US3634978A - Grinding machine - Google Patents

Grinding machine Download PDF

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Publication number
US3634978A
US3634978A US836549A US3634978DA US3634978A US 3634978 A US3634978 A US 3634978A US 836549 A US836549 A US 836549A US 3634978D A US3634978D A US 3634978DA US 3634978 A US3634978 A US 3634978A
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United States
Prior art keywords
workpiece
wheel
grinding machine
grinding
wheelhead
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US836549A
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English (en)
Inventor
Herbert R Uhtenwoldt
Frederick A Hohler
Edward G Robillard
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Heald Machine Co
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Heald Machine Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Heald Machine Co filed Critical Heald Machine Co
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Publication of US3634978A publication Critical patent/US3634978A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B5/00—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor
    • B24B5/01—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor for combined grinding of surfaces of revolution and of adjacent plane surfaces on work
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B47/00—Drives or gearings; Equipment therefor
    • B24B47/20—Drives or gearings; Equipment therefor relating to feed movement
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B49/00—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation

Definitions

  • Another object of this invention is the provision of a grinding machine for finishing a radial surface and anaxially extending surface of a workpiece at the same time while maintaining high quality of finished surface and little wear in the abrasive wheel.
  • a further object of the instant invention is to provide a grinding machine for efficiently plunge grinding with a contoured wheel workpiece surfaces having a deep radial surface.
  • a still further object of the invention is the provision of a grinding machine for plunge grinding the radial surface of a groove or the like without extreme wear on the peripheral surface of the wheel.
  • a still further object of the invention is the provision of a grinding machine for grinding the corner of a groove or the like wherein the work of removing stock is equally shared by the radial and the peripheral surfaces of the abrasive wheel.
  • Another object of the invention is the provision of a grinding machine which operates to grind a corner in a workpiece and which brings about equal wear of the radial and peripheral surfaces of the wheel to maintain the corner of the wheel sharp at all times.
  • the invention consists of a grinding machine for simultaneously finishing a workpiece having axially and radially extending surfaces.
  • This machine is provided with a base on which are mounted a wheelhead having means to rotate the workpiece about the axis of the axially extending surface, and a wheelhead having an abrasive wheel with grinding surfaces which match the said surfaces of the workpiece.
  • a first means is provided for moving the workhead and the wheelhead axially relative to one another
  • a second means is provided for moving the wheelhead and the workhead radially relative to one another
  • a control is provided to operate the first means and the second means in synchronization to advance the abrasive wheel into the workpiece surfaces along an optimum path.
  • FIG. I is a plan view of a grinding machine embodying the principles of the present invention.
  • FIG. 2 is a vertical sectional view of the machine taken on the line IIII ofFlG. 1,
  • FIG. 3 is a sectional view of a workpiece before grinding
  • FIG. 4 is a sectional view of a workpiece during grinding
  • FIG. 5 is a sectional view of a workpiece after a grinding operation
  • FIG. 6 is a cycle diagram of the operation of the grinding machine.
  • the grinding machine is of the general type shown and described in the copending patent application of Robillard et al., Ser. No. 672,222, filed Oct. 2, 1967, now U.S. Pat. No. 3,503,158 dated Mar. 3
  • it makes use of a stop which contacts the compensation slide portion of the wheelhead and makes electrical as well as mechanical contact, so that the final size gage becomes operative.
  • the compensation slide (and, therefore, the wheelhead) is moved by a stepping motor to the rear of the machine at a preset rate, i.e., 0.000050-inch increments in the preferred embodiment.
  • the rate would be set at a maximum (say, steps per sec. on the stepping motor) and the slide will only step far enough to break electrical contact between the slide and the stop. This occurs rapidly in small increments, so that there is very low force buildup on the stop.
  • the compensation slide acts, therefore, as a floating stop. This stop will be synchronized with the wheelhead cross-slide when the dress signal is obtained from the size gage.
  • the stepping motor stops the feed and a circuit is energized to remember the number of pulses of feed required.
  • the cross-slide is reset to zero" on the start feed position.
  • the cross-slide will next feed until the stop recontacts the compensation slide.
  • the compensation slide under the impetus of the stepping motor will retract to the dress size position at the IOO-step-second rate, the number of pulses required to do this being retrieved from the memory circuit.
  • this position at which the gage had previously indicated that dress should take place
  • the fine finish feed takes place by moving the compensation slide rearwardly.
  • the gage will indicate the arrival of the workpiece size; this will terminate the fine feed and grinding will continue under sparkout conditions due to the pressure of the deflection in the spindle until the gage indicates that the final size has been reached.
  • the compensation slide will be reset to the zero or start feed position.
  • a feedback circuit will also be energized to compare the number of pulses required to obtain the final size to a standard number of pulses. If the number of feed pulses is below the early gage limit, a feedback signal will shift the first size" point to a smaller point. On the other hand, if it is above the late gage limit, the feedback signal will shift the first size" point to a larger point. If the number of pulses is between the two limits (normal gage), there will be no feedback signal.
  • the grinding machine consists of a base 11 on which is mounted a workhead 12 carried on a workhead table 13 which is capable of sliding motion on ways 14 extending parallel to the axis of a surface 15 of revolution of a workpiece 16 which is to be finished. Also mounted on the workhead table 13 is a dressing apparatus 17 having a diamond. Extending through the workhead 12 for engagement with the workpiece bore (surface of revolution 15) is a pneumatic gage 18 of the type shown and described in the patent of Schmidt et al., US. Pat. No. 2,771,714 of Nov. 27, 1956.
  • This gage is suitably connected to suitable pressure switches, such as a pressure switch 19, capable of indicating when the size of the bore 15 has reached the size at which it is necessary to dress the wheel, a pressure switch 21 indicating when the bore has reached an intermediate size at which the finish grind is to be terminated, and a pressure switch 22 which is operative when the size of the bore has reached the final size.
  • suitable pressure switches such as a pressure switch 19, capable of indicating when the size of the bore 15 has reached the size at which it is necessary to dress the wheel, a pressure switch 21 indicating when the bore has reached an intermediate size at which the finish grind is to be terminated, and a pressure switch 22 which is operative when the size of the bore has reached the final size.
  • a wheelhead table 25 which is slidable on ways 23 and 24 to move transversely of the axis of the surface of revolution 15. Both the table 13 and the table 25 are movable under the impetus of hydraulic linear actuators to produce their respective motions. Lying on the base 11 and slidable over its surface is a compensation slide 26. Ex tending from the wheelhead table 25 is a finger 27 arranged to engage a forwardly facing feed stop 28 which is mounted on the forward face of the compensation slide. The finger 27 and the feed stop 28 are also arranged as an electrical switch for placing the pneumatic gage 18 in operative condition on occasion.
  • the wheelhead table 25 is also provided with a downwardly extending horn or finger 29 which is in position to engage a rearwardly directed dress stop 31 formed on the compensation slide 26. There is a considerably greater distance between this finger 27 and the finger 29 than there is between the feed stop 28 and the dress stop 31, so that the table 25 is capable of a wide range of operative movement between those two portions under the impetus of a suitable hydraulic cylinder 32.
  • This cylinder is arranged with the usual servo valves and control equipment to produce rapid action in moving the wheelhead table 25 from a first position where the finger 27 engages the feed stop 28 to the second position at which the finger 29 engages the dress stop 31.
  • a wheelhead 33 Mounted on the wheelhead 25 is a wheelhead 33 carrying a rotatable spindle 34, the outer end of which carries an abrasive wheel 35.
  • the cylinder 32 is provided with hydraulic fluid at a carefully regulated pressure so that it is possible to predetermine the force producible by the cylinder and use that force for engagement of the abrasive wheel 35 with the workpiece 16 according to the well-known controlled-force grinding principle.
  • the back end of the compensation slide 26 is threadedly engaged with a screw 36 which is driven through suitable gearing by a stepping motor 37.
  • the stepping motor, the screw 36, and the compensation slide 26 operate to give a readily selected accurate compensation at the time of dress in accordance with the teaching set forth in the said patent application of Robillard, U.Sv Pat. application Ser. No. 672,222.
  • the finger 27 is engaged with the front of the cross-slide or wheelhead table 25 through a screw 38 to provide a certain degree of adjustment.
  • This adjustment takes place by a ratchet 39 mounted on the front of the screw 38 and operated in opposite directions by pawls 40 and 41 slidable back and forth by cylinders 42 and 43.
  • a handwheel 44 operates through a rod 45 to permit manual operation of the screw 36 to provide for minor adjustments of the compensation slide 26.
  • a main control 46 feeds a pattern of electrical pulses through a cable 47 to the main stepping motor and, at the same time, to a control panel not shown.
  • a housing 48 Attached to the left side end of the base 11 is a housing 48 to the lower end of which is attached a stepping motor 49 similar to the stepping motor 37 associated with the table 25.
  • a stepping motor shaft On the stepping motor shaft is mounted a worm 51 which engages a horizontal worm gear 52 mounted on a horizontal shaft 53.
  • the shaft 53 operates through ball screw 54 and a differential screw 55 to produce a substantial reduction from the stepping motor 49 to an output shaft 56.
  • This output shaft is attached to the piston rod 57 of the table cylinder 58.
  • the ratio between the stepping motor and the shaft 56 is similar to the ratio between the stepping motor 37 and the compensa tion slide 26; that is to say, one step of the stepping motors 37 and 49 produce the same linear motion in their respective tables 25 and 13, except, of course, that the motion is transverse in one case and longitudinal in the other case.
  • Attached to the table 14 is a bar 59 having adjustable dogs 61 and 62 which operate a limit switch 63.
  • the workpiece 16 is an illustration shown as being the outer race of a roller bearing. It is already provided with a preformed groove 64 but is desired to recess the groove even further to provide a surface of revolution 65 of cylindrical form and a radial flat surface 66. In addition, a small relief groove 67 is to be formed at the intersection of these two surfaces.
  • the wheel 35 is formed with a radial surface 68, a cylindrical peripheral surface 69, and a ridge 7], these lastnamed three surfaces making up a complex shape which will provide the surfaces 65, 66, and 67 on the finished workpiece.
  • the wheel in this form is known as a contoured wheel and is produced by dressing the wheel in the manner shown and described in the patent application of Hohler et al., US. Pat. application No. 7l0,l23, filed Mar. 4, 1968, now abandoned.
  • the shapes described on the finished workpiece would be produced by feeding the wheel 35 exactly transversely to its axis, and this would result in a number of deleterious effects.
  • the spindle 34 when subjected to strong radial forces on the wheel, tends to deflect or bend, thus throwing any radial surface 68 at a slight angle.
  • plunge grinding as it has been described, in the old way, produces a cutting action through the metal along the finished surface 66, which grinding is done entirely by the comer of the wheel 35 at the intersection of the wheel surfaces 68 and 69, or the sharp edge of the ridge 7].
  • This produce extreme wear on this corner and results in the finished shape being different from the dressed shape to which the wheel was formed.
  • constant dressing of the contour of the wheel results in a reduction of the wheel in a very rapid time and, or course, such dressing is necessary in order to maintain any kind of a proper finished surface.
  • the surface 68 rubs against the finished surface 66 producing a poor finish at that point and burning of the wheel and workpiece.
  • the wheel 35 (referring to FIG. 4) is fed in along the 45 angle indicated by the arrow. ln a combined motion of the wheel which, for the purpose of the present patent application, will be referred to as "conjugate grinding, to produce this effect, the cylinder 58 is actuated to bring the abrasive wheel 35 into the bore in the workpiece 16. At that point, the feeding motion of the cylinder 58 is terminated and motion due to the two stepping motors 37 and 49 takes place.
  • the main control 46 issues pulses in accordance with the prior art teaching to both of these stepping motors, so that they operate through their gear reduction gearing and screws to produce transverse and longitudinal motion of their respective tables.
  • the stepping motor 37 will move the slide 26 rearwardly, and this will engage the finger 29 of the table and move the table rearwardly along with the wheelhead 33 and the abrasive wheel 35.
  • the same pulses emitting from the main control 46 carries through a table 50 to the stepping motor 49, thus bringing about longitudinal motion of the table 13 and similar motion of the workpiece 16 toward the abrasive wheel 35.
  • the net result is that the wheel and the workpiece 16 move relative to one another along a line, so that the corner of the wheel is introduced directly into the corner of the desired finished shape.
  • the radial surface 68 of the wheel grinds directly into the workpiece 16 to produce the finished surface 66 and the peripheral surface 69 of the wheel grinds directly radially to produce the finished cylindrical surface 65. Also, the ridge 71 produces the groove 67 in the workpiece.
  • the contour dressing apparatus dresses the surface 68 and the surface 69 and the ridge 71 of the workpiece, removing abrasive material from the wheel and restoring it to a predetermined shape.
  • the surface of the wheel when returned to the next workpiece in succession to be finished would be a considerable distance away from the surface and the wheel would be cutting air before contact with the rough workpiece took place. This would make the cycle of grinding longer and longer as time progressed.
  • FIG. 6 of the drawings This is a simple grinding cycle in which the dressing of the wheel 35 takes place during the loading and unloading of a new workpiece, rather than during the grinding cycle itself.
  • the abrasive wheel With the parts in the condition following dress and loading of a new workpiece, the abrasive wheel is in a position withdrawn from the workpiece bore at the point A.
  • the cylinder 58 operates to move the table 13 to the right to the point B where the abrasive wheel lies within the bore in the workpiece.
  • the cylinder 32 operates to move the table 25 rearwardly to the point C where the wheel is close to the part of the groove 64 of the workpiece that is to be finished.
  • the cylinder 32 continues to press the wheel into the work for a first engagement for a rough grind to the point D.
  • the stepping motor 49 being operated at that point to move the workpiece longitudinally toward the abrasive wheel to produce cutting with the wheel surface 68.
  • the finger 27 strikes the stop 28 on the slide 26 and motion of the table 25 is restricted to motion produced by introduction of pulses to the stepping motor 37, moving the slide 26 rear wardly and carrying the table with it, the finger 27 being kept in contact with the stop 28 on the slide 26 by the cylinder 32.
  • the surfaces 68 and 69 as well as the ridge 71 are being subjected to an equal amount of wear during the grinding cycle so, presumably, the shape of the wheel will remain substantially the same right up to the end of the cycles, so that the finished surfaces 65, 66, and 67 of the workpiece will be exactly as desired and a produced by the dressing apparatus 17 on the abrasive wheel 35. Since the peripheral surfaces of the wheel, i.e., surface 69 and ridge 71.
  • a grinding machine for simultaneously finishing an internal surface of revolution of a workpiece having axially and radially extending surfaces, comprising a. a base, i
  • a wheelhead having an abrasive wheel with radial and cylindrical grinding surfaces which match the said surfaces of the workpiece
  • a second means separate from the said first means for moving the workhead and the wheelhead radially relative to one another
  • a control to operate the first means and the second means in synchronization to advance the abrasive wheel into the workpiece surfaces along an optimum path.
  • each of the first and second means includes a screw mechanism driven by a stepping motor and wherein the control provides pulses to each of the stepping motors for the said advance of the wheel into the workpiece.
  • control also provides a predetermined number of pulses after the dressing of the wheel to each stepping motor to provide compensating movement both in the radial and the axial direction.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Grinding Of Cylindrical And Plane Surfaces (AREA)
  • Grinding-Machine Dressing And Accessory Apparatuses (AREA)
US836549A 1969-06-25 1969-06-25 Grinding machine Expired - Lifetime US3634978A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US83654969A 1969-06-25 1969-06-25

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US3634978A true US3634978A (en) 1972-01-18

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Application Number Title Priority Date Filing Date
US836549A Expired - Lifetime US3634978A (en) 1969-06-25 1969-06-25 Grinding machine

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US (1) US3634978A (fr)
CH (1) CH517560A (fr)
DE (1) DE2030851B2 (fr)
FR (1) FR2047919B1 (fr)
GB (1) GB1302114A (fr)
SE (1) SE384335B (fr)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3800473A (en) * 1972-08-04 1974-04-02 Brown & Shapiro Mfg Co Bore grinding machine
US3879897A (en) * 1972-12-08 1975-04-29 Nippon Seiko Kk Method and apparatus for producing the bearing races
US3911624A (en) * 1974-11-07 1975-10-14 Gen Motors Corp Polishing apparatus
US3924355A (en) * 1973-01-19 1975-12-09 Youji Tatsumi Internal grinder
DE2758275A1 (de) * 1977-02-18 1978-08-31 Warner Swasey Co Maschine und verfahren zum schleifen von rotationsflaechen
US4170851A (en) * 1977-09-20 1979-10-16 Cincinnati Milacron Heald Corp. Grinding machine
US4205488A (en) * 1977-02-18 1980-06-03 The Warner & Swasey Company Grinding machine
US4587763A (en) * 1985-02-17 1986-05-13 Hahn Robert S Grinding machine
US4615149A (en) * 1984-05-23 1986-10-07 Toyoda Koki Kabushiki Kaisha Feed control apparatus for grinding machine

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2519282B1 (fr) * 1981-12-31 1986-06-20 Gendron Machine pour rectifier simultanement deux pieces, comportant au moins une portee cylindrique et un epaulement transversal

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2600548A (en) * 1946-09-05 1952-06-17 Brown & Sharpe Mfg Grinding wheel truing apparatus
US2641873A (en) * 1949-03-05 1953-06-16 Cincinnati Milling Machine Co Automatic truing mechanism
US2699018A (en) * 1951-06-30 1955-01-11 Devilbiss Co Automatic grinding wheel dresser and feed control
US2955391A (en) * 1958-12-22 1960-10-11 Norton Co Work positioning mechanism for machine tools
US3145508A (en) * 1963-02-21 1964-08-25 Landis Tool Co Apparatus for grinding intersecting annular and cylindrical surfaces
US3436865A (en) * 1964-05-11 1969-04-08 Corning Glass Works Edge form grinding
US3503158A (en) * 1967-10-02 1970-03-31 Heald Machine Co Grinding machine

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2600548A (en) * 1946-09-05 1952-06-17 Brown & Sharpe Mfg Grinding wheel truing apparatus
US2641873A (en) * 1949-03-05 1953-06-16 Cincinnati Milling Machine Co Automatic truing mechanism
US2699018A (en) * 1951-06-30 1955-01-11 Devilbiss Co Automatic grinding wheel dresser and feed control
US2955391A (en) * 1958-12-22 1960-10-11 Norton Co Work positioning mechanism for machine tools
US3145508A (en) * 1963-02-21 1964-08-25 Landis Tool Co Apparatus for grinding intersecting annular and cylindrical surfaces
US3436865A (en) * 1964-05-11 1969-04-08 Corning Glass Works Edge form grinding
US3503158A (en) * 1967-10-02 1970-03-31 Heald Machine Co Grinding machine

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3800473A (en) * 1972-08-04 1974-04-02 Brown & Shapiro Mfg Co Bore grinding machine
US3879897A (en) * 1972-12-08 1975-04-29 Nippon Seiko Kk Method and apparatus for producing the bearing races
US3924355A (en) * 1973-01-19 1975-12-09 Youji Tatsumi Internal grinder
US3911624A (en) * 1974-11-07 1975-10-14 Gen Motors Corp Polishing apparatus
DE2760477C2 (de) * 1977-02-18 1993-11-25 Pratt & Whitney Co Verfahren zum Schleifen einer Planfläche und einer daran anschließenden zylindrischen Längsfläche eines Werkstückes
DE2758275A1 (de) * 1977-02-18 1978-08-31 Warner Swasey Co Maschine und verfahren zum schleifen von rotationsflaechen
US4115958A (en) * 1977-02-18 1978-09-26 The Warner & Swasey Company Method of cylindrical and shoulder grinding
US4205488A (en) * 1977-02-18 1980-06-03 The Warner & Swasey Company Grinding machine
DE2760474C2 (de) * 1977-02-18 1993-11-25 Pratt & Whitney Co Verfahren zum Schleifen eines Werkstücks sowie Schleifmaschine
DE2760476C2 (de) * 1977-02-18 1993-11-25 Pratt & Whitney Co Verfahren zum Schleifen eines um seine Längsachse umlaufenden Werkstücks
US4170851A (en) * 1977-09-20 1979-10-16 Cincinnati Milacron Heald Corp. Grinding machine
US4615149A (en) * 1984-05-23 1986-10-07 Toyoda Koki Kabushiki Kaisha Feed control apparatus for grinding machine
US4587763A (en) * 1985-02-17 1986-05-13 Hahn Robert S Grinding machine

Also Published As

Publication number Publication date
SE384335B (sv) 1976-05-03
CH517560A (de) 1972-01-15
GB1302114A (fr) 1973-01-04
DE2030851B2 (de) 1980-12-18
DE2030851A1 (de) 1971-02-04
FR2047919B1 (fr) 1973-01-12
FR2047919A1 (fr) 1971-03-19

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