GB2077459A

GB2077459A - An electro-mechanical control system for a grinding machine

Info

Publication number: GB2077459A
Application number: GB8108862A
Authority: GB
Original assignee: Bryant Grinder Corp
Current assignee: Bryant Grinder Corp
Priority date: 1980-05-22
Filing date: 1981-03-20
Publication date: 1981-12-16
Also published as: FR2482891A1; DE3120277A1; FR2482891B1; JPS5748459A; GB2077459B

Abstract

In an electro-mechanical control system for controlling all the movements of one or more slides on a single workhead grinding machine, a programmable controller is interfaced with a digital-to-analog converter or feed control which in turn controls a drive motor that is directly connected to a screw actuator means that directly controls the movements and positions of a slide. The positioning accuracy of the control system is derived from the accuracy of the electronic control components and the stability of the machine. The control system can control the operative movements of each slide in a compound slide assembly, simultaneously or independently, for a part of a grinding machine cycle. The compound slide assembly may alternatively carry a rotating grinding wheel or a workhead that is reciprocated at high speed for a grinding operation on a workpiece. <IMAGE>

Description

SPECIFICATION An electro-mechanical control system for a grinding machine This invention relates generally to the grinding machine art, and more particularly, to an electromechanical internal grinding machine. The invention is specifically concerned with a one station electromechanical internal grinding machine which has one grinding spindle on a cross slide, and all of the movements of the grinding spindle are electronically controlled.

It is known in the grinding machine art to employ digital electronic controls to control one parameter or movement along one axis. Such prior art digital electronic controls function through a mechanical advantage to get the positioning accuracy and other tolerances that are required in a grinding operation.

Digital electronics is very coarse and it is the mechanical advantage that provides such prior art controls with smoothness and preciseness. It is also known in the grinding machine art to control a second movement along another axis by a cam means or some other mechanical means. In the prior art grinding machines the digital electronics control only a portion of the moves of the grinding machine and not 100% of the moves. For example, the digital electronic controls in the prior art machines control the grind portion or grind movements only, as when the grinding wheel is moved in contact with the workpiece. The prior art grinding machines also have employed various means for controlling machine motions, such as hydraulic cylinders, physical mechanical stops, and adjustable stops to position various grinding machine components.

Examples of such prior art grinding machines are grinding machines sold by the Bryant Grinder Corporation, 257 Clinton Street, Springfield, Vermont 05156, and disclosed in United States patents, numbers 3,932,960; 3,958,370,4,023,310; 4,058,934 and 4,125,967.

The invention relates to a control system for a grinding machine. The control system includes a digital electronic control apparatus to control 100% of the movements of a grinding machine and a screw actuator means to transmit the control commands from the digital electronic control apparatus into a grinding machine component slide motion.

The control system of the present invention is capable of providing complete variable cross slide grinding and stroking conditions, as well as longitudinal slide grinding and stroking conditions. The electronic control apparatus is capable of providing variable reciprocation rates during each stroke of a grinding wheel slide or a workhead slide. The control system of the present invention provides length of stroke, position of stroke, reciprocation rate, and variable reciprocation rates during each stroke.

Variations of each of said attributes can be programmed on a finite basis. That is, one set of conditions can be programmed for a rough grind, a second set of conditions during a finish grind and a third set of conditions during sparkout. These conditions can also be programmed to be infinitely variable within the complete grinding cycle and can be managed as individual variables for their individual effect or in combination for their combined effect. By varying these various attributes within a grinding cycle, maximum metal removal conditions can be achieved during one portion of the cycle, while retaining a most desirable combination of attributes to optimize geometry and quality during another portion of the cycle.The control system of the present invention can also control dressing, compensation for dressing, the reciprocation part of the grind cycle, size correction, simultaneous or independent movement of two grinding machine slides, different grinding modes, and other factors.

The invention is illustrated in one embodiment as applied to a one-station electro-mechanical internal grinding machine which includes one grinding wheel spindle on a cross slide. The grinding machine includes a machine base on which is mounted a workhead that is adapted to carry a workpiece. A compound slide is mounted on one end of the machine base in an operative position adjacent the workhead, and it includes a longitudinal slide on which is movably mounted a cross slide that carries an internal grinding wheel spindle.

The illustrative longitudinal and cross slides are each driven by a drive motor which is directly connected to the respective slide by means of a screw actuator means, such as a ball screw, Acme screw, or other means. A programmable controller is programmed with all the required machine information and machine functions so that all of the movements along the longitudinal and cross slide axes are controlled. The programmable controller is operatively connected to a feed control means which in turn is operatively connected to suitable separate servo drive means for each of the drive motors. Each of the drive motors is provided with a tachometer, and a resolver, or encoder, or an "INDUCTOSYN" transducer, for motion control and command signals, respectively.

The accuracy of a grinding operation carried out by a grinding machine provided with the control system of the present invention is controlled by the digital electronics controlling a drive motor which controls a screw actuator means, and which in turn controls a slide directly. There is no mechanical or hydraulic linkage or gearing as is employed in the prior art digital control systems. The positioning accuracy is a result of the accuracy of the control system of the electronic controls and the stability of the machine.

In one illustrative grinding machine embodiment, one workhead rotates a workpiece and a grinding wheel carried by a wheel slide reciprocates on one end of the machine to grind a longitudinal bore in the workpiece.

Brief Description of the Drawings Figure 1 discloses a first illustrative embodiment wherein the control system of the present invention is employed in a schematically illustrated onestation, electro-mechanical internal grinding machine having one grinding wheel spindle on a cross slide.

Figure 2 is an enlarged plan view of an illustrative longitudinal slide employed in the grinding machine embodiment of Figure 1.

Figure 3 is a broken, longitudinal section view of an illustrative cross slide employed in the illustrative grinding machine embodiment of Figure 1, taken substantially along the line 3-3 thereof, and looking in the direction of the arrows.

Figure 4 is a vertical section view of the structure shown in Figure 3, taken substantially along the line 4-4 thereof, and looking in the direction of the arrows.

Figure 5 is a right end view of the structure illustrated in Figure 3, taken along the line 5-5 thereof, and looking in the direction of the arrows.

Figure 6 is a left end view of the structure illustrated in Figure 3, taken along the line 6-6 thereof, and looking in the direction of the arrows.

Figure 7 is a fragmentary elevation view of the structure illustrated in Figure 3, taken along the line 7-7 thereof, and looking in the direction of the arrows.

Figure 8 is a fragmentary, elevation section view of the structure illustrated in Figure 3, taken along the line 8-8 thereof, and looking in the direction of the arrows.

Figure 9 is a block diagram of an illustrative control system made in accordance with the principles of the present invention, and shown as applied to the grinding machine illustrated in Figure 1.

Figure 10 is a schematic illustration of a sequence of grinding operations capable of being carried out on a workpiece in a single workhead, by a single grinding wheel, with the grinding machine structure illustrated in Figures 1 through 8 and the control means illustrated in Figure 9.

Figure 11 is a schematic illustration of a plurality of grinding operations capable of being carried out simultaneously by a single workhead grinding machine employing the basic grinding machine structure illustrated in Figures 1 through 8 and the control means illustrated in Figure 9, together with added slide structures.

Figure 12 is a schematic illustration of a single workhead grinding machine, made in accordance with the principles of the present invention, and wherein a longitudinal slide carries a cross slide on which is operatively mounted a grinding wheel that may carry out a bore grind operation, and wherein a second slide is operatively mounted on the longitudinal slide for carrying out a face grind operation.

Figure 13 is another embodiment of a single workhead grinding machine made in accordance with the principles of the present invention, and which includes the longitudinal and cross slide structures of Figure 1,togetherwith an angularly disposed longitudinal slide that carries a grinding wheel for carrying out a simultaneous face operation.

Figure 14 is a still another embodiment of a single workhead grinding machine made in accordance with the principles of the present invention, and which includes the grinding machine structure illustrated in Figure 13, and wherein the angularly disposed longitudinal slide is operatively mounted on a cross slide.

Figure 15 is a further embodiment of a single workhead grinding machine made in accordance with the principles of the present invention, and which includes the longitudinal and cross slide structures of Figure 1, together with a second grinding wheel carried on the cross slide for sequentially carrying out a face grind operation.

Figure 16 is still a further embodiment of a single workhead grinding machine made in accordance with the principles of the present invention, and which includes the longitudinal and cross slide structures of Figure 1, together with a cross slide that carries the single workhead.

Figure 17 is still another embodiment of a single workhead grinding machine made in accordance with the principles of the present invention, and wherein the structure of Figure 1 is reversed, with the grinding wheel being fixed on the machine bed and the workhead being mounted on a cross slide that is carried on a longitudinal slide.

Figure 18 is a further embodiment of a single workhead grinding machine made in accordance with the principles of the present invention, and wherein a single grinding wheel is carried on a longitudinal slide and a single workhead is carried on a cross slide.

Figure 19 is still another embodiment of a single workhead grinding machine made in accordance with the principles of the present invention, and showing a structure reverse to that of Figure 18, wherein the grinding wheel is mounted on a cross slide and the workhead is mounted on a longitudinal slide.

Referring now to the drawings, and in particularto Figure 1,the numeral 10 generally designates a one-station electro-mechanical internal grinding machine, with one grinding wheel spindle on a cross slide, made in accordance with the principles of the present invention. The grinding machine 10 includes a conventional bed or base member 11 on which is operatively mounted a conventional workhead 13.

Operatively mounted on the right end of the machine bed 11, as viewed in Figure 1, is a compound slide assembly comprising a longitudinal slide, generally indicated by the numeral 15, on which is operatively mounted a cross slide, generally indicated by the numeral 16.

The workhead 13 may be of any suitable conventional structure, and it comprises a chucking fixture 22 for holding a workpiece. The chucking fixture 22 may be of the centerless type and be rotated by the motor 13 and an operatively connected pulley means, schematically indicated by the numeral 23.

As shown in Figure 1, a bore grinding wheel 29 is operatively carried on the compound slide assembly, on the right end of the machine 10, which comprises the longitudinal slide 15 and the cross slide 16. It will be understood that the control system of the present invention is capable of controlling any combination of motions of a grinding wheel on the compound slide assembly.

Figure 2 illustrates the general structural layout of the longitudinal slide 15. The numeral 34 desig nates a conventional slide base which is integral with the machine bed 11. Slidably mounted on the integral slide base 34 is a conventional slide 35. The slide 35 is slidably mounted on the slide base 34 by a pair of laterally spaced apart conventional ball slide bars 36 which are fixedly secured to the integral slide base 34 in the same manner as hereinafter described for the ball slides for the cross slide 16, but which last mentioned ball slides are secured to a separate slide base. The slide bars 36 are provided with stop plates 38 on each end thereof which are secured to the slide bars 36 by suitable machine screws 39.The slide 35 is slidably mounted on the slide bars 36 by suitable conventional ball slide sleeves 37 which carry balls in a conventional manner for rollably supporting the slide 35 on the bars 36. Although the illustrative embodiment employs a ball slide for the longitudinal slide 15, it will be understood that any suitable slide system may be employed, as for example a roller slide system, a hydrostatic slide system, a hydrodynamic slide system, or the like.

The slide 35 is moved on the slide bars 36 by a conventional ball screw, Acme screw, or other screw means 40 which has one end rotatably mounted in a suitable bearing means carried in a bearing block 41.

As shown in Figure 2, the bearing block 41 is fixedly secured to the integral slide base 34 by any suitable means, as by suitable machine screws 42. The slide 35 is operatively connected to the ball screw, Acme screw or other screw means 40 by a screw nut 44 which is fixed to the slide 35 by any suitable means, as by suitable machine screws 45. The other end of the ball screw, Acme screw, or other screw means 40 is rotatably supported by a suitable bearing means carried in a bearing block 43 that is integrally formed with a coupling housing 46 which is also integrally formed with a motor mount plate 50. The motor mount plate 50 is fixedly secured to the integral slide base 34 by any suitable means, as by suitable machine screws 51.The motor mount plate 50 operatively supports a suitable reversible electric drive motor 47 which has operatively mounted thereon a conventional tachometer 48 and a conventional resolver, encoder, or "INDUCTOSYN" (a trademark) transducer 49.

Figures 3 through 8 illustrate the general structural layout of the cross slide 16. As best seen in Figure 3, the numeral 54 designates the conventional cross slide base which is fixedly secured to the longitudinal slide base 35 by any suitable means, as by suitable machine screws 55. Slidably mounted on the cross slide base 54 is a conventional cross slide carriage 56. The cross slide carriage 56 is slidably mounted on the cross slide base 54 by a pair of laterally spaced apart conventional ball slides comprising a pair of parallel slide bars 57 (Figure 4) which are each mounted on a support rail 58. Although the illustrative embodiment employs a ball slide for cross slide 16, (shown in Figure 1), it will be understood that any suitable slide system may be employed, as for example, a roller slide system, a hydrostatic slide system, a hydrodynamic slide system, or the like.

The slide bars 57 and the support rails 58 are fixedly secured to the cross slide base 54 by a plurality of suitable machine screws 59 (Figure 4). The slide bars 57 are provided with fixedly mounted stop plates 60 on each end thereof. The slide carriage 56 is slidably mounted on the slide bars 57 by suitable conventional ball slide sleeves 61 (Figure 4) which carry balls in a conventional manner for rollably supporting the slide carriage 56 on the slide bars 57.

The cross slide carriage 56 is moved on the slide bars 57 by a conventional ball screw, Acme screw, or other screw means 64 which has one end rotatably mounted through a conventional ball screw nut 65 (Figures 3 and 7). The ball screw nut 65 is fixedly secured to the cross slide carriage 56 by an integral mounting plate 66 and suitable machine screws 67.

The ball screw nut 65 includes a lower retainer plate 68 (Figure 7) which is secured to the cross slide carriage 56 by a plurality of suitable machine screws 69.

The other end of the ball screw 64 is rotatably supported by suitable bearings 70, which are spaced apart by a spacer member 78. The bearings 70 and spacer member 78 are carried in a bearing housing 71 (Figure 3) that is integrally formed with a coupling housing 72 which is also integrally formed with a motor mount plate 73. The motor mount plate 73 is fixedly secured to the cross slide base 54 by any suitable means, as by suitable machine screws 74 (Figure 4). Suitable slide carriage rear bumpers 75 (Figures 3 and 4) are fixedly mounted on the inner side of the motor mount plate 73. Suitable slide carriage forward bumpers 77 are fixedly mounted on a plate 76 carried on the forward end of the cross slide base 54.

As illustrated in Figure 3, a suitable reversible electric drive motor 80 is fixedly secured by any suitable means, as by suitable machine screws 81, to the motor mount plate 73. The drive motor 80 is of the same construction as the longitudinal drive motor 47, and it has operatively mounted thereon a conventional tachometer 82, and a conventional resolver, encoder, or "INDUCTOSYN" (a trademark) transducer 83.

As illustrated in Figure 3, the output shaft 86 of the drive motor 80 is directly connected to the adjacent end 87 of the ball screw shaft 64 by a suitable coupling, generally indicated by the numeral 88. As illustrated in Figure 3, the bearings 70 are retained in the housing 71 by a suitable lock nut 89 on one end of the housing 71 and a retainer plate (Figure 8) 90 on the other end of the housing 71. The retainer plate 90 is secured to the housing 71 by suitable machine screws 91 (Figure 8). As illustrated in Figure 3, the slide carriage 56 may be provided with suitable top cover plates 94 and 95 on the front and rear ends, respectively. As illustrated in Figure 4, the slide carriage 56 may also be provided with side cover plates 96. As illustrated in Figure 1, a conventional grinding wheel spindle 97 is operatively mounted on the cross slide carriage 56 and it has operatively attached thereto the bore grinding wheel 29. The grinding wheel spindle 97 is driven by a suitable electric drive motor 98 which is also operatively mounted on the cross slide carriage 56.

Figure 9 is a block diagram of a control system made in accordance with the principles of the present invention, and shown as employed to con trol the aforedescribed first embodiment of a onestation grinding machine 10.

In Figure 9, the numeral 118 generally designates a separate, conventional programmable controller which is programmed to control all machine functions and interlocks. Such functions include lubrication status, safety interlocks, loader position, motor status and operation control station information. The programmable controller determines from the machine status which sequence the slides are to move through next. The programmable controller 118 is interfaced electronically with a suitable feed control 119 which may be any suitable digital computer. The feed control 119 has stored the positions and rates for all the axis moves for the various sequences. The sequences may be a dress cycle, a grind cycle, a new wheel dress cycle, and so forth. The feed control gives signals to the drive means 120 and 121 and they control the servo motors 80 and 47, respectively.The drive means 120 and 121 take feedback from the tachometer 82 and 48, respectively. The numerals 83 and 49 designated either resolvers, encoders or "INDUCTOSYN" transducers (a trademark), and they provide feedback signals to the drive means 120 and 121, respectively.

Any suitable programmable controller 118 may be employed, such as a Bryant Series 75 programmable controller available from the Westinghouse Electric Corporation of Gateway Center, Pittsburgh, Pennsylvania 15222. A suitable feed control 119 is one available on the market from Intel Corporation of Santa Clara, California 95054, and which is sold under the name of "INTEL", (a trademark), 80/05 Single Board Computer. The drive means 120 and 121 may be any suitable servo drive means as, for example, a servo drive available on the market from Hyper Loop, Inc., of 7459 W. 79 Street, Bridgeview, Illinois 60455, under the trademark "HYAMP". The "HYAMP" servo drive is a single-phase,fourwave, bi-directional SCR servo drive for D.C. motors, and it provides D.C. drive power for precise speed control and regulation over a wide speed range.Another suitable servo-drive, designated as Size 50, is available from General Electric Company, 685 West Rio Road, Charlottsville, Virginia 22906.

The drive motors 47 and 80 may be any suitable D.C. servo motors. Suitable D.C. servo motors of this type are available from Torque Systems Incorporated, 225 Crescent St., Waltham, Massachusetts 02154, under the trademark "SNAPPER", and identified as frame sizes 3435 and 5115. A larger motor of this type is also available from the H.K. Porter Co., of 301 Porter St., Pittsburgh, Pennsylvania 15219.

The tachometers 48 and 82 are part of the D.C.

servo motors. The resolvers, encoders or "INDUC TOSYN" transducers 49 and 83 are conventional items, and they may be any suitable conventional position feedback devices available on the market.

Resolvers of this type are available from the Clifton Precision Company of Clifton Heights, Pennsylvania 19018. "INDUCTOSYN" precision linear and rotary position transducers are available from Farrand Controls, a division of Farrand Industries, Inc., of 99 Wall Street, Valhalla, New York 10595. A suitable optical shaft angle encoder, designated by Model No. DRC-35 is available from Dynamics Research Corporation of 60 Concord Street, Wilmington, Maryland 01887.

In operation, the bore grinding wheel 29 is rotated normally at a speed of from 30,000 to 40,000 revolutions per minute, but it may be rotated at a speed of up to 150,000 revolutions per minute.

Assuming that the operator has actuated the necessary controls at the operator station, the programmer able controller 118 takes over and controls all of the programmed machine functions. The longitudinal slide 15 provides the rotating grinding wheel 29 with a sequence of movements such as rapid forward traverse, slow infeed, high speed reciprocation and back-off or retraction. The cross slide 16 provides the grinding wheel 29 with positioning movements and compensation movements to compensate for the wearing away of the grinding wheel in the grinding of each part. The control system of the present invention is so accurate that compensation movements of ten millionths of an inch may be carried out to maintain an extremely high accuracy within a plus or minus ten millionths of an inch.

After the programmed grinding operations have been carried out by the grinding wheel 29, it is retracted and the finished workpiece is removed from the workhead 13 and a new workpiece is loaded into the workhead 13. The grinding machine 10 may be provided with any suitable parts loading and unloading apparatus, gaging apparatus, and so forth. It will be seen that each axis of the machine 10 can function independently of the other axis to carry out its programmed work. The axes are coordinated where necessary to assure the proper operation. For example, in a bore grind, the longitudinal slide must be in position and reciprocate before the cross slide can start the grind operation.

As stated hereinbefore, the motor 47 moves the longitudinal slide 15 and the rotating grinding wheel 29 through a sequence of motions which include rapid forward traverse to move the grinding wheel 29 to a point adjacent a workpiece, and then a slow infeed of the grinding wheel 29 to a position inside of the workpiece. The motor 47 then provides the longitudinal slide and grinding wheel 29 with a rapid axial reciprocation to carry out the grinding part of the grinding cycle on a bore in a workpiece. The motor 80 moves the cross slide carriage 56 to bring the grinding wheel 29 into engagement with the bore of the workpiece for a finish grind. The axial reciprocation of the grinding wheel 29 is effected by the screw 40 and the motor 47 under the control of the feed control 119 of the control circuit of Figure 9.

The physical movement of reciprocation is carriedout by the motor 47. The intelligence to move the motor 47 is provided by the information supplied by the feed control 119, which goes to the drive 121 to tell it how fast to move the motor 47. The feedback information goes back into the drive 121 and tells the computer howfarthe grinding wheel 29 has moved, and the computer keeps track of how far the grinding wheel 29 is programmed to go, and how far it has moved. After the high speed reciprocation part of the grinding cycle is completed, according to the machine programming, the motors 80 and 47 are then controlled to retract the grinding wheel 29to its inoperative position.

It will be seen that the present invention provides a means for controlling the axial reciprocation part of a grind cycle with the same motor 47 and screw actuator means 40 as is used for other movements of the longitudinal slide along its axis. It will also be seen that the present invention provides a grinding machine with means to accomplish compensation in the position of the grinding wheel 29 after it has been dressed, by the same screw actuator means 64 and motor 80 as is used to provide other movements of the slide carriage 56 along the same axis. The present invention also provides size correction to the position of the grinding wheel 29 by the same screw actuator means and motor means employed for other movements along both the cross or lateral axis.

It will be seen that just as the motors 47 and 80 with appropriate controls can grind a bore with the side of grinding wheel 29, the roles of the motors can be reversed to allow for reciprocation with motor 80 and grind feed compensation for wheel we and size correction through motor 47. This will cause the face of a part to be ground with the end of the grinding wheel 29. It will also be seen that a number of bores and faces can be ground on the same workpiece or part through proper coordination of the moves of the two motors 47 and 80.

It will be seen that just as motors 47 and 80, with appropriate controls, can grind a bore with the side of a grinding wheel 29, they can also grind an external surface concentric with the bore, with the same controls, with only the positions being offset by a fixed distance.

Figure 10 is a schematic illustration of a sequence of grinding operations which are capable of being carried out on a workpiece in a single workhead by a single rotatable grinding wheel, with the grinding machine structure illustrated in Figures 1 through 8, and as controlled by the control means illustrated in Figure 9. In Figure 10 the workpiece fixture 22 is illustrated as operatively holding a workpiece, generally indicated by the numeral 99. The rotatable grinding wheel 29 is illustrated as carrying out a bore grinding operation on the workpiece 99. The numeral 29' illustrates the rotatable grinding wheel 29 in a different operative positon for carrying out a face grinding operation on the workpiece 99. The numeral 29' shows the rotatable grinding wheel 29 in another operative position for carrying out an external or peripheral grinding operation on the workpiece 99.It will be understood that the bore, face and external grinding operations illustrated in Figure 10 would be carried out sequentially by the control means illustrated in Figure 9, in a desired programmed sequence.

Figure 11 is a schematic illustration of a plurality of grinding operations capable of being carried out simultaneously by a single workhead grinding machine employing the basic grinding machine structure illustrated in Figures 1 through 8 and the control means illustrated in Figure 9, together with added slide structure. In Figure 11, the numeral 125 designates a grinding machine bed on which is operatively mounted a single workhead 126. The workhead 126 is provided with a suitable workpiece fixture that carries a workpiece 127 that is rotated by the workhead 126. The workpiece 127 is provided with a bore 128, a transverse end face 129, and a tapered shoulder face 130.The grinding machine structure illustrated in Figure 11 is adapted to simultaneously carry out a bore grinding operation on the bore 128, a face grinding on the end face 129, and a face grinding on the tapered shoulder face 130.

The grinding machine of Figure 11 includes a compound slide assembly which comprises a longitudinal slide 124 and a cross slide 131. The slides 124 and 131 correspond to the longitudinal and cross slides 15 and 16, respectively, of the embodiment of Figure 1. A rotatable grinding wheel head 132 is operatively carried on the cross slide 131, and it is provided with a grinding wheel 133 for performing a bore grinding operation in the bore 123 in the workpiece 127. A suitable bracket 134 is fixedly secured, by any suitable means, to one side of the longitudinal slide 124, and it carries a second longitudinal slide 135 which is positioned on another axis parallel to the axis of the first longitudinal slide 124.The second longitudinal slide 135 carries a rotatable grinding wheel head 136 which is provided with a rotatable grinding wheel 137 that simultaneously carries out a face grinding operation on the workpiece end face 129 while the bore grinding operation is carried out by the rotatable grinding wheel 133 in the bore 128.

The first longitudinal slide 124 is also provided on the other side thereof with a suitable bracket 138 for carrying an angularly disposed, third longitudinal slide 139. Operatively mounted on the slide 139 is a suitable drive motor 140 which has an output shaft 141 on which is mounted a drive pulley 142. The drive pulley 142 drives a belt 143 which is mounted around a driven pulley 144 carried on a shaft 145 of a grinding wheel spindle 146. The grinding wheel spindle 146 operatively carries a rotatable grinding wheel 147 which has an angled periphery that is complementary to the angularshoulderface 130 on the workpiece 127.The grinding wheel 147 is controlled so as to carry out the face grinding operation on the workpiece angled shoulder face 130 simultaneously with the face grinding operation on the workpiece face 128 and the grinding operation on the workpiece bore 128.

A suitable diamond roll dresser motor 151 is operatively mounted on the machine bed 125, and it drives a gear reducer 150 which has an output shaft 149 that carries a diamond roll dresser 148. The angular slide 139 is adapted to back the grinding wheel 147 to an operative dressing position against the rotatable diamond roll dresser 148 in a conventional manner. It will be understood that the grinding machine of Figure 11, with its two longitudinal slides 124and 135 and the one angular longitudinal slide 139 would be controlled by a control system, embodying the principles of the control system of Figure 9, for providing the aforedescribed simultaneous bore and two face grinding operations.

Figure 12 is a schematic illustration of a single workhead grinding machine made in accordance with the principles of the present invention, and wherein a compound slide assembly carries a grinding wheel that is adapted to carry out a bore grinding operation, and wherein a second longitudinal slide is operatively mounted on the first longitudinal slide of the compound slide assembly for carrying out a face grinding operation simultaneously with the bore grinding operation.The structure of the grinding machine illustrated in Figure 12 which is the same as the structure of the grinding machines illustrated in the embodiments of Figures 1 and 11 have been marked with the same reference numerals followed bythesmall letter a The rotatable grinding wheel 29a is carried on the cross slide 16a and it is adapted to carry out a bore grinding operation on a workpiece rotatably supported on a workhead 13a. A rotatable grinding wheel 137a is adapted to simultaneously carry out a face grinding operation on the last mentioned workpiece.The rotatable grinding wheel 137a is operatively carried by a grinding wheel head 136a which is operatively mounted on a longitudinal slide 135a, which in turn is carried on a bracket 134a that is fixed to the longitudinal slide 1 spa. The movements of the longitudinal slide 15a and the cross slide 16a would be controlled by a control system as em ployed for the embodiment of Figure 1.

Figure 13 is a schematic illustration of a single workhead grinding machine, made in accordance with the principles of the present invention, and which includes the combination slide assembly of the embodiment of Figure 1, together with an angularly disposed longitudinal slide 155 that carries a rotatable grinding wheel 157 for carrying out a face grinding operation on a workpiece. The structure of the grinding machine illustrated in Figure 13 which is the same as the structure of the grinding machine illustrated in Figure 1, have been marked with the same reference numerals, followed by the small letter "b". The rotatable grinding wheel 29b is adapted to carry out a bore grinding operation on a workpiece supported by a suitable rotatable work piece fixture carried by the workhead 1 3b.The longitudinal slide 155 is angularly disposed on the left end of the machine bed 11 b, and it carries a rotatable grinding wheel head 156 that operatively supports and drives the rotatable grinding wheel 156. The movements of the longitudinal slide 1 5b and the cross slide 16b, of the compound slide on the right end of the machine bed 11 b, as well as the angular slide 155 would be controlled by a control system embodying the principles of the control system of Figure 9.

Figure 14 is a schematic illustration of another embodiment of a single workhead grinding machine made in accordance with the principles of the present invention, and which includes the grinding machine structure illustrated in Figure 13, with an additional cross slide 158 for carrying the angular slide shown in Figure 13. The structure of the grinding machine illustrated in Figure 14, which is the same as the structure of the grinding machine illustrated in Figure 13, has been marked with the same reference numerals, followed by the small letter "c". The grinding machine illustrated in Figure 14 is adapted to carry out the same bore grinding and face grinding operations accomplished by the embodiment of Figure 13, with the additional control feature of the adjustability of slide 155c by the means of cross slide 158.The compound slide assemblies employed in the embodiment of Figure14 would be controlled by a control system embodying the principles of the control system of Figure 9.

Figure 15 is a further embodiment of a single workhead grinding machine, made in accordance with the principles of the present invention, and which includes the compound slide assembly of Figure 1, together with a second grinding wheel mounted on the cross slide of the compound slide assembly for sequentially carrying out a bore grinding operation and a face grinding operation. The structure of the grinding machine illustrated in Figure 15, which is the same as the structure of the grinding machines illustrated in Figures 1 and 12, have been marked with the same reference numerals, followed by the small letter "d".The movements of the longitudinal slide 15d and the cross slide 16d would be controlled by a control system employing the principles of the control system of Figure 9, for adjusting the position of the grinding wheels 29a and 137a, to sequentially carry out a bore grinding operation and a face grinding operation, respectively.

Figure 16 is still a further embodiment of a single workhead grinding machine made in accordance with the principles of the present invention, and which includes the compound assembly of Figure 1, together with a cross slide that carries a single workhead. The structure of the grinding machine illustrated in Figure 16, which is the same as the structure of the grinding machines illustrated in Figures 1 and 14, have been marked with the same reference numerals, followed by the small latter "e".

The grinding machine illustrated in Figure 16 is adapted to carry out the same bore grinding operation as the embodiment of Figure 1, with the additional control feature of the adjustability of the workhead 13e, which is carried on the cross slide 158e. The compound slide structure employed in the embodiment of Figure 14, and the workhead cross slide 158e, are controlled by a control system embodying the principles of the control system shown in Figure 9.

Figure 17 is still another embodiment of a single workhead grinding machine made in accordance with the principles of the present invention, and wherein the structure of Figure 1 is reversed, with the grinding wheel head 97f being fixed on the machine bed Ilf, and the workhead 13f being mounted on the cross slide 1 58f of a compound slide assembly including a longitudinal slide 159. The structure of the grinding machine illustrated in Figure 17, which is the same as the structure of the grinding machines illustrated in Figures 1 and 16, have been marked with the same reference numer als followed by the small letter "f". The grinding machine illustrated in Figure 17 is adapted to carry out the same bore grinding operation as the embodi ment of Figure 1, with the reverse control feature of the adjustability of the workhead 13f. The compound slide structure carrying the workhead 13f in the embodiment of Figure 17 would be controlled by a control system embodying the principles of the control system shown in Figure 9.

Figure 18 is a further embodiment of a single workhead grinding machine made in accordance with the principles of the present invention, and wherein a single grinding wheel head 979 is carried on a longitudinal slide 1589, and a single workhead 13g is carried on a cross slide 158g. The structure of the grinding machine illustrated in Figure 18, which is the same as the structure of the grinding machines illustrated in Figures 1 and 16, have been marked with the same reference numerals, followed by the small letter "g". The grinding machine illustrated in Figure 18 is adapted to carry out the same bore grinding operation as the embodiment of Figure 1, with the control features of the longitudinal adjustability of the grinding wheel 199, and the tranverse or cross adjustability of the workhead 139.The longitudinal slide 15g and the cross slide 1589 of the embodiment of Figure 18 would be controlled by a control system embodying the principles of the control system shown in Figure 9.

Figure 19 is still another embodiment of a single workhead grinding machine, made in accordance with the principles of the present invention, and showing a structure reverse to that of Figure 18, wherein a grinding wheel head 97h is mounted on a cross slide 16h, and a workhead 13h is mounted on a longitudinal slide 1 59h. The structure of the grinding machine illustrated in Figure 19, which is the same as the structure of the grinding machines illustrated in Figures 1 and 16 have been marked with the same reference numerals followed by the small letter "h".

The grinding machine illustrated in Figure 19 is adapted to carry out the same bore grinding operation as the embodiment of Figure 1, with the control features of the longitudinal adjustability of the workhead 1 3h and the transverse or cross adjustability of the grinding wheel head 97h. The longitudinal slide 159h and the cross slide 16h of the embodiment of Figure 19 would be controlled by a control system embodying the principles of the control system shown in Figure 9.

The control system of the present invention is adapted to control all of the movements of both slides in a compound slide assembly for a grinding machine. All of the movements of one compound slide assembly can be controlled simultaneously, or independently, by the electronic control system of the invention. All of the grinding machine functions and positions are controlled by the electronic control system through a screw actuator means.

Claims

1. A method for controlling all of the movements of a slide on a single workhead grinding machine characterized by the steps of: (a) programming a programmable controller with the required machine information and machine functions; (b) interfacing the electronic control means with a separate feed control means; (c) controlling the speed and directional movements of a slide drive motor with the speed control means; and, (d) controlling the movements of a slide by a screw actuator means by directly connecting it to the slide drive motor and to the slide, whereby the movements of the slide are directly controlled.

2. An electro-mechanical control system for controlling all of the movements of at least one slide on a single workhead grinding machine, characterized in that the control system includes: (a) a screw actuator means operatively attached to the slide for moving the slide when the screw actuator means is rotated; (b) a servo drive motor means connected directly to the screw actuator means for rotating the same; (c) an electronic feed control means operatively connected to said servo drive motor means for controlling the speed and directional movements of the motor means; and, (d) a programmable controller interfaced with said feed control means.

3. An electro-mechanical control system as defined in claim 2, characterized in that: (a) said feed control controls the axial reciprocation part of a grind cycle by the servo drive motor means and screw actuator means employed for moving the slide through other movements.

4. An electro-mechanical control system as defined in claim 2, characterized in that: (a) said programmable controller controls the axial reciprocation part of a grind cycle by the servo drive motor means and screw actuator means employed for moving the slide along the same axis.

5. An electro-mechanical control system as defined in claim 2, characterized in that: (a) said programmable controller controls adjustment of the slide for compensation for grinding wheel dressings by the servo drive motor means and screw actuator means employed for moving the slide through other movements.

6. An electro-mechanical control system as defined in claim 2, characterized in that: (a) said programmable controller controls the adjustment of the slide for size correction by the servo drive motor means and screw actuator means employed for moving the slide through other movements.

7. An electro-mechanical control system as defined in claim 2, characterized in that: (a) said servo drive motor means includes a servo drive means operatively connected to a drive motor which is provided with a tachometer means.

8. An electro-mechanical control system as defined in claim 7, characterized in that: (a) said drive motor is provided with a resolver means.

9. An electro-mechanical control system as defined in claim 8, characterized in that: (a) the resolver means is operatively connected to the servo drive means.

10. An electro-mechanical control system as defined in claim 7, characterized in that: (a) said drive motor is provided with an encoder means.

11. An electro-mechanical control system as defined in claim 10, characterized in that: (a) the encoder means is operatively connected to the servo drive means.

12. An electro-mechanical control system as defined in claim 7, characterized in that: (a) said drive motor is provided with a linear position transducer means.

13. An electro-mechanical control system as defined in claim 12, characterized in that: (a) the linear position transducer means is operatively connected to the servo drive means.

14. An electro-mechanical control system as defined in claim 7, characterized in that: (a) said drive motor is provided with a rotary position transducer means.

15. An electro-mechanical control system as defined in claim 14, characterized in that: (a) the rotary position transducer means is operatively connected to the servo drive means.

16. A grinding machine having a machine bed, a workhead, a longitudinal slide, a cross slide, and a grinding wheel head operatively provided with a rotatable grinding wheel for operative engagement with a workpiece carried by said workhead, characterized in that: (a) said longitudinal and cross slides are each directly connected by a screw actuator means to a servo drive motor means; (b) the servo drive motor means for each of said longitudinal and cross slides is controlled by an electronic feed control means for controlling all of the movements of each of the longitudinal and cross slides; and, (c) the electronic feed control means is controlled by a programmable controller.

17. A grinding machine as defined in claim 16, characterized in that: (a) each of said servo drive motor means includes a servo drive means operatively connected to a drive motor which is provided with a tachometer means.

18. A grinding machine as defined in claim 17, characterized in that: (a) said drive motor is provided with a resolver means.

19. A grinding machine as defined in claim 18, characterized in that: (a) the resolver means is operatively connected to the servo drive means.

20. A grinding machine as defined in claim 17, characterized in that: (a) said drive motor is provided with an encoder means.

21. A grinding machine as defined in claim 20, characterized in that: (a) the encoder means is operatively connected to the servo drive means.

22. A grinding machine as defined in claim 17, characterized in that: (a) said drive motor is provided with a linear position transducer means.

23. A grinding machine as defined in claim 22, characterized in that: (a) the linear position transducer means is operatively connected to the servo drive means.

24. A grinding machine as defined in claim 17, characterized in that: (a) said drive motor is provided with a rotary position transducer means.

25. A grinding machine as defined in claim 24, characterized in that: (a) the rotary position transducer means is operatively connected to the servo drive means.

26. A grinding machine as defined in claim 16, characterized in that: (a) the rotatable grinding wheel is adapted to perform a face grinding operation on a workpiece.

27. A grinding machine as defined in claim 16, characterized in that: (a) the rotatable grinding wheel is adapted to perform at least one internal grinding operation on the bores of a workpiece, and at least one face grinding operation on the same workpiece.

28. A grinding machine as defined in claim 16, characterized in that: (a)the rotatable grinding wheel is adapted to grind an external surface of a workpiece with the center of rotation of the surface being along the longitudinal axis of the machine.

29. A grinding machine as defined in claim 16, characterized in that: (a) the rotatable grinding wheel is adapted to grind a number of surfaces on a workpiece, in any combination of internal bore, face and external surfaces concentric with the bore.

30. A grinding machine as defined in claim 16, characterized in that: (a) the rotatable grinding wheel is mounted on a compound slide assembly comprising said longitudinal and cross slides and it is adapted to perform an internal grinding operation on a longitudinal bore in a workpiece.

31. A grinding machine as defined in claim 30, characterized in that: (a) the rotatable grinding wheel is mounted on the cross slide of said compound slide assembly.

32. A grinding machine as defined in claim 31, characterized in that: (a) the workhead is non-movably carried on the grinding machine bed.

33. A grinding machine as defined in claim 31, characterized in that: (a) the workhead is movably carried on the grinding machine bed.

34. A grinding machine as defined as claim 33= characterized in that: (a) the workhead is mounted on a cross slide, the movements of which are controlled by the same type of control means as used for the first named cross slide.

35. A grinding machine as defined in claim 32, characterized in that: (a) said rotatable grinding wheel is mounted on the cross slide of said compound slide assembly, and it is adapted to perform an internal grinding operation on the bore of a workpiece; and, (b) a second rotatable grinding wheel is mounted on the cross slide of said compound slide assembly, and it is adapted to perform a face grinding operation on said workpiece in sequence with the last named internal grinding operation.

36. A grinding machine as defined in claim 32, characterized in that: (a) said rotatable grinding wheel is mounted on the cross slide of said compound slide assembly, and it is adapted to perform an internal grinding operation on the bore of a workpiece; (b) a second longitudinal slide is carried by said first named longitudinal slide of said compound slide assembly; and, (c) a second rotatable grinding wheel is operatively mounted on said second longitudinal slide, and it is adapted to perform a face grinding operation on said workpiece simultaneously with the last named internal grinding operation.

37. A grinding machine as defined in claim 36, characterized in that: (a) an angularly disposed longitudinal slide is carried by said first mentioned longitudinal slide of said compound slide assembly; and, (b) a third rotatable grinding wheel is mounted on said angularly disposed longitudinal slide, and it is adapted to perform another face grinding operation on said workpiece simultaneously with said last named internal grinding operation and said first named face grinding operation.

38. A grinding machine as defined in claim 32, characterized in that: (a) said rotatable grinding wheel is mounted on the cross slide of said compound slide assembly, and it is adapted to perform an internal grinding operation on the bore of a workpiece; (b) an angularly disposed longitudinal slide is mounted on the grinding machine bed; and, (c) a second rotatable grinding wheel is mounted on said angularly disposed longitudinal slide, and it is adapted to perform a face grinding operation on said workpiece in a predetermined relationship with said last named internal grinding operation.

39. Agrinding machine as defined in claim 32, characterized in that: (a) said rotatable grinding wheel is mounted on the cross slide of said compound slide assembly, and it is adapted to perform an internal grinding operation on the bore of a workpiece; (b) a second cross slide is mounted on the grinding machine bed; (c) an angularly disposed longitudinal slide is mounted on said second cross slide; and, (d) a second rotatable grinding wheel is mounted on said angularly disposed longitudinal slide, and it is adapted to perform a face grinding operation on said workpiece in a predetermined relationship with said last named internal grinding operation.

40. A grinding machine as defined in claim 16, characterized in that (a) the workhead is mounted on a compound slide assembly comprising said longitudinal and cross slides; and (b) said grinding wheel is non-movably carried on the grinding machine bed.

41. A grinding machine as defined in claim 40, characterized in that: (a) the workhead is mounted on the cross slide of said compound slide assembly.

42. A grinding machine as defined in claim 16, characterized in that: (a) the workhead is mounted on said cross slide; and, (b) the grinding wheel is mounted on the longitudinal slide.

43. A grinding machine as defined in claim 16, characterized in that: (a) the workhead is mounted on said longitudinal slide; and (b) the grinding wheel is mounted on said cross slide.