US2397814A - Honing machine - Google Patents

Description

April 2, 1946. 'E. Y. SEYBORG ETAL HONING MACHINE Filed. Dec. 15, 1943 3 Sheets-Sheet 3 F6 as NV LNYORG w ,Earnea Patented Apr. 2, 1946 HONING AomNn Earnest Y. Seborg, Harry J. Caldwell, and Sheldon F. Manning, Rockford, Ill., assignors to Barnes Drill 00., Rockford, 111., a corporation oi Illinois Application December 13, 1943, Serial No. 514.066

11 Claims.

The invention relates to honing machines generally .and more particularly to improvements inthe tool adjusting mechanism of such machines whereby the abrasive elements of the tools are shifted radially into operative engagement with the surface of the work.

It has been found in practice, that accurate control'oi' the rate of adjustment of the hone, that is, the rate at which the abrasive elements are moved toward the work surface materially increases the productiveeiflciency of the tool. More specifically, the loading of the abrasive elements with material removed from thework is substantially eliminated, their useful life is increased, and greater precision of finish is attained by regulating the adjustment so as to maintain a predetermined substantially uniform pressure againstthe work surface. The optimum pressure for this purpose varies, of course, with the material being operated on, the size of the work, the grade of the abrasive employed and other factors which need not be discussed here.

Control of the adjustment of the abrasive elements of a honing tool has been effected in various ways. One of the most efficient control devices heretofore available for hone adjustment control purposes utilizes a receding mechanical abutment arranged to restrain the movements of the member which imparts the radial movements to the abrasive elements. This type of control provides accurate regulation of the rate of movement of the elements and, in addition, prevents excessive movements when soft areas in the work are encountered and before the high spots are removed from the work surface. While such control devices give generally satisfactory results'in ordinary honing operations in which the adjustment of the abrasive elements may be effected in comparatively large steps and in a relatively short time, they have been found unsuited for honing operations requiring adjustment of the elements in very small increments over a relatively long period of time.

With the above in view one object of the invention is to provide improved control mecha nismv for honing tools in which the adjusting movements of the abrasive elements are restrained by a fluid block or fluid abutment thus retaining the advantageous positive control of the mechanical devices but providing greater flexibility as to rates of adjustment whereby movements of the abrasive elements may be effected in smaller, more uniform increments and more accurately regulated over extended operating periods.

Another object of the invention is to provide in a honing machine an improved mechanism capable of effecting adjustment of the. honin tool at an exceedingly slow yet accurately controlled rate'thereby adapting the machine for certain types of precision finishing requiring relatively long honing periods.

Still another object is to provide improved control means whereby the initial adjustment of a honing tool to bring the abrasive elements into operative engagement with the work may be effected rapidly while adjustment during actual operation is effected at a much slower rate.

It is also an object of the invention to provide hone adjusting mechanism which is simple and rugged in construction, which is eflicient and reliable in operation, and which is capable of accurately controlling the rate at which the hone is adjusted.

Other objects and advantages or the invention will become apparent from the following detailed description of the preferred embodiment illustrated in the accompanying drawingsin which:

Figure 1 is a front elevational view of a honing machine equipped with hone adjusting mechanism embodying the features of the invention.

Fig. 2 is an enlarged side elevational view of the tool supporting headof the'machine shown in Fig. 1 with parts of the housing broken away to show details of the tool driving and adjusting mechanism.

Fig. 3 is a sectional view taken in a vertical plane substantially. on the line 33 of Fig. 2.

Fig. 4 is a sectional view taken in a vertical plane substantially on the line 44 of Fig. 3.

Fig. 5 is a plan view showing'details of the valve actuating mechanisms.

Fig. 6 is a schematic diagram showing the electrical and hydraulic circuits of the machine and their relation to the mechanical elements of the same.

While the invention is susceptible. of various modifications and alternative constructions, we have shown in the drawings and will herein describe in detail thepreferred embodiment, but it is to be understood that we do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

By way of illustration, the invention has been shown as embodied in a honing machine having a tool supporting head In (Fig. 1) mounted for reciprocation on horizontal ways'carried on an elongated bed I l. Reciprocation of the head it ported on an auxiliary bed i rigidly secured to the end of the main bed opposite the drum i3.

Referring to Fig. 2 of the drawings, the head It comprises a generally rectangular base l6 having suitable guide means such as rollers I! for cooperation with the ways on the bed ii. Jourasomu I p posed between a suitable abutmentin the spindle l8 and the thrust plate 3| moves the intermediate naled in the base 16 is a hollow spindle l8 arranged to project at the forward end of the base for connection with a tubular driver l8 which carries, at its outer end, a honing tool 20. The spindle I 8 is rotatably driven in this instance by a motor Ml through the medium of suitable gearing'enclosed in a housing 2| rigid with the base i8. Thus, in the exemplary machine, the honing tool is continuously rotated and simultaneously reciprocated axially of the work. It will be understOOd, of course. that the spindle drive mechanism may be arranged to turn or index the spindle intermittently for straight line honing.

The honing tool 20 herein shown is of the conventional type employed in honing internal surfaces. In such tools, the abrasive elements are moved radially outwardly from a normal retracted position to engage the surface of the work. The invention is not limited to use with this particular type of tool but may be used to advantage with other types of honing tools, as for example the tools designed for honing external cylindrical surfaces in which the abrasive elements are moved radially inwardly from their normal retracted position. In either case. the tool is initially associated with the work with the abrasive elements in retracted position and the elements are adjusted radially into operative engagement with the work surface, When so adjusted, the tool is rotated and simultaneously reciprocated axially of the work so as to act uniformly over the entire surface thereof.

As herein shown, the honing tool 20 is adapted to be adjusted by power operated means carried on the head and acting through a push rod 22 extending axiall through the driver IS. The power means is preferably of the pressure fluid actuated type and, as shown in Figs. 2, 4 and 6. comprises a piston 25 working in a cylinder 26 mounted on the base it in axial alinement with the spindle I8. The cylinder is closed at opposite ends by heads 21 and 28. A piston rod 29, rigidly attached to the piston 25, extends through a suitable gland 30 in the front cylinder head 21 toward the hollow spindle l8 to abut against a thrust push rod 32 rearwardly with the piston thus permitting the abrasive elements of the tool to be returned to retracted position in well-known manner through the action of spring means incorporated in the tool.'

In'the exemplary machine, pressure fluid is supplied to the cylinder 26 by a pump P (Figs. 2 and 6) driven by a motor M2, both mounted on the base i8 of the tool supporting head it. The pump P has an intake line 25 through which it draws fluid, such as oil, from a sump or reservoir R in the head. Fluid is delivered under pressure through a pipe 36 to a reversing valve V which may be set to direct the fluid by way of pipes 31 or 38 to either the rear end or the front end of the cylinder 28 while connecting the other end of the cylinder to an exhaustline 39. The particular valve illustrated is yieldably held in one position by suitable spring means and is adapted to be operated to its alternate position by a solenoid S connected in parallel with the spindle driving motor M. The arrangement is such that the valve is set for expanding the tool when the spindle is rotated.

In accordance with the invention, means is provided for metering out the fluid from the forward end of the cylinder 26 to regulate the forward travel of the piston 25 and thus control the rate at which the tool 20 is adjusted. To this end the forward end of the cylinder is connected to the pipe 38 through a check valve VI set to allow fluid to pass freely into the cylinder but normally preventing discharge of fluid from the cylinder through the pipe 38. The fluid trapped in the front end of the cylinder is thus divertedthrough plate 3| fixed on the end of an intermediate push rod 32 supported and guided for endwise sliding movement axially of the spindle l8. The push rod 32 is adapted to abut against the end of the tool adjusting rod 22 for imparting the movements of the piston 25 thereto.

To adjust thehoning tool for operation, pressure fluid is introduced into the rear end of the cylinder 26 thereby moving the piston 25 and the rods 32 and 22 forwardly on toward'the right as viewed in Fig. 2. The fluid connections are reversed and fluid is introduced into the forward end of the cylinder 26 to return the piston to the 1 rear end of the cylinder. Aispring 84 is later a metering device by which the rate of flow may be accurately controlled.

The metering device as herein shown, comprises a reciprocatory member or plunger 40 (Figs. 4 and v 6) reciprocable in a bore 4| formed, in this instance, in the side wall of the cylinder 25. The plunger is provided intermediate its ends with a fluid receiving pocket or recess such as a peripheral groove 42 adapted in the reciprocation of the plunger to register alternately with two ports 43 and 44 which are spaced apart longitudinally of the bore 4|.

As will be seen by reference to Figs. {and 6 of the drawings, the port 43 communicates with the forward end of the cylinder 26 and constitutes an outlet therefor while .the port is connected by a pipe 45 with the exhaust line 39. Accordingly, the groove 42 is periodically filled with fluid forced from the forward end ofthe cylinder 26 by the advance of the piston 25 which fluid is discharged through the exhaust port 44. In this way small uniform charges of fluid are metered out from the cylinder at regularly spaced intervals thus permitting incremental advances of the piston 25 and corresponding incremental movements of the abrasive elements of the honing tool 20. The quantity of fluid permitted to escape from the cylinder in each reciprocation of the plunger 40 is dependent. of course. upon the dimensions of the groove 42. The groove may be made quite small thus restricting the piston to a very slow rate of advancing movement.

Reciprocation of the plunger 40 may be effected in any suitable manner. In the exemplary apparatus, the plunger is reciprocated by-a lever 46 (Figs. 3-6) pivotally secured by a pin 41 to a bracket 48 rigid withthe cylinder head 21. One end of the lever 46 is slotted. .as at 48. 'to receive a flattened section 50 of the plunger 40 formed by recessing opposite sides of the plunger. The

longitudinally disposed slot 52 adapted to receive an eccentric crank pin 53 carried on a hub 54 fast ona shaft 55. The shaft is journaled on the bracket 48 and may be driven in any preferred manner. As herein shown, the shaft 55 is driven at a selected rate from the ,pump motor M2 through an adjustable speed changer 56 (Figs. 2 and 6) The speed changer has an outlet shaft 51 fitted with a worm 58 meshing with a worm wheel 59 keyed to the shaft 55. In the particular embodiment illustrated, the speed changer is driven from the motor M2 by a V-belt 50 (Figs. 2 and. 6). j

By suitable adjustment of the speed changer 56, the rate of reciprocation of the plunger 40 and consequently the frequency of the tool adlusting movements of the piston 25 can be regulated for any desired period of operation. The amplitude of the adjusting increments is determined, of course, by the capacity of the fluid recess 42 in the plunger recesses of various capacities will ordinarily be kept on handand may be quickly and easily placed in service to provide the adjusting increment required for any operation.

At the beginning of an operating cycle the honing tool 20 is associated in the work with the abrasive elements retracted and the elements must therefore be shifted a substantial distance to bring them into operative engagement with the work surface. To avoid loss of time in this initial or preliminary adjustment of the tool, the invention provides novel means whereby substantially unrestricted discharge of fluid from the cylinder 26 ahead of the piston 25 is permitted during a predetermined initial portion of its forward movement. To this end, provision is made for operating the valve VI to by-pass the metering device so that the piston 25 may advance at a rapid rate until the tool is in condition to operate upon the work justing rate is automatically initiated.

In the exemplary apparatus, the valve VI is a ball type check valve comprising a tubular casing (Fig. 4) adapted to be screwed into a threaded exhaust port'62 in the front cylinder head 21!. The casing is formed with an internal shoulder 63 defining an exhaust passage encircled by a tapered valve seat facing the cylinder. A movable valve member 64, herein shown as a ball, is yieldably urged against the valve seat by a spring 65 interposed between the member and a pin 65 extending transversely across the casing. The valve member 64 is therefore normally held in a position to prevent fluid flow from the cylinder through the valve while offering relatively.

little resistance to fluid flow into the cylinder.

In accordance with the invention, valve actuating means is provided for shifting the valve member 64 from its seat to open the valve while the initial adjustment of the honing tool is effected. The valve actuating means, as herein shown, comprises a plunger 61 movable longitudinally of the valve casing 6| and having at its inner end a pin 68 engageable with the valve member 54. The plunger is slidably supported in a gland formed in a plug 69 screwed into the outer end of the valve casing 5|. A spring w whereupon the slow metered ad-.

40. Plungers having interposed between the irmer end of the plunger 61 and the shoulder .83 in the valve casing urges the plunger outwardly, thus permitting the member 64 to shift forwardly under the action of the spring and close the passage through the valve.

For shifting the plunger 61 to open the valve, a push rod 1| is supported in axial alinement with the plunger and guided for endwise movement in a suitable'bearing formed in a bracket 12 rigidly secured to the cylinder head 21. Fixed on the push rod is a collar 13 having abifurcated arm 14 projecting laterally to straddle a rectangular block I5 pinned to and reciprocable with the piston rod 29. The block 15 is formed with an upstanding lug 16, into which is threaded an adjustable stop screw 11 adapted to engage the arm 14 and hold the push rod 1| and valve. actuating plunger 61 in a valve opening position until the piston has executed a predetermined portion of its advancing stroke. The screw Tl may be readily adjusted to permit the valve VI to close at the instant the abrasive elements of the honing tool are moved into operative engagement with the work.

Means is also provided whereby the machine attendant may open the valve VI at any time to effect rapid adjustment of the honing tool. For this purpose a solenoid SI (Figs. 3, 5 and 6) is mounted at one side of the bracket 12 and its armature 18 is connected by a link 19 with one end of a lever 80 having its other end pivoted as at ill on the outer end of the bracket. The lever 80 1s positionedtc engage the outer end of the push rod H and to shift the same to valve openin position when the solenoid is energized. Energization of the solenoid may be controlled through the medium of a manually operable switch SW located for convenient access by the attendant.

It will be apparent from the foregoing that the invention provides hon adjusting and control mechanism of a novel and advantageous char acter by which the abrasive elements of a honmg tool may be adjusted through a wide range of incremental steps and at a more accurately controlled rate than has heretofore been practicable. More particularly, the improved control mechanism permits the abrasive elements of the honing tool to be moved in exceedingly small increments and at various selected rates which may be adjusted to effect relatively slow adjustment of the tool over an extended period. Accurate control of the adjustment rate is obtained by arranging the control mechanism for metering out the fluid trapped in the forward end of the cylinder of the hone adjusting mechanism in the advancin movement of the piston to adjust the tool. The

metering out is efiected in a manner such that adjustment takes place in incremental steps the frequency of which can be varied as required by the particular work to be done. In general, the control mechanism is simple andfoolproof in con struction, emcient and reliable in operation and it has a wide range of adjustability that enables it to function satisfactorily under substantially any conditions met with in the honing art.

The invention also provides novel means whereby a honing tool may be adjusted rapidly to bring the abrasive elements into operatve engagement with the work surface preliminary to the actual honing of the surface. loss of time is avoided and the maximum productive capacity of the machine is realized.

We claim as our invention:

1. Adjusting mechanism for honing tools hav- In this Way.

, ing radially shiitable abrasive elements comprising, in combination, a member movable longitudinally to shift the abrasive elements of thetool,

' the forward end of the cylinder, and'means restricting the discharge of fluid from the forward end of said cylinder to predetermined increments released at accurately timed intervals,

and means for varying thelengths the inter vals between successive increments to ontrol the rate at which the abrasive elements "of the tool are shifted.

2. Adjusting mechanism for honing tools having radially movable abrasive elements comprising, in combination, a member shiftable longitudinally to move the elements of the tool, means ,for shifting said member including a cylinder closed at both ends, a piston reciprocable in said cylinder and having a piston rod engageable with said member in the forward movement of the piston, means for supplying pressure fluid to the rear end of said cylinder to move said piston forwardly, said piston acting in such movement to expel the fluid trapped in the forward end of the.

cylinder, and an intermittently operating metering device for restricting the flow of fluid from the forward end of the cylinder to increments of predetermined volume, the operating speed of said device being adjustable to regulate the rate at which the tool is adjusted.

3. Adjusting mechanism for honing tools comprising, in-combination, a cylinder, a piston in said cylinder, means for supplying fluid to both ends of the cylinder, a port communicating with the forward end of said cylinder, said piston when driven forwardly by pressure fiuidintroduced into the rear end of said cylinder-acting to force the fluid in the forward end of the cylinder through saidport, an exhaust port, a plunger having a fluid receiving recess, and means for reciprocating said plunger to present said recess at said ports alternately to receive a quantity of. fluid from said cylinder and to discharge the fluid into said exhaust port.

4. Adjusting mechanism for honing tools comprising, in combination, a cylinder, a piston reciprocable in said cylinder, means for supplying fluid under pressure to the cylinder at one side of the piston, an outlet from said cylinder at the other side ofsaidpiston, said piston acting to force'fluid from said cylinder through said outlet when advancing to adjust a honing tool, and means for controlling the discharge. of fluid through said outlet to regulate the rate of adsaid port to maintain a relatively slow rate 01 piston movement in a direction efiective to adjust the tool, and means for operating said valve to permit a flow of fluid through said fluid connections whereb to increase the rate of movement of said piston during a predetermined-portion of its advance .in said tool adjusting direction. 7

6. Adjusting mechanism for honing tools comprising, in combination, a cylinder, a piston reciproc-able in said cylinder, means for supplying fluid under pressure to said cylinder to force said piston forwardly, a pair of outlet ports in said cylinder at the advancing side of said piston, valve means operative to prevent the discharge of fluid through one of said ports, control means for metering the discharge of fluid through the other i of said ports, and means actuated by said piston in its reciprocation for operating said valve to permit unrestricted discharge of fluid therethrough during a predetermined'portion oi the piston stroke; I

7. Adjusting mechanism for honing tools com-.

prising, in combination, a shiftable member operative to adjust a honing tool, a cylinder, a piston reciprocable in said cylinder, a piston rod for transmitting the movements of said piston to said member, means for supplying fluid to each end of the cylinder, a pair of outlet ports in said cylinder at the advancing side of said piston, valve means normally closing one of said ports to the discharge of fluid from said cylinder, means for restricting the discharge of fluid through the other of said ports to control the rate of advance of said piston, an actuating member operable to open said valve, and means carried by saidpiston rod adapted to coact with said actuating member to hold said valve open during a predetermined portion of the piston stroke,

8. Adjusting mechanism for honing tools comprising, in combination, a rod shiftable to adjust a honing tool, a cylinder, a piston reciprocable vance of said piston, said controlling means in- 'cluding a member operable periodically to permit the passage of a predetermined quantity oi fluid 'through said outlet.

'5. Adjustingmechanism for honing tools comprising, in combination, a cylinder closed at both ends, a piston reciprocable in said cylinder, fluid supply connections at both ends of said cylinder, an outlet port at one end of the cylinder, a valve normally operative to prevent the discharge of fluid from the cylinder through the fluid supply connection at said one end of the cylinder thereby directing the fluid discharge through said port,

means restricting the discharge or fluid through in said cylinder, means providing a connection between said piston and said rod, means for supplying fluid to each end of said cylinder, a pair of outlet ports in said cylinder at the advancing side of said piston, valve means normally closing one of said ports to fluid flow from said cylinder, means for restricting the flow of fluid from said cylinder from the other of said ports to control the rate of advance of the piston, and means controlled manually for opening said valve to permit unrestricted discharge of fluid from said cylinder through said one port.

9. Adjusting mechanism for honing tools comprising, in combination, a rod shiftable to adjust a honing tool, a cylinder, a piston reciprocable in said cylinder, means providing a-connection be-. tween said piston and said rod, means for supplying fluid to each end oi. said cylinder, a pair of outlet ports in said cylinder at the advancing side of said piston, valve means normall closing one of said ports to fluid flow from said cylinder, means for restricting the flow of fluid from said cylinder from the other of said ports to control the rate of advance of the piston, a solenoid adapted when energized to open said valve and thereby permit substantially unrestricted discharge of fluid from said cylinder through said one port, and switch mean for controlling the energization of said solenoid.v

10. Adjusting mechanism for honing tools having radially movable abrasive elements comprising, in combination, a cylinder closed at both ends, a piston reciprocable in said cylinder, a

pump for supplying fluid under pressure to one end of said cylinder to advance said piston in a direction effective to move the abrasive elements of the tool into engagement with a surface to be operated on, said piston acting to force fluid from the other end of said cylinder through an outlet port, and means for regulating discharge of fluid through said port to control the rate of movement of said piston, said regulating means including a reciprocator member operative to release a predetermined quantity of fluid from the cylinder in each reciprocatory stroke, and powerv driven means for reciprocating said member.

11. Adjusting mechanism for honing tools comprising, in combination, a cylinder closed at both ends, a piston reciprocabie in said cylinder, a pump for supplying fluid under pressure to one end of said cylinder to advance said piston in a direction effective to adjust the honing tool, said piston acting to force fluid from the otherend of said cylinder through an. outlet port, a metering device adapted to regulate the discharge 01 fluid through said port to control the rate of movement of said piston, a motor operative to drive said pump and said metering device, and an adjustable speed changer interposed between said motor and said device.

. EARNEST Y. SEBORG; HARRY J. CALDWELL. SHELDON F. MANNING.

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