US3369330A

US3369330A - Automatic abrading machine

Info

Publication number: US3369330A
Application number: US482234A
Authority: US
Inventors: Mark R Estabrook; Donald K Greenberg
Original assignee: Barnes Drill Co
Current assignee: Barnes Drill Co
Priority date: 1965-08-24
Filing date: 1965-08-24
Publication date: 1968-02-20
Anticipated expiration: 1985-02-20

Description

Feb. 20, w68 M. R. ESTABROOK ET AL 3,369,330

AUTOMATIC ABRADNG MACHINE Filed Aug. 24, 1965 3 Shee, 1.s-Shee l 1 Feb- 20, 1968 M. R. ESTABROOK ET AL 3,369,330

AUTOMATIC ABRADING MACHINE 3 Sheets-Sheet f Filed Aug. 24, 1965 G re en b e r W /nr CAT-r onmlyf @mark IQ. zbrook, Doncdd Q( Feb. 20, 1968 M. R. ESTABROOK ET A1. 3,369,330

AUTOMAT I C ABRADING MACHI NE Filed Aug. 24, 1965 3 Sheets-Sheet 5 mg/ Cjhmosyf United States Patent O 3,369,330 AUTOMATIC ABRADING MACHINE Mark R. Estabrook and Donald K. Greenberg, Rockford,

Ill., assignors to Barnes Drill Co., Rockford, Ill., a corporation of Illinois Filed Aug. 24, 1965, Ser. No. 482,234 10 Claims. (Cl. 51-344) This invention relates generally to automatic abrading machines and more particularly to a machine for rough and tinish honing a work bore with a single rotary honing tool having two sets of alternately usable honing elements of different abrasive characteristics. One set of elements is formed of relatively coarse abrasive surfaces yfor rough honing the bore wall and the other set with relatively fine surfaces for finish honing the wall, the elements of the two sets being fed independently into the wall to perform both rough and finish honing in a substantially continuous c cle.

yThe general object of the present invention is to simplify and improve the expansion mechanism for feeding the two sets of honing elements of a honing machine of the foregoing character.

Another object is to utilize `a single expander and the identical motions of the expansion mechanism for feeding each set of honing elements into the work.

A related object is to feed the two sets of elements alternately into the work with an expansion mechanism of a type presently used with tools having -only one set of elements and requiring little modification to adapt it for use with a tool having two sets of alternately usable elements.

A more detailed object is to provide an expander having a single set of spaced cams engageable alternately with the respective sets of honing elements and brought into operative association with the selected set by a motion of the expander in a direction transverse to the direction of the feed motion.

A further object is to form the expander in a novel manner to leave one set of elements idle during the feed motion of the expander.

The invention also resides in the manner of supporting and selectively moving the expander.

Other objects and advantages of the invention will become apparent from the following detailed description takenin connection with the accompanying drawings, in which FIGURE l is `a fragmentary side elevational view of an automatic honing machine embodying the novel features of the present invention, the drive mechanism for the expander being shown schematically.

FIG. 2 is an enlarged fragmentary cross-sectional view taken substantially along the line 2-2 of FIG, 1 with the parts in moved positions.

FIG. 3 is an enlarged fragmentary View similar to a portion of FIG. 2 showing the position of the sizing device during the finishing portion of the cycle.

FIG. 4 is an enlarged end view of the honing tool.

FIG. 5 is an enlarged cross-sectional view taken substantially along the line 5-5 of FIG. 2.

FIG. 6 is an enlarged perspective view of the expander.

FIG. 7 is an enlarged perspective view of one of the honing elements.

FIG. 8 is an enlarged side fragmentary elevational view, partly in section, of the tool shank and parts of the expander and spindle.

FIG. 9 is an enlarged cross-sectional view taken along the line 9h9 of FIG. 2.

FIG. 10 is an enlarged cross-sectional View taken substantially along the line lll-1li of FIG. 2.

As shown in the drawings for purposes of illustration, the invention is incorporated in an automatic machine for 3,3 0l Patented Feb. 20, 1968 ICC honing the bore wall 10 of a workpiece 11 by reciprocating a rotary tool 12 back and forth within the bore and simultaneously rotating the tool with abrasive elements 13 thereon pressed `against the wall. The tool is fast on the lower end of a spindle 14 journaled adjacent its upper end on a reciprocating head 15 and rotated about its longitudinal axis by an electric motor 17 connected to the spindle by gearing 18. The head is movable vertically along suitable guides (not shown) toward and away from the workpiece to -reciprocate the rotating tool within the bore.

In this instance, the tool 12 comprises a hollow body 19 having a coaxial shank 20 secured to the lower end of the spindle 14 and is formed with a plurality of angularly spaced longitudinal slots 21 in which the honing elements 13 are disposed with a snug friction fit. The outer portion of each element is a stick of bonded abrasive material having an outer working surface 13a, and. is backed by a bar 22 having inwardly projecting followers 23 engageable with a cam 24 on lan expander 25 inside the body. The abrasive sticks are secured to the backing bars in a well known manner by sheet metal carriers of generally Z- shaped cross-section (see FIGS. 4, 5 and 7) formed by parallel lianges 27 and 28 projecting in opposite directions from the side edges of a crosspiece 29. The flange 27 lies lagainst one side of the abrasive stick to separate the latter from the trailing side wall of the body slot 21 with the crosspiece underlying and secured to the bottom of the stick and with lugs 30 struck out of the crosspiece and lying against the leading side of the stick to cooperate with the iiange in forming a seat for the stick. The other ange 23 is fastened to the vbacking bar 22 by pins 31 fitted snugly in holes in the bar and projecting outwardly through holes in the mounting flange into peripheral grooves 32 (FIG. 1) in the tool body 19..

As shown most clearly in FIGS. 2 and 7, the followers 23 are longitudinally spaced fingers projecting radially inwardly from the backing bars 22 for engagement with the cams 24 on the expander 25. In one direction of movement of the expander, the cams shift the followers and the associated honing elements radially outwardly relative to the tool body 19 to feed the working surfaces 13a into the bore wall at a controlled rate, while in the opposite movement, the cams permit inward motion of the honing elements and contraction of the tool by garter springs 33 around the ends of the honing elements. The expander is carried on the lower end of an expansion rod 34 extending upwardly through the spindle 14 and connected at its upper end to a power-operated feed mechanism 35 for moving the expansion rod and the expander relative to the spindle and the tool body through a preselected range of feeding and contracting movement.

To make it possible to perform both rough honing and nish honing with the same tool 12, two sets of

honing elements

13 and 37 are disposed in the slots 21 with the elements of the two sets alternating with each other around the tool body 19. The elements of one set 13 have abrasive sticks composed of relatively coarse grit and the elements 37 of the other set have abrasive sticks composed of finer `grit forming working surfaces 37a. Except for the abrasive, the two sets of elements may be identical. Initially, the coarse sticks are fed into the bore wall 10 to remove ridges and high spots therefrom at a comparatively rapid rate while enlarging the bore almost to the desired finished diameter. Then the finer sticks are used to polish the bore wall to a smooth .finish while removing a smaller amount of ystock sufiicient to bring the bore up to the preselected diameter.

Herein, the attainment of the desired bore size for both the roughing and the finishing portions of the cycle is sensed by a successively acting sizing plug 39 comprising a ring 4i) (see FIGS. 2, 3 and 9) fast on a sleeve 41 telescoped loosely over the tool shank 2t) and the lower end portion of the .spindle lf2- and preferably urged yicldably toward the tool and a stop ring Zd@ by a coiled spring 42 acting between a flanged disk 43 on the upper end of the sleeve and a ring 4d secured to the spindle aoove the sleeve. Around the periphery of the sizing ring lll are two axially spaced annular series of hardened segments d5 and 47, the lower series being externally sized to enter the work bore when the latter attains the desired rough honed size and the upper series being sized to enter when the bore attains the desired finished size. A proximity switch 4S on a plate 49 through which the spindle projects is actuated by the disk 43 to produce a signal when the lower series of segments enters the bore, this signal being used to terminate rough honing and initiate finish honing. A second switch 5t) formed by the disk 43 and contacts on the plate i9 is closed when the upper series of segments enters the bore, thereby signaling the attainment of the finished size to initiate termination of the cycle. The plate 49 and a second plate 49a disposed around the tool in FIG. 1 are supported in a well known manner described in detail in Patent No. 2,787,867.

In accordance with the present invention, the expander is formed with a single set of cams 2d engageable alternately with the followers 23 of the respective sets of

honing elements

13, 37 and brought into engagement with the selected set by a motion of the expander transverse to the direction of the feed motion. While shifting the cams into operative association with the selected set of honing elements, the selecting motion simultaneously disassociates the cams from the other set and leaves them idle during the subsequent feeding motion of the expander.

To these ends, the expander cams Zd are separated by grooves 51 which aline with and receive the followers Z3 on the idle set of

honing elements

13, 37 in each selected position of the expander 25 and thus permit the expander to act on only one set of followers while moving through its feeding motion. Moreover, the expander is freely movable in the transverse direction in one position within the range of feed motion. Thus, to change to a different set of honing elements, the expander is simply shifted to that position and then moved transversely to aline the cams with the new set of followers.

In the present instance, the expander 25 is movable axially of the tool body i9 to expand and contract the tool 12, and the selection motion is a turning motion to shift the cams 24 between two angularly spaced positions. Accordingly, the expander comprises at least one and preferably two identical generally conical cam members (see FIG. 6) each having a stem 52 of circular cross-section at its smaller end. The two cones are joined together in coaxial end-to-end relation by one of the .stems which herein is integral with the smaller end of one cone and the larger end of the other. The grooves Slt extend longitudinally of the cones and are spaced equally apart to aline angularly with the followers of alternating honing elements around the tool body and thus divide each cone into a series of wedge-shaped cams 24. rthe bottoms of the grooves are level with the peripheries of the stems and the latter merge smoothly with the smaller ends of the cams. As shown in FIGS. 2 and 9, the lower end of the expansion rod 34 is received in a recess in the upper cone and secured thereto by a pin 34a.

With this type of expander, the drive mechanism 35 shifts the so-called push rod 34.'- endwise back and forth and may take various forms that are well known to those skilled in the art. One such mechanism comprises two electric motors 53 and 54 (FIG. l) whose motions are combined by differential gearing 55 and converted into endwise motion of the push rod by a screw mechanism 57. The motors are carried by the reciprocating tool head 15 with the motor 54 coupled directly to the sun gear SS of the differential and the motor 535 driving a worm 59 meshing with external teeth on the ring gear 6d. The

spider 6l of the differential carries planet gears 62 and is fast on an output shaft 63 driving a worm 64. The latter meshes with a worm wheel 65 formed on a sleeve 67 threaded onto a screw 68 on the upper end of the push rod 3d.

When the motors S3 and 5d are operated together, the output shaft 63 is rotated at a relatively high speed to drive the push rod 34 downwardly through the spindle 14 and expand the tool ft2 at a comparatively rapid rate such as .047 of an inch per second. With the motor 53 operating alone, the tool is expanded at a much slower rate such as .00019 of an inch per second. The more rapid rate is used to bring the abrasive sticks into engagement with the bor'e wall l@ and collapse the sticks away from the wall, and the slower rate is used to expand the tool slowly during the honing cycle. The motors are controlled in a well known manner which is not described in detail herein.

To aline the cams 24 selectively with the followers 23 of either set of honing elements f3, 37 and the grooves 5l with the other followers, the expander 25 is shifted upwardly until the tool l2 is fully collapsed, thereby sliding the stems 52 into alignment with the followers of all of the honing elements, and is rotated through a preselected arc sulicient to turn the cams away from one set of followers and into alignment with the other set while similarly reversing the positions of the grooves. Herein, there are six of each type of honing elements equally spaced around the tool body 1.19 and each interposed between two similarly spaced elements of the other type. The arc of oscillation of the push rod 34, therefore, is thirty degrees.

The selective turning of the expander 25 is produced by a double-acting power actuator 69 in this instance comprising two pistons 7@ and 7l (FIGS. 2 and l0) fitted in

parallel bores

72 and 73 forming cylinders tangent to opposite sides of the push rod 34 in an enlarged cylindrical collar '7d encircling the intermediate section of the spindle f4. Each piston is formed with a longitudinal series of teeth meshing with elongated spline teeth at 75 on the intermediate section of the push rod which is rotatable relative to the upper section, and thus constitute racks for turning the push rod about its longitudinal axis. Herein, the upper section is separated from and abuts against the lower section at 77 (FlG. l) above the actuator, the two sections being held in abutting engagement by a spring 73 (FIG. 2) coiled around the lower section and compressed between an enlargement 79 thereon and an internal shoulder 3@ in the spindle lllbelow the actuator. The lower section is formed by two parts pivotally connected at 8l.

Fitted in the opposite ends of the cylinder bores 72 and 73 are two sets of

plugs

82 and 33 which close and seal the bores. The plugs S2 are simply set screws threaded into the bores for inward and outward adjustment and forming stops 84 and S5 limiting the strokes of the pistons 7l) and 7l, and the plugs 33 are sealed in the bores. The collar 7d is formed with inlet passages 87 and S3 for admitting pressurized air from a suitable source (not shown) into the bores. As shown in FIG. 2, the inlet passages extend through the collar 74- and communicate with annular grooves and 9@ around the collar inside a stationary transfer ring 9i through which supply pipes 92. and 93 deliver pressurized air to the respective grooves. The transfer ring is anchored in place by a torque arm 94 supported on the machine frame and holding the pipes stationary.

At the beginning of an automatic cycle, the tool 12. is collapsed and retracted from the workpiece lll to be honed so the followers 23 of both sets of

elements

13 and 37 are longitudinally alined with the stems 52 and are held in engagement therewith by the garter springs 33. Assuming that the cams 24 are angularly alined with the followers of the finishing elements 37, a charge of air is admitted through the pipe 92 and the inlet passage 87 to the bore 72 to shift the piston 70 forward' toward its adjustable stop 84, upwardly as viewed in FIG. 10. This motion of the piston turns the push rod and the expander 25 counterclockwise through an arc of thirty degrees, as determined by the position of the stop, and thus turns the cams 2d along the stems into angular alinement with the roughing elements i3 and the grooves 51 into alinement with the finishing elements 37.

Then honing is initiated in the usual manner to reciprocate and rotate the tool 12 within the work bore 10 while the push rod 34 is fed downward through the spindle 14 by the drive mechanism 35. This motion of the push rod shifts the expander 2S relative to the tool body 19 so that the cams 24 feed the roughing elements 13 outward through the slots 21 at the rate selected for rough honing. During this feeding motion of the expander, the followers 23 of the finishing elements 37 ride idly along the grooves 51.

When the proximity switch 48 signals the enlargement of the work bore to the desired rough size, the drive mechanism 35 is reversed to withdraw the push rod 34 and collapse the tool l2 thereby returning all the followers 23 to the stems 52. Then a charge of air is directed through the pipe 93 and the inlet passage 88 to the bore 73 to shift the piston 71 forward against its stop 8S. This rotates the push rod and the expander clockwise through a thirty degree arc and alines the cams 24 with the finishing elements 37 while returning the piston 7) to its retracted position. The pin 34a projects radially outward through an inverted U-shaped slot 95 in the tool shank and thus provides a visible indication of the angular position of the expander 25, riding back and forth across the upper portion of the slot during the selection of the respective honing elements and moving down the parallel vportions during the different portions of the cycle,

After the changeover has been completed, the tool i2 again is reciprocated and rotated within the bore lit) while the push rod 34 is fed downward by the drive mechanism 35. This time, however, the finishing elements 37 are fed into the wall while the roughing elements i3 remain contracted. When the switch 50 signals the attainment of the desired finished bore size, the tool is withdrawn from the bore and collapsed.

From the foregoing, it will be seen that the expander utilizes the same type of drive mechanism 35 that has been in use in prior honing machines, and uses only one set of cams 2d for the selective feeding of both sets of honing elements A13, 37. The full range of expander motion is available for each set of elements, and a relatively simple actuator 69 is used to produce the selecting motion of the expander. Thus, conventional honing machines are easily adapted for operation with a dual tool, and the honing operation with each set of elements has all the advantages of honing with separate machines. At the same time, the need for a second machine or `a separate tool is eliminated.

We claim as our invention:

1. A honing machine having, in combination, a hollow rotary body having a plurality of angularly spaced longitudinal slots, first and second sets of honing elements having abrasive surfaces of different characteristics disposed in said slots and alternating with each other around said body with said abrasive surfaces facing outwardly for engagement with a bore wall to be honed, each of said elements having a follwer on its inner side, an expander disposed within and movable axially of said body through a preselected range of feed motion from a first position to a second position, said expander having a set of angularly spaced wedge-shaped cams selectively alineable with the followers of either set of honing elements and operable upon axial movement of said expander in one direction to feed the alined set of elements outwardly relative to said body, from a collapsed condition in said first position to a fully expanded condition in said second position, said cams being separated by longitudinal grooves for receiving the followers of the other set' ofV elements during said feed motion, a section on said expander of circular cross-section merging smoothly with the smaller ends of said cams and level with the bottoms of said grooves, said followers engaging said section when said expander is in said first position, means for selectively turning said expander to bring said cams into alinement with the followers of either set of honing elements in said first position, and mechanism for moving said expander axially of said body in alinement with each selected set of elements. i

2. A honing machine having, in combination, a hollow rotary body having a plurality of equally spaced longitudinal slots, first and second sets 0f honing elements having abrasive surfaces of different characteristics disposed in said slots and alternating with each other around said body with said abrasive surfaces facing outwardly for engagement with a bore wall, an expander disposed with. in and movable axially of said body and having a series of wedge-shaped cams angularly spaced apart for engagement with the inner sides of alternating elements around said body, said expander also having a plurality of angularly spaced longitudinal grooves separating said cams and adapted to be alined with the inner sides of alternating elements around said body, mechanism for selectively turning said expander in one longitudinal position thereof back and forth between a first angular position in which said cams are alined with the elements of said first set and a second angular position in which the cams are alined with the elements of said second set, and means for moving said expander axially relative to said body in both of said angular positions to feed said elements outwardly relative to said body.

3. A honing machine having, in combination, a rotary spindle, a hollow tool body on said spindle having a plurality of angularly spaced radial slots, first and second sets of honing elements having abrasive surfaces of different characteristics disposed in said slots and alternating with each other around said body, an expansion rod disposed within and reciprocable longitudinally of said spindle, an expander disposed within said body and movable with said rod, said expander having a plurality of angularly spaced cams thereon, mechanism for turning said rod and said expander selectively between two angularly spaced positions to aline said cams selectively with the respective sets of honing elements, and means for moving said rod and said expander axially back and forth relative to said body in each of said positions to control the feeding and retracting of the selected set of honing elements.

4l. The combination defined in claim 3 in which said turning mechanism comprises a double-acting actuator acting on said rod and operable to rotate the latter and said expander back and forth through an arc equal to the spacing of adjacent elements around said body.

5. The combination defined in claim 4l in which said actuator includes a rack meshing with elongated spline teeth on said rod and movable back and forth on said spindle relative to the rod to turn the latter through said arc.

d. The combination defined in claim in which said rack comprises a piston fitted in a cylinder in said spindle tangent to said rod, and further including means for admitting pressureI fluid to one end of said cylinder to operate said actuator in one direction.

7. The combination defined in claim 6 further ineluding a second piston fitted in a second cylinder tangent to said rod and having teeth meshing with said spline teeth, and means for admitting pressure iiuid alternately to said cylinders to reciprocate said pistons and turn said rod and said expander back and forth through said arc.

8. A honing machine having, in combination, a hollow rotary body having a plurality of angularly spaced longitudinal slots, first and second sets of honing elements disposed in said slots and alternating with each other around said body and having abrasive surfaces of different characteristics facing outwardly for engagement with a bore wall, an expander disposed within and movable axially of said body and having a single set of cams spaced angularly apart for engagement with the inner sides of each set of honing elements, said cams being operable upon move-ment of said expander in one direction to feed the alined set of elements outwardly relative to said body, means for turning said expander selectively between two angularly spaced positions in which said cams are alined 'with the inner sides of the respective sets of elements, mechanism for moving said expander axially of said body in both of said positions to feed the selected set of elements, and means on said expander for disabling7 each set of elements when said cams are alined with the other set.

9. In an abrading machine, the combination of, an abrading tool, a pair of spaced abrading elements mounted on said tool for independent feeding and retracting movement, each of said elements having an outer abrading surface and an inner follower, an expander having a cam selectively alineable with either of said followers and shaped to move the alined follower outwardly upon movement of the expander in one direction and to permit retraction of the follower upon movement of the expander in the opposite direction, mechanism for selectively moving said cam into alinement with either of said followers,

0 O and means for moving said expander back and forth in ainement with each follower to `control the feeding and retracting movement of said elements.

Iitl. A honing machine having7 in combination, a hollow rotary body having a plurality of angularly spaced longitudinal slots, rst and second sets of honing elements disposed in said slots and alternating with each other around said body with abrasive surfaces facing outwardly for engagement with a bore wall to be honed, an expander disposed within said body and having a set of cams spaced apart for engagement with the inner sides of either set of honing elements, said expander being movable relative to said body through a preselected range of motion to feed said elements outwardly relative to said body, means for bringing said cams selectively into operative association with either of said sets of honing elements by a selecting motion transverse to said feed motion while disassociating said cams from the `other set of honing elements, and mechanism for efectin g said feed motion with said cams in operative association with each set of cams.

References Cited UNTED STATES PATENTS ROBERT C. REORDON, Primary Examiner.

Claims

1. A HONING MACHINE HAVING, IN COMBINATION, A HOLLOW ROTARY BODY HAVING A PLURALITY OF ANGULARLY SPACED LONGITUDINAL SLOTS, FIRST AND SECOND SETS OF HONING ELEMENTS HAVING ABRASIVE SURFACES OF DIFFERENT CHARACTERISTICS DISPOSED IN SAID SLOTS AND ALTERNATING WITH EACH OTHER AROUND SAID BODY WITH SAID ABRASIVE SURFACES FACING OUTWARDLY FOR ENGAGEMENT WITH A BORE WALL TO BE HONED, EACH OF SAID ELEMENTS HAVING A FOLLOWER ON ITS INNER SIDE, AN EXPANDER IS DISPOSED WITHIN AND MOVABLE AXIALLY OF SAID BODY THROUGH A PRESELECTED RANGE OF FEED MOTION FROM A FIRST POSITION TO A SECOND POSITION, SAID EXPANDER HAVING A SET OF ANGULARLY SPACED WEDGE-SHAPED CAMS SELECTIVELY ALINEABLE WITH THE FOLLOWERS OF EITHER SET OF HONING ELEMENTS AND OPERABLE UPON AXIAL MOVEMENT OF SAID EXPANDER IN ONE DIRECTION TO FEED THE ALINED SET OF ELEMENTS OUTWARDLY RELATIVE TO SAID BODY, FROM A COLLASPED CONDITION IN SAID FIRST POSITION TO A FULLY EXPANDED CONDITION IN SAID SECOND POSITION, SAID CAMS BEING SEPARATED BY LONGITUDINAL GROOVES FOR RECEIVING THE FOLLOWERS OF THE OTHER SET OF ELEMENTS DURING SAID FEED MOTION, A SECTION ON SAID EXPANDER OF CIRCULAR CROSS-SECTION MERGING SMOOTHLY WITH THE SMALLER ENDS OF SAID CAMS AND LEVEL WITH THE BOTTOMS OF SAID GROOVES, SAID FOLLOWERS ENGAGING SAID SECTION WHEN SAID EXPANDER IS IN SAID FIRST POSITION, MEANS FOR SELECTIVELY TURNING SAID EXPANDER TO BRING SAID CAMS INTO ALINEMENT WITH THE FOLLOWERS OF EITHER SET OF HONING ELEMENTS IN SAID FIRST POSITION, AND MECHANISM FOR MOVING SAID EXPANDER AXIALLY OF SAID BODY IN ALINEMENT WITH EACH SELECTED SET OF ELEMENTS.