they may be adjusted radially outwardly or inwardly relative to the axis of rotation of the tool support in any manner well known in the art whereby the stones may be moved toward and away from the bore surface which is to be plated and honed. One means for moving the honing stones 26 and for supporting them on the tool support 24 is more fully disclosed in the aforementioned Ellis patent and in US. Pat. No. Re. 26,499 issued to J. H. Greening on Dec. 3, 1968. It will be understood that any other suitable means may be employed to support and move the honing stones.
In the embodiment of the invention illustrated, the tool support 24 includes an integral flange 25 which is secured to the quill 12 by a retaining ring 27 whereby the tool support reciprocates with the quill 12, and the tool support 24 is supported for rotation within the quill 12 by hearings such as 29.
Surrounding the honing tool support 24 is a sleeve member 30 which is also adapted to project into the bore 28. The sleeve 30 is provided with longitudinally extending slots 32 adapted to receive the honing stones 26 so that upon radial adjustment, the stones may protrude through the slots 32 and into engagement with the bore surface 28 with any desired surface pressure or they may be retracted out of engagement with the surface 28. The inside diameter of the sleeve member 30 'alfords sufficient clearance between the sleeve and the honing tool support 24 to permit reciprocation or relative movement of the tool support relative to the sleeve member 30. The outside diameter of the sleeve member is of a selected size to afford a small clearance with the wall surface 28 of the bore 20 in the workpiece 18.
As schematically shown in FIG. 1, the quill 12 is adapted to be reciprocated by a conventional piston and cylinder unit 34 mounted on the machine while the sleeve member 30 is adapted to be releasably clamped to the quill 12 through the agency of conventional piston and cylinder units 36 and 38 for selective reciprocation with the tool support 24. The pistons of the piston and cylinder units 36 and 38 are connected to a flange 39 provided on a bearing collar 40 which supports the sleeve 30 while the cylinders of the piston and cylinder units 36 and 38 are connected to the opposite ends of an outwardly projecting arm 37 fixed to the quill 12. A rotatable drive mechanism, generally designated 41, is also provided for simultaneously rotating the tool support 24 and the sleeve 30. The rotatable drive mechanism 41 is comprised of a driving cage 42 which may be rotated about the axis of the quill 12 by any suitable rotating driving mechanism such 'as a splined gear drive (not shown). The cage 42 includes angularly spaced, vertically extending driving members, such as 44 and 46, the lower end portions of which are fixed to an integral flange 48 provided on the sleeve 30, as by bolts 50, while the upper end portions of the driving members 44 and 46 are driven by the aforementioned driving mechanism. The driving members 44 and 46 define longitudinally extending slots 52 and 54, respectively, in which are mounted rollers, such as 56 and 58, the rollers 56 and 58 in turn being fixed to the tool support 24. With such a construction, rotation of the drive members 44 and 46 imparts simultaneous rotation to both the tool support 24 and the sleeve 30, the sleeve 30 being supported for rotation by bearings 60 and 62 carried by the bearing collar 40. In addition, the tool support 24 is permitted to be reciprocated independently of the sleeve 30 through the agency of the piston and cylinder unit 34 and the sleeve 30 is permitted to be reciprocated with the tool support 24 by actuating the piston and cylinder units 36 and 38 so that the arm 37, the flange 48 of the sleeve 30 and the bearing collar 40 are clamped together for reciprocation with the quill 12. Thus, such a construction either permits the rotating tool support 24 to move vertically relative to the simultaneously rotating but longitudinally stationary sleeve 30 within the range afforded by the length of the slots 32, or both the tool support 24 and sleeve 30 may be simultaneously reciprocated.
The lower end of the collar 40 is insulated from the fixture 16 by an insulator 64 made of any suitable electrically non-conductive material, the insulator 64 remaining stationary relative to the fixture 16 while permitting rotational and reciprocable movement of the sleeve member 30.
As is well known, it is necessary during plating to pro- 10 vide an electrolyte or plating solution in the area between the tool and the work surface to be plated. As shown in FIG. 1, the flow path or circuit by which plating solution may be circulated, includes a reservoir 66 of electrolytic solution which is pumped by means of a pump 68 through a conduit 70 to a port 72 in the fixture 16 and thereafter through passage 74 into the lower end 76 at the semi-blind bore 20. The plating solution is free to flow through the enlarged radial bore portion 77 and through the annular space formed by the outer diameter of the sleeve member 30 and the bore surface 28 of the workpiece to a passageway 78 provided at the upper end of the fixure 16. The plating solution flows from the passageway 78 through a conduit 80 which returns the plating solution to the reservoir 66. In order to prevent reverse flow through the system, a check valve 82 is provided in the conduit 70 and a pressure gauge 84 may be provided if desired.
in order to seal the plating solution within the system,
a seal 86 is provided at the upper end of the fixture 16 for engagement with the outside diameter of the rotating sleeve member 30. Another seal 88 is provided which is located between the inner diameter of the sleeve member and the outer diameter of the tool support 24. A
static seal 90 is also provided between the stationary fixture 16 and the upper surface of the workpiece 18 while the lower portion of the workpiece is sealed relative to the supporting fixture by means of the seal 92. V The plating solution acts to form an electrically conductive path between the electrically conductive sleeve member 30 and the electrically conductive workpiece 18. As shown in FIG. 1, a power supply 94 of direct current is provided adjacent the honing machine 10 and is provided with positive and negative output terminals 96 and 98. The power supply unit functions to supply direct electric current of a selected magnitude to the work environment. The positive output terminal 96 is connected by a conductor 100 to a brush take-otf unit 102 by means of which the electric current may be transmitted between the power source and the sleeve member 30 during rotation of the latter. From the sleeve member, the current flows through the electrolyte to the workpiece 18 which is of electrically conductive material. A conductor 104 between the workpiece and the negative terminal of the power supply unit completes the electrical circuit.
Thus far the invention has been described in connection with operations on a workpiece with a modified blind bore. It will be understood, however, that the invention may be employed to hone and plate an open ended or straight cylindrical bore in a workpiece. In this instance, the fixture may be provided with an enlarged inlet passageway to eliminate any restriction to the free flow of plating solution into the bore of the workpiece during the plating and honing process.
In operation, the apparatus 10 is employed for honing and electroplating by first retracting the quill 12 together with the honing-plate tool 14 to its uppermost position.
A workpiece 18 is then positioned in the fixture 16 so that the workpiece bore 20 is in axial alignment with the axis of rotation of the tool 14. With the honing stones 26 retracted within the slots 32 of the sleeve member 30,
the tool support 24 and sleeve member 30 are moved as a unit vertically downward until the lower end of the sleeve 30 is located at a position near the lower end of the modified stepped bore as shown in FIGS. 1 and 2 after which the sleeve 30 is unclamped from the quill 12 by releasing the piston and cylinder units 36 and 38. With the combined honing and plating tool 14 in this position, the flow of plating solution is initiated to cause fluid flow between the outer surface of the sleeve member 30 and the bore surface 28 of the workpiece. Thereafter, the honing stones are brought into engagement with the surface 28 and the tool support 24 is reciprocated by the piston and cylinder unit 34 and both the tool support 24 and sleeve 30 are rotated through the agency of the drive mechanism 41 to cause an abrading action to take place between the honing stones and the work surface. After a desired degree of abrading has taken place, the work surface will be sufliciently clean and be prepared for the subsequent plating cycle.
Thereafter, the electrical current is initiated so that the sleeve 30 acts as an anode and the workpiece acts as a cathode and a plating cycle is accomplished during continued rotation of the sleeve member 30 but with the honing stones 26 retracted slightly to relieve the pressure on the work surface of the workpiece. Under these conditions and with the continued flow of plating solution, plating of the surface 28 is effected. It will be understood that the DC. current flows in the electrical circuit previously described and particularly between the sleeve member 30 which acts as an anode, through the electrolyte to the workpiece which acts as a cathode. As is well known, this causes a depositing of the plating material on the surface 28 of the workpiece. After a sufficient period of time and suflicient depositing and honing of plating material on the work surface 28 of the workpiece, the electrical current flow may be terminated. If desired, honing may be continued after the flow of electrical current is terminated.
While preferred embodiments of the invention have been illustrated and described, it will be understood that various changes and modifications may be made without departing from the spirit of the invention.
What is claimed is:
1. A method of finishing a surface of an electrically conductive cathodic workpiece with tool means having an electrically conductive anodic sleeve portion and an abrasive member supported by the tool means and adjustable outwardly relative to said sleeve portion comprising the steps of positioning said anodic sleeve portion in predetermined spaced relationship with respect to the cathodic workpiece, flowing a plating solution between said surface and said electrically conductive cathodic sleeve portion, passing a direct electrical current between said sleeve portion and said surface through said plating solution to apply metal electrochemically to said surface, simultaneously rotating said tool means and said sleeve portion and reciprocating said tool means independently of said sleeve portion so that the metal on said surface is abraded, terminating the supply of electrical current, and retracting said tool means and sleeve portion from said workpiece.
2. In plating and honing apparatus for plating metal on and removing metal from a surface defining a bore in an electrically conductive cathodic workpiece, the combination comprising honing tool means supported for rotational and reciprocable movement, means for supporting an electrically conductive cathodic workpiece defining a bore coaxially aligned with the longitudinal axis of said honing tool means, an anodic sleeve member surrounding said honing tool means and adapted for positioning in closely spaced relationship to said surface defining said bore, said sleeve member being provided with at least one longitudinally extending slot, abrasive means supported on said tool means and projecting through said slot for movement radially relative to the axis of said tool means into and out of abrading engagement with said bore surface, means for flowing a plating solution between said sleeve member and said bore surface, means for moving said abrasive means over said bore surface in a combined reciprocating and rotating motion to remove metal mechanically from said bore surface, means for moving said sleeve member longitudinally in said bore and for maintaining said sleeve member in a fixed longitudinally position in said bore during rotation of said sleeve member, means for passing a direct electric current between said sleeve member to said bore surface through said plating solution, and means for terminating the supply of direct electric current at the completion of the work cycle.
3. In a combined plating and honing apparatus for removing and plating metal on a surface defining a bore in an electrically conductive cathodic workpiece, the combination comprising a honing tool, an anodic sleeve formed of electrically conductive material surrounding said tool and defining at least one elongated slot, said sleeve being adapted for positioning in spaced relationship to a workpiece, abrasive means mounted on said honing tool and projecting through said slot for abrading engagement with said bore surface of said workpiece, means for flowing a plating solution between said sleeve and said bore surface of said workpiece, means for simultaneously rotating said sleeve and said abrasive, means for moving said abrasive means in a reciprocating motion independently of said sleeve to remove metal mechanically from said bore surface, means for passing a direct electric current between said anodic sleeve and said bore surface through said plating solution to apply plating materials to said bore surface, means for terminating the supply of direct electric current when the bore of said workpiece has been plated to the desired size, and means for simultaneously retracting said honing tool and sleeve at the end of the plating cycle.
4. A combined plating and honing apparatus as delined in claim 3 including means for simultaneously rotating said honing tool and sleeve, and means for reciprocating said honing tool and sleeve.
5. A combined plating and honing apparatus as defined in claim 3, wherein said means for passing a direct electric current between said sleeve and said bore surface includes means for connecting said workpiece to one electrical terminal and said sleeve to the other electrical terminal of a direct electric current power supply.
6. In combined plating and honing apparatus for removing and plating metal on a surface defining a bore in an electrically conductive workpiece, the combination comprising a honing tool means including a sleeve member having an electrically conductive surface, means for supporting an electrically conductive workpiece with a bore surface in a position with the longitudinal axis of the bore coaxially aligned with the longitudinal axis of said sleeve member, abrasive means on said tool means adapted for abrading engagement with said bore surface, means for flowing a plating solution between said sleeve member and said bore surface, means for rotating said tool means and reciprocating said abrasive means independently of said sleeve member while said abrasive means is in contact with said bore surface, means for passing a direct electric current between said sleeve member and said bore surface through said plating solution whereby said workpiece is renderd cathodic and said sleeve member is rendered anodic, means for terminating the supply of direct electric current when the bore has been plated to the desired size, and means for simultaneously retracting the tool means and sleeve including the abrasive means.
References Cited UNITED STATES PATENTS 3,390,068 1/1968 Ellis et a1 204143 G 3,637,469 1/ 1972 Ellis et al. 20426 3,619,401 11/1971 Eisner 204217 JOHN H. MACK, Primary Examiner T. 'IUFARIELLO, Assistant Examiner US. Cl. X.R.
204-129.46, 217, 224 M, DIG. 10