US2176316A - Honing machine - Google Patents

Description

Oct. 17, 1939.

F. A. SWANSON 502mm MACHINE Filed July 21, 193.7

VENTO 3 Sheets-Sheet 1 Oct. 17, 1939. F, A SWANSQN 2,116,316

HONING MACHINE Filed July 21, 1937 3 Sheet's-Sheet 2 FEED PER REVOLUTION 8/ I i 1NVE-NTOQd v 0 a 04 .5200 son Oct. 17, 1939.

F. A. SWANSON 'HONING MACHINE 3 Sheets-Sheet 3 Filed July 21, 1957 NVENTOR,

/5 E (9795 0 04. 840cm Patented Oct. 17, 1939 -2,176,316 7 HONING MACHINE Floyd A. Swanson, Rockford, Ill., assignor to Barnes Drill 00., Rockford, Ill., a

of Illinois corporation Application July 21, 1937, Serial No. 154,783

2 Claims.

both ends and therefore permit a substantial overrun of the tool in each stroke, so that the tool is enabled to act uniformly over the entire surface of the cylinder. .For honing cylinders having a closed or blind, end or other obstruction, such as a shoulder, interrupting the surface, it has been proposed to provide the machine with means for introducing a dwell in the reciprocation of the tool adjacent the obstruction whereby to equalize the action of the tool. A similar procedure is followed in finishing. the external cylindrical surfaces of bushings or other similar work in which the surface to be finished is interrupted by a shoulder or flange.

In the above operation, the cutting action of the tool is dependent upon its rotation during the dwell in the reciprocation. This makes it difficult to obtain absolute uniformity throughout the length of the cylinder, and moreover the surface acted on by the tool during the dwell is given a finish closely similar to that produced by an ordinary grinding operation instead of the superior crosshatch finish produced by a true honing operation in which the tool is rotated and simultaneously reciprocated. There is also more of a tendency for the tool to load during the dwell in the reciprocation.

The present invention aims to overcome the difllculties heretofore encountered in honing work having interrupted surfaces. This is accomplished by the provision of a novel driven means whereby thetool may be given a relatively short, accurately controlled reciprocatory movement while rotating adjacent the obstruction which interrupts the surface.

More specifically stated, one object of the invention is to provide auxiliary means of novel and advantageous character for efiecting relative reciprocation of the tool and work piece, which means is arranged to act independently of the usual reciprocating mechanism and while the mechanism is either active or inactive.

Another object is to provide a novel honing machine having a rotatable spindle joumaled on a reciprocatory head and embodying means for reciprocating the spindle relative to the head.

Still another object is to provide a novel mechanism for effecting relative reciprocation between a rotating abrasive tool and work piece to prevent excessive loading of the abrasive stones of the tool and to cause the faces of the stones to wear evenly.

Other objects and advantages of the invention will become apparent from the following detailed description of the preferred embodiment illustratedin the accompanying drawings, in which:

Figure 1 is a fragmentary side elevational view of a honing machine embodying the features of the invention.

Fig. 2 is a front view of the machine.

Fig. 3 is a sectional view taken along the line 3-3 of Fig. 2, showing details of the auxiliary spindle reciprocating mechanism.

Fig. 4 is a diagram illustrating the relative movements of the tool and work I Fig. 5 is a front view of the machine arranged for honing external cylindrical surfaces.

Fig. 6 is a schematic diagram showing the hydraulic circuits of the machine.

By way of illustration, the invention has been shown as applied to a vertical honing machine in which the work is held stationary while the tool is rotated and reciprocated. It will be understood, of course, that the invention may be used equally well with other types of honing machines and that the work itself may be rotated and reciprocated while the tool is held stationary if desired. It is also to be understood that various changes and modifications in the form, construction and arrangement of the elements of the machine may be made by those skilled in the art without departing from the spirit and scope of the invention as expressed in the appended claims.

Referring now to Fig. l of the drawings, the machine selected to illustrate the invention comprises generally an upright column I carrying on its front face a pair of spaced parallel guide bars 8 forming a guideway for a reciprocatory tool head 9. A tool spindle l0 journaled on the head 45 and reciprocable therewith supports a cylindrical abrasive tool or bone H which may be of any suitable construction.

Hydraulically operated means is provided for reciprocating the tool head 9, which means com- 50 prises in the present instance a pair of vertically disposed hydraulic cylinders I2 mounted on the upper end of the column I in overhanging relation to the tool head. A piston i3 is arranged to operate in each of the cylinders l2 and is op- '65 eratively connected with the head 9 through the medium of arigid piston rod l4. In the particular machine illustrated, the piston rods are secured to opposite sides of the head so that pres- Patent No. 2,108,354, Feb. 15, 1938, andincludes a reversing valve i! (Fig. 6) controlled by a pilot valve l8 which is operated in response to the reciprocation of,the tool head. For this purpose a controlrod l9 mounted for reciprocation parallel to the path of the "tool head is provided with suitable limit stops 20 and 2i and an intermediate or pawl stop 22 positioned for engagement by,a strokearm 23 carried by the tool head. The control rod is also mounted for ro-.

*tation whereby the intermediate stop 22 may be moved out of the path of the stroke arm to effect withdrawal of the tool from the work.

Suitable means is provided for rotating the spindle Ill while it is reciprocating with the tool head. As herein shown, this means comprises a motor 26 mounted on the upper end of the column I and connected by a train of gears 21 with a splined drive shaft 28 which is drivingly connected with the spindle by a suitable train of gears enclosed within the head.

In addition to the means for reciprocating the tool head 9 and spindle l0, above described, auxiliary means is provided in accordance with the present invention to, impart a short-stroking movement to the spindle. In its preferred form, the auxiliary or short-stroking mechanism comprises a sleeve 30I1aving a peripheral cam groove '3! formed therein. As will be seen by reference to Fig. 3, the sleeve 30 is formed with a recessat its upper end to receive a shoulder 32 on the spindle. An annular plate 33 bolted or otherwise secured to the end of the sleeve is arranged to bear against the upper surfaceof the shoulder 32 and thus hold the sleeve rigid with the spindle. A key 34 engaging keyways formed respectively in the plate 33 and the spindleprevents relative rotation of the parts.

Cooperating with the cam groove 3! is a cam engaging member in theform of a roller-35. As herein shown, the roller 35 is formed with a .reduced end portion 36 supported for rotation about a horizontal axis on antifriction bearings 31 and 38. The bearings are mounted in a housing 39 rigidly secured to a side wall 39 of the tool head 9. It will be apparent that upon rotation of the shaft, the action of the cam surface on the roller 35 will cause the shafttoreciprocate relative to the head. 4 i

In order to reduce the friction of the moving parts to a minimum,'the spindle is supported on antifrlction bearings arranged to permit rotation and reciprocation. To. this end, the sleeve 30 is formed with a peripheral groove 40 in which are arranged a series of steel balls 4| adapted to engage. the inner surface of a hardened steel race ring 42 bolted or otherwise suitably secured to the tool head structure. The groove 40 is preferably substantially wider than the diameter of the balls so as to-permit axial movement of the spindle as well as rotational movement.

cylindrical surface.

- gages a crest of the cam 35.

the entire length of the cylinder.

Additional bearing support for the spindle is provided by a series of balls43 interposed between a bushing 44 mounted on the spindle and a hardened steel'race ring 45 heldin place bytaining rings 41 and 48 encircling the spindle above and below the cam sleeve 30 respectively.

The chamber thus formed may be filled. with oil or other suitable lubricant with the coacting parts submerged therein at all times.

The amplitude of the reciprocatory movement imparted to the spindle by the cam mechanism, above described, depends of course upon the throw of the cam. Moreover, the rate of reciprocation depends upon the number of lobes with which the cam surface is formed and the rate of rotation of the spindle. These factors may be varied as desired to suit the requirements of the particular class of work to be operated on. In the particular embodiment shown, the cam is formed with seven lobes each having a throw of approximately three-sixteenths of an inch. Accordingly, in each revolution of the spindle, seven upward and seven downward strokes will be imparted to the spindle.

With the above construction, rotation of the spindle III while the head 9 is reciprocated by the hydraulic mechanism will cause a point on the tool to follow the path illustrated in Fig. 4. Due to the movement of the head, the tool will be reciprocated through a relatively long stroke and superimposed upon this movement is the rapid short-stroking movement imparted by the cam mechanism.

Referring to Fig. 4, Arepresents a developed Let B represent the relative position of a point on the tool at the beginning of an operating cycle. Due to the action of the cam mechanism, the point initially is given a generally upward movement even though the head is travelingdownwardly. Such upward movement continues until the crest of the cam surface is passed. The extent-of upward movement is determined by the throw ofthe cam and the relative rotative speed of the spindle and reciprocating speed of the head. With the particular cam mechanism shown, the highest-point C is reached as the roller 35 en- After passing the crest of the cam, the movements imparted to the tool by the hydraulic means and cam'mechanism are cumulative, thus carrying the point substantially below its initial position to the the point describes an inclined path of generally sinusoidal'form around the surface of the cylinder. This path, of course, extends through 0n the return stroke, the inclination of the path is reversed sothat the two paths intersect each other at an angle determined by the relative rotational and reciprocal speeds. Thus the surface of the work is given a crosshatch finish characteristic of honing machines, which is highly advantage ous in the case of internal combustion cylinders and other mechanisms requiring constant lubrication.

ment with the shoulder when the cam 3| is in its lowermost position; The operation ofthe hydraulic mechanism is interrupted at this point, preferably for a predetermined short interval during which the tool is reciprocated solely by the cam means. As the reciprocal stroke effected by the cam is of relatively small amplitude and confined closely within predetermined limits, the tool can be operated close to the obstruction without danger of injury to the tool or machine, thus permitting the area adjacent the obstruction to be honed. This area is thus given a crosshateh finish, in general, like that of the remainder of the surface of the work.

While the interruption of the hydraulic reciprocating mechanism may be effected man- 'ually, it is.preferred to equip the machine with automatic means for introducing the dwell in the reciprocation of the tool head to facilitate finishing the surface with a perfectly true and uniform contour. Suitable means for accomplishing this result is disclosed and claimed in my copending application, above referred to, and the essential parts and hydraulic circuit of a machine so equipped are shown in Fig. 6 of the drawings of the present: application.

Referringto Fig. 6 of the drawings, the pump I5 is arranged to discharge pressure fiuid into a duct 5| leading to a central port of the reversing valve suitable construction, and as herein shown is provided with a reciprocable plunger 52 having piston enlargements 53 operative to open and close the outlet ports of the valve.- of the plunger 52 are received in cylinders 54 and 55 to which pressure fluid is admitted alternately to shift the plunger from one position to the other. When the plunger is moved to the left, as viewed in the drawings, pressure fiuid introduced through duct 5| is directed by way of a duct 56 to the upper ends of the cylinders l2, while the spent pressure fluid in the lower ends of these cylinders is exhausted through a duct 51, the valve l1, and a discharge duct 58 and returned to a sump 59 from which it may be withdrawn again by the pump 5. When the valve plunger is moved to the right end of the cylinder, the connections of the ducts are reversed and pressure fluid is supplied by way of ducts 5| and 51 to the lower ends of the cylinders, while spent fluid from the upper ends of the cylinders is returned to the sump through the ducts 56 and 58.

The means for shifting the valve plunger between its two positions includes thepilot valve l8 controlled 'by the reciprocation of the head. With the head in the position shown in Fig. 6, the pilot valve is set to direct pressure fluid from a duct 60, constituting a branch of the pressure duct 5|, to a duct 5| leading to the cylinder 54 of the valve H. The pressure fluid thus supplied to the cylinder 54 operates to move the plunger 52 to the right end of the valve casing. Spent pressure fluid from the cylinder 55 is discharged through a duct '62 and a delayed action valve 63 to a duct 64 which is connected by the pilot valve l8 with a discharge duct 65 leading to the sump 59.

The valve 63, as herein shown, includes a valve stem 65 formed with a series of circumferentially spaced orifices 61 of different relative diameters which r zulate the rate of flow of the spent The valve Il may be of any The ends the normal cutting efficiency of the tool.

pressure fluid from the cylinder 55. The valve stem 66 may be rotated to render any orifice effective selectively sothat the. rate of movement of theplunger 52 may be varied at will. It will be apparent that by reason of the small orifice available for discharge of spent pressure fluid from the cylinder 55, the movement of the plunger 52 to the right end of the cylinder will be delayed substantially, thus introducing a dwell in the return movement of the head 9.

-When the tool head reaches the limit of its upward stroke, the stroke arm 23 engages the intermediate stop 22 on the control rod and shifts the rod vertically, thereby reversing the position of the pilot valve I8. Pressure fluid from the duct 60 is then directed by way of the duct 54 and a check valve 68, which is arranged to bypass the delay valve 63, to the cylinder 55 of the reversing valve H. The cylinder 54 is connected with the discharge duct by way of ducts 6| and 85. It will be observed that under these conditions the delay valve will have no effect upon the action of the reversing valve due to the by-pass provided by the check valve 68. The action of the reversing valve will therefore be rapid and the movement of the head will be reversed with substantially no relay. Thus the dwell in the reciprocation of the tool head and tool is introduced only at one end of the stroke and preferably as the tool approaches a shoulder or other interruption in the surface being operated on. During this dwell, the tool spindle is reciprocated rapidly relative to the head so that the tool is able to act efliciently on the area of the surface adjacent the obstruction and thus produce an extremely true and accurate contour on the work, as explained above.

The rapid reciprocation or short-stroking" of the tool during the dwell in the reciprocation of the head is also advantageous in maintaining This is for the reason that the whetting" motion thus produced materially reduces the loading of the tool with material removed from the work. Moreover, the wear on the abrasive stones of the tool is distributed evenly over the operating face thereof so that the faces, remain straight over long periods of use. R

In the modified machine disclosed in Fig. 5, the tool II is replaced by an external honing tool arranged to fit over the outside of a cylindrical work piece, such as a bushing 12, which may be conveniently supported on a mandrel 13. The tool is guided into operative relation with the work by means of a guide sleeve 14 carried on a. fixture '15 of any suitable character.

As will be seen by reference to the drawings, the bushing is formed with ashoulder I5, and in order to finish the surface accurately adjacent this shoulder, the stops on thecontrol rod H] are preferably arranged to permit downward movement of the tool until the lower ends of the abrasive elements of the tool. are substantially in contact with the shoulder. The delay valve 63 may be adjusted to provide the necessary dwell at this point, and during this dwell the cam mechanism associated with the spindle serves to reciprocate the same in a restricted area adjacent the shoulder. The other operations of the machine are the same in all respects as the internal honing machine hereinbefore described.

It will be apparent from the foregoing that the invention provides a honing machine of novel and advantageous character adapted for honing a wide variety of work. In addition to I the usual means for efi'ecting relative reciprocation between the tool and the work, the invention provides auxiliary means for imparting a short-stroking movement to the tool independently of the reciprocating means. Thus the tool may be traversed over the surface of the work to produce a distinctive finish superior to that produced in the ordinary honing operation. Moreover, the machine may be used advantageously 'for finishing interrupted cylindrical surfaces. For this purpose means is provided for introducing a. dwell in the hydraulic reciprocation, the short-stroking mechanism thus being effective to reciprocate the tool rapidly in a restricted area adjacent the obstruction in the surface whereby that areais given a true honing finish so as to produce a perfectly uniform and true contour over the entire surface of the work.

Further, the useful life of the tool is increased and its cutting eificiently maintained over long periods of use since the whetting motion to which it is subjected substantially prevents loading of the abrasive stones and causes the faces thereof to wear uniformly.

I claim as my invention:

1. In a machine for honing cylindrical work pieces of the type having one end open and the other end closed or interrupted by a shouldered portion or the like, the combination of a support for a work piece to be honed, a support for a honing tool, means for rotating the tool, power actuated means for reciprocating one of said supports through a series of strokes to traverse the tool repeatedly from'one end of the work piece to the other, said strokes being adjusted to cause the tool to overrun one end of the work piece and thereby equalize the action of the tool at that point with the action at intermediate points on the work piece, control means for said power actuated means operative to delay the return movement of the reciprocatory support and thereby introduce a dwell while the tool is operating adjacent the closed end of the work piece to compensate for the lack of overrun at that end, and means for reciprocating the tool with relatively short rapid strokes during said dwell in the movement of the reciprocatory support to enable the tool to produce a honed finish on the area adjacent the closed end of the Work piece.

2. In a honing machine, in combination, a tool head and means for reciprocating it, a tool supporting spindle, means for rotatably supporting said spindle on said head including a cylindrical sleeve encircling the spindle and rigidly secured thereto, an outwardly opening peripheral groove formed adjacent one end of said sleeve,

and constituting a raceway for a. series of steel balls engageable with a bearing ring secured to the head, said groove being substantially wider than the diameter of a ball to permit limited axial movement of the spindle relative to the head, and means for imparting a series of relatively short axial movements to the spindle com- FLOYD A. SWANSON.

Images