US3605348A - Honing tool - Google Patents

Abstract

A HONING TOLL FOR ATTACHMENT TO A ROTOTABLE ADAPTER ON A HONING MACHINE WHICH INCLUDES A SLOTTED TUBULAR MANDREL FOR SUPPORTING HONING STONE ASSEMBLIES FOR RADIAL MOVEMENT BY THE CAMMING ACTION OF LINGITUDINAL RIBS ON A CAM SHAFT ROTATABLY DISPOSED WITHIN THE MANDREL, CAM MEANS ARE OPERATIVELY ASSOCIATED WITH THE CAM SHAFT WHICH ARE ACTUATED BY AN AXIALLY RECIPROCATING ACTUATING ELEMENT CONNECTED TO THE HONING MACHINE SO AS TO ROTATE THE CAM SHAFT ALTERNATELY IN OPPOSITE DIRECTIONS DURING THE STROKING OF THE ACTUATING ELEMENT TO EXPAND AND RETRACT THE HONING STONE ASSEMBLIES AS THE HONING TOOL IS ROTATED BY THE HONING MACHINE ADAPTER.

Description

Sept. 20, 1971 c. w. MCCLURE HONING TOOL 2 Sheets-Sheet 1 Filed Sept. 17, 1969 INVENTOR CHARLES W. McCLURE ATTORNEY Sept. 20, 1971 c. w. MCCLURE HONING TOOL 2 Sheets-Sheet 2 Filed Sept. 17, 1969 ATTORNEY United States Patent (3 Filed Sept. 17, 1969, Ser. No. 858,815 Int. Cl. B241) 9/02 US. Cl. 51338 8 Claims ABSTRACT OF THE DISCLOSURE A honing tool for attachment to a rotatable adapter on a honing machine which includes a slotted tubular mandrel for supporting honing stone assemblies for radial movement by the camming action of longitudinal ribs on a cam shaft rotatably disposed within the mandrel. Cam means are operatively associated with the cam shaft which are actuated by an axially reciprocating actuating element connected to the honing machine so as to rotate the cam shaft alternately in opposite directions during the strok ing of the actuating element to expand and retract the honing stone assemblies as the honing tool is rotated by the honing machine adapter.

Many types of honing machines are available today for performing a honing operation on a hole or bore within a workpiece by utilizing honing stones supported on a mandrel for radial movement outwardly into honing engagement with the workpiece bore. In one type of honing machine, such as shown in US. Pat. No. 3,152,424, a honing tool or mandrel is detachably mounted on the honing machine and rotated while the honing stones are alternately expanded and retracted radially by tapered surfaces or wedges on a member moved in a reciprocating manner by an axially reciprocating drive member or feed up rod incorporated in the honing machine. However, present day industrial practices for honed and machined articles require extremely close manufacturing tolerances and although present day honing tools generally perform satisfactorily, it is difficult to obtain the desired degree of precision with such present day honing tools to meet such industrial requirements. For instance, many present day honing tools utilize a plurality of honing stones arranged in circumferentially spaced relationship and the use of camming surfaces such as wedges of the aforementioned stones results in wear on the honing stones during use i which is not uniform. This means that not only is the eccentricity of the honed surface increased, but frequent replacement of the honing stones is necessary for adherence to close manufacturing tolerances adding considerably to manufacturing costs from both the standpoint of the replacement costs as well as the time and labor involved.

Other shortcomings are also found in present day honing tools. For instance, in the honing of blind holes or bores in a workpiece, honing tools of present day construction fail to hone the entire surface of the bore so that the honed surface terminates short of the bottom wall of the bore due to the engagement of the end of the mandrel supporting the honing stones with the bottom wall. This means that either a less finished honed article is pro- 3,605,348 Patented Sept. 20, 1971 duced or some supplemental operation is required to completely hone the inner surface of the workpiece bore. In addition, many present day mandrels are not capable of smoothly and uniformly applying honing pressure to the honing stones for radially increasing the honing diameter during the stroking action performed by the honing machine due to the various constructions of present day honing mandrels adding further to the difficulty in obtaining the close tolerances and concentricity desired for such finished honed articles.

Accordingly, a primary object of this invention is to provide a new and novel honing tool for attachment to a honing machine.

Another object of this invention is to provide a new and novel honing tool for attachment to a honing machine for a bore of a workpiece within extremely close manufacturing tolerances.

A further object of this invention is to provide a new and novel honing tool which permits a plurality of honing stones to be expanded smoothly and with uniform pressure into honing engagement with the bore of a workpiece and which permits the honing operation to be performed throughout the entire inner surface of the bore.

This invention further contemplates the provision of a new and novel honing tool for attachment to a honing machine which is inexpensive and rugged in construction, which utilizes a minimum number of parts, which permits uniform distribution of wear over all of the honing stones during use and which is capable of prolonged use without breakdown.

Still another object of this invention is to provide a new and novel honing tool which permits a honing operation to be performed at a high production rate on the bore of a workpiece with a resultant honed surface characterized by a total absence of eccentricity and extremely close manufacturing tolerances.

Other objects and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings.

In general, the object of this invention and other related objects are accomplished by providing a honing tool which includes a tubular mandrel having a central bore in which is rotatably mounted a cam shaft having a plurality of longitudinally extending, circumferentially spaced, upstanding ribs, adjacent one end of the mandrel, the mandrel being mounted on a housing having a central bore which is positioned for rotation in an adapter of a honing machine. The ribs are provided with camming surfaces engageable with the inner ends of a plurality of honing stone assemblies positioned for sliding radial movement in slots provided in the mandrel. An axially slidable actuating element is positioned in the housing'bore for attachment to the stroking means of the honing machine and cam means are provided on the actuating element and the other end of the cam shaft for rotating the cam shaft alternately in opposite directions as the actuating element is stroked for expanding and retracting the honing stone assemblies alternately during the rotation of the honing tool by the adapter.

The novel features which are believed to be characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation may be best understood by reference to the following description taken in conjunction with the accompanying drawings in which:

FIG. I is a side elevation view, partially in section, of a honing tool constructed in accordance with the invention mounted in an operating position;

FIG. 2 is an enlarged sectional view of the honing tool of FIG. 1;

FIG. 3 is a sectional view taken substantially along line 33 of FIG. 2 in the direction of the arrows;

FIG. 4 is a sectional view of a portion of the tool of FIG. 2 with the parts in another position;

FIG. 5 is an enlarged end view of a portion of the honing tool of FIG. 2;

FIG. 6 is an enlarged sectional view taken substantially along line 6-6 of FIG. 2 in the direction of the arrows;

FIG. 7 is a view similar to FIG. 6 showing the parts in the position corresponding to FIG. 4;

FIG. 8 is a side elevation view of a portion of the honing tool of FIG. 2; and

FIG. 9 is a sectional view taken substantially along line 9-9 of FIG. 2 in the direction of the arrows.

Referring now to the drawings and to FIG. 1 in particular, there is shown a honing tool constructed in accordance with the invention which is designated generally by the letter T. As is well known, the honing tool T is arranged to be mounted in the bore 11 of a holder or adapter 12 of a honing machine of any well known construction. The adapter 12 is positioned on the forward end of a rotatable shaft 13 journaled in the honing machine frame 14 as shown and described in the aforementioned patent. As described in this patent, the shaft 13 is rotatably driven by suitable means (not shown) incorporated in the associated honing machine and the honing machine includes an axially reciprocating feed-up means or drive member 16 driven by suitable means (not shown) also incorporated in the honing machine for axially reciprocating or stroking the drive member as indicated by the double arrow I of FIG. 1. It should be understood, however, that any suitable type of honing machine may be utilized with the honing tool T of the invention and reference is made to the honing machine of the aforementioned patent by way of example only.

As is well known, the honing tool T is of the type for performing a grinding or honing operation on the bore 18 of a workpiece designated generally in FIG. 1 by the letter W, the outer end of the honing tool T being arranged to be inserted within the workpiece bore 18 as shown in FIG. 1.

Referring now to FIG. 2, the honing tool T includes a housing 21 having a central bore 22 which is arranged to be received within the honing machine adapter 12 and secured thereto for rotation therewith by means such as a set screw 23' engageable with a flat 24 on the adapter 12. A tubular mandrel 26 is provided having a central bore 27 and an enlarged inner end portion 28 which is arranged to be accommodated within a recess 29 of the housing 21 so that the mandrel 26 projects forwardly therefrom for insertion of its forward end 26a within the workpiece bore 18. The mandrel 26 is preferably detachably secured to the housing 21 by means of a set screw 31 threadedly accommodated within a tapped hole 32 in the housing 21, the inner end of the set screw 31 being provided with a dowel or pin 33 accommodated with a radial passage 34 in the enlarged inner end portion 28 of the mandrel 26.

A plurality of circumferentially spaced, longitudinally extending slots 36-38 are provided in the mandrel 26 adjacent its forward or outer end 26a which open into the mandrel central bore 27 and which are preferably interrupted intermediate their ends by bridging mandrel portions 41-43 respectively for a purpose to be explained hereinafter.

In the illustrated embodiment three of such slots 36-38 are provided which are uniformly spaced circumferen- As the slots 36-38 are interrupted by the bridging portions 41-43, the honing stone assembly 44 which is accommodated in each slot is therefore formed of two longitudinally aligned segments as shown best in FIG. 2, the shorter segment being designated by the numeral 44 and the longer segment by the numeral 44". It will be noted that in the preferred embodiment, each of the slots 36-38 are provided with longitudinally spaced arcuate recesses 37a-38a respectively on opposite sides which are arranged to accommodate similarly spaced, lateral projections or ears 49 on the honing stone holders 46 when the honing stone assemblies 44 are positioned within the slots 3'6-38. As both the ears 49 and recesses 36a-38a extend radially, there is no interference with the free sliding movement of the honing stone assemblies 44 but longitudinal tilting or canting of the stone assemblies in the slots is prevented.

A cam shaft 51 is positioned for axial rotation in the mandrel bore 27 with its outer end 51a adjacent the mandrel outer end 26a and its inner end extending within the housing bore 22. A plurality of circumferentially spaced, longitudinally extending upstanding ribs 56-58 are provided on the cam shaft 51 which extend from adjacent the cam shaft outer end 51a in underlying relationship with the mandrel slots 36-38 respectively. One side of each of the ribs 56, 57, 58 is provided with an arcuate camming surface 56a, 57a, 58a respectively for camming engagement with the respective bearing surfaces 46a on the inner end of honing stone assemblies 44 as shown best in FIG. 6. As shown in FIGS. 2, 4 an annular groove 60 is provided on the periphery of the cam shaft 51 which receives the inner end of the pin 33 on the set screw 31 in the assembled condition of the tool T so as to prevent axial movement of the cam shaft 51 as the cam shaft is rotated. The inner end of the cam shaft 51 includes a portion of enlarged diameter 61 which extends within the central bore 62 of an actuating element 63 slidably positioned within the central bore 22 of the housing 21.

Means are provided for connecting the actuating element 63 to the reciprocating drive member 16 of the honing machine. More specifically, a countersunk bore 64 is provided in the end of the actuating element 63 adjacent the honing machine for snugly accommodating an end plate 66 which is provided with an axially extending hook 67 preferably formed integrally therewith and arranged to be detachably coupled to a similar hook 68 formed on the adjacent end of the drive member 16 in the form of a bayonet connection or the like. The end plate 66 is retained in the recess 64 by suitable means such as a set screw 68 having a pin 69 on its inner end and threadedly engageable as shown, with a tapped radial hole 71 in the actuating element 63 for retaining engagement of the pin 69 within a recess 72 in the end plate 66.

Means are provided for guiding the actuating element 63 for axially reciprocating, sliding movement in the housing central bore 22. More specifically, a longitudinally extending slot 73 is provided in the outer periphery of the actuating element for accommodating the inner end portion of a guide pin 74 secured by press fitting or the like in a radial hole 76 in the side wall of the housing 21.

Cam means are provided on the actuating element 6 3 and the portion of enlarged diameter 61 on the cam shaft 51 for alternately rotating the cam shaft 51 in one direction during the axial movement of the actuating element 63 in one direction for camming the honing stone assemblies 44 radially outward to increase the honing diameter of the honing stones 47 and for rotating the cam shaft 51' in the other direction during the axial movement of the actuating element 63 in the other direction to permit thehoning stone assemblies 44 to be moved radially inward for reducing the honing diameter of the honing stones 47. More specifically, the enlarged portion 61 which is of cylindrical shape is provided with at least one and preferably two helical slots 81, 82 arranged in diametrically opposed relationship somewhat in the form of a drum or cylinder cam for receiving follower pins 83, 84 also arranged in diametrically opposed realtionship and mounted by press fitting or the like in radial holes 86, 87 respectively in the wall of the actuating element 63.

The honing tool T also includes means for supplying a lubricating fluid to the interior of the workpiece W for lubricating the surface of the workpiece bore 1-8 during the honing operation. More specifically, a lubricating fluid is fed in the direction of the arrow L of FIG. 2 from suitable means (not shown) within the associated honing machine into the bore 22 of the housing 21 for subsequent introduction into the actuating element bore 62 through a passage 91 in the end plate 66, suitable sealing means for the housing 21 being provided by an O-ring 92 positioned in an annular groove 93 in the outer periphery of the housing 21. The lubricating fluid then flows through an axial passage 94 in the cam shaft 51 and through radial passages 96, 97 and radial ports 98, 99 in the cam shaft 51 and mandrel respectively out wardly into the bore 18 of the workpiece W.

In the operation of the honing tool of the invention, the tool T is mounted in the operating position by inserting the housing 21 into the honing machine adapter 12 and the set screw 23 tightened down against the housing flat 24 to retain the tool T on the adapter 12 as shown in FIGS. 1, 2. The hook 67 on the cam shaft 51. is attached to the hook 68 on the drive member 16-. Operation of the honing machine axially rotates the housing 21 together with the mandrel 26 and cam shaft 51 with the outer end of the mandrel being inserted within the bore 18 of the workpiece W to be honed. At the same time, the axial reciprocation of the drive member 16 by the honing machine reciprocates the actuating element 63 axially, rotation of the actuating element 63 being prevented by the pin 74 extending within the actuating element slot 73. The actuation of the drive member 16 may be initiated by any suitable means such as foot pedal or the like under the control of the operator. The axial movement or stroking of the actuating element 63 moves the actuating element from a rearward position such as shown in FIG. 4 with the actuating element pins 83, 84 traveling in the helical groove 81, 82. of the cam shaft portion 61 to rotate the cam shaft in one direction so that the longitudinal ribs 56-5 8 are moved to the position of FIG. 7 permitting the honing stone assemblies 44 to retract and decrease the honing. diameter of the stones 47 Forward movement of the actuating element 63 from the position of FIG. 4 to the position of FIG. 2 rotates the cam shaft 5 1 in the opposite direction so that the cam surfaces 56a-58a on the ribs 56-58 engage the inclined surfaces 46a on the honing stone assemblies 44 smoothly and uniformly camming the stone assemblies 44 radially outward into the position shown in FIG. 6 thereby increasing the honing diameter of the stones 47. During the honing operation, the cam shaft 51 is rotated alternately in opposite directions with the axial reciprocation of the actuating element 63 and lubricating fluid is supplied to the interior of the workpiece W through the various passages and chambers described above.

It has been found in practice that the stroke or axial movement of the actuating element 63 should be no less than one inch although it should be understood that any desired stroke length may be employed in accordance with the honing requirements. Also, it has been found in practice that a cam shaft rotation of approximately 60 between the positions of FIGS. 6, 7 produces satisfactory results in the operation of the invention and, if desired, the ribs 5658 and honing stone assemblies 44 may have their camming surfaces reversed so that the honing stone assemblies 44 are expanded radially outward in the opposite direction of rotation of the cam shaft 51 from that shown in the illustrated embodiment.

As shown in the drawings, the slots 36-38 in the mandrel 26 are open at their ends adjacent the mandrel end 26a to thereby permitting blind hole honing so that the entire surface of the workpiece bore .18 may be honed with the tool T of the invention. In order to maintain the cross-sectional shape of the portion of the mandrel 26 adjacent the end 26a, an insert or end cap 101 is suitably secured by welding or the like Within the mandrel bore 27 at the end 26a of the mandrel thereby preventing flexing of the mandrel portions between the slots adjacent the mandrel end 26a.

While there has been described What at present is considered to be the preferred embodiment of the invention, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the invention.

Having thus described the invention, what is claimed is:

1. A honing tool for attachment to a honing machine of the type having a rotatably driven adapter and an axially reciprocating drive member comprising, in combination, a housing having a central bore, means for mounting said housing on said honing machine adapter for rotation therewith, a forwardly extending tubular mandrel having a central bore mounted at one end on said housing and the other end arranged to be inserted into the bore of a workpiece to be honed, a plurality of circumferentially spaced, longitudinally extending slots in said tubular mandrel adjacent said mandrel other end and opening into said mandrel central bore, a honing stone assembly including a. honing stone mounted in each of said slots for freely slidable, radial movement, an actuating element having a central bore and positioned in said housing central bore, means for guiding said actuating element for axially reciprocating sliding movement in said housing central bore, means for connecting said actuating element to said honing machine drive member, a cam shaft positioned for axial rotation in said mandrel central bore and having an inner end portion extending within said actuating element central bore, a plurality of circum ferentially spaced, longitudinally extending, upstanding ribs on said cam shaft adjacent the outer end of said cam shaft and in underlying relationship with said mandrel slots, each of said ribs having a camming surface on one side engageable with the inner end of one of said honing stone assemblies, cam means on said actuating element and said cam shaft inner end portion for rotating said cam shaft in one direction during the axial movement of said actuating element in one direction for camming said honing stone assemblies radially outward to increase the honing diameter of said honing stones for honing engagement with said workpiece bore and for rotating said cam shaft in the other direction during the axial movement of said actuating element in the other direction to permit said honing stone assemblies to be moved radially inward for reducing the honing diameter of said honing stones.

2. A honing tool in accordance with claim 1 wherein each of said honing stone assemblies comprises a holder and a honing stone secured to the outer end surface of said holder and wherein the inner end of said holder is provided with an inclined surface for camming engagement with said camming surface on the associated rib.

3. A honing tool in accordance with claim 1 wherein said plurality of circumferentially spaced ribs comprise three of said ribs arranged in a spaced-apart relationship and wherein said plurality of mandrel slots comprise three of said slots arranged in a 120 spacedapart relationship.

4. A honing tool in accordance with claim 3 wherein one end of said slots in said mandrel open into said mandrel other end and including an end cap fixedly secured to said mandrel within said mandrel bore at said mandrel other end to maintain the cross-sectional shape of the portion of said mandrel adjacent said other end.

5. A honing tool in accordance with claim 4 including a plurality of circumferentially aligned arcuate segments on said mandrel each extending transversely of one of 7 said slots and intermediate the ends of said slot to define on opposite side thereof a pair of longitud'mally aligned slot portions and a honing stone assembly in each of said slot portions.

6. A honing tool in accordance with claim 3 wherein said cam means include at least one helical slot on the outer periphery of said cam shaft inner end portion and at least one radially extending follower pin on said actuating element having an inner end portion slidably accommodated within said helical slot for rotating said cam shaft alternately in opposite directions during the axial reciprocating movement of said actuating element.

7. A honing tool in accordance with claim 6 wherein a pair of said helical slots arranged in diametrically opposed relationship are provided on the said cam shaft inner end portion and wherein a pair of said follower pins are provided in diametrically opposed relationship on said actuating element each arranged to be accommodated in one of said helical slots.

8. A honing tool in accordance with claim 7 wherein said guide means include a longitudinally extending slot on the outer periphery of said actuating element and a radially extending pin on said housing having an inner end portion slidably accommodated with said slot on said actuating element for guiding said actuating element for said axially reciprocating sliding movement in said housing bore.

References Cited UNITED STATES PATENTS 1,981,258 11/19'34 Wagner 51-347 1,926,835 9/19'33 Cook 51-347 HAROLD D. WHITEH'EAD, Primary Examiner US. Cl. X.R. 51339, 347

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