US3352067A - Automatic sizing device for a honing machine - Google Patents

Description

Nov. 14, 1967 M. R. EsTABRooK :352,067

V AUTOMATIC SIZING DEVICE FOR A HONING MACHINE Filed March 5o, 1965 l 2 sheets-sheetA 1 MVEADTokm/z l5 ark Stab/OOM tjlv-ramsyJ 2 sheets-Shea 2 IO @a w \\w\v. l M um, QW, om@

QfTTTO RME Y/ Nov. 14, 1967 M. R. ESTABRCOK v v AUTOMATIC SIZING DEVICE FOR A HONING MACHINE Filed March 30, 1965 United States Patent 3,352,067 AUTOMATIC SIZIN G DEVICE FOR A HONING MACHINE Mark R. Estabrook, Rockford, Ill., assignor to Barnes Drill Co., Rockford, Ill., a corporation of Illinois Filed Mar. 30, 1965, Ser. No. 443,876 9 Claims. (Cl. 51-165) ABSTRACT F THE DISCLOSURE An automatic honing machine having a reciprocating rotary tool that is progressively expanded within a work bore to feed the honing stones into the bore wall, thereby removing surface roughness and enlarging the bore to a predetermined size. The endwise motion of .the usual expander rod is transmitted to a sizing rod supported for movement along a parallel path and magnified by a rack-and-pinion linkage which moves the sizing rod at a substantially greater rate toward an adjustable micrometer stop, the stop and the sizing rod constituting the two contact elements of an electric switch which, when closed, signals that a preselected amount of tool expansion has occurred.

This invention relates to a honing machine for enlarging and finishing bore in a workpiece by reciprocating and rotating an expandable honing tool within the bore while gradually expanding the tool to press abrasive elements thereon against the bore wall. Expansion of the tool is produced by endwise movement of an expander rod carrying a cam engaging the inner sides of the abrasive elements and operable during movement of the rod in one direction relative to the tool to cam the elements outwardly at ar ate determined by the rate of movement of the rod. The invention has particular reference to a device for sensing the attainment of a predetermined bore' size and terminating the honing cycle in a machine having non-wearing honing elements.

The general object of the present invention is to sense the attainment of a preselected bore size in a novel manner which provides an accurate indication of the changing bore size during honing and eliminates the need for direct measurement of the bore.

Another object is to utilize the motion of the expander rod as a direct and precise indication of the bore size.

A more detailed object is to magnify .the expander rod movement during expansion of the tool and transmit the magnified motion to a sizing device which measures the magnified motion for precise` measurement of the bore size during honing.

The invention also resides in the novel manner of using the sizing device to signal the attainment of a preselected bore size.

Other objects and advantages of the invention will become apparent from the following detailed descriptions taken in connection with the accompanying drawings, in which: v

FIG. 1 is a fragmentary front elevational view of a honing machine embodying the novel features of the present invention with parts broken -away and shown in section for clarity of illustration:

FIG. 2 is an enlarged fragmentary side elevation of part of FIG. 1 with other partsrbroken away and shown in section.

FIG. 3 is a schematic perspective view of the expander rod and sizing device.

FIG. 4 is an enlarged fragmentary cross-sectional view taken substantially along the line 4-4 of FIG. 1.

FIG. 5 is a fragmentary front elevation of the machine.

As shown in the drawings for purposes of illustration, the invention is incorporated in a machine for honing a bore wall 10 in a workpiece 11 by reciprocating an expandable tool 12 back and forth through the bore and simultaneously rotating the tool with abrasive elements or stones 13 thereon pressed against the bore wall. In this instance, the tool is supported on the lower end of a shank 14 carried on a spindle 15 journaled at its upper end in a head 17 slidable up and down along vertical guide rods 18 (FIG. 5) on the machine frame to reciprocate the tool Within the bore. During such reciprocation, the spindle is rotated by a motor (not shown) drivingly connected to the spindle through gearing shown at 19 in FIG. 5.

The honing tool 12 is formed by a plurality of elongated non-wearing stones 13 fitted in and projecting radially outwardly through a series of slots 20 (FIG. 1) angularly spaced Iaround a hollow, generally cylindrical body 21 on the lower end of the shank 14. For example, the

non-wearing stones may be of a well known type composed of diamond grit held together by a suitable adhesive. Followers 22 on the inner sides of the stones engage -a conical cam 23 guided for axial motion in the bore defining the interior of the tool body, and the cam is moved downwardly relative to the tool by means of an elongated rod 24 extending coaxially through the shank and connected adjacent its upper end to a suitable mechanism mounted on the head 17 and operable to feed the rod endwise and downwardly at a controlled rate, the cam being fastened to the lower end of the expander rod. In this instance, the rod comprises a lower section 25 carrying the cam, a short intermediate section 27 threaded onto the upper end of the lower section `to permit adjustment of the length of the expander rod, and an upper section 28 Iabutting against the upper end of the intermediate section within a coupling 29 which forms a universal joint in the spindle. Adjustment of the length of the rod is effected by a sleeve 30 rotatably supported on the spindle between a downwardly facing shoulder -31 (FIG. 1) thereon and a snap ring 32 fitted in a groove below the sleeve. The sleeve iS formed with internal teeth meshing with a pinion 33 journaled on the spindle as shown in FIG. 1 and meshing Y with external teeth on the intermediate section. Thus,

turning of the sleeve 30 turns the intermediate section relative to the lower section to extend or contract the expander rod.

The mechanism for moving the expander rod 24 endwise through the spindle 15 and the shank 14 may take various forms well known in the art and forming no part of the present invention. For example, it may be a reciprocating hydraulic actuator 34 (FIG. 5) at the upper end of the expander rod, or any other well known type of expansion mechanism. When the upper section 28 of the expander rod is moved upwardly to permit contraction of the tool, a coiled spring 35, compressed between a downwardly facing shoulder 37 on the lower section 26 and an opposed shoulder 38 on the shank around the expander rod, pushes the lower and intermediate sections upwardly to draw the cam 23 upwardly and away from the followers 22.

During the honing cycle, the expander rod 24 is moved downwardly :at a controlled rate to feed the stones 13 outwardly into the bore wall 10 until the bore has been enlarged to the desired size. Then, tool expansion is terminated and the tool is withdrawn from the finished bore.

In accordance with the present invention, theV motion of the expander rod 24 relative to the stones 13 during the honing cycle is used as a direct and precise indication of the changing size of the bore, and this motion is measured by a novel sizing device 39 which determines when the bore has attained precisely the desired finished size. To these ends, a sizing member in the form of a rod 40 is supported on the head 17 for endwise movement along a path spaced from the expander rod and is coupled to the latter by a drive connection which magniiies or amplies the expander rod motion and transmits the magnified motion to the sizing rod to move the latter along its path at a rate precisely correlated with but substantially greater than the rate of expander rod movement.

Thus, the position of the sizing rod 40 along its path at all times during the honing cycle is directly related to the tool size and bore size at that time. Moreover, a sensing element 41 is mounted along the path of the sizing rod and adjustably positioned on the frame to produce a signal when the sizing rod reaches a preselected point along the path, thereby indicating that the bore has attained the preselected size.

In the present instance, the sizing rod 40 is guided on the head 17 for endwise movement alonga path paralleling the path of the expander rod 24 by a vertically disposed sleeve 42 (FIGS. 1 and 2) supported on a mounting plate 43 movable with the head along one of the guides 18. The drive connection for moving the sizing rod is formed by a rack 44 fast on the upper end of the expander rod and meshing with a pinion 45 (FIGS. l and 3) on one end of a cross-shaft 47 journaled in the head for rotation about a horizontal axis. The other end portion of the cross-shaft is disposed alongside a second rack 48 on the upper end portion of the sizing rod and meshing with a second pinion in the form of a gear sector 49 supported on the cross-shaft for rotation with the latter in the plane of the rack 48.

The cross-shaft is journaled in a spacer sleeve 50 (FIGS. 1 and 5) extending through a bracket 51 supporting the mounting plate 43 on the side of the head 17, and the radius of the pinion 49 is substantially greater than the lradius of the pinion 45. A shoe 52 (see FIG. 2) adjustably supported on the mounting plate by bolts 53 overhangs the rack 48 and holds the latter in meshing engagement with the associated pinion.

With this arrangement, downward motion of the expander rod 24 is transmitted by the rack 44 and the pinion 45 to the cross-shaft 47 and thence to the rack 48 through the pinion 49 while being magnified or amplied as a result of the substantial difference in pinion sizes. Thus, the sizing rod 40 is moved downwardly with the expander rod but at a substantially greater rate capable of being sensed with much greater accuracyv than the slower motion of the expander rod.

To sense the position of the sizing rod 40 and signal the attainment of a preselected bore size, the element 41 is a micrometer mounted for movement with the head 17 on a sleeve 54 (FIGS. 1 and 5) slidable along one of the guides 18 and positioned along the path of the sizing rod for engagement therewith when the rod reaches a preselected position along its path. As shown most clearly in FIG. 1, the micrometer is threaded through an L- shaped bracket 55 on the sleeve 54 in axial alinement with the sizing rod for adjustment toward and away from the latter by turning ot' the micrometer relative to the bracket. Thus, the upper end 57 of the micrometer forms a stop engageable with the leading end 58 of the sizing rod during downward movement of the latter, and the position of the stop is adjustable to vary the position in which the sizing rod engages the stop.

In the present instance, the sizing signal is produced automatically as an incident to engagement of the sizing rod 40 and the micrometer 41. For this purpose, the micrometer and the rod constitute the two contact elements of an electric switch which is closed upon engagement of these two elements to ,complete a circuit from a source 59 through a relay 60 in the control circuits of the machine. This is accomplished by electrically insulating the rod from the rack 48 by means of a plastic plug 61 (see FIG. 4) having a central cylindrical portion dividing the sizing rod and oppositely extending studs 62 telescoped into and secured to the rack and the sizing rod. Thus, the plug suspends the rod from the rack while, at the same time, preventing metal-to-metal contact at the joint. In addition, the rod is connected to the relay 60 through a conductor 63 fastened to the rod at 64, and the micrometer is grounded, as indicated schematically in FIG. 3, so that engagement of the rod and the micrometer completes the circuit from the source through the relay, the conductor and the rod to the micrometer. The operation of the relay may be used in various well known Ways to terminate the honing cycle.

In addition to controlling the termination of hone expansion, the sizing rod motion may `be sensed at an intermediate stage during the expansion and used to terminate the initial rapid expansion of the tool customarily used to bring the stones 13 close to or against the bore wall 10 and then to initiate slow feeding of the stones into the wall. For this purpose, a cam 65 is provided on the sizing rod intermediate the ends of the latter for engagement with a follower 67 which operates a switch 68 mounted alongside the rod, the follower being disposed along the path followed by the cam during expansion of the tool. Herein, the cam is a conical surface formed on the leading end of a cylindrical nut 69 threaded onto the sizing rod and thus capable of being adjusted along the sizing rod to vary the point of actuation of the switch 68. A set screw 70 (FIGS. 2 and 3) holds the nut in diierent selected positions along the rod.

In operation, the nut 69 and the micrometer 41 are adjusted to selected positions relative to the sizing rod 40 and the bracket 55, respectively, and the rapid expansion actuator (not shown) is started with the honing tool 12 contracted. Thus, the expander rod 24 begins to move downwardly relative to the tool at a rapid rate, and the rack-and-pinion connections transmit this motion to the sizing rod to move the latter downwardly at an even faster rate. When the stones are close to the bore wall, the cam 65 actuates the switch 68 and begin slower movement of the expander rod. Of course, the stop 57 is spaced from the lower end 58 of the sizing rod at this time a distance correlated with the amount of slow tool expansion required to bring the bore up to the desired size.

Then, as the bore wall 10 is worn away and the bore is gradually enlarged, the sizing rod 40 approaches the micrometer stop 57 at a rate substantially greater than the rate of expander rod movement and eventually engages the stop, completing the circuit through the relay 60 and thereby signaling that the bore has attained precisely the size desired.

I claim as my invention:

1. In a honing machine, the combination of, a support, an expandable honing tool having non-wearing honing elements mounted on said support for back and forth reciprocation and, simultaneous rotation to hone a Work bore, an expander rod supported for endwise movement relative to said tool during reciprocation and rotation and operable upon movement in one direction to expand the.

tool at a rate determined by the rate of expander rod movement, a sizing rod supported for endwise movement` along a path spaced from and paralleling said expander rod, means connecting said rods and operable to magnify the motion of said expander rod and transmit the magnied motion to said sizing rod, a stop positioned along said path for engagement with the leading end of said sizing rod during expansion of said tool, means for sensing engagement of said sizing rod and said stop and producing a signal indicating that said tool has been expanded a predetermined amount, and mechanism for adjusting the position of said stop along said path to vary the position in which said sizing rod engages said stop.

2. The combination defined in claim 1 in which said connecting means comprises racks on said expander and sizing rods meshing respectively With a pinion and la gear mounted on a cross-shaft, the gear meshing With the rack on said sizing rod and having a substantially greater radius than the pinion meshing with the rack on said expander rod.

3. The combination defined in claim 1 in which said sensing means is an electrical circuit including said sizing rod and said stop and `completed by engagement of the sizing Irod and the stop.

4. The combination defined in claim 3 in which the leading end portion of said sizing rod is electrically insulated from said connecting means and is a portion of said circuit.

5. The combination defined in claim 1 further including ra cam on said sizing rod between the ends of the latter, and a follower positioned along the path of said sizing rod during expansion of said tool for engagement with said cam before said leading end engages said stop thereby to indicate an intermediate stage in the expansion of said tool.

6. The combination delined in claim 5 in which said cam is formed on a nut threaded onto said rod for selective adjustment along the Irod to vary the point of engagement of the cam and said follower.

7. In a honing machine, the combination of, a support, an expandable honing tool mounted on said support for back and forth reciprocation to hone a Work bore, an expander rod support for endwise movement relative to said tool during such -reciprocation and operable upon movement in one direction to expand the tool at a rate determined by the rate of expander rod movement, a sizing rod mounted for endwise movement along a path spaced Afrom said expander rod, means for magnifying the movement of said expander rod and transmitting t-he magnified movement to said sizing rod to move the latter along said path at a rate precisely correlated with but greater than the rate of expander rod movement, a sensing element disposed along said path for engagement With said sizing rod, mechanism for adjusting said element along said path to vary the position in which said sizing rod engages said element, and means operable in response to engagement of said sizing rod and said element to produce a signal indicating that the tool has attained a preselected size.

8. In a honing machine, the combination of, a support, an expandable honing tool mounted on said support for back and forth reciprocation to hone a work bore, an expander rod supported for endwise movement relative to said tool during such reciprocation and operable upon movement in one direction to expand the tool at a rate determined by the rate of expander rod movement, a sizing rod mounted for endwise movement along a path spaced from said expander rod, means for magnifying the movement of said expander rod and transmitting the magnified movement to said sizing rod to move the latter along said path at a rate precisely correlated with but greater than the rate of expander rod movement, and means for sensing the motion of said sizing rod and producing a signal when the latter reaches `a predetermined point along said path during expansion of said tool thereby indicating that the tool has attained a predetermined size.

9. In a honing machine, the combination of, a support, an expandable honing tool mounted on said support for back .and forth reciprocation to hone a work bore, an expander rod supported for endwise movement relative to said tool during such reciprocation and operable upon movement in one direction to expand the tool at a rate determined by the rate of expander rod movement, a sizing member movable back and forth along a predetermined path spaced yfrom said expander rod, means for magnifying the motion of the rod and transmitting the magnified motion to said sizing member, and means for sensing the motion of said sizing member and producing a signal when the member reaches a predetermined point along said path during expansion of said tool thereby indicating that the bore has attained a predetermined size.

References Cited UNITED STATES PATENTS 2,377,310 6/ 1945 Caldwell et al. 51-34 2,386,901 10/ 1945 Kline 51-34 2,631,414 3/ 1953 Muehling 51-34 LESTER SWINGLE, Primary Examiner.

Claims (1)

1. 7. IN A HONING MACHINE, THE COMBINATION OF, A SUPPORT, AN EXPANDABLE HONING TOOL MOUNTED ON SAID SUPPORT FOR BACK AND FORTH RECIPROCATION TO HONE A WORK BORE, AN EXPANDER ROD SUPPORT FOR ENDWISE MOVEMENT RELATIVE TO SAID TOOL DURING SUCH RECIPROCATION AND OPERABLE UPON MOVEMENT IN ONE DIRECTION TO EXPAND THE TOOL AT A RATE DETERMINED BY THE RATE OF EXPANDER ROD MOVEMENT, A SIZING ROD MOUNTED FOR ENDWISE MOVEMENT ALONG A PATH SPACED FROM SAID EXPANDER ROD, MEANS FOR MAGNIFYING THE MOVEMENT OF SAID EXPANDER, ROD AND TRANSMITTING THE MAGNIFIED MOVEMENT TO SAID SIZING ROD TO MOVE THE LATTER ALONG SAID PATH AT A RATE PRECISELY CORRELATED WITH BUT GREATER THAN THE RATE OF EXPANDER ROD MOVEMENT, A SENSING ELEMENT DISPOSED ALONG SAID PATH FOR ENGAGEMENT WITH SAID SIZING ROD, MECHANISM FOR ADJUSTING SAID ELEMENT ALONG SAID PATH TO VARY THE POSITION IN WHICH SAID SIZING ROD ENGAGES SAID ELEMENT, AND MEANS OPERABLE IN RESPONSE TO ENGAGEMENT OF SAID SIZING ROD AND ELEMENT TO PRODUCE A SIGNAL INDICATING THAT THE TOOL HAS ATTAINED A PRESELECTED SIZE.

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