US2246199A - Horizontal honing machine - Google Patents

Description

June 17, 1941. H. J. CALDWELL HORI ZONTAL HONING "MACHINE Filed July 21, 1939 2 Sheets-Sheet l bhvx June 17, 941. Hl J, CALDWELL 2,246,199

HORIZONTAL HONING MACHINE Filed July 21, 1959 2 Sheets-Sheet 2 y14436 ma v f2/amy Q/ UCI/dava# 541K@ .SL., fpw, Mum/ Patented June 17, 1941 HoRIzoNrAL'HoNING MACHINE K Harry J. Caldwell, Rockford, Ill., assignor .toY

Barnes Drill CompanyIRockford, Ill., a corporation of Illinois Application July 21, 1939, Serial No. 285,751

`4 Claims. :Y (Cl. 51-34) The invention relates to machines for dressing cylindrical surfaces by a honing or lapping operation and more particularly to honing or lapping machines of the horizontal type.

The honin-g operation involves the relative rotation and simultaneous relative reciprocation of a cylindrical abrasive tool or hone and the Work piece. The lapping operation is substantially the same as the honing operation except that the relative rotation of the tool and work is intermittent instead of continuous. The term honing as employed hereinafter with reference to the 'dressing of cylindrical surfaces is inten-ded to embrace both of the above operations.

"Horizontal honing machines are commonly employed in dressing .the cylindrical surfaces of Work pieces Which, because of certain char-acteristics such as substantial length, are most conveniently supported in a horizontal position during the operation. In such machines either the tool or the Work may be reciprocated and either or bot-h may be simultaneously rotated to produce the relative movements necessary for the performance of the honing operation.

The relative reciprocation of the tool and the work presents a different problem in machines intended to operate on long Work pieces since the reciprocaltory stroke must be of suiiicient amplitude to traverse the tool from one end of the Work piece to the other. As honing isA a precision operation, the reciprocation should be extremely smooth and with a minimum of shock or jar at the ends of the stroke. This is to prevent vibration or chattering of the tool which seriously affects the quality ofy the Work and makes it diiiicul-t, if not impossible, to obtain the smooth true surface iinish and the high degree of accuracy for roundness and straightness demanded in finishing operations of this character.

It has been found in practice that pressure fluid operated means such as hydraulic actuators, of either the rotary or reciprocatory type, are most suitable for eiecting the relative reciprocation of the tool and Work because of the inherent smoothness of operation and the ease and accuracy with Which such actuators can be controlled. The reciprocatory actuators are preferable as they are of simple construction and relatively inexpensive to manufacture and easy to maintain in proper operating condition.

The use of reciprocatory actuators has been limited heretofore to short-stroke honing machines of the vertical type in which the actuator can be coupled directly with the moving part. that is, the reciprocatory head ol' @alliage Q the machine, Direct coupling of the actuator with the head has not Worked out in the case of long# stroke honing'machines because of the impracticability of incorpo-rating in the machine a reciprocatory actuator capable of providing the wide range of movement required in such machines. Various motion transmitting and amplifying devices have been proposed for use in connection with reciprocatory actuators. Such devices v'as heretofore constructed, embodyv gear trains, rack and pinion mechanisms or the like, which' 'are unsuitable for effecting the smooth, shockless reciprocation'essential for precision honing.

With the above in View, one object of the present invention is to providean'improved horizontal honing machine embodying novel reciprocating mechanism includinga pressure liiuid operated actuator ofthe reciprocatory type and motion transmitting and amplifying means of novel and improved construction capable of eftecting smooth, shockl-ess relative reciprocation of the honing tool and thework piece. I

Another object is to provide ynovel motion transmitting and amplifying'means adapted to be operated by a reciprocatory actuator and capable of effect-ing the relative reciprocation of a honing tool and the work piece in a manner suitable ior precision honing. v y

, Still another object is tov provide an improved pressure uid actuator of the reciprocatory type icapabl-e o-f imparting uniformmovements tothe reciprocatory head ,or carriage of a yln'u'izorital honing machine in bot-h its forward and return l strokes. f

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 sidey elevational view of a horizontal honing machine embodying the features of the invention. 4 f l Fig. 2 is a vertical sectional View taken longitudinally of the machine showing details of the mechanism for reciprocating the head Yor carriage. A

Fig. 3 is a transverser sectional view ofv themachine. A v Fig. 4 is a schematic diagram View showing the hydraulic circuits and the relationship of the hydraulic and mechanical elements of the machine. I .v

By way of illustration the invention has been shown and will be described hereinafter as em-- bodied in a machine for honing internal'cylindrical surfaces in which the tool is rotated and reciprocated relative to a stationarily supported work piece. It is to be understood, however, that the invention is readily applicable to other types of honing machines and that various changes and modifications may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention as expressed in the appended claims.

Referring to the drawings, the machine selected to illustrate the invention is of the type intended for honing the internal cylindrical surface of a hollow work piece W such as an elongated tube or cylinder. This operation is performed by means with a cylindrical abrasive tool or hone T which may be of any suitable and well known construction. In this particular machine the work piece W is held stationary while the tool T is rotated and simultaneously reciprocated relative thereto.

As shown in Fig. 1, the machine comprises generally an elongated base consisting of a main sectionV II and an outboard section I2 bolted or otherwiseY secured together in end-to-end relatien.'V The latter section constitutes in the present instanceV a stationary work support Vand for this purpose is equipped with suitable xtures I3 for rigidly holding the work piece W in a substantially horizontal position.

In order to obtain the necessary relative movements ofthe 'tool and work'under these conditions, the tool T is carried by a reciprocatory support herein shown asa' head or Acarriage |4 arrangedto: reciprocate on a horizontal guideway extendinglongitudinally of the main base section The'guideway,` as herein shown, is formed by suitableguide bars I5 (Fig. 3) mounted in parallel spaced relation on the side walls of the base section-and the head is supported thereon bya series 7^of Vgenerallyspool-shaped rollers I6 journaled on studs projecting from the under side of the machine.- The Arollersare preferably positioned so as to engage the respective-guide bars between theirV inclined bearing `faces and thus serve to'hold the head securely against-lateral movement relative tothe guideway while permitting it to reciprocate freely thereon.

As the tool T` must be inserted within the work piece and traversed from one end thereof to the other, vit is conveniently mounted on the projecting end of an elongated driver I1 which constitutes, in this instance, an extension of a rotary tool Vsupporting spindle I8. The spindle is journaledV on the head I4 for reciprocation therewith and is driven in any suitable manner as by a motor M mounted on the head. l

Relative reciprocation of the tool and work is effected in the present instance by reciprocation of the head I4 on its guideway. For this purpose there is installed, preferably within the main base section II, a pressure fluid operated actuator of the reciprocatory type arranged to drive the head through the medium of motion'transmitting and amplifying mechanism of novel and advantageous construction.y y

The actuator may be of any suitable type but is preferably constructed so that the movements of the reciprocatory part are uniform, thatis, the movements are executed at the same speed-in both directions. Such movements are obtained in the present instance by a double cylinder -arrangement wherein equal active pressure areas are utilized for moving the reciprocatory partin each direction. A

Referring more particularly to Fig. 2, the actuator in its preferred form comprises an outer cylinder 2| disposed within the main base section I I in a substantially horizontal position with its longitudinal axis generally parallel to the guideway for the head. The opposite ends of the cylinder are closed respectively by cylinder heads 22 and 23, the latter having a central opening for the reception of a cylindrical ram 24 which constitutes the reciprocating part of, the actuator. The cylinder 2| is anchored to the machine base as by a pin 25 engaging in an aperture in an extension 26 of the cylinder head 22, the pin acting to support the outer end of the cylinder and to permit limited pivotal movement of the same in a vertical plane for reasons that will appear presently. A cylindrical enlargement 21 on the inner end of the ram constitutes a working piston for the outer cylinder. Suitable packing rings 28 may be t'ted in the piston enlargement to prevent leakage of pressure fluid from the outer end of the cylinder to the inner end which, however, isventedfin Wellknown manner to take care of drainage. Y

As herein shown, the Vram 24 is of tubular construction and its outer end is closed by a tightly fitted plug 3| toform a second or inner cylinder for the actuator. A cylindrical member 32 rigidly secured at one end to the cylinder head 22 of the outer cylinder'and projectin'gforwardly therefrom so as to telescope-into the hollow ram, constitutes a stationary pistonfor the inner cylinder; These parts are `assembled with a, tight sliding t to preventv leakage of pressure fluid from the inner cylinder.

To move the ram inwardly or to'the right as viewed in Fig, 2, pressure fluid is introduced into the outer cylinder-2| through a port 33 to act on the rear face of the Vpiston enlargement 21. Movement of the ram in the opposite direction is effected by the introduction of pressure fluid into the inner cylinder to act on the front face of the plug 3| which closes the end of the cylinder. For this Ypurpose the stationary member-32 is formed with a bore 34 communicating at one end With the inner cylinder and-atthe other end with a port 35 in the` cylinder Ahead 22. By suitably proportioning the areas-presentedV by the pis-ton enlargement 21 .and the plug 3|, the-rate of movement of the ram in4 opposite directions can be accurately controlled. :In the present instance these-parts are constructed so asto present. equal `pressure areas and :the movements of theram are therefore executed with the same speed in both the-forwardand return strokes, equal columns of `fluid at the-same pressure lbeing supplied in each instance.

Pressure fluid for reciprocating the ram -is supplied by a suitable pump Pfthrough' a-suitable pressure fluid circuit such as that illustrated diagrammatically in Fig',l 4.- As hereinshown, the pump is driven by an electric motor Ml.- A reversing. Valve rV ,-of. the we1l-known pressure fluid operated type, isinterposed in the circuit between the pump and the `actuatorto control the supply Yof pressurefluid thereto. When the valve is operated to the positionshown in .the drawings, it is effective to direct pressureuid intothe outercylinder 2| and to connect the inner .cylinder of the ram 24.with a drain 36 for returning spent` pressure fluid/to a reservoir or sump R.V Under these conditions the Aram is moved to the right. `When operated to its alternate position l, the `valve V directs pressure fluid into the inner .cylinder and connectsy the outer cylinder .to the drain sothat the ram is moved in the reverse direction, or to the left. The operation of the valve V is preferably controlled by a pilot vvalve V1 operated in well known manner by the head |4 in its movements backand forth on the guideway.

The movements of the reciprocatory part of the actuator or ram 24 are .transmitted to the tool head |4 through a transmission mechanism which additionally acts to amplify these movements. In the particular machine illustrated the transmission mechanism is arranged to double the movement of the ram, that is, the tool head is moved through a stroke of twice the length of the stroke of the ram. This construction permits the use of a cylinder and ram of only onehalf the length of the guideway. Apparatus of this size can be conveniently installed in the base of the machine since the over-all length of these elements when fully extended, can be accommodated within the main base section. If desired, of course, a greater degree of amplification may be provided without departing from the principles of the present invention.

The motion transmitting and amplifying mechanism in its preferred form includes an elongated generally rectangular metal frame 4| (Figs. 2 and 3) rigidly connected at one end to the projecting end of the ram 24 and reciprocable therewith. 'I'he frame is supported and guided for reciprocation by roller means, herein shown as flanged rollers 42 and 43 operating on spaced parallel rails or bars 44 which form a track extending below and generally parallel to the guideway for the head. The rails may be supported in any suitable manner as by U-shaped supporting members 45 suspended from brackets 46 projecting inwardly from the side walls of the base section Il. The pivotal mounting of the cylinder 2| permits the rollers to follow irregularities in the track without placing undue strains on the cylinder or associated parts.

As will be seen by reference to Fig. 3, the rollers 42 and 43 are rotatably supported on antifriction bearings 41 carried on horizontal pins 48 fitted into the side members of the frame 4|. Each of the rollers is formed with a pair of outwardly facing flanges 49 which serve the double purpose of guiding the rollers on the rails 44 and defining a generally V-shaped groove 50 for a flexible traction member such as a wire cable by which the movements of the frame and rollers are transmitted to the tool head.

In the particular machine illustrated, one cable (Figs. 1 and 2) is provided for moving the head forwardly or toward the work piece while a second cable 52 is provided for moving the head back to retracted position. These cables are both anchored to the head and connected respectively to the opposite ends of the base, connection with the head being effected in the present instance by a connecting device 53. It will be understood, of course, that a single cable may be used if desired, in which case it will be anchored at its mid-point to the head and the respective end sections will function in the same manner-as the cables 5| and 52 above described.

The cable 5| is carried forwardly from the head over a sheave 54, then back over the roller Y 42 and forwardly again to a suitable connecting device 55 which anchors it to the forward end of the base section 'I'he cable 52 extends rearwardly from the head and passes over a sheave 56, thence forwardly over the roller 43 and again rearwardly to a tensioning device 51 which anchors it to the rear end of the machine base. It will be understood that the sheaves 54 and 56 are rotatably supported on the base section at opposite ends of the guideway.

The tensioning device 51 acts to maintain the cables 5| and 52 under proper tension at all times to prevent any slack or looseness-in these cables which would interfere with the smooth, uniform reciprocation of the tool head. The device, as herein shown, comprises a cylinder 6| rigidly secured at one end to the machine base below the reciprocatory actuator. The cylinder is fitted with a piston 62 having a forwardly projecting piston rod 63 to which the end of the cable 52 may be secured in any suitable manner as by a connector 64. l

Pressure fluid introduced into the cylinder 6| through a port 65 in the forward end vof the cylinder tends to force the piston rearwardly or to the right as viewed in Fig. 2. The `piston thus exertsa pull on the cable 52 in a direction such as to draw the cable 5| taut. Thistends-to pull the head |4 rearwardly against the-resistance of the cable`5| and thus both cables are maintained under tension as long as pressure fluid is supplied to the cylinder. Preferably the pressure fluid for this purpose is derived from the same source as the pressure fluid for operating the reciprocatory actuator, that is, the pump P so that the tension applied to the cables or traction members is directly proportioned to the force required to reciprocate the head. Thisis for'the reason that the pressure in the hydraulic circuit ordinarily increases in accordance with the resistance offered by the head and this added pres-v sure is effective to increase the tension on the traction members. Smiooth and shockless reciprocation of the head is therefore insured under all conditions of operation. f

The operation of the pressure fluid actuator and motion transmitting and amplifying mech'- anisrn will be readily apparent from the foregoing description. Briefly, they reciprocatory part of the actuator, that is the ram 24 and the frame 4| is reciprocated through uniform forward and return strokes by the introduction of pressure fluid 'alternately into the inner and outer cylinders 2| and 24 of the actuator. The frame is supported and guided in this reciprocation by the rollers 42 and 43, which roll on rails or bars 44 arranged in the machine base below and generally parallel to the guideway.

The motions of the frame are transmitted to the head through flexible traction members in the form of Wire cables 5| and 52. Upon movement of the ram 24 toward the position shown in Fig. 2, the cable 5| is drawn in over the sheave 54 and the cable 52 is paid out in equal amount so that the head is moved forwardly on the guideway to the position shown in Fig. 1. Upon movement of the ram to the left, the cable 52 is taken up by the roller 43 while the cable 5| is paid out, thus moving the head back to retracted position.

During the operation of the machine the tension device 51 maintains the cables taut and thus prevents any lost motion from slack or loose cables. The flexible character of the traction members also assists in producing the proper motion of the head for precision honing by absorbing any shock or jar at the ends of the reciprocatory stroke.

It will be apparent from the foregoing that the invention provides a honing machine of novel and advantageous construction. The machine is provided with novel reciprocating mechanism including a pressure fluid operated actuator of the reciprocatory type andV motion transmittingand amplifying mechanism of novel and improved construction capable of eiecting smooth shockless relative reciprocation of the honing tool and the Work piece. Due to the novel construction of the actuator, the movements of the head or carriage are executedat a uniform rate in both its forward and return strokes.

1 claim as my invention:

1. A honing machine having, in combination, an elongated base, a horizontal guideway on said base, a head mounted for reciprocation on said guideway, means for reciprocating said head comprising, a power operated actuator including areciprocable part, a track Vdisposed within said base below the guideway and extending generally parallel thereto, a roller on said part engageable with the track for supporting and guiding the part; in its reciprocation, a rotatable member supported on the base at each end of the guideway, and a pair of flexible traction members anchored to the head and connected respectively to opposite ends of the base, said members each passing over one of said rollers and over the rotatable member at the end of the base to Which the member is connected.

2. A honing machine having, in combination, an elongated base, a horizontal guideway on said base, a head mounted for reciprocation on said guideway, means for reciprocating said head comprising, a power operated actuator including a reciprocable part, a pair of elongated bars mounted in the base in spaced parallel relation to deiine a track extending generally parallel to the guideway, a pair of rollers on said part engageable with said bars to support the part, said rollers having oppositely facing flanges spaced apart to dene a peripheral groove around the roller and adapted to cooperate With the bars to guide the'part in its reciprocation, a sheave rotatably supported on the base at each end of the guideway, and a pair of flexible cables anchored to the head and connected respectively to opposite ends of the base, each of said cablesrunning in the peripheral groove of one of said yrollers and over the sheave at the end of the base to which the cable is connected.

3. A honing machine having, in combination, van elongated base, a guideway on said base, a head mounted for reciprocation on said guide- Way, means for reciprocating said head comprising lan actuator having a reciprocable part, pressure fluid operated means Yfor reciprocating said part, means operatively connecting said part with the head including a member rotatably supported on the base `at each end of the guideway, roller means rotatably supported on the reciprocating part, a pair of flexible traction members anchored to the head and connected respectively to opposite ends ofthe base, said members each passing over'one of said roller means and over one of said `rotatable members, a second pressure fluid operated means acting on one of said traction members to maintain the members under tension, and a common source of pressure uid for operating both vof said pressure fluid means.v

4. A honing machine having, in combination, an elongated base, a guideway on said base, a head mounted for reciprocation on said guide- Way, a cylinder disposed in said base with its axis generally parallel to said guideway, a ram projecting rfrom said cylinder, means for supplying `pressure fluid to the cylinder to reciprocate said ram, a frame Vsecured to said ram for reciprocation therewith, rolle-rs journaled on said frame for supporting the frame in its reciprocation, means operatively connecting the head with said frame to reciprocate'therewith comprising, a pair of rotatable members supported on the machine base, one at each end of the guideway, and a pair of flexible traction members anchored to the head each passing over one of said rota-table members and one of said rollers.

HARRY J. CALDWELL,

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