ADJUSTABLE GRINDING MACHINE

Abstract: Arrangements of four-axis adjustable grinding machines (l0) are disclosed having four separately driven and adjustable grinding wheels (43,44,48,50) carried in opposed pairs on opposite sides of a movable support (l2, 60,66,7l) for a workpiece (67) to grind simultaneously the opposite sides (79-83) of both ends (76,78) of the workpiece, such as an engine connecting rod or the like with sequential feeding of plural workpieces. Adjustable means (l4,l5,l9,20,27-3l) supporting the grinding wheel pairs provide flexibility for setting up to process engine or runs.

Description: This invention relates to adjustable grinding machines and more particularly to adjustable four-axis grinding machines for simultaneously grinding the opposite faces of both ends of small articles, such as engine connecting rods. At present, two different types of grinding machines are in common use for grinding the opposite faces of small parts such as engine connecting rods and the like. In the case of planar, or flat, connecting rods in which the faces of the opposite ends lie in common parallel planes, the faces may be ground on a double disc grinding machine in which a rotary feed wheel passes between two grinding wheels carrying the connecting rods to be ground so that the faces of both ends are ground in common planes at the same time. In the case of stepped connecting rods, which have different dimensions between the faces of the opposite ends, use of a double disc grinding machine is not practical. However, such stepped connecting rods may be ground on a multiple vertical spindle centre column grinding machine in which only one side of the connecting rod is ground at a time, separate grinding wheels being provided for grinding the faces of the stepped opposite ends. Thus, a double disc grinding machine works well on flat sided, or planar, connecting rods but cannot be used in its present form for stepped connecting rods. On the other hand, a centre column grinding machine can be used to finish either stepped or flat sided connecting rods but, in both cases, requires that the sides be finished separately and that the part be turned over between these finishing steps. In accordance with the present invention, an adjustable grinding machine is characterised by the features specified in the characterising portion of Claim l. The present invention provides adjustable grinding machines which are capable of finishing four parallel surfaces on opposite sides of opposite ends of engine connecting rods and other similar workpieces, all during a single grinding step. A feature of the adjustable grinding machines is that they provide four individual grinding wheels arranged in two opposing pairs, the grinding wheels of which are laterally spaced to grind both faces of the opposite ends of the engine connecting rods or the like. The opposing grinding wheels are arranged on separate axes, preferably aligned or intersecting. Another feature is that the grinding wheels are individually adjustable toward and away from the workpieces to provide for finishing all forms of flat or stepped surface configurations. Another feature is that the dual opposed grinding wheels are carried on separate means which are laterally adjustable to accommodate engine connecting rods and other workpieces of different lengths. An additional feature is that alternative reciprocating or continuous feed means may be provided for transporting a plurality of workpieces to be ground past the grinding surfaces of the grinding wheels. Thus the adjustable grinding machines of the present invention are adjustable to provide flexibility for conversion to grind various sizes and styles of engine connecting rods or other articles to be ground and can be easily adjusted to provide for the machining of differing styles of parts in individual batches of like parts. These and other features and advantages of the invention will be more fully understood from the following description of selected embodiments taken together with the accompanying drawings, in which:- Figure l is a side elevational view of an adjustable grinding machine formed in accordance with the invention; Figure 2 is a fragmentary cross-sectional view downward from the plane indicated by the line 2-2 of Figure l and illustrating the grinding and reciprocating traversing mechanisms of the adjustable grinding machine; Figure 3 is a fragmentary transverse cross-sectional view from the plane indicated by the line 3-3 of Figure l showing an engine connecting rod clamping device; Figure 4 is a side view of a continuous feed mechanism provided as an alternative to the reciprocating mechanism of Figure 2; Figure 5 is a plan view of an alternative embodiment of adjustable grinding machine having an annular feed device in accordance with the invention; Figure 6 is a transverse cross-sectional view in the direction of the arrows from the plane of the line 6-6 of Figure 5; Figure 7 is a longitudinal cross-sectional view in the direction of the arrows from the plane indicated by the line 7-7 of Figure 5; Figure 8 is an enlarged view of the portion of Figure 5 indicated by the circle 8 and showing one of the holding fixtures for the engine connecting rods with portions broken away to illustrate the interior mechanism; and Figure 9 is an outer end view of the holding fixture from the plane 9-9 of Figure 8. In Figures l-3 of the drawings, numeral l0 generally indicates an adjustable grinding machine which has four axes and which is formed in accordance with the invention. Adjustable grinding machine l0 includes a base ll on which is mounted a central table support l2, a pair of guide ways l4,l5 which are longitudinally extending and on either side of the central table support l2, and a pair of motors l6,l8 which are longitudinally traversing and at the ends of the base and the guide ways. The base ll also supports a pair of pedestals l9,20, which are vertically upstanding and which engage the guide ways l4,l5, respectively, and are longitudinally movable therealong by the action of traversing screws 22,23, driven by the motors l6,l8, respectively. Pedestal l9 defines the first means of mounting means, and pedestal 20 defines the second means of mounting means. On their inner sides 24,26, facing one another and the central table support l2, the pedestals l9,20, respectively, carry vertically spaced and aligned pairs of guide ways 27,28 and 30,3l with motors 32,34,35,36, which are vertically traversing, being mounted at their ends. Guide ways 27 and 30 define upper guide ways, and guide ways 28 and 3l define lower guide ways. Motors 32 and 35 are above the upper guide ways 27,30, respectively, and motors 34,36 are underneath the lower guide ways 28,3l, respectively. Guide ways l4,l5,27-3l define adjusting means associated with the mounting means. Four separate grinding wheel drive motors 38,39, 40,42 are provided, mounted for vertical adjustment on the guide ways 27,28,30,3l, respectively. Grinding wheel drive motors 38 and 39 carry grinding wheels 43,44, respectively which are axially aligned and which have grinding surfaces 46,47, respectively which are opposed, vertically spaced and coaxial. In like manner, grinding wheel drive motors 40,42, respectively, carry grinding wheels 48,50 which are axially aligned and which have grinding surfaces 5l,52, respectively, which are opposed, vertically spaced and coaxial. Each of the coaxial opposed pairs of grinding surfaces 46,47 and 5l,52 is adapted to grind the opposite surfaces at one of the ends of engine connecting rods 67 and other similar articles, as will subsequently be more fully described. The clearance between the opposed pairs of grinding surfaces 46,47 and 5l,52 is adjustable as desired through individual vertical movement of the grinding wheel drive motors 38,39,40,42 by vertical traversing screws 54,55,56,58 driven by the motors 32,34,35,36, respectively. The upper edge of the central table support l2 constitutes a laterally extending guide way 59 on which there is supported a reciprocable workholder or work table 60 which is laterally reciprocably movable. A table drive motor 62, mounted at one end of the central table support l2, drives a laterally traversing screw 63 to provide lateral reciprocation of the work table 60. Table drive motor 62 and traversing screw 63 define power actuating means for the work table 60. On the top of the work table 60, there is a mounting surface 64 having a plurality of upstanding transverse abutments 66, spaced along the direction of work table reciprocation and adapted to support an equal number of the engine connecting rods 67, or the like, as workpieces for finishing by the adjustable grinding machine l0. The engine connecting rods 67 conventionally include central I-sections 68, each having a web 70 which is supported on one of the central upstanding abutments 66 of the work table 60. A U-clamp 7l (which defines retaining means), provided for each of the engine connecting rods 67, includes legs 72,74 which respectively engage the mounting surface 64 and the web 70 on the side opposite that engaging the respective upstanding transverse abutment 66, in order to hold the associated engine connecting rod 67 in position on the work table 60. A clamping screw 75 extends through each of the U-clamps 7l and threadably engages the work table 60 to exert a clamping force upon its U-clamp and the associated engine connecting rod 67. Central table support l2, work table 60, upstanding transverse abutments 66 and U-clamp 7l define support means for holding the engine connecting rods 67. Each of the engine connecting rods 67 further conventionally includes a pin end 76 and a crank end 78 at opposite ends connected together by the central I-section 68. As mounted upon the work table 60, the crank end 78 includes side faces 79,80, which extend upwardly and downwardly respectively, and the pin end 76 includes side faces 82, 83, which face upwardly and downwardly respectively. As the drawings indicate, the work table 60 is positioned for lateral reciprocation along a path that extends laterally between the dual pairs of grinding wheels 43,44 and 48,50. The work table 60 supports a plurality of engine connecting rods 67 with their side faces 79,80,82, 83, positioned to move into opposed engagement with the grinding surfaces 46,47,5l,52, respectively, of the four grinding wheels. In operation, a plurality of workpieces, such as engine connecting rods 67, are placed one on each of the upstanding transverse abutments 66 of the work table 60 and are clamped into position by locating the U-clamps 7l with their legs 74 engaging the central I-sections 68 of the engine connecting rods and tightening the clamping screws 75. The pedestals l9,20 are properly positioned or adjusted longitudinally and the grinding wheel drive motors 38,39,40,42 are properly positioned or adjusted vertically to provide, upon traversing of the work table 60, for the side faces 79,80,82,83 of the engine connecting rods 67 to pass between and lightly engage the respective grinding surfaces 46,47,5l,52 of the grinding wheels 43,44,48,50. If desired, the stock removal may be completed in a single pass of the work table 60 or the operation may occupy several traversing passes, between which the grinding wheel drive motors 38,39,40,42 are vertically repositioned to reduce the space between the paired grinding surfaces 46,47,5l,52 and sequentially advance the finishing process to the desired thicknesses and relative dimensions of the ends of the engine connecting rod. It should be apparent that the individual vertical adjustments provided for the four grinding wheel drive motors 38,39,40,42, individually carrying the grinding wheels 43,44,48,50 of the associated pairs, and the longitudinal adjustments provided for the pedestals l9,20, allow complete flexibility of the adjustable grinding machine l0 to accommodate engine connecting rods 67 and other articles of various lengths and thicknesses, including both parallel and stepped end designs, thus providing a fully adjustable flexible grinding machine arrangement. Referring now to Figure 4, there is shown an alternative embodiment of feed arrangement usable with the adjustable grinding machine l0 of Figures l-3 but replacing the work table 60 and central table support l2 of the first described embodiment. In Figure 4, a feed mechanism generally indicated by numeral 84 includes a pair of sprockets 86,87 which are laterally aligned, rotatable and connected by a conveyer chain or belt 88 (which defines a unidirectionally movable continuous path carrier) and rotatably driven by means not shown. The conveyer belt 88 supports a plurality of support members 90, each having an upstanding abutment 9l adapted to mount an engine connecting rod 67. Clamp members 92 (which define retaining means), having clamping screws 94, are mountable upon the support members 90 and engagable with the engine connecting rods 67 for retaining them in position during the grinding process. Conveyer belt 88 and support members 90 define support means for the engine connecting rods 67. In operation, the upper run of the conveyer belt 88, extending between the sprockets 86,87 passes between the pairs of grinding wheels, one pair 43,44 of which are indicated by phantom lines in the drawing. Engine connecting rods 67 are installed upon the support members 90 as the support members approach the grinding wheels 43,44,48,50 from the sprocket 86. The ends of the engine connecting rods 67 are finish ground in a single pass, after which the finished engine connecting rods are removed from the conveyer belt 88 as they approach or reach the location of the sprocket 87. Referring now to Figures 5-9, numeral l00 generally indicates another alternative embodiment of adjustable grinding machine in accordance with the invention. Adjustable grinding machine l00 includes a base l02 having a pair of supports l03,l04, which are longitudinally spaced, carrying four tables l06,l07,l08,ll0 which are rectangularly spaced. The tables l06,l07,l08,ll0 are arranged in laterally spaced pairs l06,l07 and l08,ll0 on the supports l03 and l04, respectively, and are each laterally movable in guides lll. The latter may include locking means, not shown, to provide means for individually laterally adjusting the tables l06,l07,l08,ll0 on the supports l03,l04. Tables l06 and l08 define the first means of mounting means, and tables l07 and ll0 define the second means of mounting means. On each of the tables l06,l07,l08,ll0 there is mounted a grinding wheel ll2,ll4,ll5 or ll6 rotatable on a generally horizontal axis ll8,ll9,l20 or l22, respectively. Each of the grinding wheels ll2,ll4,ll5,ll6 is carried on it own spindle l23 which is driven by an electric motor l24. The spindles l23 are longitudinally adjustable along the axes of their respective grinding wheels ll2,ll4,ll5, ll6 to provide individual longitudinal adjustment of the grinding wheels. Guides lll and spindles l23 define adjusting means associated with the mounting means. The arrangement of the grinding wheels ll2,ll4,ll5, ll6 on the tables l06,l07,l08,ll0 is such as to locate the grinding wheels in laterally spaced pairs of longitudinally spaced grinding wheels, the pairs of grinding wheels being nominally coaxial although adjustable to substantially parallel non-coaxial positions. Grinding surfaces l26 are formed on the ends of the grinding wheels, with the grinding surfaces l26 for each longitudinally spaced pair of grinding wheels facing one another. The adjustable grinding machine l00 is also provided with a feeder apparatus, generally indicated by numeral l27, for engine connecting rods l39 or other workpieces. This feeder apparatus l27 includes a support plate or structure l28 mounted on the inside of support l04 and extending upwardly therefrom. Support plate l28 fixedly mounts a circular track or race l30 guiding bearing means l3l on which is rotatably mounted an annular fixture wheel l32 (which defines a unidirectionally movable continuous path carrier or annular work supporting member) having external gear teeth l34. A drive motor l35 mounted on the support plate l28 carries a gear l36 engaging the external gear teeth l34 to rotate the annular fixture wheel l32 during operation. On the annular fixture wheel l32, there are mounted a plurality of holding fixtures l38 (which define retaining means for clamping the engine connecting rods l39), which are annularly spaced and longitudinally extending, for the engine connecting rods l39. The holding fixtures l38 may be of any suitable construction for accomplishing the desired functions. Their specific features, to be subsequently described, form no part of the present invention. Support plate l28, annular fixture wheel l32 and holding fixtures l38 define support means for holding the engine connecting rods l39. These holding fixtures l38 are adapted to accept and hold in position near their ends, the engine connecting rods l39 or other similar articles to be ground on both faces of opposite ends thereof. The engine connecting rods l39 are held in their central beam or rod portions l40 intermediate their respective crank ends l42 and pin ends l43 (which are at opposite ends). The crank ends l42 and the pin ends l43 extend radially outwardly and inwardly of the holding fixtures l38 for grinding of the opposite sides of the crank ends l42 and the pin ends l43. Suitable loading means, not shown, may be provided to insert an engine connecting rod l39 into each holding fixture l38 as it passes a loading station l44 at the front of the adjustable grinding machine l00. An unloading chute l46 is also provided to receive finished parts released from the holding fixtures l38 at an unloading point l47 near the top of the travel of the annular fixture wheel l32 and direct the falling articles to a discharge station l48 on the front of the adjustable grinding machine l00. As is best shown in Figures 8 and 9, the holding fixtures l38 each include a body l50 extending outwardly from the annular fixture wheel l32 to a slot l5l near the outer end of the body to receive an engine connecting rod l39. A guide bar l52 attached to the body l50 opposite the slot l5l is provided with locating surfaces to properly position each engine connecting rod l39 as it is placed in the slot. During grinding, spring loaded push rods l54 actuated by a cam engaged slider l55 clamp the engine connecting rods l39 against seats l56 on the outer side of the slot l5l. Subsequently, the cam engaged slider l55 is cam actuated to release the spring loaded push rods l54 at the appropriate point to release the engine connecting rod l39 at the unloading point l47 previously mentioned. In operation, the annular fixture wheel l32 rotates, causing the holding fixtures l38 to carry the engine connecting rods l39 in an arcuate orbital path from the loading station l44, between the pairs of grinding wheels ll2,ll5 and ll4,ll6 and up to the discharge point l47 where the finished parts are released. The pairs of grinding wheel ll2,ll5 and ll4,ll6 are positioned respectively outside and inside of this arcuate orbital path and are located so that the grinding surfaces l26 of each pair of grinding wheels engage and grind the opposite sides of one of the ends of each engine connecting rod l39 as it passes between the pairs of grinding wheels. Since the grinding wheels ll2,ll4,ll5,ll6 are individually longitudinally adjustable through adjustment of their respective spindles l23, the adjustable grinding machine l00 may be used to simultaneously grind both sides of both ends of engine connecting rods l39 having different end thicknesses. Also, other parts, such as offset end wrenches can be ground in this fashion. Further, parts of different lengths can be accommodated by lateral adjustment of the tables l06,l07,l08,ll0 which carry the grinding wheels ll2,ll4,ll5,ll6 to provide the proper spacing between the pairs of grinding wheels.

Claims: 1. An adjustable grinding machine (l0,l00) for simultaneously grinding a pair of opposite side faces (79-83) at two opposite ends (76,78,l42,l43) of a workpiece (67,l39), the adjustable grinding machine being characterised by support means (l2,60,66,7l,88,90,l28,l32, l38) for holding the workpiece intermediate its opposite ends with the opposite ends extending beyond opposite sides of the support means; mounting means (l9,20,l06,l07,l08, ll0) drivably carrying a first pair of grinding wheels (43, 44,ll2,ll5) at one of the opposite sides of the support means and a second pair of grinding wheels (48,50,ll4,ll6) at the other of the opposite sides of the support means, the grinding wheels of the first pair each having a grinding surface (46,47,l26), one engagable with each of the opposite side faces of one of the opposite ends of the workpiece and the grinding wheels of the second pair each having a grinding surface (5l,52,l26), one engagable with each of the opposite side faces of the other of the opposite ends of the workpiece; and adjusting means (l4,27, 28,l5,30,3l,lll,l23) associated with the mounting means for separately adjusting the grinding surfaces of the grinding wheels to simultaneously grind the pairs of opposite side faces at the opposite ends of the article and to provide independent location of the relative positions of each of the opposite side faces on both ends of the workpiece. 2. An adjustable grinding machine as claimed in claim l, wherein the first and second pairs of grinding wheels (43,44,ll2,ll5,48,50,ll4,ll6) are adjustable toward and away from one another and the support means (l2,60,66, 7l,88,90,l28,l32,l38) to allow for grinding similar workpieces of differing lengths. 3. An adjustable grinding machine as claimed in claim l or claim 2, wherein the support means (l2,60,66,7l, 88,90,l28,l32,l38) is capable of holding a plurality of workpieces (67,l39) and of traversing the workpieces sequentially across the grinding surfaces (46,47,5l,52, l26). 4. An adjustable grinding machine as claimed in claim 3, wherein the support means (l2,60,66,7l) includes a reciprocable workholder (60) mounted on transverse ways and movable thereon by power actuating means (62,63) carried by the support means. 5. An adjustable grinding machine as claimed in claim 3, wherein the support means (88,90,l28,l32,l38) comprises a unidirectionally movable continuous path carrier (88,l32). 6. An adjustable grinding machine as claimed in claim 5, wherein the unidirectionally movable continuous path carrier includes a conveyer belt (88). 7. An adjustable grinding machine as claimed in claim 5, wherein the unidirectionally movable continuous path carrier includes an annular work supporting member (l32) located so as to transport the workpieces (l39) in an arc of a circle that, as viewed axially, encompasses the peripheries of the grinding wheels (ll2,ll5) of one of the pairs, approaching the peripheries most closely at a point between them and the peripheries of the other of the pairs of grinding wheels (ll4,ll6). 8. An adjustable grinding machine as claimed in any one of the preceding claims, and comprising a base (ll,l02), the support means (l2,60,66,7l,88,90,l28,l32,l38) being carried on the base and comprising retaining means (7l,92,l38) for clamping the workpieces (67,l39) intermediate their opposite ends (74,78,l42,l43); 9. An adjustable grinding machine as claimed in any one of the preceding claims, wherein the mounting means comprises first means (l9,l06,l08) drivably carrying the first pair of grinding wheels (43,44,ll2,ll5) and second means (20,l07,ll0) drivably carrying the second pair of grinding wheels (48,50,ll4,ll6). l0. An adjustable grinding machine as claimed in claim 9, wherein the first and second means (l9,20,l06-ll0) are adjustable toward and away from one another and the support means (l2,60,66,7l,88,90,l28,l32,l38) to allow for grinding similar workpieces of differing lengths. 11. An adjustable grinding machine as claimed in claim 9 or claim l0 in which the adjustable grinding machine includes a base (ll), wherein the first means comprises a first pedestal (l9) mounted on the base; and the second means comprises a second pedestal (20) mounted on the base. 12. An adjustable grinding machine as claimed in claim l, wherein the support means rotatably carries an annular fixture wheel (l32) carrying a plurality of holding fixtures (l38), which are annularly spaced, for holding a plurality of the workpieces (l39) intermediate their opposite ends (l42,l43), and a drive motor (l35) for rotating the annular fixture wheel to transport the holding fixtures in an annular orbital path; the mounting means (l06-ll0) drivably carrying the first pair of grinding wheels (ll2,ll5) on the outside of the annular orbital path and the second pair of grinding wheels (ll4,ll6) on the inside of the annular orbital path.

Inventors: FETOUH, MOHAMED A., MALARZ, ANTONI JOSEPH
Applicants: GENERAL MOTORS CORPORATION
Application year: 1986
Main classification: B24B7
IPC codes: B24B7